Homeostatic Control Of Heart Rate, Breathing Rate, Temperature, And Blood Sugar Regulation, Kidney Structure And Function, Skin Structure And Burn Impact

Please answer the questions as follows:

Q1. Explain the normal homeostatic control for the heart and breathing rate (nerves control,chemicals,hormone levels of oxygen and carbon dioxide), temperature (hypothalamus,heat promoting ,heat loss mechanism) and blood sugar regulation (insulin ,glucagon,stomatostatin).

Explain why his heart and breathing rate increased,why his temperature increased and why his energy use increased.

Q2. Discuss the structure and function of the kidneys ,mention the urethra,bladder and uretrus.

Explain what glomerulonephritis is ,how it affects the filtering of the blood , the reabsorption of important substances and the removal of salt and water.

Q3. Discuss the structure and the function of the skin. Explain the impact of the skin structure and function of the skin on a full thickness burn .

Explain the effect of hypothermia and hyperthermia in the body. Explain heat loss and heat promoting mechanisms , mention the hypothalamus

Heart Rate Control

The heart rate is usually regulated and/or controlled by impulses which are produced by both the sympathetic and the parasympathetic nerves within the Sino-atrial node. The parasympathetic nerve system mainly functions as a calming system and thus functions when the heart is at rest (Zhang, 2009). The vagus nerve as part of this system makes the heart to beat slower when need be. The sympathetic system on the other hand according to Cook & Hess (2010) engages the cardiac nerves to initiate the triggering of an increase in the heart rate when the body is under stress. It also triggers the production of adrenaline hormone especially when in fear.

The breathing rate is controlled by the respiratory center located in the medulla oblongata at the lower brain stem section. The brain stem relies on chemoreceptors to determine the arterial oxygen and pH levels. The chemoreceptors can detect high levels of Carbon dioxide in the internal environment and relay this information to the central respiratory center through expiration and inspiration neurons to initiate deeper breathing which is also faster. According to Swami (2009), as the breathing rate increases, more oxygen accumulates and reaches more tissues in the body until sufficient levels are reached after which the respiratory center re-stabilizes the breathing rate. 

The body temperature is regulated in the brain by the hypothalamus. The hypothalamus sends impulses to the effectors such as the sweat glands in the skin to regulate body temperature (Kanosue et al, 2009). When it is cold, the hypothalamus initiates vasoconstriction where blood vessels near the skin vasoconstrict to reduce blood flow to the skin and prevents heat loss. The hairs on the skin also stand to trap air within them to act as insulators against heat loss. The hypothalamus also initiates shivering to ensure that muscles promote heat generation (Tortora & Derrickson, 2009). When temperatures are high, the hypothalamus initiates vasodilation to increase blood flow to the skin in order to lose heat. Sweating is also initiated to lose excess water, salts and urea while at the same time cooling the body through the evaporation effect.

Blood sugar regulation is done by the pancreas involving Glucagon and Insulin hormones which are produced by the Alpha and the Beta islet cells of this particular organ respectively. High blood glucose stimulates the release of insulin by the Beta islet cells of the pancreas which stimulates the muscle cells, fat cells and even red corpuscles to absorb and convert excess glucose to glycogen (Warade, 2014). This normalizes the blood sugar level to between 70mg/dl and 110mg/dl of blood. Glucagon on the other hand is released by the Alpha islet cells of the pancreas when there are low glucose levels in blood. It triggers the liver, muscle cells and even fat cells to convert glycogen into glucose (Yang, 2012). It can also induce these cells to manufacture glucose from proteins. This brings the glucose levels in blood to normal. Somatostatin which is a growth hormone facilitates a stable blood sugar level by inhibiting over-secretion of these pancreatic hormones.

Breathing Rate Control

The heart rate increased as a response to the stress the body was undergoing through during the running exercises. The sympathetic system on the Sino atrial node of the heart engaged the cardiac nerves to initiate the triggering of an increase in the heart rate in line with Westfall & Westfall (2010). The breathing rate also increased because of the respiratory center’s response to detected high levels of CO₂  in the internal environment and the blood. The central respiratory center through expiration and inspiration neurons thus initiated deeper breathing which is also faster to ensure that more oxygen is taken up. Energy use increased as a result of its high demand by the muscles and vital organs including the brain, the heart, kidneys (Yang, 2012). The running exercises raised the energy demands by these organs to facilitate faster breathing, faster waste excretion, faster heart rate and thermoregulation.

