Week One (Part One)

Question 1

General Structure of GI Wall

Outer to Inner:

Answer 1

Peritoneum
Serosa
Longitudal Layer of Smooth Muscle
Circular Layer of Smooth Muscle
Submucosa
Mucosa

Question 2

General Structure of GI Wall

Submucosa (Define):

Answer 2

Nerves, blood vessels, digestive glands

Question 3

Upper GI Tract

Structure (General):

Answer 3

Mouth
Esophagus
Stomach

Question 4

Upper GI Tract

Mouth (Purpose):

Answer 4

Used for chewing, mixing, and swallowing

Question 5

Upper GI Tract

Mouth (Enzyme):

Answer 5

Saliva. Used for protection, lubrication, and digestion.

Amylase is also present in saliva, which helps to break down starch.

Question 6

Upper GI Tract

Esophagus (Purpose):

Answer 6

Moving food down the stomach by peristalsis motion; connects mouth to the stomach.

Question 7

Upper GI Tract

Esophagus (Structure):

Answer 7

Upper and lower sphincter, controlled by the Cranial Nerve X and gastrin.

Question 8

Upper GI Tract

Stomach (Purpose):

Answer 8

Used for storage, digesting (peristaltic mixing, churning, moving secretions.

Question 9

Upper GI Tract

Stomach (Structure):

Answer 9

Connected to esophagus at cardia sphincter and to the small intestine at the pyloric sphincter.

Composed of fundus, body, antrum, and pylorus (in descending order).

Question 10

Upper GI Tract

Stomach (Secretions):

Answer 10

Mucus, HCL, and pepsinogen. Stimulated by the parasympathetic nervous system, gastrin, and histamine

Question 11

Upper GI Tract

Digestion:

Answer 11

Little to no absorption occurs in the Upper GI Tract except for the absorption of alcohol.

Question 12

Middle GI Tract

Structure (General):

Answer 12

Duodenum
Jejunum
Ileum

Question 13

Middle GI Tract

Structure (Purpose):

Answer 13

Digestion, absorption, secretion of enzyme, moving. Most digestion and absorption happens here.

Produce secretions of serous (Lieberkuhn), peptidase, disaccharidase

Question 14

Middle GI Tract

Duodenum (Purpose):

Answer 14

Receive secretion from liver and pancreas.

Secrete mucus, cholecystokinin, gastrin, and secretin

Question 15

Middle GI Tract

Jejunum (Purpose):

Answer 15

Main site of absorption.

Secretes mucus.

Question 16

Middle GI Tract

Ileum (Purpose):

Answer 16

Connected to the cecum by the ileocecal valve.

Question 17

Lower GI Tract

Structure (General):

Answer 17

Cecum
Ascending Colon
Transverse Colon
Descending Colon
Sigmoid Colon

Question 18

Lower GI Tract

Purpose (General):

Answer 18

Moving stool by haustration and propulsion.
Defecation.
Absorption of water and electrolytes (minor).

Question 19

Lower GI Tract

Defecation and the Sphincter:

Answer 19

Internal sphincter is controlled by the sacral spinal cord (and the automatic nervous system).

External sphincter is controlled by the cerebral cortex (and the conscious nervous system).