Category: Nervous System

The Brain

The brain is protected by the skull and is made up of soft tissue, which includes grey and white matter, containing nerve cells, non-neuronal cells, and small blood vessels (Medical News Today, 2018). The brain controls the thoughts, memory, speech, and movements of the body, such as arms, legs, and organs. The brain and spinal cord are the bodies central nervous system, the brain is the command centre for the body and the spinal cord is the pathway for messages by the brain to the body and from the body to the brain. (Mayfield Clinic, 2020)

• Skull
• Cerebellum
• Spinal cord
• Meninges
• Cerebrum

Spinal Cord

The spinal cord is protected by the vertebral columns and is made up of bundles of nerve fibres. It runs down from the brain through a canal in the centre of the bones of the spine. These bones protect the spinal cord, like the brain, the spinal cord is covered by the meninges and cushioned by cerebrospinal fluid (Neurosurgery, 2020). The spinal cord consists of nerves that carry incoming and outgoing messages between the brain and the rest of the body. If the spinal cord is injured, the exchange of information between the brain and other parts of the body is disrupted.

The Peripheral Nerves

The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body. Unlike the brain and spinal cord, the peripheral nerves are not protected by the skull or vertebral column, which leaves it exposed to toxins and mechanical injuries. The peripheral nerves consists of the nerves and ganglia, the main function of the PNS is to connect the CNS to the limbs and organs, essential serving as a relay between the brain and spinal cord and the rest of the body (Teach Me Physiology, 2020)

Autonomic Nervous System Parts

The Autonomic nervous system is a control system that acts largely unconsciously and controls bodily functions. It divides in two, the sympathetic division, which is associated with the fight of flight responses and the parasympathetic division, which refers to by the epithet of rest and digest. Homeostasis is the balance between the two systems (Lumen, Unknown date)

The Reflex arc

Throughout the body, neurons have special proteins in their membrane called receptors, receptors respond to signals in the environment, some receptors respond to pressure. Sensory receptors in the ears respond to vibrations in the air that are interpreted as sound, and receptors in the eyes to respond to light. Interneurons are the middleman of the nervous system, they connect sensory input to other cells that required for action, in a reflex arc, the sensory neurons send signals to the interneuron and activates it, the interneuron then relays that signal to the next neuron, a motor neuron. The motor neuron connects with interneurons in the spinal cord, they send messages from the central nervous system to the body. The motor neurons run out of the spinal cord and connect with a muscle. Motor neurons, like sensory neurons, can be long, connecting the spinal cord with the most distant appendage. (Study, 2020)

Most nerve pathways have cells that communicate with each other by means of neurotransmitters. A neurotransmitter is released from one presynaptic membrane, onto the postsynaptic membrane. Excitatory presynaptic cells release neurotransmitters that make that postsynaptic membrane more excitable and more likely to generate nerve impulses. (Micheal kent, 2000). An action potential is the mode through which a neuron transports electrical signals. It is defined as a brief change in the voltage across the membrane due to the flow of certain ions into and out of the neuron (Teach me Physiology, 2020). Transmission of a signal within a neuron (in one direction only, from dendrite to axon terminal) is carried out by the opening and closing of voltage-gated ion channels, which cause a brief reversal of the resting membrane potential to create an action potential (Biology, 2020)

In an electric synapse, ions move directly from one neuron to another via gap junctions, the membrane depolarization associated with an action potential in the presynaptic cell passes through the gap junctions, leading to a depolarization, and thus an action potential, in the postsynaptic cell. An action potential travels down the axon of the per-synaptic, sending cells and arrives at the axon terminal. The axon terminal is adjacent to the dendrite of the post-synaptic, receiving cell. This spots of close connection between axon and dendrite is the synapse An electric synapse, ion pass directly from the per-synaptic cell to the post-synaptic cell through gap junction. These synapses are much less common than chemical synapses. Impulse transmission at chemical synapses occurs with a small-time delay but is nearly instantaneous at electric synapses.

Pineal Gland

The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep patterns in both circadian and seasonal cycles. The hormones produced control so many different processes in the body. It senses the bodies needs and sends signals to different organs and glands throughout the body to regulate their functions and maintain an appropriate environment (Your Hormones, Unknown date)

Hypothalamus and Pituitary gland

The pituitary gland in the brain is known as a master gland, it secretes serval hormones into the blood in response to the bodies condition, such as blood water levels. These hormones can also act on other glands to stimulate the release of different type of hormones and bring about effect (BBC bite size, 2020). The hypothalamus is based at the base of the brain next to the pituitary.

The Thyroid parathyroid and Gland

The thyroid gland is a small butterfly-shaped gland which sits in front of the trachea. One of its main function is to produce hormones that help regulate the bodies metabolism, which helps turn food into energy. These hormones are called triiodothyronine (T3) and thyroxine (T4) (NHS, 2020). The parathyroid gland sits behind the thyroid gland, it plays the role in regulating the bodies levels of the minerals, calcium, and phosphorus.

The thymus

Thymus is a small organ located behind the breastbone, its hormones are called thymosin, they are generally small protein, which regulates the development and selection of an immune-competent repertoire of T cells, and stimulate antibody production by B cells. Unlike most organisms it is at its largest in children, and once they reach puberty, the thymus starts to slowly shrink and become replaced by fat (Very well health, 2020)

The Adrenal Gland

The adrenal glands are small glands located on top of each kidney. They produce hormones that the body can not live without, including hormones such as, cortisol and aldosterone. Cortisol helps the body respond to stress and has many other important functions. With adrenal gland disorder, the gland in the body makes to much or not enough hormones (Medline Plus, 2020)

The Ovaries

The ovaries are located in the lower abdomen of a female. The ovaries produce and release eggs (oocytes) into the female reproductive tract at the mid-point of each menstrual cycle. They also produce the female hormones oestrogen and progesterone. Oestrogen stimulates female characteristics at puberty and controls a woman’s reproduction cycle. Progesterone prepares the endometrium for the potential of pregnancy after ovulation, it triggers the lining to thicken to accept a fertilized egg. (Hormones health, 2020).

The Testes

The testes are two small organs that are found inside the scrotum, next to the penis, they have two functions, to produce sperm and to produce a hormone called testosterone. Testosterone is a sex hormone that plays important roles in the body. In men, it is thought to regulate sex drive (libido), bone mass, fat distribution, muscle mass and strength, and the production of red blood cells and sperm (National Institutes of Health, 2013)

Lipid hormones, such as steroid hormones diffuse across the membrane of the endocrine cell, which are released into the blood stream and carried via the blood to the target cells. Peptide hormones are a class of proteins which are bound by receptor proteins and enable of disable a biological pathway.

Peptide hormones are mostly water-soluble and can travel freely in the blood because it is similar to the blood’s consistency. However, they are repelled by lipid or fatty structures such as the membrane that surround the cell and nucleus (E.hormones, Unknown date). Hormones are released into the bloodstream through which they travel to target sites. The target cell has receptor specific to a given hormone and will be active by either a lipid- soluble, or water-soluble hormone (Lumen, Unknown date).

