Phyiological Function Of The Excretory System Flashcards
What is the process of reabsorption?
Small molecules such as ions, glucose and amino acids are transformed from the filtrate back into the circ
Uses co transporters, active transporters, osmosis and solvent drag
How does the proximal convoluted tubule reabsorb molecules?
Glucose, amino acids and Cl into the capillaries
Na into the capillaries in exchange for K
H enters the fluid
Bicarb and Na into the capillaries with water following
How does the loop of Henlé concentrate the urine?
Thin descending limb is permeable to water and impermeable to solutes (only water leaves
Thick ascending limb is imperator to water and carries our active solute transport
As the medulla surroundings is very watery, Na and Cl leave the loop into the surroundings
What is the function of the counter-current multiplier?
NaCl leaves the thin limb even at equil
Cotta sported in thin limb, L
Drives Na and Cl into capillaries, lose of K
Water leaves the thick as blood is high in souls
How does the thick ascending limb function?
Na/K/Cl enter from fluid into limb
Cl And K into interstitial space
K re-emerges in exchange for Na back into the fluid
Describe the renin-angiotensin system?
Macula Densa senses low blood flow or low Na conc and juxtaglomerila cells secrete renin
Released into the blood
Liver produces angiotensinogen that is converted to ANG I by renin
The lungs prod ACE to convert ANG I into II, this causes widespread vasoconstrict
Also ANG II activates the adrenal cortex to produce aldosterone which causes K and Na reab
Describe the process of ADH system?
Osmorecpetors in the hypothalamus sense Na conc of blood
Nerve endings of osmoreceps locates in posterior pituriatru gland which secretes ADH
Na conc high ADH secreted (vice versa)
ADH causes aqua potions to move to the collecting duct plasma mem to reab water
How does the body make urine?
Excess water is excreted in the collecting duct
Ammonia is excreted (urea)
Acid-base maintenance
