kidney, excretory system

Question 1

functions of liver

Answer 1

stores glucose as glycogen
makes urea and releases into blood
breaks old heme into bilirubin which is excreted with bile, alongisde hydrophobic or large wastes that the kidney can’t handle

Question 2

large intestine

Answer 2

reabsorbs water and ions, stores feces. IT can also, interestingly, actively transport excess ions into feces. But no digestion here

Question 3

what ends up in urine?

Answer 3

water, urea, sodium, bicarbonate. But there shouldn’t be amino acids nor glucose. Furthermore, large proteins such as albumin should never enter filtrate in the first place

Question 4

for both urine and feces

Answer 4

there is internal sphincter of smooth muscle; external one of skeletal muscle

Question 5

order for kidneys

Answer 5

glomerular basement membrane > Bowman’s capsule > PCT > loop of Henle > DCT > collecting duct > papilla > calyx > renal pelvis > ureter

Question 6

efferent arteriole

Answer 6

it is this vessel that constricts to generate the high pressure in the glomerulus to force out filtrate

Question 7

in the PCT

Answer 7

most of reabsorption occurs here.

Glucose, amino acids - active transport

Question 8

descending limb

Answer 8

thin walled. It is permeable to water, which exits, but not to ions.

Question 9

ascending limb

Answer 9

the bottom half is THICK walled.
Here there is active transport of ions OUT of filtrate alongside passive return of K.
Thus, as filtrate moves up it grows more dilute

Question 10

DCT

Answer 10

reabsorption of water and urea into filtrate. Here, aldosterone acts to promote Na reabsorption.

Question 11

collecting duct

Answer 11

secretion of K and H+ ions

Question 12

ADH

Answer 12

released by posterior pituitary. It puts aquaporins the the collecting duct, thus encouraging water retention
What triggers? Low blood volume or high blood osmolarity

Question 13

aldosterone

Answer 13

secreted by adrenal cortex. It increases Na reabsorption in the distal nephron. (Meanwhile it makes K+ LEAVE the filtrate) Same result as ADH: increases bp.
What triggers Aldosterone release? Angiotensin II, low blood osmolarity, low bp

Question 14

vasa recta

Answer 14

venous blood here flows in opposite direction of filtrate. It is a countercurrent exchanger
Principally, it pulls water out of filtrate to make it more concentrated

Question 15

RAA

Answer 15

low bp > juxtaglomerular baroceptorssenses bp in aff arteriole > renin > cleaves angiotensinogen (of liver) into angio I > ACE in lungs cleaves into angio II > stimulates aldosterone release and causes vasoconstriction

Question 16

carbonic anhydrase

Answer 16

converts CO2 into H2CO3 and is found all throughout nephron. To control blood pH, nephron may increase secretion of HCO3- and H+ alternately

Question 17

calcitonin

Answer 17

increases Ca excretion in urine. PTH does the oppsoite

Question 18

erythropoietin

Answer 18

released by kidney, increases RBC synthesis in marrow

Question 19

brush border enzymes

Answer 19

both proteases and disaccharidases. Whereas pepsin and amylase break the polymers majorly; brush border enzymes break them into monomers (AAs and monosaccharides)

Question 20

GI epithelium

Answer 20

have microvilli to increase SA. The cells are connected by tight junctions

Question 21

GI smooth muscle

Answer 21

contracts spontaneously due to enteric pacemaker cells. The smooth muscle also has a functional syncytium like cardiac muscle

Question 22

ENS

Answer 22

myenteric plexus - primarily does gut motility, which is contraction. Found btw 2 muscle layers
submucosal - found in submucosa - regulates enzyme secretion, blood flow, and osmolarity

Question 23

goblet cells

Answer 23

make mucus. Line the GI tract

Question 24

teeth types

Answer 24

incisors - cut
cuspids - tear
molars - grind

Question 25

components of saliva

Answer 25

amylase, lipase, lysozyme

Question 26

chief cells

Answer 26

these make pepsinogen

Question 27

G cells

Answer 27

make gastrin, which acts locally. G cells themselves stimulated by histamine

Question 28

parietal cells

Answer 28

make acid and intrinsic factor

Question 29

which 2 ducts empty into duodenum?

Answer 29

pancreatic - digestive enzymes and bicarb
common bile duct - bile made in liver stored in gallbladder.
They both empty through the sphincter of Oddi

Question 30

secretions of duodenum

Answer 30

enterokinase which cleaves trypsinogen into trypsin
CCK - secreted in response to fats. It stimulates bile release and decreases gastric motility
secretin - in response to acidity It stimulates pancreatic bicarb release
enterogastrone - decrease stomach emptying

Question 31

intrinsic factor

Answer 31

made by stomach cells but promotes B12 absorption only in ileum

Question 32

components of pancreas

Answer 32

EXOCRINE - amylase, lipase, nuclease, protease
ENDOCRINE -
alpha secretes glucagon
beta secretes insulin
celsl secrete somatostatin (inhibitory effect)

Question 33

glucose must be in what form to travel thru blood?

Answer 33

pure glucose. If it is glucose-6-P it cannot cross membrane due to charge

Question 34

peptide YY

Answer 34

secreted by jejunum to reduce appetite. Due to filling of colon

Question 35

vitamins

Answer 35

fat soluble
A - vision
D - increases Ca absorption
E - protects against ROS
K - blood clotting
water soluble
B1 - needed for decarboxylations
B2 - made into FAD
B3 - made into NAD+
B6 - protein metabolism
B12 - reduction of NTs to deoxyNTs
C - collagen formation
Biotin - transport of CO2 groups in rxn
Folate - synthesis of nitrogenous bases, and for fetal nervous system develop

Question 36

macula densa

Answer 36

sense blood osmolarity. When low, they dilate aff arteriole to increase urine production