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Biology Essay: A Case Study Analysis


Case Study: Jane
Jane is a 38yo marathon runner who has presented to her GP clinic after completing a training run. She trains three days per week, and has experienced light-headedness, and significant muscle pain after her last three runs. Whilst talking to the clinic nurse, Jane admits to feeling lethargic, and like her “heart is racing”. She has also been a little unsteady on her feet and stumbled climbing the stairs in her home the previous evening. She reveals her fluid intake has been lower than usual, and although she is still eating well, her caloric intake has been less than usual. She has lost 2kg in the last month. She also states her resting heart rate used to be 51 bpm according to her Garmin watch.

Jane applied Voltaren Emulgel, a topical non-steroidal anti-inflammatory drug (NSAID), to her quadriceps and calves immediately after this morning’s run, hoping to relieve some of her muscle soreness.

Consider the above case study and develop a biology essay answering the following question:

Question 1

  1. Describe the changes in volume and pressure that will be occurring in Jane’s chest cavity to achieve exhalation during a long run. Explain why these changes are occurring, and the effect upon airflow.
  2. Describe the gas exchange occurring between air in Jane’s alveolar air and pulmonary blood. Will the rate of gas exchange change during exercise? Explain your answer.

Question 2

  1. Which ANS response would you expect to dominate during Jane’s runs? Explain your answer.
  2. Which hormone associated with glucose homeostasis would you expect to be most active during this ANS response? Why? Using your knowledge of glucose homeostasis, explain your answer.

Question 3

  1. Describe the role of the kidneys in maintaining fluid balance with reference to the role of antidiuretic hormone (ADH). Is Jane at risk of not maintaining homeostatic fluid mechanisms? Why/why not?
  2. What is a urinalysis and what is its significance for this case? With respect to the specific gravity (SG) component of Jane’s urinalysis result, and using your knowledge of normal kidney function, would you expect this result? Why/why not?

Question 4

  1. Consider Jane’s blood pressure result and discuss whether the mean arterial pressure is likely to be varied from normal. In your answer you must include reference to a possible change in blood volume and briefly mention the consequences of any change in BP upon kidney function.
  2. In this circumstance, do you think the renin-angiotensin-aldosterone system or natriuretic peptides will dominate in the maintenance of Jane’s blood pressure. Discuss the role of your chosen system in blood pressure homeostasis to explain your answer.

Question 5

  1. Jane suffered a significant haemorrhage during her caesarean delivery and required a blood transfusion. Which blood type(s) could have been safely administered to Jane? Explain the potential consequences if Jane had been administered A+ blood.
  2. At the time of her caesarean delivery, Jane was found to have a calcium deficiency. How would this have affected the ability of her blood to clot? Explain your answer


The current case analysis presented in this biology assignment concerns Jane, who is presented to the GP clinic, aged 38 years post completion of a training run. Recently she has been facing light-headedness, significant muscle pain with complaints of feeling lethargic, racing heart, unsteadiness along other symptoms of dehydration. She applied Voltaren Emulgel for relieving her muscle soreness. The case analysis examines transformations taking place in her body examining relevant homeostasis, the role of the kidney in the maintenance of fluid balance as well as analysis of blood pressure analysis of Jane.

During the long run, there will be changes taking place in the pressure and volume in Jane's chest cavity for attaining exhalation. Exhalation is dependent on the pressure gradient between the lungs and atmosphere as well as the muscles present in the thoracic cavity. The chest cavity has slightly negative pressure which assists in holding the lungs airways open. Thus, the volume of the chest will increase highly during running upon inhalation and decrease upon exhalation. Whilst the exhalation process, the lung recoil forces the air from within the lungs (chest) outside relaxing the intercostal muscles. This returns the chest wall back to the original position, relaxing the diaphragm, that goes higher in the thoracic cavity. It leads to an increase in pressure in the thoracic activity about the environment as air rushes outside of the lungs as the gradient of pressure between the atmosphere and thoracic activity (Shao et al., 2014). These changes take place for removing air from the lungs is regarded as a passive event as no muscles contracts for expelling the air.

