Lecture 32

Question 1

How long is the GI tract?

Answer 1

4.5m from mouth to anus

Question 2

What part of the GI tract is external environment and why?

Answer 2

The lumen because everything in there is leaving the body

Question 3

What are the accessory glands and organs that are used in the GI tract BUT food does not pass through it?

Answer 3

• gallbladder
• pancreas
• liver
• salivary glands

Question 4

The organs that food passes through?

Answer 4

• oral cavity
• esophagus
• stomach
• small intestine
• large intestine (colon & rectum)

Question 5

what’s the function of the esophagus?

Answer 5

transport food to stomach

Question 6

what’s the job of the small intestine

Answer 6

mostly chemical but mechanical as well in the duodenum

Question 7

What are sphincters?

Answer 7

one way valves made from smooth muscles that closes and open to create compartments

Question 8

What spinster separates the mouth an the esophagus

Answer 8

Upper esophageal sphincter

Question 9

what spinster separates the esophagus and the stomach

Answer 9

low esophageal sphincter

Question 10

what separates the stomach and the small intestine?

Answer 10

pyloric sphincter

Question 11

what separates the small and large intestines?

Answer 11

ileocecal sphincter

Question 12

What separates the rectum and the outside? which are do you have control of?

Answer 12

voluntary control of external sphincter
involuntary control of internal sphincter

Question 13

what are the 4 tissues of the Gl Tract?

Answer 13

1) Mucosa- most inner layer
2) Submucosa
3) Muscularis Externa
4) Serosa

Question 14

function of the mucosa

Answer 14

has a epithelium with
- stems cell to replace
- transporting cells
- secreting cells
lamina propria with lymph, blood vessels and nerves

Question 15

function of submucosa

Answer 15

loose tissue contains blood vessels, lymph and nerves
- has the submucosal plexus (secretion function)

Question 16

function of muscularis externa

Answer 16

layers of smooth muscle to
- constrict lumen (inner layer)
- shorten lumen (external layer)
contains the myenteric plexus for motility

Question 17

function of the serosa

Answer 17

lubricates and protects using secretory epithelium and connective tissues

Question 18

Which organ has 3 layers of muscularis externa

Answer 18

stomach and its the oblique layer to contract diagonally/transverse

Question 19

what is the submucosal and myenteric plexus?

Answer 19

it is a part of the enteric nervous system which allows for secretion and motile of the GI. it is apart of the autonomic nervous system and doesn’t need input form the CNS and PNS

Question 20

what are the 4 basic functions of the GI Process?

Answer 20

1) secretions
2) digestion
3) absorption
4) motility

Question 21

what are the 2 types of motility?

Answer 21

peristaltic - pushing down like a empty toothpaste tube
segmental- move side to side to mix up food

Question 22

After food leaves the mouth, when is it called?

Answer 22

bolus

Question 23

after bolus enters the stomach, what is it called?

Answer 23

chyme

Question 24

What is secreted into the GI Tract

Answer 24

saliva, bile, gastric , pancreatic and intestinal enzymes

Question 25

how much fluid is absorbed?

Answer 25

7.5 in small and 1.5 in large
0.1 is excreted

Question 26

long reflexes

Answer 26

integrated with the CNS to contribute feedback and emotional reflexes to digestion

Question 27

short reflexes

Answer 27

no outside input

Question 28

GI peptides

Answer 28

secreted by the long and short reflexes to alter motility and/or secrections