excretory and digestive system

Question 1

liver function

Answer 1

chemically modifies wastes and releases them into bile, deals with waste that can’t be filtered out by the kidneys,
synthesizes urea

Question 2

colon function

Answer 2

reabsorbs water and ions from feces

Question 3

kidney function

Answer 3

functions as a filtration system that removes unwanted materials from the blood and passes them to the bladder for storage and eventual elimination

1. excretion of hydrophilic waste
2. maintenance of constance solute concentration and constant pH
3. maintenance of constant fluid volume (important for blood pressure and cardiac output)

Accomplished by filtration, selective reabsorption, and secretion, ultimately resulting in urine

Question 4

renal artery

Answer 4

where blood enters the kidney

Question 5

internal/external sphincter

Answer 5

control release of bladder

Question 6

nephron

Answer 6

functional unit of the kidney

Question 7

urine direction in kidney

Answer 7

empties from collecting ducts

Question 8

direction of blood in filtration

Answer 8

renal artery to afferent arteriole to glomerulus to efferent arteriole.

Fluid then passes through filter (glomerular basement membrane) and enters Bowman’s capsule.

Question 9

selective reabsorption

Answer 9

returning of some substances to the blood stream, usually via active transport.

They are then picked up by peritubular capillaries, which drain into venues that lead to the renal vein.

Question 10

secretion

Answer 10

movement of substances into the filtrate, increasing the rate at which they are removed from the plasma

Question 11

ADH function

Answer 11

prevents water loss in urine, increases water reabsorption in distal nephron (primarily the collecting duct), making it permeable to water.

Increases blood pressure

Question 12

parts of nephron

Answer 12

capsule and renal tubule, which empties filtrate into a collecting duct

Question 13

aldosterone function

Answer 13

released by adrenal cortex when blood pressure is low, causes increased reabsorption of Na+ by the distal nephron, causing increased thirst and water retention .

Question 14

loop of Henle

Answer 14

where PCT empties into, has a long loop that dips into renal medulla.

Consists of a thin descending limb, which heads into the medulla, and an (part thin, part thick) ascending limb, which heads back out toward the cortex

Question 15

different permeabilities of loop of Henle

Answer 15

descending limb is permeable to water, ascending limb is only permeable to ions,

This results in the loop of Henle being a countercurrent multiplier that creates a salty medulla facilitating water resorption from the collecting duct

Question 16

distal/ proximal tubules

Answer 16

function in reabsorption

Question 17

JG cells

Answer 17

found in afferent arteriole, monitors systemic blood pressure and secretes renin when a decrease In BP occurs. This catalyzes formation angiotensin II, which functions as a vasoconstrictor and raises blood pressure.

Question 18

Glomerular filtration rate and pressure

Answer 18

correlated

Question 19

How does kidney maintain constant blood pH

Answer 19

when plasma pH is too high, HCO3- is excreted in urine and when plasma pH is too low, H+ is excreted.

Question 20

erythropoietin

Answer 20

made by kidneys, causes increases synthesis of red blood cells in the bone marrow

Question 21

gastrointestinal tract

Answer 21

accomplishes digestion, long muscular tube extending from the mouth to the anus

Question 22

GI lumen

Answer 22

inside of the gut, continuous with the space outside the body, innermost lining is composed of epithelial cells, which are responsible for most of the secretory activity of the GI tract

Question 23

GI motility

Answer 23

rhythmic contraction of GI smooth muscle, serves the purpose of mixing food and moving food down the gut

Question 24

peristalsis

Answer 24

orderly form of contraction responsible for movement of food down the GI tract

Question 25

enteric nervous system

Answer 25

branch of ANS that helps to control digestion via innervation of the gastrointestinal tract, pancreas, and gall bladder made up of two networks of neurons: myenteric plexus, which primarily helps to regulate gut motility and submucosal plexus, which is found in the submucosa and helps to regulate enzyme secretion, gut blood flow, and ion/water balance in the lumen

Question 26

GI secretions

Answer 26

stimulated by food in the gut and by the parasympathetic nervous system, inhibited by sympathetic stimulation. two types: exocrine (composed of specialized epithelial cells organized into sacs called acini) and endocrine, which empty into nearby capillaries.

Question 27

gastric glands

Answer 27

found in stomach, secrete acid and pepsinogen.

Question 28

goblet cells

Answer 28

found along entire GI tract, secrete mucus.

Question 29

mouth function in digestion

Answer 29

fragmentation, lubrication, some enzymatic digestion

Question 30

salivary amylase

Answer 30

found in saliva, hydrolyzes starch, breaking it into fragments.

