guinea pig ileum

Question 1

second brain

Answer 1

enteric nervous system

Question 2

What is the structure of the gastrointestinal tract?

Answer 2

continuous tubular

Question 3

How many layers is the gastrointestinal tract made up of?

Answer 3

4

Question 4

What layer replaces the serosa layer in the oesophagus?

Answer 4

adventitital

Question 5

mucosa

Answer 5

intermost layer of the GI tract that contains cells responsible for secretion + absorption

Question 6

What tissue is the mucosa made up of?

Answer 6

thin epithelial

Question 7

Where is the lamina propria found?

Answer 7

mucosa

Question 8

What does the lamina propria contain?

Answer 8

numerous lymph nodules that are important in protecting the intestine against disease

Question 9

musscularis mucosa

Answer 9

thin muscle layer that is responsible for forming the numerous small folds evident in certain regions of the GI tract

Question 10

How do goblet cells the GI tract?

Answer 10

lubricate the ingested material + aid the passage from mouth to anus

Question 11

Is the submucosa thicker or thinner than the mucosa?

Answer 11

thicker

Question 12

What does the submucosa contain?

Answer 12

large proportion of blood vessels that supply the mucosal layer/glands/nerve plexuses

Question 13

What does the submucosal plexus supply?

Answer 13

muscularis mucosa with autonomic nerve input

Question 14

What type of muscle does the muscularis contain?

Answer 14

longitudinal + circular

Question 15

What are the muscularis muscles responsible for?

Answer 15

moving ingested material through segmental contractions + peristaltic movement

Question 16

Where is the myenteric plexus located?

Answer 16

between the longitudinal + circular muscles

Question 17

What does the myenteric plexus do?

Answer 17

provides the major nerve supply to the GI tract and includes fibres + ganglia from both the symapthetic + parasympathetic divisions of the autonomic nervous system / controls += synchronises the contractility of the muscularis propria

Question 18

serosa/adventitia

Answer 18

outer layer of fibrous connective tissue surrounding the intestine (and 2 serous membranes/mesothelium which secretes serous fluid to lubricate against frictional forces for the serosa)

Question 19

What is the general organisation of the gastrointestinal tract?

Answer 19

1) mucosa (epithelium/lamina propria/muscularis mucosa)
2) submucosa
3) muscularis propria (circular muscle/Auerbach’s (Myenteric) plexus/longitudinal muscle)
4) serosa/adventitia

Question 20

How many neurons does the enteric nervous system contain?

Answer 20

approximately one hundred million

Question 21

What are the 2 discrete, but interconnected layers of the enteric nervous system?

Answer 21

1) myenteric plexus

2) submucosal plexus

Question 22

Where is the submucosal plexus located?

Answer 22

between the muscularis mucosa + muscularis propria

Question 23

What does the submucosal plexus do?

Answer 23

1) controls the secretion of digestive peptides/mucus/hormones
2) integrates sensory inputs + signals to the myenteric plexus

Question 24

What does the enteric nervous system do?

Answer 24

relays information up + down the length of the gastrointestinal tract, resulting in short/intrinsic reflexes

Question 25

How do smooth muscle cells of the gastrointestinal tract link to one another?

Answer 25

gap junctions