The pituitary glad is referred to as the master gland because it monitors and regulates many of the bodies functions through hormones that it produces. It is connected by a stalk to a part of the brain called the hypothalamus, together, the brain and pituitary gland form the neuroendocrine system. This system constantly monitors glands and organs to determine whether to send or to stop the chemical messages or hormones that control their functions (Barrow, Neurological Institute, 2020)

When a threat is perceived, the sympathetic nerve fibres of the autonomic nervous system are activated. This leads to the release of certain hormones from the endocrine system. A major action of these hormones generates the fight or flight response (Britannica, 2020). The endocrine system works together with the nervous system to influence many aspects of human behaviour, including the fight or flight response. The nervous system can respond quickly to stimuli, through the use of action potentials and neurotransmitters. Response to nervous system stimulation are typically quick but short lived. The endocrine system responses to stimulation by secreting hormones into the circulatory system that travels to the target tissue (Medicine, 2020)

The hypothalamus is a section of the brain that controls thermoregulation. When it senses the internal temperature becoming too low or high, it sends signals to the muscles, organs, glands, and nervous system. It then responds in a variety of ways to help return the bodies temperature to normal (Health line, 2017) when the hypothalamus senses the body is getting to hot, it will send signals to the bodies sweat glands to make the body sweat and cool itself off. When it sense that the body is too cold, it will send signals to the muscles that make the body shiver and create warmth, this is called maintaining homeostasis (ASU for you, unknown date).

The autonomic division of the nervous system modulates the release of insulin and glucagon. Glucagon is a hormone found in the alpha cells of the islet in the pancreas, which is a polypeptide, which raises blood glucose concentration (Micheal Kent, 2000). The sympathetic stimulation that occurs with exercise stimulates glucagon production and this maintains blood-glucose levels that would otherwise fall as muscles use glucose for this energy. Regulation of blood glucose is largely done through the endocrine hormones of the pancreas, a balance of hormones achieved through a negative feedback loop. The main hormones of the pancreas that affect blood glucose include insulin, glucagon, someatostain and amylin (ATrain, 2020). Insulin is a hormone found in the beta cells of the isles which is a protein, it lowers the blood glucose concentration in the body. (Micheal Kent, 2000).

Reference

1. ASU for You, Unknown date, Ask a BIOLOGIST, [Online] Available at: https://askabiologist.asu.edu/bird-hypothalamus (Accessed, 2020)
2. A Train, 2020, Diabetes Type 2: Nothing Sweet About it – Reguation of Blood Glucose, [Online] Available at: https://www.atrainceu.com/content/4-regulation-blood-glucose#:~:text=Regulation%20of%20blood%20glucose%20is,glucagon%2C%20somatostatin%2C%20and%20amylin. (Accessed, 2020)
3. Barrow, Neurological Institute, 2020, About the Pituitary Gland, [Online] Available at: https://www.barrowneuro.org/get-to-know-barrow/centers-programs/pituitary-center/about-the-pituitary-gland/#:~:text=The%20pituitary%20gland%20is%20connected,hormones)%20that%20control%20their%20functions (Accessed, 2020)
4. BBC bite size, 2020, Coordination and control – The human endocrine system, [Online] Available at: https://www.bbc.co.uk/bitesize/guides/z8t47p3/revision/1 (Accessed, 2020)
5. Biology, 2020, Nerve Impulse Transmission within a Neuron: Action Potential, [Online] Available at: https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_General_Biology_(Boundless)/35%3A_The_Nervous_System/35.2%3A_How_Neurons_Communicate/35.2B%3A_Nerve_Impulse_Transmission_within_a_Neuron%3A_Action_Potential#:~:text=Transmission%20of%20a%20signal%20within,to%20create%20an%20action%20potential. (Accessed, 2020)
6. Britannica 2020, Fight-or-flight response, [Online] Available at: https://www.britannica.com/science/stereotyped-response/Taxes (Accessed, 2020)
7. E.hormone, Unknown date, Endocrine System: Types of Hormones, [Online] Available at: http://e.hormone.tulane.edu/learning/types-of-hormones.html#:~:text=Most%20water%2Dsoluble%20hormones%2C%20like,surround%20the%20cell%20and%20nucleus. (Accessed, 2020)
8. Health line, 2017, Thermoregulation, What is thermoregulation? [Online] Available at: https://www.healthline.com/health/thermoregulation (Accessed, 2020)
9. Hormone Health, 2020, Progesterone and Progestins, [Online] Available at: https://www.hormone.org/your-health-and-hormones/glands-and-hormones-a-to-z/hormones/progesterone#:~:text=What%20Does%20Progesterone%20Do%3F,body%20to%20reject%20an%20egg. (Accessed, 2020)
10. Kent, MK, (2000), Advance Biology, Oxford University Press.
11. Luma, Anatomy and Physiology, Unknown date, Division of the Autonomic Nervous System, [Online] Available at: https://courses.lumenlearning.com/epcc-austincc-ap1-2/chapter/divisions-of-the-autonomic-nervous-system/ (Accessed, 2020)
12. Luma, Unknown date, Hormones, [Online] Available: https://courses.lumenlearning.com/boundless-ap/chapter/hormones/#:~:text=Hormones%20are%20released%20into%20the,a%20cell%2Dsurface%20receptor). (Accessed, 2020)
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16. Medline Plus, 2020, Adrenal Gland Disorder, [Online] Available at: https://medlineplus.gov/adrenalglanddisorders.html#:~:text=The%20adrenal%20glands%20are%20small,much%20or%20not%20enough%20hormones (Accessed, 2020)
17. National Institutes of Health, 2013, Understanding How Testosterone Affects Men, [Online] Available: https://www.nih.gov/news-events/nih-research-matters/understanding-how-testosterone-affects-men#:~:text=Testosterone%20is%20a%20sex%20hormone,red (Accessed, 2020)
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23. Very Well Health, 2020, An Overview of the Thymus Gland, [Online[ Available at: https://www.verywellhealth.com/thymus-gland-overview-4582270 (Accessed, 2020)
24. Your Hormones, Unknown date, Where is my pituitary gland? [Online] Available at: https://www.yourhormones.info/glands/pituitary-gland/#:~:text=The%20pituitary%20gland%20is%20called,and%20maintain%20an%20appropriate%20environment. (Accessed, 2020)

Introduction

The given paper revolves around the cockroach ventral nerve cords main parts, their peculiarities, and the most important characteristics that could be investigated to obtain the data needed to improve the understanding of the functioning of the nerve system. The paper provides detailed characteristics of the cockroach nervous system and the way it responds to numerous stimuli. The main sense organs are analyzed, and the initiation of the main processes that are responsible for the creation of one or another reaction is investigated.

