Homeostasis: Body’s Regulatory Mechanism

Introduction

Homeostasis is referred to as the body's control mechanism to maintain an optimal physiological environment. This is required so that the body cells and tissues have a constantly controlled environment within the body to perform their role and function effectively. In this assignment, the needs of the body in relation to homeostasis are to be discussed. The way the body's temperature is regulated is also to b discussed along with understanding is to b developed regarding the waste products of the body are eliminated. For those seeking assistance, healthcare dissertation help can provide valuable insights. The role of endocrine glands is to be discussed and the basic structure of the nervous system is to be explained. The way the body regulated the pH is also to be discussed.

1.1 Explaining the concept of homeostasis

The Homeostasis is referred to as the mechanism in which an organism maintains a stable and constant condition of temperature and pH within the body. The external and internal stimuli are able to affect the body's homeostasis. As mentioned by Yang et al. (2017), the homeostatic system of the body is mainly controlled by three independent components which include a sensor, control centre and effectors. The sensor mainly detects any changes in the internal as well as external environment whereas the control centre acts to receives information from sensors for initiating response to perform homeostasis. The effectors are referred to the tissues or organ which receiving information from the control centre brings changes in the body to maintain homeostasis. As argued by Kotas and Medzhitov (2015), failure of the body to maintain homeostasis would lead the body system to develop deteriorated condition creating fatal consequences. This indicates that body cells are dependent on homeostasis to live as well as function properly.

1.2 Explaining the way cells survive

The cells are regarded as the structural and functional unit of all living organisms. As mentioned by Placenti et al. (2017), proper delivery of oxygen to the cells is to be ensured for its survival. This is because proper oxygen to the cells leads them to produce the proper amount of Adenosine Triphosphate (ATP) which acts to effectively manage energy production through Na+/K+-ATPase. As argued by Elsayad et al. (2016), proper water supply to the cells is required for their survival. This is because the proper water content in the cells helps them to maintain their osmolarity, in turn, allowing them to bring in nutrients and remove waste as well as transport oxygen. The cells for its survival also require essential nutrients and minerals as they support them to maintain proper functioning and structure. This indicates that the minerals act as co-factors for the cell to survive (Placenti et al. 2017). The cells to survive needs to properly remove wastes as storage of waste materials would lead to create toxic effects on the cells result the body unable to maintain homeostasis. This is evident as accumulation of waste in the body alerts the temperature and pH of the body resulting to inhibit the functioning of enzymes and lowering the rate of body’s metabolism (Fuchs and Steller, 2015).

1.3 Explaining the role of negative feedback in homeostasis

The negative mechanism in homeostasis has the key role to reduce the activity or output of a system or an organ to reach its normal functioning range. For instance, regulation of blood pressure in the body is a negative feedback mechanism of homeostasis. This is evident as baroreceptors which are sensors in the blood vessels detect if the flow of blood is too high then accordingly delivers signals to the hypothalamus. In the brain, the hypothalamus then sends signals to the effectors which are kidneys, heart and blood vessels to control their actions to normalise the blood pressure (Modell et al. 2015). During high blood pressure, the heartbeat is decreased so that the blood vessels are dilated and the kidneys are signalled to release water. The changes lead to the pressure of blood flow in the vessels to return to normal range. These changes are reversed when decreasing blood pressure is detected which results the blood vessels to be constricted and the kidneys to retain water (Nemazanyy et al. 2015).

2.1 Explaining the role of other organ and skin in regulating body temperature

The temperature of the body is regulated by the integumentary system through tight association with the sympathetic nervous system that further includes accessory skin structures, sweat glands and other organs to perform the action. As mentioned by Tansey and Johnson (2015), during high body temperature the sympathetic nervous system sends signals to the sweat glands to produce increased amount of sweat. This is because a large amount of sweat in evaporation from the skin surface would cool the body as the excess heat is dissipated. As argued by McKinley et al. (2015), during high body temperature the arterioles present in the dermis of the skin are dilated. This is done so that the excess heat is able to be dispersed through the skin in the surrounding and it leads the skin to develop redness. However, when the temperature of the body drops, the arterioles present in the dermis of the skin are constricted and blood flow is lower so that heat loss is minimised (Walløe, 2016). This action leads the skin to develop a whitish blue tinge as blood circulation is reduced towards the skin.

