Gastrointestinal Anatomy: Small Intestine

Question 1

What are the 3 main regions of the small intestine?

Answer 1

Duodenum, Jejunum and Ileum

Question 2

This region of the small intestine receives chyme (from stomach), bile (fr. liver), enzymes and bicarbonate (fr. pancreas)

Answer 2

Duodenum

Question 3

This is the smallest and shortest region of the small intestine.

Answer 3

Duodenum

Question 4

This is the longest region of the small intestine.

Answer 4

Ileum

Question 5

The small intestine is held in place by the?

Answer 5

Mesentery

Question 6

In terms of peritoneal locations, where are the duodenum, ileum and jejunum found?

Answer 6

Duodenum = retroperitoneal

Ileum and jejunum = intraperitoneal

Question 7

This part of the small intestine contains arteries, veins, nerves and lymphatics.

Answer 7

Mesentery

Question 8

Where does deoxygenated blood drain to from the mesenteric veins?

Answer 8

To the hepatic portal vein

Question 9

These are large permanent folds of small intestine. It has a core of submucosa with overlying mucosa which helps to increase the SA for secretion.

Answer 9

Plicae Circulares

Question 10

These are found on the surface of the plicae circulares and made of mucosa. It produces localised movements to help with digestion.

Answer 10

Villi

Question 11

The core of each villus is made of?

Answer 11

Laminate propria

Question 12

Villi contain two important structures, what are they?

Answer 12

Lymph lacteals and capillary network

Question 13

Lymph lacteals and capillary networks are products of?

Answer 13

Lymph lacteal = products of fat digestion

Capillary network = products of protein and carbohydrate digestion

Question 14

What type of epithelium dominates the small intestine?

Answer 14

Simple columnar epithelium / absorptive cells

Question 15

What is found on the surface of enterocytes?

Answer 15

Microvilli brush border

Question 16

This is a component of microvilli that tethers enzymes in place.

Answer 16

Glycocalyx

Question 17

These are cells which have granules that release antibacterial enzymes. It is important for monitoring gut bacteria.

Answer 17

paneth cells

Question 18

These cells are important for hormonal control.

Answer 18

Endocrine cells

Question 19

These cells make all cell types and are responsible for migrating cells up and down.

Answer 19

Stem cells.

Question 20

What are the 3 structures of the small intestine that increase SA?

Answer 20

Plicae circulares, villi, and microvilli on brush border

Question 21

True or false. The intestinal wall has 3 muscle layers.

Answer 21

False. Two muscle layers.