Furthermore, the paper provides a detailed description of the experiment which is conducted to outline the main aspects of the functioning of the cockroach nervous system. Finally, there is a discussion that rests on the obtained data. At the end of the paper, the conclusion is provided. The given research work explores credible sources that contribute to its credibility significantly. Altogether, the paper provides important data needed to improve the comprehension of the given issue.

Main body

The investigation of the main aspects of the functioning of insects nervous system could be considered a common practice in science as it could provide a researcher with the important data that could help him/her to obtain credible results. In this regard, the cockroach nervous system is a good background for the given paper. It is decentralized and has several important characteristics. The central nervous system consists of the ventral nerve cord (VNC), which is linked to the spinal cord and several ganglia (Klowden, 2013).

Along the VNC there are three specific thoracic ganglia and six abdominal ganglia that contain cell bodies of neurons and interneurons (Nation, 2015). Besides, a cockroach has a number of sensory organs similar to those that could be found in humans. Neurons that could be determined in these organs are responsible for converting various stimuli and triggering numerous reactions. Yet, all excitable cells that comprise the nervous system have a certain difference across their cell membranes (Saifullah & Page, 2009).

The given differences predetermine the existence of a significant divergence in the way various cells respond to stimuli and guarantee the appearance of various reactions. Yet, an electrical current passing across a cell could demonstrate their action potential. At the same time, the neuronal cell membrane also contains voltage-gated ion channels that help these neurons to generate the above-mentioned action potential (Cockroach ventral nerve cord, n.d.). In other words, the possibility of the nervous systems cell to respond to various stimuli and generate action potential should be given a great attention as it could help to obtain the important data.

Besides, the way in which a cockroach nervous system responds to numerous stimuli is investigated with the help of the following experiment. The PowerLabs differential amplifier (Bio Amp) is used to record an important data related to the extracellular signals from the cockroach ventral nerve cord. A specially prepared cockroach is used as the object for the investigation.

The above-mentioned equipment will help to record and measure action potentials in the venture nerve cord. These potentials will be generated as the response to various stimuli applied to the sensory spines and hairs in the cerci. Having acquired the data, we compare the showings related to action potentials evoked by different stimuli (Cockroach ventral nerve cord, n.d.).

In the course of the experiment, the following data is obtained. First, cockroach responds to various stimuli in different ways. Yet, spontaneous stimulation has the greatest impact on the central nervous system and generates the most powerful action potential. A cockroach shows a strong reaction and responds in the clear and distinctive way. Additionally, touch could be considered another powerful driver that contributes to the appearance of a certain response. Finally, tap and puff have the almost similar effect on the nervous system. The given data shows that generation of the action potential depends on the kind of irritator and triggers the appearance of a certain reaction that helps a cockroach to survive or act in the appropriate way.

Resting on the above-mentioned data, it is possible to provide the following topics for the discussion. First, one could not deny the fact that spontaneous activity could be considered the strongest stimulus that affects the cockroach nervous system and guarantees generation of a great action potential. A cockroach demonstrates distinct reaction and equipment also admits significant oscillations in the work of neurons and cell membranes. The given pattern could be used to prove the idea that the whole nervous system is focused on the creation of the appropriate response to a certain driver that could be dangerous to a unit (Jabde, 2005). Yet, there are still numerous possibilities for the research as it provides the basis for the further assumptions.

In conclusion, investigation of the main aspects of the central nervous system of a cockroach provides numerous concerns for the discussion. It should be said that its structure and main peculiarities help an insect to provide appropriate responses and guarantee the survival of a unit (Wassmer & Page, 1993). Besides, investigation shows that spontaneous activity and touch should be considered the most powerful stimuli that trigger the appearance of certain reaction and generate action response. Besides, there are numerous opportunities for the further investigation of the given issue.

References

Cockroach ventral nerve cord. (n.d.).

Jabde, P. (2005). Text book of general physiology. New Delhi, India: Discovery Publishing House.

Klowden, M. (2013). Physiological systems in insects. San Diego, CA: Academic Press.

Nation, J. (2015). Insect physiology and biochemistry. Boca Raton, FL: CRC Press.

Saifullah, A., & Page, T. (2009). Circadian regulation of olfactory receptor neurons in the cockroach antenna. Journal of biological rhythms, 24(2), 144-152. doi:10.1177/0748730408331166

Wassmer, G., & Page, T. (1993). Photoperiodic time measurement and a graded response in a cockroach. Journal of biological rhythms, 8(1), 47-56. doi:10.1177/074873049300800104

The human body’s systems operate interdependently, and all physical feelings, brain-developed memories, thoughts, strategic actions, and other capacities lead to the nerves’ instant reaction. Sousa et al. (2017) state that “even though the way our brain is built is not exceptional, we differ by a unique combination of mental abilities, combined with higher general intelligence” (p. 243). This paper aims to describe how human capacities are associated with nervous system activities and structures and discuss what damage might affect them.

The nervous system is responsible for the cognitive abilities development of those helped humans make a leap in evolution and become the most sentient species. The central part of the system is located in the brain and spinal cord, and all reactions appear there, while the peripheral one operates all over the body to deliver the signals to the organs (Rathus, 2020). As the nervous system’s general role is to recognize changes and force organs to react to them, human sensations, actions, and thoughts would not work without proper systems’ operation (Rathus, 2020). Moreover, the nervous system has three main functions: motor, sensory, and integration, all connected with human capacities (Sousa et al., 2017). The first collects information from the receptors, the second process the sensory-given data in the central nervous system, and the last one enables efferent neurons to respond in action (Sousa et al., 2017). For example, when the brain recognizes the gut’s hunger sensation, it makes nerves react to force an individual to crave food.

If a particular type of damage affects the brain and nervous system, severe consequences can appear for other organs and systems because the whole body is dependent on the nerves’ functioning. Various infections, chronic diseases, and injuries can severely influence the system, and the disorders like multiple sclerosis, Alzheimer’s, epilepsy, and stroke are considered the most dangerous (Liberman et al., 2018). Indeed, when a stroke occurs, it injures the brain’s nerve cells, making them unable to communicate with other organs. In Alzheimer’s, nervous networking is disrupted, and the lost connection affects individual cognitive abilities.

Brain and nervous system development moved humans to the edge of evolution, and individuals’ cognitive abilities help them thrive. Nerves are crucial for organs’ communication and responsible for the reactions of external circumstances. Human thoughts, actions, memories, and sensations appear due to the nervous system’s work that forces the brain cells to coordinate with other parts. The nervous system can be damaged due to the diseases like stroke or Alzheimer’s, severely affecting human cognitive abilities.

References

Liberman, A. C., Trias, E., da Silva Chagas, L., Trindade, P., dos Santos Pereira, M., Refojo, D., & Serfaty, C. A. (2018). Neuroimmune and inflammatory signals in complex disorders of the central nervous system. Neuroimmunomodulation, 25(5-6), 246-270. Web.