3.1 Explaining the structure as well as the function of the kidney

There are two kidneys present in the human body and each of them is bean-shaped which are located one of the right and another of the left of the retroperitoneal space. In the abdominal cavity, the asymmetry created by the position of the liver has led the right kidney to be slightly smaller and lower compared to the left kidney. The right kidney is present below the diaphragm and in the posterior side of the liver whereas the left kidney is present in the posterior position to the spleen (Jourde-Chiche et al. 2019). The kidneys have a functional substance that is parenchyma which divides it into two key structures that are renal medulla on the inner side and renal cortex on the outer side. These structures develop 18 cone-shaped renal lobes with each of the lobes containing portion of the renal cortex which is surrounded by renal medulla developing into renal pyramids. The renal pyramids are mainly the projections of renal columns. The nephrons are the functional structures in the kidney which produces urine and acts to span the medulla and cortex. The inner part of the nephron contains a renal corpuscle located in the cortex and it is followed by renal tubule which passes from the inner part of the cortex to the medullary pyramids (Maiden et al. 2016). The papilla of the renal pyramid empty the urine into minor calyx which eventually empties into major calyces and this empties into renal pelvis which becomes the ureter (Lee et al. 2018). The functions of the kidney include regulating the proper amount of extracellular fluid volume to ensure adequate plasma is present to keep normal blood flow to the vital organs and excretion of wastes and toxins. The other functions include regulating osmoregulation, pH of the blood, production of hormone erythropoietin and maintaining proper ion concentration in the body (Terasaki et al. 2019).

3.2 Explaining the hormonal control related to osmoregulation

The kidney maintains osmoregulation with the help of proper functioning of hormones produces by different parts of the kidneys and body. It is the process through which constant osmotic pressure in the body is maintained by controlling salt concentrations and water (Ruiz-Jarabo et al. 2019). The epinephrine and norepinephrine are mainly produced by the adrenal medulla as well as the nervous system. They act as flight-fight hormones and is released when the body is under stress. The release of epinephrine and norepinephrine temporarily halts the release of waste by the kidney and the hormones directly act on the blood vessels present in the smooth muscles for constricting them. After the arterioles are constricted, the blood flow stops towards the nephron and the action of the hormone leads the rennin-angiotensin-aldosterone system to be triggered (Ruiz-Jarabo et al. 2019). The rennin-angiotensin-aldosterone system proceeds through various steps to finally produce angiotensin II that acts to normalise the blood volume and pressure. The rennin which is produced in the kidney nephron reacts on angiotensinogen that is globulin produced in the liver to be converted into angiotensin I (Ruiz-Jarabo et al. 2019). The Angiotensin-Converting Enzyme (ACE) then converts angiotensin I to angiotensin II and the angiotensin II then acts to increase the blood pressure through the constriction of blood vessels to trigger the release of mineralocorticoid aldosterone to stimulate reabsorption of increased sodium by the renal tubules. The anti-diuretic hormone (ADH) release is triggered by the angiotensin II so that water is retained by the kidneys by acting on the glomerular filtrate rate to be decreased (Ruiz-Jarabo et al. 2019). Thus, this informs that by the help of angiotensin II, epinephrine, norepinephrine, rennin- angiotensin, aldosterone and ADH the kidneys are able to retain water and sodium to maintain proper osmoregulation.

