Part 1: Answer the following questions.
- List and briefly explain the 3 stages of urine formation (6 pts)
- Why is tubular reabsorption of sodium and water critical to maintaining homeostasis (2 pts)?
- Explain the role of anti-diuretic hormone on urine production (2 pts).
- A build-up of uric acid can cause what condition (2 pts)?
Part 2: Evaluate the following case study and answer the questions.
For the following case study, use your book as a reference and include specific details from the chapter in your answer. Use credible outside resources if necessary. Cite all resources in APA format.
Aaliyah, who is 5-years old, is taken to the doctor. Her father mentions that she has been experiencing increased urination. Aaliyah is taken to the doctor where a urinalysis is performed.
a. Explain the normal components of urine (2 pts).
b. Aaliyah's urinalysis shows the presence of large amounts of protein in her urine. Using what you know about the process of urine formation, explain why it would be abnormal to find large amounts of protein in Aaliyah's urine (be specific and relate your answers to the stages of urine formation) (2 pts).
c. Aaliyah's urinalysis also shows the presence of glucose in the urine. Explain what normally happens to glucose during the urine formation process and why glucose would be spilling over into the urine (2 pts).
d. If red blood cells would have been found in Aaliyah's urine, what might this indicate about her glomerulus? (2 pts)
Full Answer Section
2. Importance of Sodium and Water Reabsorption
Sodium and water reabsorption is crucial for maintaining homeostasis because:
- Blood Volume Regulation: It helps regulate blood volume and blood pressure.
- Electrolyte Balance: It helps maintain the balance of electrolytes in the body.
3. Role of Anti-Diuretic Hormone (ADH)
ADH regulates water reabsorption in the collecting ducts of the kidneys. When ADH levels are high, more water is reabsorbed, leading to concentrated urine. When ADH levels are low, less water is reabsorbed, resulting in dilute urine.
4. Uric Acid Build-up
A build-up of uric acid can cause gout, a painful inflammatory arthritis.
Part 2: Aaliyah's Case Study
a. Normal Components of Urine
Normal urine primarily consists of water, urea, uric acid, creatinine, and electrolytes (such as sodium, potassium, and chloride).
b. Protein in Urine
Protein is normally filtered out of the blood in the glomerulus but is then reabsorbed in the renal tubules. The presence of large amounts of protein in Aaliyah's urine suggests a problem with the glomerulus, such as glomerulonephritis, where the glomeruli are damaged and unable to filter properly.
c. Glucose in Urine
Glucose is normally completely reabsorbed in the proximal tubules. The presence of glucose in Aaliyah's urine indicates a condition called glucosuria. This can occur when blood glucose levels are too high, as in diabetes mellitus, or when the kidneys are unable to reabsorb glucose effectively.
d. Red Blood Cells in Urine
The presence of red blood cells in the urine, known as hematuria, can indicate damage to the glomerulus, such as glomerulonephritis, or damage to the lower urinary tract, such as a urinary tract infection or kidney stones.