Discussion on Nervous and Other Body Systems-Samples for Students

Question: Discuss about the Crosstalk between Nervous and Other Body Systems. Answer: Introduction: Nervous system is the control centre of the body, responsible for sending instruction to various parts and maintains the functional and organizational system. Every other system of the body has to coordinate with the nervous system in order to sustain life. The basic mechanism of nervous system occurs through neurotransmission and response to external stimuli is done by reflex action. Endocrine system is another important organ system which works parallely with nervous system to regulate proper body function. The aim of this report is to reflect upon the crosstalk between nervous and endocrine system. Discussion: Nervous system is the organ system of the body, present in animals responsible for directing and synchronizing different activities of the body by generating electro-chemical impulses. The nervous system comprises of the following organs like, brain, spinal cord, and a dense network of nerve cells that spread all over the body (PubMed Health, 2018). The nervous system is subdivided in two categories, the Central Nervous System (CNS) and the Peripheral Nervous System (PNS) Central nervous system:It consisted of the brain and the spinal cord. It receives integrated information from the body and conveys coordinated instructions to control the activities of various parts of the body. Peripheral nervous system: It consists of nerve cells and ganglia cells which are required to form a link between CNS and the rest of the body. The peripheral nervous system consists of two subdivisions, autonomous nervous system and somatic nervous system. Autonomic nervous system or ANS consists of motor nerves that are responsible for controlling involuntary actions like respiration, heartbeat, and peristaltic movements of the digestive system. The difference between CNS, PNS and ANS is as follows: Central Nervous System Peripheral Nervous System Autonomous Nervous System 1. It is the controlling centre of the nervous system. 2. It consists of brain and spinal cord. 3. It controls the total function of the body and is responsible for all the reactions against any stimulus. 1. It is the system that links the CNS with the rest of the body 2. It consists of neural cells and ganglia cells. 3. It is responsible for interlinking and connecting the brain and spinal cord with that of the rest of the systems of the body. 1. It is the part of the PNS that controls the involuntary actions of the body. 2. It consists of sympathetic and parasympathetic nervous system. 3. Autonomous nervous systems stimulate all the functions which occur without the cognition of the muscle. Nerve Impulse Transmission: The stimulus carried by a nerve to one end of the cell to the brain is done through a series of electrochemical gradient, called a nerve impulse. The transmission of a neuronal impulse along a neuron from end to end is a result of generation of an electrical gradient due to difference in electrical potentials between two charged membrane surfaces. Incidence of a stimulus starts a series of biochemical reactions to generate chemicals called neurotransmitters which acts as a signaling molecule to open ion channels to allow influx of ions which leads to difference of membrane potential. The internal compartment of the cell is usually more negative than outside in an unstimulated nerve. Membrane polarization is established when an excessive sodium ions is present on the outside and an excessive potassium ions is present on the inside of a cell. The ion channels maintains the balance between n K+ and Na+ ions to impair constant charge leakage. Fig 1: Generation of action potential Source: (Sensory Nervous system, 2018) When action potentials travel along neuronal axons, the membrane potential changes from -70mV to approximately +30mV, after which it returns to its resting state (Fig 1). This change in electric potential results from swift chronological opening and closing of voltage-gated Na+ and K+ ion channels. Na+ ions flows rapidly inside the cell, promoted by both concentration and membrane potential. The rapid entry of Na+ ions leads to sudden change in the membrane potential, which immediately increases to approximately +30 mV, where the Na+ channels are inactivated by opening of voltage-gated K+ channels, significantly increasing the membrane permeability towards K+ ions. Then K+ ions flows rapidly out of the cell, driven by action of membrane potential and its concentration gradient, rapidly leading to a decrease in membrane potential about -75mV. This change in membrane potential inactivates K+ channels and the membrane returns to its resting potential of -70mV. The flow of K+ and Na+ thr ough the channels determines the membrane potential in unstimulated cells. Mechanism of Reflex Action: Reflex action is a neurological mechanism that occurs in the autonomous nervous system in response to an external stimulus (Saladin, 2015). The reflex arc consists of five steps described in the Fig 2. Fig No: 2 Pathway of Reflex Arc in Tissues. Source: (Marieb and Hoehn, 2013) Receptor centre This is the nerve ending (dendrite) attached to skin surface receptors which detects the external stimulus. Sensory nerve cell The function of this nerve is to transmit the stimulus in the form of electrical impulses to the brain and spinal cord. Inter-nerve cell: These types of neurons are called relay neurons, which functions as a processing centre, conducting impulse and relaying reflex from the grey matter to the motor