4.1 Explaining the function of the nervous system in homeostasis

The nervous system is mainly managed through proper blood flow and any interruption in the process triggers brain damage which may lead to fatal consequences. The homeostasis is maintained by the nervous system through control and regulation of different body parts. This is evident as any deviation from normal range or level of functioning of the body develops stimulus to be received by the nerve impulse present in regulation of the centre of the brain. The brain on receiving the signal directs an effector for acting in such a way so that adaptive response happens to stabilise the functioning of the body. For instance, if the deviation was to reduce body temperature then the effector acts to raise the body temperature. The adaptive response sends the body back to a condition in which the temperature is normal and the receptor along with the regulating centre and effector stops their activity on temporary basis. This nature of regulation to reach normalcy creates fluctuations in two extreme levels until the body temperature is lowered below normal range when the receptors are again stimuli the effectors along with the control centre to increase the body temperature. The regulating centres for homeostasis are present in the central nervous system (Park and Ahima, 2015).

4.2 Describing the features and function of neurons

The neurons are known as specialised cells which transmit signals through the entire body. The basic components of neuron include dendrite, nucleus, axon, nodes of Ranvier and axon terminal. The dendrites are the branched structures which extend from the cell body of the neuron has the key role to accept messages from other neurons and they have dendritic spines which extend their surface area to develop connections with other neurons (Pannese, 2015). The cell body has a nucleus along with smooth endoplasmic reticulum, mitochondria, Golgi apparatus and other components of cells (Pannese, 2015). The axon is a nature of tube-like structure which is present at the end of the neuron and it has the function to carry electrical impulse from the cell body to the other neurons through the axon terminals. The axon divided into the structure and is covered by a myelin sheath. In between the myelinated axon, the nodes of Ranvier are present who have the role to speed the propagation of signals from axon to another (Pannese, 2015). The synapse is referred to as the chemical junction present between one neuron to the axon terminal of another neuron (Pannese, 2015). The function of the neuron is to transmit the signals in the nature of the electrical impulse from the brain throughout the body and back to the brain. The neurons remain connected to one another through synapses to allow the electrical signals to flow smoothly between them to reach the destination (Kawauchi and Nabeshima, 2019).

4.3 Explaining the way nerve conduct impulses

The nerve impulse is mainly triggered through strong impulse and with the stimulus chemical and electrical changes occur in the neuron. The outside of the neuron has increased number of sodium ions and is charged positively and whereas in the inside of the cell there are potassium ions and the inner side of the cell is negatively charged. The presence of different charges creates an electrochemical difference and with the effect of the nerve impulse, the cell membrane permeability is changed allowing the sodium ions to flow inside the potassium ions to be released outside the neuron creating depolarisation cell (Castelfranco and Hartline, 2016). This ion exchange through the membrane of neuron leads to develop an action potential which makes the impulse to move forward the axon to reach the axon terminals to be transferred to next neuron. The increased flow of sodium ions on the inside of the cells and the potassium channel being open leading potassium ions to be released out creates repolarisation through the restoration of the original polarity of the membranes. However, in this condition the neurons are hyperpolarised as increased number of potassium ions have moved out. In this condition, the axon would be unwilling to respond to any more impulse until the original sodium and potassium ion distribution are established as seen in resting potential (Freeman et al. 2016). After the impulse reaches the end of the axon through action potential, the neurotransmitters release some chemicals which diffuse in the synaptic gap allowing the nerve impulse to be transmitted to other neurons through chemical or electrical synapse (Maïna et al. 2015).

4.4 Explaining the reflex arc

The reflex arc is referred to the neural pathway which controls a reflex action. The reflex arc is of two types which are somatic reflex arc and the automatic reflex arc. In somatic reflex arc, the nerve impulse travel from the somatic receptors present in the muscle, skin and tendon to the afferent nerve fibers. The fibers carry the impulse received to the posterior horn of the spinal cord. The impulse is carried forward to the integration centre which is the point at which the neuron that made up the gray matter is present. The impulse then passes through short interneuron to the efferent nerve fibers to be carried by the motor nerve signals to the muscles from the anterior form of the spinal cord. The effectors muscle which is innervated by effecter nerve fiber executes action in response to the impulse received (Zubrzycki et al. 2015). The autonomic reflex arc is similar to the somatic reflex arc with the exception that it includes motor action which is an autonomic output where tow motor neurons are involved (Möller and May, 2019).