During the long run, gas exchange occurs between the air in alveolar air and pulmonary blood will alter also during exercise. Oxygen that is inhaled goes into the lungs then reaches the alveoli. There the layers of cells that lines the alveoli along with the capillaries in the surrounding remain in close contact with one another. During running/ exercise by Jane, this process will be done rapidly to accommodate for more oxygen and purify the blood from carbon dioxide. Oxygen passes in a fast manner through the air blood barrier in the blood present in the capillaries. Then the carbon dioxide is passed from the blood to the alveoli to be exhaled. The blood that is oxygenated goes from the lungs from the pulmonary veins to the left side of the heart, then pumping blood to the remaining parts of the body (Qureshi, 2011). Blood will then be pumped through the pulmonary artery to the lungs where oxygen will be picked up and for releasing of carbon dioxide.

During Jane's runs, ANS response includes the regulation of the cardiovascular response that will dominate her runs. During its onset, the central nervous system (CNS) creates a cardiorespiratory pattern regarded as a central command that is relevant to the somatomotor signal. This central command will create withdrawal of parasympathetic activities within the heart to create increased ventilation rates and resets the arterial baroreflex for greater pressure. The primary purpose of the cardiorespiratory system during running of Jane is delivering adequate oxygen amounts and waste removal from the body tissues. Cardiovascular regulations maintain adequate blood flow across all body tissues. Whilst exercising the demand for oxygen to the muscles running running is increased 15 to 25 times more than at rests (Liu et al., 2013). The heart cannot work in isolation as it cannot accomplish its functions then. An increase in oxygen demand on the body tissues leads to an increase in heart rate, blood pressure, and respiratory rates. This requires major adjustments of blood flow from the various inactive organs towards the active muscles in the skeletal system.

The brain has a primary activity in the regulation of peripheral metabolism of glucose through pathways as well as by signaling mechanisms. Several regions in the brain are impacted by exercises bringing about transformations in the expression of genes that encodes proteins that are engaged in synaptic plasticity, cellular bioenergetics, neurotrophic factor signaling, cellular stress resistance, and disposal of damaged organelles and proteins. Glucagon and insulin hormones are most active during ANS response where the pancreas maintains blood glucose levels differ between a very narrow range of 4-6 mM (Mitrakou, 2011). The process of glucose homeostasis is achieved through preservation by opposing a well as balanced actions of glucagon as well as insulin. Glucose Homeostasis response will be most active during ANS response for attaining a balance of glucagon and insulin for maintenance of blood glucose levels.

The role of the kidneys is to adjust the concentration of the urine for reflecting on the body’s need for water by conserving water in case the body is dehydrated or by producing more urine dilute for expelling out excess water when needed. In Jane's case, her kidney will retain more water as she is dehydrated and the ADH hormone enables the body for retaining water by increasing water reabsorption by the kidneys. ADH stimulates reabsorption of water by insertion of water channels in the kidney tubules membranes. The channels then transport water that is solute-free through the tubular cells back in the blood that leads to reduce plasma osmolarity and leading to an increase in osmolarity of urine (Cuzzo, & Lappin, 2019). Jane is at a greater risk of not maintaining a homeostatic fluid mechanism as she is already dehydrated. Hydration concentration of the body is controlled by osmoreceptors in the hypothalamus detecting electrolytes concentration in the extracellular fluid. These electrolytes concentration in the blood increases when the water loss takes place due to excessive perspiration, which results in neuronal signals being transferred from the osmoreceptors present in hypothalamic nuclei. The hormone responsible for the maintenance of electrolyte concentrations in extracellular fluids is aldosterone, produced by the adrenal cortex, a steroid hormone. As contrasted to ADH, aldosterone helps in maintaining proper water balance by increase NA+ reabsorption and K+ secretion from the extracellular fluid in the cells in the kidney tubules (Zittema et al., 2012). The release of this hormone is stimulated by a decrease in blood potassium levels, preventing the loss of Na+ from saliva, sweat, and gastric juice.

