Question

A friend of yours has twin 5 year old girls and loves to take them to the pool. You friend tells you, however that the most annoying thing is that although the girls are asked to pee before going into the pool, they generally say they don't have to pee, just to ask to go pee 5 minutes after being in the pool! "What's up with that?!" your friend asks, "Could there be something wrong with the girls, are they just being mischievous? Do you think I should take them to the doctor to see if there is a problem with their bladders? It only ever happens when they go into the pool". As a physiology student, apply your knowledge to explain why the girls tend to have to pee when they go swimming.

Question 1) Using your knowledge of physiology and circulation, how does the body respond if it gets cold, as would be the case during swimming?

1. Which receptor is responsible for detecting cold?
2. What pathway does the information travel up to the brain?
3. Where in the brain is the information received?
4. To conserve heat, where will blood be directed? To the limbs, or to the vital organs?
5. How is blood directed?

Question 2) Now that we know where blood is being directed when the body gets cold, how does that affect the following?

1. Blood pressure
2. Cardiac output
3. ANS
4. Osmoreceptors, Posterior Pituitary and ADH

Questions 3) How do the kidneys respond to the changes that can occur in blood pressure, cardiac output, ANS, Osmoreceptor, Posterior Pituitary and ADH, as noted in the previous questions?

1. How do the kidneys respond to changes in blood pressure?
2. How do the kidneys respond to changes in cardiac output and blood volume?
3. How do the kidneys respond to changes in ANS?
4. How do the kidneys respond to changes detected by osmoreceptors?
5. What hormones regulate water uptake in the kidneys?
6. What are water channels called?
7. In which part (s) of the nephron is water absorbed?

Question 4) Now that you have applied your knowledge, what can you tell your friend about their question? Is there something wrong? (Yes or no). What is your diagnosis?

******PLEASE INDICATE WHICH QUESTION YOU ARE ANSWERING

Answer 1

1. Swimming in cold water leads to increased blood pressure and increased rate of breathing to keep the body warm and protect form hypothermia. The thermoreceptors are responsible for detecting cold. The information of the cold travels to the brain through the somatosensory pathway. The informaton about the cold is received in the trigeminal ganglion. In order to conserve heat, the blood is directed to the limbs by constricting the blood vessels and the arteries.

2. The blood pressure and heart rate are increased in case of cold. The osmoreceptors expands leading the blocking of the posterior pituitary hormones which affects the release of ADH.

3. The increased blood pressure leads to the filtering out of theexcess fluid by the kidneys so that the volume of the blood decreases. The Anti-diuretic hormone controls the water uptake by the kidneys. The decrase in the ADH levels during cold lads to less water reabsorption. Most of the water is absorbed in the proximal convulated tubule. The water channes are called as aquaporins.

4. There is nothing wrong with teh girls. The tendency to urinate during swimming in cold water is a natural body response which is a result of the body defense mechansism against cold to conserve body heat.