Sousa, A. M., Meyer, K. A., Santpere, G., Gulden, F. O., & Sestan, N. (2017). Evolution of the human nervous system function, structure, and development. Cell, 170(2), 226-247. Web.

Rathus, S.A. (2020). PSYCH introductory psychology (6th ed.). Wadsworth Cengage Learning.

The Nervous System is the “command and control center of the body.” It is controlled by the brain and governs people’s actions, thoughts, and instinctive responses. Furthermore, it regulates other bodily systems and activities like digestion, respiration, and sexual development (puberty). Diseases, accidents, poisons, and the aging process may all harm an individual’s neurological system. Functions: The human nervous System employs specialized cells known as “neurons” to deliver impulses or messages throughout the body (Rose, 2019). These electrical impulses go between the brain, the skin, the organs, the glands, and the muscles. Individuals can move their limbs and feel feelings such as pain thanks to communication. People’s eyes, ears, tongues, noses, and nerves all over their bodies get information about their surroundings. The info is then sent to and from the individual’s brain through nerves. Different types of neurons give out distinct messages. Motor neurons, for example, tell people’s muscles to move. On the other hand, sensory neurons collect information from an individual’s senses and convey it to their brain. Other neurons regulate automatic bodily activities such as breathing, shivering, maintaining a steady heartbeat, and digesting food.

In fact, Schwann cells are glial cells found in the peripheral nervous system. Schwann cells are classified into two types: myelinating and non-myelinating. The Schwann cell is sometimes referred to as a neurilemma cell. These are peripheral nervous system cells that produce a myelin coating around neuron axons. On the other hand, Myelinating Schwann cells to aid in the propagation of action potentials between neurons. These cells act similarly to oligodendrocytes, a kind of glial cell found in the central nervous system. During embryonic development, neural crest cells differentiate and give rise to Schwann cells.

Tetanus is a potentially lethal nerve system infection. It is caused by nerve poisons generated by the bacterium “Clostridium tetani.” The bacteria can also remain latent for years in the form of spores before becoming active. Tetanus is a commonly lethal infectious illness. This is because germs frequently enter the body through a puncture wound, which can be produced by a skin burn or break, as well as insect bites. Tetanus toxin impacts the connection between the nerve and the muscle that it stimulates, referred to as the “neuromuscular junction.” This illness has an approximately 14-day incubation period. Children and adults should be protected against tetanus using the traditional vaccination approach.

In fact, since they include both sensory and motor neurons, spinal nerves are referred to as mixed nerves. Sensory neurons transport sensory impulses from the organ to the spinal cord. “Afferent nerves” are another name for them. In fact, “motor neurons” carry impulses from the spinal cord to the target organ, causing it to perform some action. These are also referred to as “efferent nerves.”

The parietal lobe is responsible for reasoning, planning, problem-solving, attention, movement, and controlling the functioning of other lobes such as emotion and communication. It is the brain’s biggest lobe. Parietal lobe functions include movement, perception of stimuli, and, to a lesser extent, memory, orientation, and recognition (Casillo et al., 2020). The temporal lobes are engaged in most memory functions (since the hippocampus and amygdala are situated in this lobe), direction, perception of auditory stimuli, speech, and understanding. The occipital lobe is largely responsible for visual perception and processing. To a lesser extent, it is also engaged in other higher-order functions. Each lobe has its primary purpose, although they all work together to complete tasks.

References

Casillo, S. M., Luy, D. D., & Goldschmidt, E. (2020). A History of the Lobes of the Brain. World Neurosurgery, 134, 353–360. Web.

Rose, S. (2019). Nervous system (1st ed.). Macmillan Publishers.

Advantages of Nervous System

Sponges are the only multicellular animals that do not consist of the nervous system and neurons. Research indicates that sponges lack organized tissues and have no organs. The advantages of the nervous systems in animals vary from one animal to the other. The nervous system relates the exterior environment to the body of the animals. The procession and interpretation of the sensory organs is then effected by the nervous system to facilitate an understanding and interpretation of the surrounding. The ‘nerve net’ is illustrated as the most prehistoric and simplest structure of the nervous system in existence. The animals have a means of interacting with each other and with the environment. This is established by the assistance of the nervous system which acts as communication gadget in the animals to learn and adopt to their surroundings with ease.

Different research practitioners give varying findings and conclusions on the evolution and operation of the nervous systems. The presence of non-nervous systems that coordinate with each other is a complicated issue that is yet to yield the full results of its evolution. The evolution and related progression of the nervous system can be defined and illustrated through the cephalization and centralization concepts. Cephalization consists of the actual concentration and accumulation of the functions and structures of the nervous system in the head. Consequently, the centralization of the nervous system indicates the different structural institutes that are collectively centered and organized integrally. The nervous system relates the exterior environment to the body of the animals. The procession and interpretation of the sensory organs is then effected by the nervous system to facilitate an understanding and interpretation of the surrounding.

Disadvantages of Complex Nervous System

In the cases of the nervous systems that are more complex, the presence of centralized nervous systems is common. This results from nerve cords that are longitudinal and arranged in tracts and clusters. The motor neurons tend to widen from the centralization nervous system into the effectors whereas the sensory neurons originate from the periphery section and enters the centralization nervous system. On the other hand, cephalization involves the use of anterior degrees that vary with the concentration of organized nervous systems.

Advantages and Disadvantages of Asexual Reproduction

There are a number of organisms and plants that uses the asexual reproduction method. There exist various advantages and disadvantages aliened to asexual reproduction. This mode of reproduction requires minimum use of energy during the reproduction process. This is due to the fact that these organs and plants have the different fertilizations organs and uses minimal time and energy to facilitate the fertilization process. The processes of searching for mating partners which are commonly experienced in the case of sexual reproduction do not arise. This is because of the presence of both the female and male organs in the organisms and plants.

The amount of time taken before reproduction takes a lot of time in the case of those organisms that use sexual reproduction. On the other hand, little time is required to facilitate reproduction and the time taken to reproduce again is also minimal. This indicates that the asexual reproduction do not involve the use of time and duration of reproduction process. Sexual reproducing organisms face a lot of environmental challenges and fail to survive in certain occurrences. When faced with harsh and brutal environments, the sexual reproducing organisms have low chances of survival unlike the asexual reproducing organisms which face little and minimal environmental and external hazards. The establishment of asexual reproducing organism in an ideal or suitable area or habitat indicates the high chances of survival and the high rate of reproduction. This means that the asexual reproducing organisms reproduce rapidly when established in relevant and appropriate regions that favor their conditions.