Urinalysis is a urine test for detecting and managing a wide range of disorders. It includes checking the appearance, concentration, and urine content. An abnormal urinalysis might lead to an illness or disease. The significance of urinalysis, in this case, is in detecting increased protein levels or detecting signs of kidney disease (Callens & Bartges, 2015). Concerning the specific gravity 1.035 in Jane's urinalysis results and applying knowledge of normal kidney functions, increased specific gravity in the urine indicates that the adrenal glands do not produce enough hormones, presence of high levels of sodium in the blood, dehydration due to loss of body fluids, and narrowing of the kidney artery or associated syndrome of inappropriate ADH secretion (Ristic, & Skeldon, 2011). These are the case detected due to her increased levels of physical activities with consumption of protein and dehydration, these will be seen to be the associated conditions of Jane.

Considering Jane’s blood pressure, it is more likely to be varied as compared to normal levels due to dehydration. Dehydration can lead to lower levels of blood pressure due to a decrease in blood volume. For maintaining normal blood volume, the blood must be able to reach all tissues of the body and during dehydration, the blood volume decreases which leads to a drop in blood pressure. During such a drop in pressure levels, the organs will not receive the oxygen and nutrients needed. The kidneys will reduce the formation of urine that causes the capillaries to constrict in regions of the brain and the heart (Daugirdas et al., 2013). As the kidneys with reduced pressure in the blood will not be able to filter out urine as in normal cases, it can create tremendous pressure on the walls of the kidney. With urine retention, the kidneys can be severely damaged leading to kidney disease.

In the situation, the renin-angiotensin-aldosterone system and not natriuretic peptides will dominate the maintenance of Jane's blood pressure. The RAS regulates pressure in the blood as well as the balance of fluid in the blood. When blood volume or levels of sodium in the body becomes low, then the blood potassium gets high and the cells in the kidney release the enzyme, renin. In Jane's case renin converts angiotensinogen produced in the liver, due to the hormone angiotensin I. The enzyme ACE found in the lung metabolizes angiotensin I into the angiotensin II (Provenzano, & Sparks, 2020). Aldosterone and angiotensin II works towards raising blood volume, sodium levels in the blood, and blood pressure for restoration of the potassium, sodium, and fluids for getting blood pressures to normal levels.

During Jane's hemorrhage during her cesarean delivery, requiring blood transfusion, the blood type to be safely administered to her will be her blood group. In case Jane had been administered A+ blood then she would have recovered fast. At the time of cesarean delivery in case, Jane was found to have a calcium deficiency then it would have deterred the ability for her blood to clot (Fyfe et al., 2012). Clotting needs calcium ions and is the most important mineral in the blood.

In conclusion, Jane has faced considerable challenges regarding her dehydration leading to an excessive impact on her kidneys. She immediately requires medical attention to restore levels of hydration such that the functioning of her kidneys and other organs be restored along with her blood pressure levels.

Callens, A. J., & Bartges, J. W. (2015). Urinalysis. Veterinary Clinics: Small Animal Practice, 45(4), 621-637.

Cuzzo, B., & Lappin, S. L. (2019). Vasopressin (antidiuretic hormone, ADH). Europe PMC. Accessed from []

Daugirdas, J. T., Greene, T., Rocco, M. V., Kaysen, G. A., Depner, T. A., Levin, N. W., ... & Kliger, A. S. (2013). Effect of frequent hemodialysis on residual kidney function. Kidney international, 83(5), 949-958.

Fyfe, E. M., Thompson, J. M., Anderson, N. H., Groom, K. M., & McCowan, L. M. (2012). Maternal obesity and postpartum haemorrhage after vaginal and caesarean delivery among nulliparous women at term: a retrospective cohort study. BMC pregnancy and childbirth, 12(1), 112.

Liu, Q., Yan, B. P., Yu, C. M., Zhang, Y. T., & Poon, C. C. (2013). Attenuation of systolic blood pressure and pulse transit time hysteresis during exercise and recovery in cardiovascular patients. IEEE Transactions on Biomedical Engineering, 61(2), 346-352. DOI: 10.1109/TBME.2013.2286998

Mitrakou, A. (2011). Kidney: its impact on glucose homeostasis and hormonal regulation. Diabetes research and clinical practice, 93, S66-S72.

