Lecture 22

Question 1

what structures make up the small intestine?

Answer 1

Duodenum
Jejunum
Ileum

Question 2

What holds the small intestine in place?

Answer 2

Mesentery

Question 3

Role of Mesentery?

Answer 3

Anchors SI to abdominal wall, allows movement but prevents it from getting tangled.

Question 4

What structures does the mesentery contain?

Answer 4

Arteries, veins, nerves and lymphatics

Question 5

whats’s delivered to the small intestine?

Answer 5

Chyme

Question 6

What happens in the small intestine?

Answer 6

Further digestion and then absorption.

Question 7

What are the major layers of the digestive tract?

Answer 7

Mucosa
Submucosa
Muscular Layer
Adventitia

Question 8

What are Plicae Circulares

Answer 8

Permanent large folds in the small intestine. Create the core of the submucosa.

Question 9

Where can villi be found

Answer 9

Bound on the surface of plicae circulares

Question 10

What allows villi to move back and forth ?

Answer 10

Muscularis Mucosae

Question 11

Structure of villi?

Answer 11

Core of each villi is made of FCT (lamina propria) Contains vessels; lymph lacteal., capillary network.

Question 12

Role of lymph lacteal?

Answer 12

Transports products of fat digestion

Question 13

Role of Capillary network?

Answer 13

Transports products of protein digestion

Question 14

What is drained via mesenteric veins?

Answer 14

Nutrient rich, deoxygenated blood absorbed in the small intestine.

Question 15

Where does mesenteric veins drain?

Answer 15

Into the hepatic portal vein

Question 16

Where do lymph lacteals drain into?

Answer 16

Cistema chyli, thoracic duct and then left subclavian vein

Question 17

What structures increase the surface area of the small intestine?

Answer 17

Plicae Circulares

Villi

Question 18

What epithelia are found in the small intestine?

Answer 18

Simple columnar

Question 19

What is the role of he microvilli on the surface?

Answer 19

increase surface area fuerther

Question 20

What is contact digestion?

Answer 20

Involves brush boarder enzymes

Question 21

What are the junctions between epithelial cells?

Answer 21

Plasma membrane and tight junctions

Question 22

Features of the plasma membrane?

Answer 22

Selectively permeable, Has proteins - channels transporters.

Question 23

features of tight junctions?

Answer 23

Very tight, small molecules may diffuse through

Question 24

What cells are found in the epithelium of the small intestine.

Answer 24

Enterocytes (absorptive cells) 
Goblet cells (mucous secreting for protection) 
Stem cells (Make all cell types) 
Paneth cells (granules, antibacterial enzymes) 
Endocrine cells ( secrete hormones)