Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Phys 2 Exam 2 > GI physiology > Flashcards

GI physiology Flashcards

(52 cards)

Start Studying
1
Q

functions of GI

A

digestion & absorption

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

4 major activities of GI tract

A

Motility propels ingested food from mouth toward the rectum & mixes and reduces the side of food

Secretions from salivary glands, pancreas, and liver add fluid, electrolytes, enzymes, and mucus to the lumen

Ingested foods are digested into absorbable molecules

Nutrients, electrolytes, and water are absorbed from the intestinal lumen into the blood stream

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

Extrinsic innervation of GI tract

A

sympathetic and parasympathetic

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

parasympathetic innervation of GI tract

A

supplied by Vagus & Phrenic nerve

Vagus - innervate upper GI

Phrenic - innervate lower GI

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

Sympathetic innervation

A

preganglionic fibers – postganglionic adrenergic nerve fibers

directly innervate:

  • smooth muscle
  • endocrine
  • secretory cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Intrinsic innervation of Gi tract

A

enteric nervous system

can carry on if extrinsic failed/ contained in 2 plexuses

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

GI peptide function

A

Contraction/ relaxation of smooth muscle wall/ sphincters

Secretion of enzymes for digestion

Secretion of fluid and electrolytes

Trophic (growth) effects of GI tract

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

Paracrine

A

Do not enter the systemic circulation but act locally – reaching their target cells by diffusing over short distances

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

2 types of paracrine

A

Somatostatin - secreted by D cells of GI mucosa in response to decrease luminal pH

Histamine- secreted by endocrine cells of GI mucosa (H+ secretion region)

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

smooth muscle

A

no striations / move things along / maintain tension

all contractile tissue of GI tract is smooth muscle

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

where is smooth muscle not present in GI

A

pharynx , upper 1/3 of esophagus & external sphincter

striated muscle

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

motility

A

Grinds, mixes, and fragments ingested food to prepare it for digestion & absorption —- then propels food along GI tract

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

When circular muscle contracts =

A

there is shortening of a ring of smooth muscle

This DECREASES the diameter of that segment

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

When longitudinal muscle contracts =

A

there is shortening in the longitudinal direction

This DECREASES the length of the segment

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

phasic & tonic contractions of GI

A

phasic - opening & closing

tonic - chronic contraction

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

3 functions of chewing

A

mix food with salvia
decreases size of food particles
mixes ingested carbohydrates w/ salivary amylase (carb digestion)

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

involuntary component of chewing

A

reflexes initiated by food in mouth (mechanoreceptors)

brain stem orchestrates reflex oscillatory pattern of activity to the muscles involved in chewing

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

swallowing & sensory information (CNS)

A

o Initiated voluntary in the mouth –> but after it is under involuntary (reflex) control

Controlled by swallowing center in medulla

Sensory information (food in mouth) is detected by somatosensory receptors by pharynx

Sensory (afferent) information is carried to swallowing center

The medulla coordinated and directed motor (efferent) output to pharynx and upper esophagus

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

what happens to swallowing if vagus nerve is damaged?

A

it effects receptive relaxation

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

Oral phase

A

initiated when tongue forces bolus of food back toward pharynx

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

Pharyngeal Phase

Study These Flashcards
A

Propel food bolus from the mouth through the pharynx to espoguagus in the following steps:

  • Soft palate is pulled upward
  • Epiglottis moves to cover the opening to the larynx & larynx moves upward against epiglottis
  • Upper esophageal sphincter relaxes
22
Q

Esophageal Phase

Study These Flashcards
A

Controlled in part by the swallowing reflex and by enteric nervous system
 Food is propelled through esophagus to the stomach

• The swallowing reflex closes the sphincter so food cannot reflux into the pharynx

23
Q

primary peristaltic wave

Study These Flashcards
A

Travels down the esophagus propelling the food along

24
Q

swallowing function

Study These Flashcards
A

Upper esophageal sphincter to prevent air from entering the upper esophagus

Lower esophageal sphincter to prevent the acidic gastric contents from entering the lower esophagus