nerve. Motor nerve cell: This nerve carries the output impulse of action from brain or spinal cord to the effecter nerve cell. Effecter nerve cell: This type of nerve cell gives off the reflex response to the stimulus which may or may not be at the same position of the reception centre. Relationship between Skin, Circulatory and Nervous System: The skin, nervous system and circulatory system work in harmony to protect the body from harm. The nerve endings on the skin receives stimulus which directs it to move away from danger in a matter of milliseconds. The protection of the skin is done by the somatic nervous system. The lymphatic system connects the nervous and the circulatory system and helps maintaining the cardiac output and blood pressure (Mancia and Grassi, 2014). The nervous system sends impulses that direct the circulatory system to provide blood circulation to various parts of the body. Incoming of an external stimulus on skin or other dangers, nerve impulses are sent to the brain via neurons which in turn increases heart rate via sympathetic nervous system. Also in contact with danger the kidney starts secreting epinephrine (adrenaline) which also increases heart rate to stimulate flight or fight instinct. The circulatory system in turn regulates body temperature as an effect of adrenaline. Crosstalk between Endocrine system and Nervous system: The nervous system and endocrine system work in union with each other to maintain growth, homeostasis, and reproduction. Functionally, both the nervous and endocrine systems work together with one another by reacting to chemical, environmental and endocrinal changes. Homeostatic maintenance and response to internal and external changes to the body is coordinated by them. An example of this can be observed in a lactating mother. The sensory cells in a lactating mothers nipple receive when a baby sucks on it, thereby sending signal into hypothalamus where the hormone oxytocin is released. Oxytocin then travels via blood stream and stimulates the mammary gland and produces milk (Crowley, 2014). Similarly, during puberty hormones are released, testosterone in males and estrogen in females which controls sexual maturity. Nervous system responds to sexual stimulus after the onset of puberty (Plant, 2015). Difference between Endocrine system and Nervous system: Endocrine system and Nervous systems work together in higher animals and regulate various activities and coordinate billions of cells. The endocrine systems secrete various signaling molecules (hormones) to send instructions to specific target cells. Nervous system on the other hand communicates with their target cells via chemical neurotransmitters which connects neurons. The Endocrine system secretes hormones into the blood stream which is taken up by target cells through the extracellular fluid. Nervous system communicates with target cells via paracrine signaling, interconnected by neurons which convey electrochemical messages using neurotransmission (Alberts, 2015). Endocrine systems are slowly transmitted while Nervous system is extremely rapid. Conclusion: All the organ systems in the body work in harmony to sustain life. Skeletal system provides structure, circulatory system provides blood, oxygen and hormonal circulation, alimentary system provides nutrition, respiratory system carries out gaseous exchange, reproductive system transfers genetic material to progeny, immune system protects body from foreign infection and excretory system removes waste. All of these processes are dependent on the combination of both nervous and endocrine system. Arguably, it should be mentioned that endocrine system is first system to mature during the early development of fetus. The crosstalk between nervous system and endocrine system is intercalated in such a manner that disorder in either will affect both as well as the rest of the body system. Neurological disorders are often times the resultant of a premature endocrine disorder during developmental stages. References: Alberts, B., 2015.Molecular biology of the cell. New York, NY [u.a.]: Garland Science. Crowley, W., 2014. Neuroendocrine Regulation of Lactation and Milk Production.Comprehensive Physiology, pp.255-291. Hall, J.E., 2015.Guyton and Hall textbook of medical physiology e-Book. Elsevier Health Sciences. Lacroix, J.J., Campos, F.V., Frezza, L. and Bezanilla, F., 2013. Molecular bases for the asynchronous activation of sodium and potassium channels required for nerve impulse generation.Neuron,79(4), pp.651-657. Mancia, G. and Grassi, G., 2014. The Autonomic Nervous System and Hypertension.Circulation Research, 114(11), pp.1804-1814. Marieb, E., Hoehn, K. and Hutchinson, M., 2013.Human anatomy physiology. [San Francisco, Calif.]: Pearson Education/Benjamin Cummings. Nieuwenhuys, R., Hans, J. and Nicholson, C., 2014.The central nervous system of vertebrates. Springer. Plant, T., 2015. Neuroendocrine control of the onset of puberty.Frontiers in Neuroendocrinology, 38, pp.73-88. Pohl, H.R., Wheeler, J.S. and Murray, H.E., 2013. Sodium and potassium in health and disease. InInterrelations between essential metal ions and human diseases(pp. 29-47). Springer, Dordrecht. PubMed Health., 2018.Nervous System - National Library of Medicine - PubMed Health. [online] Available at: https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0025454/ [Accessed 8 Feb. 2018]. Saladin, K., 2015.Anatomy physiology. New York: McGraw-Hill. SENSORY NERVOUS SYSTEM., 2018.Electrical Signals. [online] Available at: https://sensoryandnervous.wordpress.com/nervous/physiology/electrical-signals/ [Accessed 8 Feb. 2018]