The kidneys are bean-shaped and highly vascularized by blood vessels and served by the renal artery and renal vein. The kidney has three major parts and these include the renal cortex, renal medulla and the renal pelvis each with its own functions. The renal cortex consists of numerous renal tubules approximated at 1.25 million and has numerous nephrons for blood filtration (Tortora & Derrickson, 2009). The renal medulla is the collecting chamber for waste products while the pelvis receives wastes in form of urine from the nephrons which are the basic functions units of the kidney. The ureters as part of the renal system are muscular tubes which transport the produced urine for each kidney into the urinary bladder; which is a sac that collects and holds urine before removal to the outside. The urethra is the passageway for urine from the urinary bladder heading to the outside during urination.

The functions of the kidney include first, the excretion of wastes; toxins, excess salts and even urea in the blood. It secondly maintains the body’s water balance according to (Henriksen, & Henriksen, 2015) where it ensures a balance between water and blood electrolytes. The kidneys are reactive to any changes in water and electrolyte level changes within the body. In cases where there is low water and/or electrolyte balance, the kidneys initiate water reabsorption while minimizing its loss in order to regulate these levels, as a homeostatic response (Tortora & Derrickson, 2009). Thirdly, kidneys play a major role in regulating blood pressure by producing angiotensin hormone during hypotension, which triggers the constriction of blood vessels. It also acts as a signal to the body to ensure retention of both Sodium ions and water in case of low blood pressure. The kidneys regulate red blood cell numbers in the body by producing erythropoietin hormone which triggers the production of more red blood cells by the bone marrow (Henriksen, & Henriksen, 2015). Further, kidneys regulate the levels of acidity in the body and particularly in blood. Acids which result from the body’s metabolic processes especially lactic acid must be neutralized by bases in order to prevent cell destruction. The kidneys ensure there is a stable acid base balance within the body in order for an individual to be healthy.

Temperature Regulation Mechanism

Glomerulonephritis refers to the inflammation of the glomeruli which are the minute filters within the kidney whose main role is to remove excessive fluids, wastes and even electrolytes from the blood and eventually pass these contents into urine (Henriksen, & Henriksen, 2015). The sudden inflammation of the glomeruli is referred to as acute glomerulonephritis while a gradual and long term occurrence of this condition is referred to as chronic glomerulonephritis (Tortora & Derrickson, 2009). The condition may therefore occur on its own but can also be caused by other conditions such as diabetes. Glomerulonephritis impairs the kidney functions due to the inflammation of the filters. The condition leads to hematuria where urine contains red blood cells as a result of poor filtering of blood by inflamed filters. It also leads to proteinuria where urine is foamy as it has excessive proteins (Henriksen, & Henriksen, 2015). Glomerulonephritis also causes high blood pressure due to fluid retention and a poor ridding process of excess fluids in blood. The poor removal of salts and water increase the bold pressure.

The skin comprises of the epidermis, dermis and subcutaneous layers. The first and outermost layer is the keratinous epidermis which has the Stratum conium that is water proof and acts as a barrier to chemical substances and foreign infectious organisms. The epidermis also prevents internal organs and tissues from trauma (Wilkinson, 2009). It has the melanocytes that not only determine color but prevent the effect of ultraviolet radiations from causing skin cancer. The dermis has nerve endings for sensing pressure, touch, temperature and pain. It has sweat glands that produce sweat to cool the body and excrete excess salts and water. The sebaceous gland in the dermis secretes sebum for softening and moistening the skin and thus acts as a barrier to foreign bodies. The dermis has hair follicles that produce hairs which enhance sensation, regulate body temperature and prevents skin injury (Rojas et al, 2012). The blood cells in the dermis supply nutrients and heat to the skin tissues and cells. The third skin layer is the subcutaneous tissue composed of fat cells and acts as insulation to cold and heat and further as storage for energy.

Full thickness burns destroy all the skin layers including muscles, bones fat, nerves and glands temporarily and/or permanently according to Rojas et al (2012). The burns are usually open and therefore the body loses fluid through them which contributes to shock in some burn victims. They also act as highly potential entry points for infectious organisms and substances (Peck, 2012). Full thickness burns also leads to scarring rendering the area insensitive to pain, touch and temperature changes.

Hypothermia occurs when the body temperature drops below 35 Degrees Celsius and the body loses heat faster than the amount it generates. This leads to reduced heart and nervous system functioning among other vital organs like the brain, kidneys and lungs (Karakitsos & Karabinis, 2008). This translates to a reduced functioning of the circulatory and respiratory system which eventually leads to the possibility of death. Hyperthermia on the other hand occurs when the body temperature goes above 37.5 Degrees Celsius or ranges between this particular temperature and 38.3 Degrees Celsius. Hyperthermia leads to depletion of brain glycogen resulting into seizures and even coma (Haider & Anis, 2015). The condition also leads to tachycardia and hypotension as there is increased vasodilation. Hyperthermia victims experience heat strokes that involve acute tubular necrosis within the kidneys making them inefficient and eventually failing.

References

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