CLOSED except for when food is passing

25
3 components of gastric motility
relaxation -receive food contractions -reduce size & mix gastric emptying - propels chyme to small intestine
26
Innervation of stomach
``` extrinsic = ANS Intrinsic = Plexus ```
27
receptive relaxation
decreases pressure and increases volume of the orad stomach
28
mixing and digestion contractions
contractions start in the middle and move distally in the cuadad of stomach
29
gastric emptying
rate must be closely regulated to provide time for - neutralization of H+ in duodenum - digestion and absorption of nutrients liquid empty faster than solids
30
two major factors that slow gastric emptying (increase gastric emptying time)
presence of fat | presence of H+ ions (decrease pH in duodenum)
31
Small Intestine Motility serves to
Mix chyme with digestive enzymes and pancreatic secretions Expose nutrients to the intestinal mucosa for absorption Propel unabsorbed chyme along the small intestine into the large intestine
32
Parasympathetic Small Intestine Motility
stimulation increases contraction
33
Sympathetic Small Intestine Motility
decreases contraction
34
Large Intestine Motility
Destined for excretion After the contents of the small intestine enter the cecum and proximal colon, the ileocecal sphincter contracts, preventing reflux into the ileum Fecal material then moves from the cecum through the colon to the rectum and to the anal canal
35
secretions are produced by
salivary glands gastric mucosa exocrine of pancreas liver
36
saliva functions
dilution, buffering, & lubrication of food
37
HCl secretions
stomach ph = 1 & 2 low pH of the stomach converts pepsinogen to pepsin
38
pepsin
protease that begins the process of protein digestion
39
Intrinsic factor secretion
mucoprotein/secretroy produce of parietal cells required for absorption of vitamin B12 only essential secretion of stomach
40
pancreatic secretion consist of
An aqueous component that is high in HCO3- which functions to neutralize the H+ delivered to the duodenum from the stomach An enzymatic component that functions to digest carbohydrates, proteins, and lipids into absorbable molecules
41
Bile
mixture of bile salts, bile pigments, and cholesterol solves the problem of insolubility
42
organic constituents of bile
bile salts bile pigments (bilirubin) cholesterol phospholipids bile also contains electrolytes and water (secreted by hepatocytes lining the bile ducts)
43
functions of gallbladder
stores bile concentrates bile when stimulated to contract -->ejects bile into lumen of small intestine begins w/in 30 minutes after a meal is ingested
44
villi & microvilli
Increase surface area of the small intestine Maximize the exposure of nutrients to digestive enzymes Create a large absorptive surface
45
Villi are longest in the ___
duodenum Most digestion and absorption occurs Shortest in the terminal ileum
46
Digestion of Proteins
o Amino acids, dipeptides, and triptidies Dietary proteins are digested to absorbable forms by proteases in the stomach and small intestine and then absorbed into the blood
47
Intestinal Absorption
Intestinal epithelial cells lining the villi absorb large volumes of fluid fluid is always isosmotic o The solute absorptive mechanism vary among the jejunum, the ileum, and the colon
48
functions of liver
o Processing of absorbed substances o Synthesis & secretions of bile acids o Bilirubin production/ excretion o Participation in metabolism of key nutrients (Carbohydrates, protein, and lipids) o Detoxification and excretion of waste products
49
Metabolic Functions of the Liver
Liver participates in the metabolism of carbohydrates, protein, and lipids
50
In carbohydrate metabolism of the LIver
o The liver performs gluconeogenesis o Stores glucose as glycogen o Releases stored glucose into the bloodstream when needed
51
In protein metabolism of liver
o The liver synthesizes the non-essential amino acids o Modifies amino acids so that they may enter biosynthetic pathways for carbohydrates
52
Detoxification of Substances
The liver protects the body form potentially toxic substances that are absorbed from the GI tract

Phys 2 Exam 2 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions