Alimentary canal

Question 1

what are the 4 functions of the digestive system

Answer 1

digestion (by process of absorption and secretion)
secretion
absorption
motility

Question 2

function of gallbladder

Answer 2

stores and concentrates bile

Question 3

function of small intestine

Answer 3

chemical digestion and nutrient absorption

Question 4

what is the structure of the alimentary canal like?

Answer 4

continuous hollow tube
varying diameter
starts at oesophagus and ends at the rectum

Question 5

what are the 4 layers of the alimentary canal called?

Answer 5

mucosa
submucosa
muscularis externa
serosa/adventitia

Question 6

3 layers of mucosa

Answer 6

epithelium
lamina propria
muscularis mucosae (thin smooth muscle layer)

Question 7

what type of epithelium is in the mouth, oesophagus and anal canal?

Answer 7

stratified squamous

Question 8

what type of epithelium is in the stomach, small and large intestine?

Answer 8

simple columnar

Question 9

what is the submucosa

Answer 9

thick, irregular connective tissue that supports mucosa

contains neurones, blood vessels and lymphatic vessels

Question 10

where are there submucossal glands? (2 places)

Answer 10

oesophagus

duodenum

Question 11

what does the adventitia do outside the peritoneal cavity?

Answer 11

Adventitia attaches oesophagus and rectum to surrounding structures

Question 12

what does the serosa do inside the peritoneal cavity?

Answer 12

Serosa surrounds the liver, the stomach, spleen, start of the small intestine and the ileum, the transverse colon and the sigmoid colon.

Question 13

muscularis externa 2 layers are made of what types of muscle?

Answer 13

smooth muscle

inner layer - circular muscle - constricts the tube
outer layer - longitudinal. When they contract the tube shortens

Question 14

what is the plexus called between circular and longitudinal muscle

Answer 14

myenteric

Question 15

what is the enteric nervous system made up of? what is it’s function/ significance

Answer 15

submucosal and myenteric plexuses

independent control of gut function - like the gut’s own brain

Question 16

autonomic control of alimentary function

Answer 16

long parasympathetic and short ENS reflexes

Question 17

parasympathetic control of alimentary function is carried out by what?

Answer 17

vagus nerve
N.B parasympathetic = peace = rest and digest
so it is therefore stimulatory

stimulatory - increases secretion and motility

Question 18

what nerves are used for salivation

Answer 18

facial and glossopharyngeal

Question 19

sympathetic control of alimentary function

Answer 19

splanchnic nerve

inhibitory (except salivation) decreases secretion and motility

Question 20

3 branches of abdominal aorta?

Answer 20

Celiac trunk
superior mesenteric artery
inferior mesenteric artery

Question 21

which organs does the celiac trunk supply?

Answer 21

Stomach
Small intestine
Pancreas
Liver

Question 22

which organs does the superior mesenteric artery supply?

Answer 22

Small intestine
Caecum
Ascending colon
Transverse colon

ie the midgut

Question 23

which organs does the inferior mesenteric artery supply?

Answer 23

Descending colon
Sigmoid colon
Rectum

ie the hindgut

Question 24

where does the heptaic portal vein drain to?

Answer 24

the hepatic vein which in turn drains to the inferior vena cava

Question 25

Blood from the stomach drains into which veins?

Answer 25

gastric veins

Question 26

Blood from the pancreas drains into which veins?

Answer 26

splenic veins

Question 27

where does blood from the Small intestine, Caecum, Ascending colon and Transverse colon drain to?

Answer 27

superior mesenteric vein

Question 28

where does blood from the descending colon, sigmoid colon and rectum drain to?

Answer 28

inferior mesenteric vein

Question 29

lymphatic system link with gut?

Answer 29

products of fat digestion go through this

Question 30

what is the myenteric plexus?

Answer 30

nerve network between circular and longitudinal muscle

Question 31

true or false: there is no conscious control of gut function?

Answer 31

true - it is all done automatically

some reflexes occur just within the ENS whereas some also involve the CNS