Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human Physiology > Lecture 4 > Flashcards

Lecture 4 Flashcards

1
Q

what are the parts of the small intestine called?
What is their function?

A

duodenum - chemical digestion at proximal end
jejunum
ileum

all are responsible for absorption

duodenum receives secretions from pancreas and liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

located right after the stomach and is responsible for the second phase of the digestive process

A

proximal duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

proximal duodenum in very efficient due to surface are…
- folds in the mucosa increase surface area by ____
- crypts and villi _____
- microvilli ____

A

3 fold
10 fold
20 fold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is an enterocyte?

A

lines the gut and is responsible for digestion and absorbtion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

enterocyte type of surfaces

A

apical (luminal)
Basal (lateral)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what occurs in the apical surface of enterocyte?

A

digestion and absorbtion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what happens in the basal or lateral surface?

A

products of digestion pass through into bloodstream

intestinal veins then drain into the portal vein and transport absorbed nutrients to the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what two functions does the pancreas have?

A

exocrine function produces secretionswith digestive enzymes that enter thru duodenum

endocrine function releases insulin into blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

pancrease is regulated by ?

A

acetylcholine, CCK, secretin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

types of exocrine pancreatic cells?

A

acinar cells
duct cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what percent of exocrine pancreatic cells are acing cells? what do they do?

A

more than 80%
synthesize stroe and secrete digestive enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what do pancreatic duct cells do?

A

line the ducts and supply the bicarbonate to nuetralize gastric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

pancreatic enzymes with the role of protein digestion?

A

trypsin (most abundant)
chymotrypsin
carboxypolypeptidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

pancreatic enzyme for carbohydrate digestion

A

amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

pancreatic enzyme for fat digestion?

A

lipase
cholesterol esterase
phospholipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the turn off mechanism in the pancreas

A

trypsin inhibitor produced by acinar cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

where is the gallbladder located

A

undere the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does the gallbladder do?

A

stores 50 ml of bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how does bile release from gallbladder?

A

fats in duodenum stimulate CCK, which caused gallbladder to contract and release some bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the layers of the gallbladder?

A

innermost
musculature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

innermost layer of gallbladder consists of what kind of cells? what do they do?

A

highly absorptive epitheleal cells linked by tight junction

  • absorbs water and lytes (not Ca++) concentrating the bile
  • goblet cells protect the epithelean from injury
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what cells are in musculature layer of gallbladder? also, what does the layer do?

A

muscle cells

contract and relax gallbladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what causes the gallbladder to contract?

A

-surface receptors that respond to Ach and CCK cause gallbladder to contract (some food causes contraction too like apple skin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what causes the gallbladder to relax?

A

vsoactive intestinal polypeptide (VIP) and nitric oxide (NO)

allows it to fill with bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

bile is synthesised by the _______.

A

hepatocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

we make ____ bile a day and it has a pH of about ____?

A

1 L
7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what are the components of bile?

A

water, bile salts, bilirubin, cholesterol, fatty acids, lecithin, Na+, K+, Ca++, Cl-, HCO3-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what does bile do?

A

emilsify fat particles facilitating intestinal absorbtion

transports waste products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

bile salts form a sphere called _____, which collect where in the body?

A

micelles
around fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what do bile salts do?

A

help absorb fatty acid in the small bowel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is postpeandial

A

postt eating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

after eating, the gallbladder will _____

A

contract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what causes the gallbladder to contract after eating?

A

WHEN MEAL EMPTIES STOMACH (INTO DUODENUM)
fats trigger the release of cholecystokinin
bind directly to CCK-A receptors on gallbladder
acetylcholine release increases contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where is the sphincter of oddi?

A

where gallbladder releases into the bile duct to duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

when does sphincter of oddi relax?

A

gallbladder contraction

CCK, VIP, and nitric oxide reduce tone of sphincter to release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what are the parts of the large intestine

A

cecum

colon
- ascending
- transverse
- descending
- sigmoid

rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

mucous production that protects the lining of large intestine from bacterial activity

A

crypts of Lieberkuhn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

does the large intestine have any villi or enzymes ?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what are the primary functions of the large intestine?