Provenzano, A. M., & Sparks, M. A. (2020). The renin-angiotensin–aldosterone system update: full-court press. Nephrology Dialysis Transplantation, 35(9), 1488-1490.

Qureshi, S. M. (2011). Measurement of respiratory function: an update on gas exchange. Anaesthesia & Intensive Care Medicine, 12(11), 490-495.

Ristic, J., & Skeldon, N. (2011). Urinalysis in practice–an update. In Practice, 33(1), 12-19.

Shao, D., Yang, Y., Liu, C., Tsow, F., Yu, H., & Tao, N. (2014). Noncontact monitoring breathing pattern, exhalation flow rate and pulse transit time. IEEE Transactions on Biomedical Engineering, 61(11), 2760-2767. DOI: 10.1109/TBME.2014.2327024

Zittema, D., Boertien, W. E., van Beek, A. P., Dullaart, R. P., Franssen, C. F., de Jong, P. E., ... & Gansevoort, R. T. (2012). Vasopressin, copeptin, and renal concentrating capacity in patients with autosomal dominant polycystic kidney disease without renal impairment. Clinical Journal of the American Society of Nephrology, 7(6), 906-913. DOI:








Content coverage and accuracy of answers (40 marks)

Very extensive explanations and exceptional accuracy on each question of the case study.

(34-40 marks)

High level of accuracy with minor omissions in some questions.

(30-33.5 marks)

Some omissions and lapses of accuracy, perhaps in the more complex areas of the questions on the case study.  These would normally require some revision.  (26-29.5 marks)

Some major omissions and significant errors of facts or misinterpretations of core concepts on the questions of the case study.  Material requires significant revision.  (20-25.5 marks)

Serious omissions and errors of facts or misinterpretations of core concepts on the questions of the case study.  Material requires extensive revision.  (0-19.5 marks)


Quality of written communication

(10 marks)

Accurate and concise scientific language and terminology used throughout.  Minimal to no errors in grammar, syntax and spelling.  Essay is consistently structured in a clear and logical manner that is easy to read.

(8.5-10 marks)

Accurate and concise scientific language and terminology used throughout.  Few errors in grammar, syntax and spelling.  Overall, essay is structured in a clear and logical manner that is easy to read.

 (7.5-8 marks)

Mostly accurate and concise scientific language and terminology used throughout.  Some errors in grammar, syntax and spelling.

Essay is mostly structured in a clear and logical manner that is easy to read. (6.5-7 marks)

Some accurate scientific language and terminology was used, some was inaccurate and unclear.

Many errors in grammar, syntax and spelling.  Aspects of essay structure are clear, logical and easy to read.  (5-6 marks)

Answers to questions not converted to essay style and/or limited or no scientific language and terminology was used.

Errors in grammar, syntax and spelling that detract from meaning.  Essay is poorly organized with illogical flow of ideas and difficult to read.  (0-4.5 marks)


Mark Deductions

0 marks (no deductions)

-1 mark

-2.5 marks

-5 marks


APA referencing conventions

In-text citations are present and appropriate.  Reference list includes fully accurate information about all sources used.  All formatting as per APA 7th edition conventions.  All sources are reputable and current (as appropriate).  Minimum of 5 sources cited. 

In text citations used.  Reference list includes accurate and sufficient source information.  Minor errors in APA formatting.  Use of some less reliable and/or current sources.  Less than 5 sources.  

No in-text citations used.  Reference list does not include all necessary information about sources used.  Persistent errors in APA formatting.  Use of some less reliable and/or current sources.  Less than 5 sources.

No in-text citations used.  No reference list or does not provide sufficient information about sources used.  Serious errors in APA formatting.  Poor quality sources and/or less than 5 sources.


Word Count

Essay response, including in-text citations (but excluding reference list), is between 1350 and 1650 words


No deductions


Essay response, including in-text citations, is more/less than 1500±10% words.

Essay response, including in-text citations, is more/less than 1500±15% words.








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