In asexual reproduction, the genetic diversity does not exist due to the self-reproducing characteristics. On the hand, the sexual reproducing organisms take advantage of genetic diversity and multiplication. Variations of production of offspring are minimal due to the presence of individual pollination and reproduction. The organisms involved in the asexual reproduction are disadvantaged in that they adapt to certain environmental conditions and an occurrence of environmental change can lead to extinction. The high rates of reproduction by the asexual reproducing organisms lead to overcrowding and competition for existence. Sexual reproducing organisms face a lot of environmental challenges and fail to survive in certain occurrences. When faced with harsh and brutal environments, the sexual reproducing organisms have low chances of survival unlike the asexual reproducing organisms

Reproductive Systems of Vertebrates and Invertebrates

The main difference between the vertebrates and invertebrates is that vertebrates have backbones whereas invertebrates do not. The vertebrates have a higher rate of adapting to different habitats without constraints. The variations of habitats visited and inhibited by vertebrates are many as compared to those inhibited by invertebrates. Invertebrates are relatively small in size and have limited movement abilities due to their levels of instability. On the other hand, the vertebrates move freely and are bigger in size as compared to the invertebrates. The nervous system of vertebrates is highly stable and developed unlike that of the invertebrates. Consequently, the vertebrates and invertebrates have similarities. They both have notochords which lie along their bodies.

Introduction

The nervous system is made up of cells. Various receptors and effectors in different parts connect these cells. The nervous system consists of two parts, including the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is divided into the brain and the spinal cord. The PNS consists of the nerves that link the CNS to receptors and effectors in the body. The nerves that emanate from the brain are referred to as cranial nerves while those that emanate from the spinal cord are referred to as spinal nerves.

The nerve cell

The nerve cells play a critical role in the body system. They consist of structural and functional units. They are charged with the responsibility of circulating impulses within the body. The human body has three types of neurons, including motor, sensory, and intermediate neurons. Each type has a specific function.

Motor Neurons

They transmit impulses from the CNS to the effectors. Its structure consists of a cell body whose cytoplasm and the nucleus are surrounded by a cell membrane. Dendrons emanate from the cell body forming dendrites, which look like filaments. Dendrites receive impulses from the neurons and transmit them to the cell body.

At the opposite end of dendrites is the axon, which is also referred to as the nerve fiber. An axon transmits impulses from the body to a muscle or a gland. The myelin sheath covers the axon and is an electrical insulator as it enhances the speed at which the impulse moves along the axon. The sheath has the nodes of Ranvier that also perform similar duties.

Sensory neurons

They transmit impulses from receptors to the CNS. Most parts of the sensory neuron are located in a peripheral nerve, with a small portion of dendrites found in the CNS.

Intermediate Neurons

They link the sensory and motor neurons. This role gives them a different name. They are found in the brain and the spinal cord. They also do not have a myelin sheath. Their structures differ as they emanate from different parts of the CNS.

The nerve impulse

The impulse transmitted by a nerve fiber is electric in nature. A nerve cell has an electric gradient between the outer and the inner surface. The internal surface contains negative electrons and the external surface contains positive electrons. Upon stimulation, the inner membrane becomes positive and the outer membrane becomes negative. The membrane becomes depolarized. The change is short-lived since the environment keeps changing hence creating an action potential (Starr and McMillan 14).

The movement of sodium and potassium ions in and out of the cell respectively controls this state. Potassium ions are found in plenty in the internal surface, as sodium ions are many in the external surface. Permeability of the cell membrane increases when the cell is stimulated causing the movement of ions across the cell. This causes polarization and depolarization, which in turn have tremendous effects to the functioning of the central nervous system.

The changes consist of the action potential. The events on one part of a cell membrane stimulate the adjacent part whose permeability properties also change. This leads to the formation of another action potential. The result leads to the movement of ions along the nerve cell membrane. The synapse ensures that the impulse flows in one direction only.

Works Cited

Starr, Cecie, and B. McMillan. Human Biology. New York: Brooks/Cole Publishing Co., 2012. Print.

Introduction

The nervous system is rightfully considered to be one of the most complicated and significant systems of the human body, which is responsible for the quality communication and interaction between the organs. However, while exploring the specifics of this system, it is vital to understand that no system exists in isolation from other body parts in order to secure homeostasis or one’s ability to maintain conditions for body functioning for the sake of survival (Eskov et al., 2017). Thus, the primary aim of the present paper is to explore the connections between the nervous system and other systems and define how these connections are designed to maintain homeostasis.

Anatomy

The structure of the nervous system is highly complex as it encompasses two major subsystems responsible for communication within the whole body: the central and periphery nervous systems. The notion of the nervous system may be generally defined as a part of the human body responsible for one’s actions and perception of information through the transmission of signals with neurons (Sturgeon, 2018). The functional units of the nervous system are the neurons and glial cells (“Basic structure and function of the nervous system,” n.d.). The central nervous system (CNS) comprises the brain and spinal cord as primary instruments for human coordination and response to external triggers.

The commonly accepted structure of the brain consists of the cerebrum, brainstem, and cerebellum. The largest part of the brain, the cerebrum, consists of left and right hemispheres divided by a longitudinal fissure (Sturgeon, 2018). The brainstem is a part of the human brain that connects the brain and spinal cord in order to form the CNS, which consists of three major components: midbrain, pons, and medulla (Sturgeon, 2018). The last part of the brain, known as the cerebellum, is located at the back of the brain and coordinates one’s movement and balance. Another part of the CNS, the spinal cord, consists of four regions: cervical, thoracic, lumbar, and sacral (Dafny, 2020). The spinal cord is a functional unit that secures communication between human extremities and the brain.

The peripheral nervous system consists of nerves and ganglia. Nerve is a common constituent of the nervous system, as it stands for the cord structure with nerve fibers that secure the communication between the nervous system and another system. The nerves are divided into cranial and spinal, with the latter forming 31 nerve pairs and the former accounting for 12 pairs (Dafny, 2020). The nerves are also divided into distal and proximal, with the former located closer to the spinal cord and being more evident than their distal counterparts.

Ganglia, for their part, may be defined as the groups of nerve cells responsible for communicating signals between the nervous system and other body parts. Thus, such neurons are divided into afferent and efferent (Sturgeon, 2018). The afferent, or motor nerves, carry information from peripheral organs to the CNS, whereas the efferent neurons are responsible for carrying signals from the CNS to the periphery.

Physiology

Considering the fact that the nervous system comprises brain function, it would be reasonable to outline that the system itself plays a crucial role in terms of people’s thinking and learning patterns, as they perceive the environment through the lens of receiving and sending signals with the help of nerve cells. According to the National Cancer Institute (NIH, n.d.), the nervous system is the primary body system in terms of communicating, regulating, and controlling human response to both the internal and external environment. The significance of the nervous system is manifested through its three primary functions:

• Sensory input. The work of the afferent neurons secures that human rain receives information about the internal and external environment of the human body. Once the sensory input is delivered to the CNS, the nervous system processes the information in order to generate the body’s response and send efferent signals to the peripheral nerves.
• Integration. The process of communication between the neural pathways in the human body secures a coherent interaction between all the human body systems, as the nerves transmit information to the human brain, where the decision to act in a certain manner is made.
• Motor response. This function of the nervous system allows for the human’s reaction to the signals entering the nervous system through neural pathways (“Introduction to the nervous system,” n.d.).
• Social homeostasis. Over the past years, researchers ponder the relevance of humans’ social response to the environment with the help of neural patterns. According to Matthews and Tye (2019), similarly to the conventional nervous system defining the person’s energy and fluid needs, neural systems may generate afferent signals requiring social interactions and other endeavors in order to preserve the social homeostasis of an individual.

