Lower GI Tract

Question 1

What is the purpose of the small intestine?

Answer 1

Receives chyme from the stomach, performs majority of digestion and absorbs nutrients

Question 2

What three body parts make up the small intestine?

Answer 2

Duodenum, jejunum/lleuym, plicae circulares

Question 3

What is the duodenum?

Answer 3

The upper region of the small intestine receives chyme/digestive enzymes/bile

Question 4

What is the jejunum/lleum?

Answer 4

Lower region of small intestine where absorption occurs

Question 5

What is the plicae circlares?

Answer 5

Permanent folds in the mucosa/submucosa which slows movement of chyme

Question 6

What are villi?

Answer 6

Fingerlike projections that increase SA of the small intestine

Question 7

What are microvilli?

Answer 7

Tiny projections on the plasma membranes of columnar cells (look fuzzy0

Question 8

Functions of the large intestine?

Answer 8

Reabsorption of water/electrolytes
Production/absorption of vit B and K
Elimination of feaces

Question 9

Teniae coli?

Answer 9

Bands of smooth muscle creating pocket-like sacs (haustra) in the large intestine

Question 10

Caecum?

Answer 10

The sac like connection between the small and large intestines

Question 11

Appendix?

Answer 11

Small structure containing lymphoid tissue

Question 12

What four types of colon are there?

Answer 12

Ascending
Descending
Transverse
Sigmoid

Question 13

What is the rectum for?

Answer 13

Temporary storage of food residues
Expandable structure
rectal valves slow movement

Question 14

What is the anus for?

Answer 14

Regulates defecation

Question 15

Where is the anorectal canal located?

Answer 15

Begins where the rectum penetrates the levator ani muscle

Question 16

What are the two sphincters which control movement of faeces?

Answer 16

The internal sphincter (involuntary) and external (voluntary)

Question 17

What are the 4 secretions of the small intestine?

Answer 17

Secretin, somatostatin, cholecystokinin, brush border enzymes

Question 18

What is secretin?

Answer 18

Released by the enteroendocrine cells when acidic chyme enters the small intestine

Question 19

What is somatostatin?

Answer 19

It is secreted by the small intestine and it slows gastric

Question 20

What is gastric motility?

Answer 20

The movement of food through the digestive tract by rhythmic contractions

Question 21

What is cholecystokinin?

Answer 21

A hormone released when chyme enters the SI - causes the release of pancreatic juices and bile

Question 22

What do brush border enzymes do?

Answer 22

They process long peptides/nucleic acids/sugars intro smaller ones

Question 23

What are the four layers of the GI tract made up of?

Answer 23

The mucosa, Submucosa, Muscularis externa, Serosa

Question 24

What is the purpose of the mucosa layer of the GI tract?

Answer 24

Secretes hormones/mucus, absorbs end products of digestion and protects against infection

Question 25

What is the purpose of the submucosa layer of the GI tract?

Answer 25

It contains lymphoid follicles and elastic tissue

Question 26

What is the purpose of the muscularis externa layer of the GI tract?

Answer 26

Contains inner circular layer and outer longitudinal layer of this both control peristalsis

Question 27

What is the serosa?

Answer 27

The outer layer of the GI tract surrounded by a serous membrane - also known as visceral peritoneum

Question 28

What do goblet cells in the crypts do?

Answer 28

Makes surface slippery, protects lining, lubricates faeces

Question 29

What tissue type primarily makes up the large intestine?

Answer 29

Simple columnar epithelium, except in the anal canal

Question 30

What tissue type is present in the anal canal?

Answer 30

Stratified squamos

Question 31

What do goblet cells do in the anal canal?

Answer 31

Lubrication of feces

Question 32

What is the Teniae Coli?

Answer 32

Bands of smooth muscle that create pocket like sacs (In the LI)

Question 33

What is the Caecum??

Answer 33

Sac like connection between the small and large intestines

Question 34

What is the appendix?

Answer 34

Small structure on the bottom end of the ascending colon on the LI - containing lymphoid tissue (small immune function)

Question 35

What four sections make up the colon in the LI?

Answer 35

Ascending, Descending, Transvers and Sigmoid Colon.

Question 36

Where are each of the four sections of the colon in order in the LI?

Answer 36

Ascending colon- First section (going upwards) Transverse colon - Second section (sideways along the top) Descending colon - Third section (going downwards) Sigmoid colon - Last section (closet to rectum and anus)

Question 37

What is the hepatic flexure?

Answer 37

The right colic - separates the ascending and transverse colon

Question 38

What is the splenic flexure?

Answer 38

The left colic - separates the transverse and the descending colon

Question 39

What is the rectum?

Answer 39

Temporary storage of faecal matter

Question 40

What are three functions of the large intestine?

Answer 40

Reabsorption of water and electrolytes Production and absorption of vitamins B and K Elimination of faeces

Question 41

What is the anorectal canal?

Answer 41

It begins where the rectum penetrates the levator ani muscle

Question 42

What is the structure of the anorectal canal?

Answer 42

Has longitudinal folds (rectal columns) | It has two sphincters which control the movement of faeces out of the body

Question 43

In the anorectal canal, what is muscle makes up the internal and external sphincter?

Answer 43

Internal sphincter - smooth muscle (involuntary) | External sphincter - Skeletal muscle (voluntary)

Question 44

What is the main difference between infancy/childhood defecation compared to adulthood defecation?

Answer 44

It is an involuntary act when younger which through learned behaviour becomes a voluntary act

Question 45

What is the defecation reflex initiated by?

Answer 45

Through mass movements and stretching of rectal wall