5.1 Explaining the role of the respiratory centre in regulating pH

One of the key roles of the respiratory system apart from respiration is regulating proper blood pH. The normal pH of the blood is 7.4 making it be alkaline in nature as pH of 7 is regarded as neutral and above it is alkaline whereas below 7 is regarded as acidic (Fiorino et al. 2015). When the pH of the blood becomes acidic, the respiratory acidosis occurs that leads to damage the tissues of the body. The acidosis is mainly caused due to less breathing that lower the removal of carbon dioxide leading it to get build up in the bloodstream (Fiorino et al. 2015). The respiratory alkalosis occurs when there are less hydrogen ions as a result of less amount of carbon dioxide (Ricard et al. 2018). The respiratory centre in the human body are seen to contain chemoreceptors which properly detects the pH of the blood and in case any abnormality is detected they sends signals to the part of the brain that control ventilation system to increase breathing in case of acidosis and decrease breathing in case of alkalosis to maintain proper pH of the blood (Fiorino et al. 2015).

5.2 Explaining the role of the kidney in regulating the pH of the body

The kidneys are found to be comparatively slower in comparison to the lungs to maintain proper pH level of the blood. The renal physiology executes the task to control the normal pH of blood through excreting excess acid or base. The bicarbonate ions present in the renal tubules do not have a proper transporter and so the ions are mainly reabsorbed through a number of actions in the tubule lumen and tubule epithelium (Nagami and Hamm, 2017). During acidosis, the tubular cells in the kidney mainly reabsorb bicarbonate from the collect tubular fluid and cells in the collecting duct secrete extensive hydrogen along with bicarbonate to normalise acidosis in the blood. The ammoniagenesis occurs in the proximal tubule of the kidney which leads to increased production of NH3 buffer that acts to lower the increased pH of the blood (Nagami and Hamm, 2017). However, during alkalosis, the kidneys act to secrete an increased amount of bicarbonate and lower the production of hydrogen ion from the tubular epithelial cells along with lower ammonia excretion and glutamate metabolism to lower the alkalinity of the blood (Nagami and Hamm, 2017).

5.3 Explaining the significance of buffers in regulating blood pH

The haemoglobin acts as key protein buffer for the red blood cells where they allow buffering of the hydrogen ions that are released during CO2 conversion to bicarbonate so as to lower dissociation with the O2. This buffering action assists to maintain normal blood pH (Fago et al. 2017). The phosphate buffers are present in either weak acid (Na2H2PO4−) or weak base form (Na2HPO42-) in the blood. The Na2HPO42- on coming in contact with hydrochloric acid picks up a single hydrogen ion from the weak acid to form sodium chloride and Na2H2PO4− but when Na2HPO42- contacts with sodium hydroxide which is a strong base it produces water and weak acid to maintain proper blood pH (Li et al. 2017). The bicarbonate-Carbonic Acid buffer also acts in the similar way like the phosphate buggers. The bicarbonate present in the blood is mainly regulated through sodium ions. The sodium bicarbonate when contacts with hydrochloric acid develop carbonic acid as weal acid along to sodium chloride whereas when it contacts with sodium hydroxide then it forms water and bicarbonate to maintain normal blood pH (Cheng and Jusof, 2018).

Conclusion

The above discussion informs that homeostasis involves maintaining equilibrium within the body through the constant and unchanging state. The cells to survive properly are to be provided constant supply of key substances such as minerals, oxygen, sugar and others as well as the proper disposal of waste materials are to be maintained. The kidney is bean-shaped and they have the key function to throw out wastes from the body and marinating osomoregulation. The nervous system with the help of central nervous system control homeostasis in the body. The respiratory system, kidney and buffer in the body by neutralising acid-base components in the blood manage proper blood pH.

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