A

extract and reclain water from the intestine
process feces for elimination
modify bile acids and bilirubin by bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

colonic reflexes of the large intestine

A

defication reflex
gastrocolic reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

during mixing, the colon shuttles contents back and forth between …

A

haustral shuttling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

periodically contractions sweep through the colon

A

peristalsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

simultaneous contraction of smooth muscle that happens 10 times per day

A

mass action contraction

44
Q

transit time from cecum to the rectum (large intestine)

A

1-2 days average

45
Q

following a meal it takes…
___ hrs to reach cecum
___ hrs to reach hepatic flexure
___ hrs to reach splenic flexure
____ hrs to reach sigmoid colon
and rectum at ___.

A

4
6
9
12
1-3 days

46
Q

what is the role of the cecum?

A

absorbs fluid and salts that remain after completion of intestinal digestion and absorption

removes 90% of the fluid it receives from small intestine

47
Q

what is the role of the ascending and transverse colon?

A

recover fluid from the digestive process that is left
(5L total per day)

can absorb short chain fatty acids

48
Q

what is the role of descending and sigmoid colon?

A

serve as reservoirs
stores waste

49
Q

what is feces made out of?

A

3/4 water
1/4 solid matter

50
Q

what contributes to the solid matter in feces?

A

30% dead bacteria
10-20% fat
10-20% inorganic matter
2-3% protein
30% undigested roughage

51
Q

what is responsible for the color of feces?

A

stercobilin
urobilin

52
Q

what are the sphincters that assist in defication

A

innervation internal sphincter
innervation external sphincter (pudendal nerve)

53
Q

what is the function of the innervation internal sphincter?

A

sympathetic nerve supply to the internal (involuntary) excites it

parasympathetic inhibits it

relaxes when rectum is distended (full of shit)

54
Q

what is the function of the innervation external sphincter: pudendal nerve

A

maintained in tonic contraction until moderate distension increases the force of contraction

55
Q

urge to defecate first occurs when rectal pressure increases to about ____mmHg

A

18

56
Q

both sphincters relax when pressure reaches ______mm Hg to eliminate the contents

A

55

57
Q

voluntary defecation can be initiated by ______.
what does straining do?

A

straining

  • forces the abdonimal muscles to contract, lowers pelvic floor 1-3 cm, and relaxes the puborectalis muscle.
  • reduces anorectal angle
  • external anal sphincter relaxes
58
Q

what is the puborectalis muscle

A

muscle strap that goes around rectum
the contracting shortens the muscle and makes angle sharper and prevents defication

59
Q

why do carbs and proteins have a hard time reaching cells?

A

they are too large to cross lipid bilayer

60
Q

how do proteins and carbs get thru membrane if they are too big?

A

enzymes hydrolases break down proteins and carbs so they can move thru epithelial membranes

61
Q

where does fat breakdown happen?

A

stomach
small intestine

62
Q

proteins are made up of _____ from amino acids, held together by ____.

A

polypeptides
peptide bonds

63
Q

amino acids in a…
peptide?
Polypeptide?
protein?

A

les than 2
less than 10
less than 50

64
Q

where does protein digestion occur?

A

stomach
small intestines
pancreas

65
Q

protein digestion in the stomach

A

gastrin stimulates parietal cells to secrete HCL and chief cells to produce pepsinogen which denatures protein

66
Q

protein digestion in the small intestines

A

polypeptides broken down at intestinal brush border by peptidases

67
Q

carbohydrates are composed of sugar molecules, such as ?

A

simple (mono/disaccharide)
complex (starches, polysaccharides)
fiber (dont digest this tho)

68
Q

examples of polysaccharides that cannot be directly absorbed?

A

Starches
Amylose
Amylopectin
Dextrin
Glycogen

69
Q

examples of disaccharides (some are absorbed)

A

sucrose
lactose
maltose

70
Q

examples of monosaccharides, that can be transported across membrane and absorbed)

A

glucose (80% of calories)
galactose (10% of calories)
fructose (10% of calories)

71
Q

absorbtion in the duodenum includes the capacity to absorb _______.

A

sugars, dipeptides, tripeptides, fats, Ca++, phosphate, sodium, nonheme iron.

72
Q

absorbtion in jejunum include ______

A

majoritey of nutrients

73
Q

absorption in the ileum include _____

A

nutrients absorption if jejunal absorption is impaired

74
Q

small intestion has surface area of _____. with what to help absorption ?

A

320 ft

folds of kerckring
villi
microvilli of the brush border

75
Q

where do lipids get sent to after absorption at digestive tract?

what stimulates this?