Homeostasis

Endocrine System

The endocrine system is considered the most closely related to the nervous system due to the fact that while the latter regulates natural human response to various factors, the former stimulates and controls the inner body development through the release of hormones into the brain. The two systems are linked with the help of the hypothalamus, an organ that receives the information from the automatic nervous system regarding the body’s internal balance and hormonal state (Sturgeon, 2018). The motor response generated by the nervous system is highly dependent on the person’s ability to produce reactions on the behavioral level, which depends on the release of such hormones as epinephrine and norepinephrine. The nervous system is able to control the release of hormones with the help of pituitary glands attached to the hypothalamus, and such control plays a dramatic role in the person’s growth, behavioral patterns, and even sexuality and reproductive health. For this reason, it may be concluded that the interrelation between the nervous and endocrine systems is vital for the development of a proper human response to the external world and internal growth.

Skeletal System

The skeletal system, which stands for the bone framework of the human body that moves with the help of muscle contractions, exists in symbiosis with the nervous system. First, the skeleton system provides the nervous system with protection from injuries. For example, the skull and vertebrae protect the brain and spinal cord from potential injuries. Second, bones store calcium vital for the functioning of nerve cells. As far as benefits for the skeletal system are concerned, the nervous system provides positional information to the brain, protecting the bones from improper positioning of bones and joints.

Muscular System

The muscular system of the human body, which is mostly comprised of various types of muscles, serves as a means of motion of the human body and process within it, including digestion (Sturgeon, 2018). The neural signals make muscles contract, as the muscles attached to the bones execute the movement pattern programmed by the brain. Moreover, the nervous system also receives information concerning external factors such as temperature, making the muscles adjust the body heat according to the environment. Finally, the nervous system has the ability to regulate the speed with which the food should go through the digestive tract (Rubin, 2020). Hence, the cooperation between these two systems secures the initiation of such vital processes and nutrient digestion and motion.

Cardiovascular and Lymphatic Systems

These two systems are highly dependent on the proper functioning of the nervous system, as they are responsible for the fluid circulation within the body, including blood, oxygen, and lymph fluid. The nervous system accounts for the regulation of heart rate and blood pressure by employing a vagus nerve. The nervous system also obtains a specific neural receptor called baroreceptor, which is responsible for signaling information about blood pressure to the brain in order for it to make necessary adjustments. Endothelial cells that belong to a circulatory system aim at maintaining the blood-brain barrier that prevents the CNS from the invasion of toxic pathogens. Hence, it may be concluded that both circulatory and lymphatic systems cannot exist without the nervous system, as the brain that receives afferent neurons is in charge of transmitting the fluids across the body.

Digestive System

The patterns of digestion depend explicitly on the nervous system, as the brain is responsible for the human’s eating and drinking behavior regarding one’s environment. The brain receives information from the digestive system through the neural pathways, making people eat and drink. Moreover, it was mentioned previously that the coordination of nervous and muscular systems regulates the pace of food through the digestive tract. The digestive processes provide a foundation for the proper functioning of neurotransmitters, as nutrition contributes to the transmission of hormones.

Respiratory and Reproductive Systems

The respiratory system that accounts for the circulation of oxygen and carbon dioxide within the body is also highly dependent on the nervous system. The nervous system consists of respiratory neurons that signal the respiratory muscles in order to circulate air. The reproductive system, for its part, impacts the brain’s development and behavioral patterns through the release of reproductive hormones. The system itself is affected because the brain is responsible for the overall sexual behavior of the individual. Thus, with the help of the nervous system, the reproductive organs communicate to the brain their readiness to mate and reproduce.

Urinary and Integumentary Systems

The urinary system, comprising the bladder, urethra, and kidney, is co-dependent with the nervous system, as waste elimination is performed through channeling the signals to the brain. The integumentary system, for its part, encompasses such body parts as skin and hair, and they play a significant role in the functioning of the nervous system, as skin is a major external receptor that renders the information concerning one’s environment. In its turn, the nervous system regulates the growth and condition of hair and skin regarding the inner state of the human body, hormonal, and vitamin balance.

Conclusion

The nervous system is a highly complex combination of body parts that exist in cooperation with each other in order to control and regulate human movement and behavior. However, while the nervous system obtains a variety of autonomous features, it cannot exist in isolation from all the other body systems. The process of discovering interconnections between the nervous system and the other systems has shown that the proper functioning of the nervous system requires interaction with every single part of the human body.

References

Basic structure and function of the nervous system. (n.d.). Lumen Learning. Web.

Eskov, V. M., Filatova, O. E., Eskov, V. V., & Gavrilenko, T. V. (2017). The evolution of the idea of homeostasis: Determinism, stochastics, and chaos–self-organization. Biophysics, 62(5), 809-820.

Introduction to the nervous system. (n.d.). Lumen Learning. Web.

Matthews, G. A., & Tye, K. M. (2019). Neural mechanisms of social homeostasis.Annals of the New York Academy of Sciences, 1457(1), 5–25.

Rubin, N. (2020). Overview of the peripheral nervous system.

Sturgeon, D. (2018). Introduction to anatomy and physiology for healthcare students. Routledge.

The heart requires its own nutrient and oxygen resources for it to continue pumping blood throughout the organism on a daily basis. A compound set of veins and arteries preserve the heart and deliver blood to it; moreover, they permit the blood to flow from end to end of the organism.

Coronary arteries stock the heart with blood that is rich with oxygen. The right coronary artery begins at the right aortic sinus and goes within the coronary sulcus that is situated amid the right atrium and ventricle. It consists of four outlets: sinoatrial nodal artery, right marginal artery, posterior interventricular artery, and atrioventricular nodal artery (Lamont 39). The left coronary artery comes out of the left aortic sinus and does within the atrioventricular groove which is situated amid the atria and ventricles on the exterior side of the cardiac organ. It consists of three outlets: anterior interventricular artery, circumflex artery, and left marginal artery (Corada 2375). The majority of the veins that pump blood from the cardiac muscles and constructions discharge into the coronary sinus, which goes behind the cardiac organ. The veins that go to the coronary sinus comprise the great, middle, and small cardiac veins, the left posterior ventricular vein, and the left marginal vein (Fleckenstein and Tranum-Jensen 7).

