Urinary System

Question 1

What is the main organ responsible for the urinary system?

Answer 1

Kidney

Question 2

Trace the path of urine in the nephron

Answer 2

(CORTEX)-presence of corpuscles 
•glomerulus:
Ionic salts
Water
Glucose 
Pass through

•proximal tubule:
Critical for recapture of 
Ions
Water
Nutrients
NH3 acts as buffer- the more acidic filtrate is, more ammonia produced.

•Distal tubule:
Helps maintain pH
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(OUTER MEDULLA)-
•descending loop of Henley:
***aquaporin proteins makes transport epithelium freely permeable to water.
No channels for salt and other small solutes

Intersistial fluid=hyperosmotic to filtrate for water to move into by osmosis.

•thick segment of ascending loop:
Active transport of NaCl
Filtrate=dilute
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•thin segment of ascending loop:
Lacks water channels
Helps maintain osmoregularity of interstitial fluid

Question 3

ADH

Answer 3

(vasopressin)
•Reabsorption of water in collecting duct
•causes construction of blood vessels
=increases volume of water=decreases osmolarity(osmoreceptor)=increases pressure(baroreceptor)

Question 4

Osmolarity

Answer 4

osmoles(individual ions)/liter

Extracelular fluid=infra cellular fluid
**if unequal water moves to side with high[]

Question 5

Body water

Answer 5

60:40:20
(Total:intercellular:extra cellular)
Extra cellular=interstitial fluid&plasma

Water=1/fat
Generally women have move far than men hence men have more water content than women

ECF=easily affected by physiological processes

Question 6

Scenarios that can affect body water

Answer 6

1. SIADH
2. Adrenal insufficiency
3. Marathon
4. Diarrhea
5. Eating salty chips
6. Infusion of isotonic NACl

Question 7

ADP response pathway in collecting duct

Answer 7

1. ADH bonds to membrane receptor
2. Receptor triggers signal transduction(cAMP and protein kinase
3. Vesicles with aquaporins are inserted into cell membrane
4. Aquaporin channels enhance reabsorption of water