Question 31

pharynx

Answer 31

contains opening to trachea, which conveys air to and from the lungs and the esophagus, conveys food and drink to the stomach

Question 32

stomach function

Answer 32

partial digestion of food, regulated release of food into small intestine, destruction of microorganisms

Question 33

what causes conversion of pepsinogen to pepsin

Answer 33

acidity

Question 34

pepsin

Answer 34

secreted by chief cells, catalyzes proteolysis

Question 35

effect of pyloric sphincter contracting

Answer 35

inhibition of further stomach emptying, preventing passage of food from stomach into the duodenum

Question 36

gastrin

Answer 36

hormone secreted by G cells when food is in the stomach, stimulates acid and pepsin secretion and gastric motility

Question 37

small intestine

Answer 37

where food leaving the stomach enters, divided into the duodenum, jejunum, and ileum

Question 38

villus

Answer 38

projection of the wall of the gut into the lumen, has three important structures: 1. capillaries that absorb dietary monosaccharides and amino acids 2. lacteals, capillaries which absorb dietary fats 3. Peyer's patches, which function as part of the immune system

Question 39

two ducts that empty into the duodenum

Answer 39

pancreatic duct, which delivers the exocrine secretions of the pancreas, and the common bile duct which delivers bile.

Question 40

function of bile

Answer 40

vehicle for disposal of waste products by the liver, essential for the digestion of fats

Question 41

duodenal enzymes

Answer 41

enterokinase and brush border enzymes, which hydrolyze the smallest carbohydrates and proteins

Question 42

three main duodenal hormones

Answer 42

CCK- secreted in response to fats in the duodenum, stimulating gallbladder contraction (bile release) and decreasing gastric motility secretin - released in response to acid in the duodenum, causing pancreas to release large amounts of a high-pH aqueous buffer, neutralizing HCl released by the stomach enterogastrone - decreases stomach emptying

Question 43

jejunum and ileum

Answer 43

where substances are absorbed if not absorbed in duodenum

Question 44

colon

Answer 44

large intestine, role is to absorb water and minerals, and to form and store feces until time of defecation

Question 45

colonic bacteria function

Answer 45

presence of large numbers of normal bacteria keeps dangerous bacteria from proliferating and they supply us with vitamin K

Question 46

GI accessory organs

Answer 46

pancreas, liver, gallbladder, and salivary gland

Question 47

function of pancreatic enzymes

Answer 47

released into duodenum and essential for digestion

Question 48

how does nervous system affect pancreatic secretion

Answer 48

parasympathetic nervous system activation increases it, sympathetic reduces it

Question 49

glucagon and insulin

Answer 49

hormones secreted by islets of Langherhans in pancreas glucagon responds to low blood sugar, causing release of glucose and fats into the blood stream, insulin has opposite effect of glucagon, removing glucose from blood for storage as glycogen and fat

Question 50

liver function

Answer 50

secretes bile, which emulsifies large fat particles in the duodenum, also processes absorbed nutrients, can release free glucose into blood stream functions in lipid metabolism

Question 51

hepatocytes and their functions

Answer 51

liver cells that extract nutrients from blood

Question 52

ghrelin and leptin

Answer 52

ghrelin stimulates appetite while leptin acts as an appetite suppressant

Question 53

vitamins

Answer 53

must be include in diet, since they can't be synthesized in the body, divided into fat soluble and water soluble categories

Question 54

proximal convoluted tubule function

Answer 54

where most of the reabsorption occurs in the part of the tubule nearest to Bowman's capsule

Question 55

renal cortex

Answer 55

outer layer of the kidney

Question 56

where does loop of Henle lead to?

Answer 56

the distal convoluted tubule, which dumps into a collecting duct.

Question 57

vasa recta function

Answer 57

forms a loop that maintains a high concentration of salt in the medulla, they return to the bloodstream any water that is reabsorbed from the filtrate

Question 58

What is GI muscle made of

Answer 58

two layers of Smooth muscle, one that is longitudinal and one that is circular

Question 59

What does it mean that GI smooth muscle is a functional syncytium?

Answer 59

When one cell has an action potential and contracts, the impulse spreads to neighboring cells

Question 60

sphincter of Oddi

Answer 60

the orifice in which the bile duct and the pancreatic duct empty into

Question 61

what is bile made of?

Answer 61

bile acids made from cholesterol in the liver

Question 62

What is true about duodenal pH?

Answer 62

It must be kept neutral or even slightly basic for pancreatic digestive enzymes to function

Question 63

What hydrolases are in the pancreas?

Answer 63

amylase, lipase, nuclease, and proteases

Question 64

hepatic portal system function

Answer 64

helps liver process absorbed nutrients 1. liver receives oxygenated blood from hepatic arteries 2. Liver receive veinous blood draining the stomach and intestine through the hepatic portal vein

Question 65

chylomicrons

Answer 65

molecules in which lipids exit the intestine and enter the lymphatic system, degraded into chylomicron remnants, taken up by hepatocytes, and combined with protein to make lipoproteins