The cardiac organ is invigorated by parasympathetic and sympathetic fibers. The medulla is the main location in the brain that controls sympathetic and parasympathetic discharge to the cardiac organ and blood vessels. The hypothalamus and higher centers adjust the commotions of the medullary midpoints and are predominantly significant in controlling cardiovascular replies to various sensations, such as excitement and pressure (Uflacker 634).

This topic is important, as the veins, arteries, and nerves of the heart are vulnerable to numerous diseases. For example, coronary heart illness is the contraction of the coronary arteries that is triggered by the accumulation of patches inside its dividers. This sickness leads to the diminished blood stream (and reduced oxygen levels) to the muscles of the cardiac organ. A myocardial infarction, or else called a heart attack, might take place when the obstruction in the coronary arteries leads to the impairments in the musculature of the cardiac organ. The indications of a myocardial infarction consist of severe discomfort in the upper body that possibly will sense like pressing or heaviness on the upper body. Aching can be current in other fragments of the organism as well.

Furthermore, atherosclerosis includes infection and the accumulation of patches that are full of fat, or atheromas, in the dividers of the heart, and this buildup ultimately results in the toughening and contraction of the arteries. When a patch breaches, a blood lump is able to appear and generate a heart attack (Terfera par. 2).

As the progress of atherosclerosis in the organism is a compound procedure, the academics are trying to discover innovative methods in order to comprehend and treat this severe sickness.

There are various interesting researches regarding the topic of veins, arteries, and nerves of the heart, such as the topic of the stem cells. Hominoid pericytes that enclose capillaries and microvessels are proven to provide an increase in values to unaffected mesenchymal stem cells (which are also called MSCs). This statement elevated the inquiry as to whether every mesenchymal stem cell is resulting from pericytes. According to the authors of the research, pericytes and further cells demarcated on the various countenance of CD34, CD31, and CD146 appeared to be organized from the stromal vascular segment of hominoid white adipose material (Corselli 1301).

Works Cited

Corada, Monica. “ATVB in Focus: New Advancements on the Regulation of Angiogenesis.” Arteriosclerosis, Thrombosis, and Vascular Biology 34.1 (2014): 2372-2377. Print.

Corselli, Mirko. “The Tunica Adventitia of Human Arteries and Veins as a Source of Mesenchymal Stem Cells.” Stem Cells and Development 21.8 (2012): 1299-1308. Print.

Fleckenstein, Peter and Jørgen Tranum-Jensen. “Arteries and Veins.” Anatomy for Diagnostic Imaging. Ed. Stephanie Ryan. Philadelphia: Saunders. 2010. 5-13. Print.

Lamont, Ryan. “MAPping Out Arteries and Veins.” Science Signaling 2006.355 (2006): 38-39. Print.

Terfera, David 2010, Arteries and Veins that Feed the Heart. Web.

Uflacker, Roland. “Atlas of Vascular Anatomy: An Angiographic Approach.” Journal of the Pancreas 11.6 (2010): 633-637. Print.

The paper represents a comparative analysis of somatic and autonomic nervous systems, which regulate the major body control systems. According to the medical theory, the somatic nervous control refers to all voluntary body movements while autonomic system regulates involuntary impulses of a human body. Specifically, an autonomic nervous system manages such divisions as connections between spinal, brain, and other organs. In contrast to it, the system of voluntary control concerns the connections between neurons and human muscles (“The Somatic and Autonomic Nervous Systems” par. 2).

Two systems play a critical role in regulating the major organism functions. For instance, autonomic nervous control relates to such processes as digestion, perspiration, the utilization of body energy as well as the management of sexual and temperature arousals. The system of involuntary impulses realizes its major functions through the revelation of two subdivisions such as parasympathetic and sympathetic nervous regulations. The first system refers to the smoothing of all body functions. Mainly, sympathetic regulation embraces the stimulation of normal blood circulation, the restriction or extension of bronchial size, delivering regulatory effects through digestion mediation as well as catalyzing the basic sexual arousal effects (Stroetmann and Bowald, 21).

The sympathetic system provides the opposite effect by delivering nervous stimulation (“Sympathetic Nervous System” par. 6). Mainly, the regulation is responsible for enhancing the flows of blood and leading them to the muscles, increasing heart rate and lungs’ diameter, constricting urinary sphincters, and stimulating orgasm reaction. In contrast to autonomic nervous system, the somatic regulatory mechanism embraces a different set of functions. Specifically, the system acts through the stimulation of nerve impulses, which concern the contraction of muscles and sending commands to different body areas (Westfall 23).

The optimal illustration of nervous systems’ functioning may be transmitted through the examples of their regulatory action. Thus, the bright picture of the somatic system’s functioning is feeling cold or heat. Thus, when human skin comes in contact with the object, which differs in extreme temperature regime, the task of the somatic regulation is to transmit the impulse from the brain to the definite body area so that the organism could react on the impulse. The exemplification of autonomic system’s reaction refers to blood circulation. Thus, a human does not notice blood coming through veins, which expresses involuntary regulation character (“Autonomic Nervous System” par. 4). The mentioned illustrations might serve as the optimal subjects for remembering systems’ action.

The perception of the nervous systems’ functioning is vital for every individual since the understanding of the organism’s regulation work relates to the ability to manage one’s own body. The specification of all-embracing nervous systems’ functioning stimulates the appearance of multiple studies on the issue. Specifically, in the last years, the investigators worked out the methodologies of cognitive decline prevention, which stems from the analysis of nervous brain connections. Moreover, the assistance of new medical technologies helps in the identification of the diseases, which might potentially arise in adulthood. Conclusively, one may claim that nervous systems’ investigations stimulate critical clinical improvements (“Nervous System News and Research” par. 5). The evidence reveals that the study of the nervous systems’ promotes both human awareness of their own organisms’ work as well as relates to the identification of diverse body reactions to the external impulses. The clinical research of somatic and automatic regulations’ elaboration offers the innovative solutions for medical disputes and controversies.

Works Cited

Autonomic Nervous System. 2013. Web.

Nervous System News and Research. 2016. Web.

Stroetmann, Brigitte and Staffan Bowald. “Method and Apparatus for Cardiac Therapy by Stimulation of a Physiological Representative of the Parasympathetic Nervous System.” The British Medical Journal 22. 1 (2005): 1-25. Print.

Sympathetic Nervous System. 2012. Web.

The Somatic and Autonomic Nervous Systems. 2015. Web.

Westfall, Thomas. The Pharmacological Basis of Therapeutics, New York: McGraw-Hill, 2014. Print.

Introduction

The procedure adopted in the study was a standard way of assessing neurological functions of the nervous system. It is one of the methods that are used in hospital settings to estimate the state of nerves in the body. Andreassi (2000) argues that an essential component in nerve conduction is the speed at which impulses and responses are transmitted along the motor or sensory pathways.