A

adipose tissue for storage (insulin)

skeletal muscle for ATP production (insulin)

76
Q

where does amino acids get sent after being absorbed in the digestive tract?

what stimulates this ?

A

all tissues for protein synthesis

(insulin)

77
Q

where does glucose go after being absorbed in digestive tract?

what stimulates this?

A

all tissues for ATP production
liver and skeletal muscle for storage

insulin

78
Q

what does the absorptive process require?

A

luminal processing
absorption into the intestional mucosa
transport into the circulation

79
Q

what is required for luminal processing to occur and what is it?

A

process things thru the cytosol

Adequate enzymes
sufficient bile salts and juices
necessary bacteria
alkaline environment

80
Q

absorption into the intestinal mucosa

A

absorption into the interstitial brush border of jejunum and ileum

81
Q

transport into the circulation inlcudes what transport
Nutrients
Water
Ions

A

pinocytosis - nutrients
osmosis - water
active transport with ion change (Na, Cl)

82
Q

what do pumps do for transport

A

moves ions against an electrochemical concentration gradient

83
Q

what do channels do in transport

A

high capacity pores in the plasma membrane to transport

84
Q

what do carriers do to transport?

A

exchanger carriers transport in opposite directions
co transporters move species in same direction

85
Q

How does water transport?

A

passive process across intestinal epithelial cells

86
Q

how does sodium transport?

A

facilitates transport of glucose, amino acids
co transports and exchanges

87
Q

how does potassium transport?

A

passive and active

88
Q

how do Cl- ions get transported?

A

dragged along by Na+ and exchanged for bicarbonate ions

89
Q

how are bicarbonate ions (HCO3-) transported?

A

chemical reaction of hydrogen coupling with HCO3- and followed by carbonic acid breakdown

90
Q

carbohydrates are _____ soluble.

Membrane bound ______ at the brush border of epithelial cells break down ______ before absoption.

A

water soluble

hydrolases
disaccharides

91
Q

glucose and galactose are absorbed by __________. it uses energy stored in _____ gradient to move glucose into the cell. _____ has no role

A

facilitated diffusion
Na+

insulin

92
Q

protein absorbtion occurs more in _____ than _________.

A

jejunum
ileum

93
Q

at least _____ diferrent transport systems transport amino acids into enterocytes

A

7

94
Q

smaller protein molecule are transported through _______ dependent amino acids cotransporter
Hows it work ?

A

sodium/Cl-

low intracellular sodium concentratin provides a strong inward gradient for sodium entry, which drives amino acids in

95
Q

what is ammonia?

A

a metabolite of amino acid deamination
(ammonia/keto acids)

96
Q

why is ammonia bad?
How do we get rid of it?

A

it crosses epithelial barriers and is highly toxic to the nervous system

cleared by liver and excreted by kidneys in the form of urea
-some excreted from stool in form of ammonium ions

97
Q

FA diffuse immediately out of micelles into the epithelial cells by ______ diffusion. FA that are less than ____ carbons pass through the entercytes and can be absorbed into the blood.

A

facilitated
10-12 (short chain)

98
Q

what happens to fatty acids that have more than 12 carbons?

A
  1. reesterfied to form triglyceride in smooth ER
  2. TG and cholesterol esters are then coated with proteins to form chylomicrons
  3. these CMs are then secreted from basolateral wall of enterocytes by exocytosis and enter the lymphatic system
99
Q

where are vitamins and minerals brought into our system?

A

proximal half of the small intestine

100
Q

examples of water soluble vitamins

A

B (1,2,3,5,6), C

101
Q

these water soluble vitamins are absorbed in the ________ through ______ transport

A

jejunum
Na cotransport

102
Q

how is B12 and folic acid get absorbed?

A

terminal ileum through intrinsic factor
(low can cause annemia)

103
Q

what are the fat soluble vitamins?

A

A,D,E,K

104
Q

how are fat soluble vitamins absorbed into the system?

A
  1. must be digested by cholesterol esterase before absorption
  2. insoluble in gut, so use micelles
105
Q

how is the mineral calcium absorbed?

A

active transport in the duodenum

facilitated by vitamin D by stimulating synthesis of calcium binding protein (helps calcium get absorbed)

106
Q

when is calcium absorption inhibited?

A

excess fatty acids

phosphates and oxalate anions
- form insoluble salts with Ca++ in intestine

Human Physiology (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions