Excretory System

Question 1

Passage through excretory system

Answer 1

nephron , renal pelvis, ureter, bladder, urethra

Question 2

Kidney structure

Answer 2

cortex, medulla, renal hilum (deep slit in the center of its medial surface, renal artery vein and ureter enter/ exit via the renal hilum)

Question 3

Portal system

Answer 3

2 capillary beds in series for blood to travel through before returning to the heart

Question 4

Afferent arterioles

Answer 4

flow from cortex to the medulla. glomeruli are highly convoluted tufts derived from afferent arterioles

Question 5

efferent arterioles

Answer 5

lead blood away from the afferent form the vasa recta. which isth e secondary capillary bed surrounding the loop of henle

Question 6

what surrounds the glomerulus

Answer 6

bowmans capsule

Question 7

renal corpuscle

Answer 7

bowmans capsule and glomerulus. leads to the pct, descenidng loh, ascending loh, dct, collecting duct

Question 8

micturition reflex

Answer 8

stretching of bladder = parasympathetic nerves fire and detrusor muscle contracts the bladder causins the interal sphinctor to relax

Question 9

osmoregulation

Answer 9

filtration , secretion, reabsorption

Question 10

filtration

Answer 10

hydrostatic pressure in glomerulus is higher than in bowmans space, which causes blood to travel to the nephron. but osmolarity of blood is higher than that in bowmans space, pressure moves against blood into nephron. since hydrostatic pressure is greater than oncotic pressure the blood will move to the nephron

Question 11

kidney stone

Answer 11

buildup of urine behind the stone increases the hydrostatic pressure of bowmans space and therefore filtration is hindered

Question 12

Filtrate is

Answer 12

isotonic to blood

Question 13

secretion

Answer 13

movement of solutes from blood to filtrate anywhere besides bowmans capsule. nephron secretes salts, acids, bases and urea directly into tubule by active or passive transport

Question 14

reabsorption

Answer 14

componds, glucose amino acids and vitamins. movement of solutes from filtrate to blood. what we want to keep

Question 15

bowmans capsule, pct and dct = primarily focused on

Answer 15

identity of particles in urine (keep what body needs, lose what it doesnt)

Question 16

LOH and collecting duct

Answer 16

focused on volume and concentration of urine

Question 17

PCT proximal convoluted tubule

Answer 17

reabsorbed= a. a , glucose water soluble vitamins and salts na cl, and water. secreted= H ions, urea , NH3 and K. Dump the “HUNK”

Question 18

descending loop of henle

Answer 18

permeable to only water. the deeper you go into the medulla we have increased intertitial conc, so water moves out

Question 19

ascending loop of henle

Answer 19

permeable to salts but impermeable to water. so na and cl move out of the filtrate.

Question 20

Diluting segment LOH

Answer 20

transition between inner and outer medulla , cells lining are larger, more mitochondria and therefore more active transport. filtrate becomes hypotonic (more dilute) compared to the interstitium in the ascending lOH.

Question 21

countercurrent multiplier system

Answer 21

flow of filtrate through LOH is opposite direction from flow of blood through the vasa recta. by making both components flow in opp directions, the filtrate is constantly being exposed to hypertonic blood, which allows for the maximum reabsorp of water

Question 22

DCT - distal convoluted tubule

Answer 22

responds to aldosterone, which is a steroid hormone that promotes sodium reabsorption, water follows and this results in concentrated urine and decreased urine volume.

Question 23

Collecting Duct

Answer 23

Responsive to ADH and aldosterone. Reabsorbes H20 as permeability of CD increases. Hydrated= means it is impermeable to salt and H20. “point of no return”

Question 24

Mechanism of Aldosterone

Answer 24

Basics= aldosterone is a steroid hormone that is secreted by adrenal cortex in response to low bp. How is low bp sensed ? Juxtaglom cells release renin. renin cleaves angiotensinogen to angiotensin I. Angiotensin I gets converted to angiotensin II via ACE. angiotensin II is what promotes the release of aldosterone. Mainly aldosterone alters the ability of DCT and CT to reabsorb sodium. so blood volume increases and bp will then increase. K ion and H ion excreted

Question 25

Mechanism of ADH / Vasopressin

Answer 25

Peptide hormone synthesized by hypothal and released by posterior pit in response to increased blood osmolarity. This basically alters the permeability ofo the collecting duct allowing more water to be reabsorbed by making the cell junctions of the duct leaky. extension of this is alcohol and caffiene, which inhibit adh release and therefore can cause frequent excretion of dilute urine

Question 26

What will happen if afferent arteriole constricts

Answer 26

bp drops and renin can be secreted to raise bp

Question 27

osmotic pressure

Answer 27

sucking pressure that draws water into vasculature by all dissolved particles

Question 28

oncotic pressure

Answer 28

osmotic pressure that is attributed to proteins specifically

Question 29

blood osmolarity

Answer 29

290-300 mOsm/L

Question 30

Bicarb buffer equation

Answer 30

Co2 (g) + H2o (l) H2Co3 (aq) H+ (aq) + HCo3 - (aq)