The nervous system is an important part of the body because it is involved in responding to stimuli in the external environment (Misulis 1997). The CNS is important in mediating stimuli processing in the brain and spinal cord. On the other hand, the PNS is characterised by thousands of nerves that are appear as long fibres. They are used in linking various parts of the CNS. It has been shown that the long fibres form motor neurons, which are involved in coordinating voluntary movement (Misulis 1997). The PNS also contains nervous components that mediate involuntary functions. In healthy individuals, the transmission of impulses should be within standard ranges of speeds. Thus, a nerve conduction velocity is the pace of conducting electrochemical impulses along neurons. A number of factors could influence the speed of nerve conduction. For example, disease, age and sex, among other factors could make different persons have diverse velocities of conducting impulses (Izhikevich 2000). It has been shown that changes to the constant velocity of nerve conduction could be an indication of damage (Andreassi 2000).

The architecture of the nervous system shows that both motor and sensory axons are found in the same neurons. Thus, if a disease affects either of the axons, then the other type of axon could also be affected. Patients who present with nerve diseases could be characterised by various symptoms. For example, they could feel numbness when some stimuli are applied to their bodies. Also, they may have tingling thoughts even in the absence of stimulus. Individuals whose nerves are damaged could have altered responses with regard to temperature and pain. In fact, they could be exposed to elevated temperature and a lot of pain, but they show little responses. Nerve damages have been shown to result in loss of sense with regard to position and vibration. The nervous system may be damaged and appear through acute or chronic manifestations.

Demyelination is a common cause of diseases in the nervous system (Misulis 1997). The process involves a loss of the myeln sheath that surrounds axons. Due to the importance of myelin sheath in increasing the speed of nerve conduction, loss of the component results in reduced speed of conducting impulses along neuron fibres (Kandel, Schwartz & Jessell 2000). Nerve diseases that affect axons are caused due to the interruption of conduction velocity with regard to demyelination. In fact, deterioration of the destruction of the myelin sheath affects axons that are involved in conducting impulses at similar speeds. Thus, the initial functions that are compromised in nerves following nerve diseases are action potentials that have similar speeds of transmission. Some of these are tendon reflexes and vibratory sensation (Kandel et al 2000; Misulis 1997). The reduction of nerve conduction velocity was investigated in the experiment.

Procedures

All procedures in the experiment were carried out keenly while recording all readings. The recording was important to ensure that all details were captured and used in the required calculations.

Sensory nerve conduction

Ulnar and median nerves were located and the skin surface was prepared by cleaning it with alcohol. Coil stimulating electrodes were attached to recording electrodes and ground electrode. The skin impedance was tested using a metre to ensure that the readings were within the recommended range before starting the nerve conduction velocity measurement procedure. The equipment set by averaging various parameters in order to obtain the right measurements. The subject was made to seat comfortably while stretching the right arm and relaxing to minimise the chances of introducing muscle artefact during measurements. The equipment was set to start stimulating the subject while recording observations. Various intensities of stimuli were applied to the subject with the aim of recording different response readings. In addition, different stimuli were used to obtain the threshold of stimulus that could elicit the best response. Nerve action potential readings were recorded. The next step involved measuring the distance between the stimulating and recording electrodes. In addition, the latency of the action potential responses were recorded. From the readings, the conduction velocities of the motor fibres were calculated.

The ulnar nerve was located on the subject taking part in the experiment. A preparation with regard to the recording and ground electrodes was made by abrading the skin and cleaning it using alcohol. In addition, a daub of conductive gel was applied on the skin surface to facilitate the sensitisation of the skin. The stimulating electrodes were soaked in saline solution. The skin impedance was tested using the impedance metre. The isolated stimulator in the equipment was used to determine the threshold of the subject. It was important to make the order of stimulating electrodes and recording electrodes the same. In order to ensure that the stimulating electrodes were kept wet, they were dipped in saline solution. The recording electrodes were placed on the flashy palm using the proper orientation of the negative and positive electrodes of the equipment. The stimulating electrode was placed on the nerve sight behind the elbow. At that point, it was essential apply different stimuli from the equipment. With regard to the experiment, a stimulus intensity of applied on about 5muA. The intensity of current that was used to stimulate the subject was increased. At the same time, the recording electrode around the skin region to determine the best stimulation site.

Results and discussion

This section of the report includes the results of the experiments and key discussion points.

Figure 3. A table that summarises the calculations of nerve conduction velocities using distances between peaks and latency.

The velocities were calculated using the following steps:

Velocity = distance/latency

MNCV = (d2-d1)/((t2-t1)

For the wrist, velocity = (10-0)/(7.58-3.77) = 2.62467 m/s.

For the elbow, velocity = (35)/(9.49) = 3.688 m/s

The results obtained in the experiment show important findings with regard to the nerve conduction velocity and latency values. The latency value obtained from the wrist experiment falls within the normal range that is found in healthy persons. However, the nerve conduction velocity of 2.62 m/s is below the standard value that is documented in physiology literature. A number of reasons could cause variations. First, it could be due to experimental errors that could have occurred during the experiment. Errors result in wrong findings that cannot be used to make conclusions about clinical observations. For example, wrong readings could have been taken. Doing calculations with wrong readings increases the chances of obtaining wrong results.

Second, there could have been wrong targeting of the site with the best stimulation responses. The effect of a wrong region could be that a region that was identified could not give the best readings of responses. This could have been avoided during the preparation stage when the skin of the subject was being prepared for measurement.

Third, there could be a possibility the conduction gel applied on the skin did not help in conducting stimuli onto the skin of the subject. Thus, it could have acted as a barrier to effective sensitisation of the skin.

Fourth, it would also be important to consider the variation noted the results from a pathological perspective. There could be nerve damage in the subject used in the experiment. Although the subject might not be aware of the pathological state of the nerves, the damage might be in the early stages of chronic damage. Myelin sheath of the axons of the neurons could be characterised by some form of degeneration (Misulis 1997). Damage of the myelin sheath interferes with the normal transmission of impulses along axons. This is due to the disruption of the patterns of the nodes of ranvier that act as crucial points of facilitating the speed to impulse transmission. Thus, the pace at which the impulses that were induced in the subject were transmitted was relatively slow and could not fall below the normal range.

Conclusion

The experiment showed that latency values could be normal in a subject whose nerve conduction velocity values are abnormal. The findings indicated that it is essential to conduct experiments that are free from errors. Based on the results, it could be concluded that the subject was suffering from some of nerve damage or errors were common in the procedures.

References

Andreassi, JL, 2000, Psychophysiology: Human behavior and physiological response. Psychology Press, London, United Kingdom.

Izhikevich, E M, 2000, ‘Neural excitability, spiking and bursting’, International Journal of Bifurcation and Chaos, vol. 10, no. 06 pp. 1171-1266.

Kandel, ER., Schwartz, JH, & Jessell, TM, Eds, 2000, Principles of neural science, McGraw-Hill, New York, NY.

Misulis, KE, 1997, Essentials of clinical neurophysiology , 2^nd ed. Butterworth-Heinemann , Upper Saddle River, NJ.