L11: Digestive System Anatomy

Question 1

How is the primitive gut formed?

Answer 1

Developing embryo undertaking 2 folds

1) cranial-caudal axis
2) lateral plane

Question 2

What is the primitive gut held in position by?

Answer 2

Mesenteries

Question 3

What are mesenteries?

Answer 3

Tissue derived from the mesodermal layer

Question 4

Define mesentery

Answer 4

Fold of membrane that is continuous with both the peritoneal layers

Can be dorsal/ventral

Question 5

Role of the mesentery

Answer 5

1) Suspend the abdominal organs
2) Serve as the pathway for blood, innervation to reach the abdominal organs

Question 6

Role of dorsal mesentery

Answer 6

Attaches abdominal organs to the posterior abdominal wall (back)

e.g
greater omentum
mesentery of small & large intestine

Question 7

Examples of ventral mesentery

Answer 7

• falciform ligament
• lesser omentum

Question 8

role of the lesser omentum

Answer 8

lesser omentum links the lesser curvature of the stomach to the back of the liver

Question 9

WHat is the result of organ rotation?

Answer 9

Lesser/greater sac

Question 10

Define lesser/greater sac

Answer 10

Lesser: Space behind the stomach
Greater: Rest of the peritoneal cavity

Question 11

What does the lesser/greater sac communicate via?

Answer 11

Epiploic foramen- small vertical passage between greater sac & lesser sac

Question 12

Role of the alimentary system

Answer 12

ingestion
secretion of digestive fluids
mixing
digestion
absorption
defacation

Question 13

3 layers in the alimentary canal

Answer 13

1) mucosal layer
2) muscular layer
3) serous layer

Question 14

describe the serous layer

Answer 14

outer membrane, secretes a lubricating fluid

Question 15

describe the muscular layer

Answer 15

longitudinal/circular, responsible for movement of lumen contents

Question 16

describe the mucosal layer

Answer 16

inner layer, lines internal organs/organs, secrete mucus

Question 17

Describe pharynx

Answer 17

Hollow, muscular tube inside the neck behind the tongue that allows food to go down

Question 18

Function of palate

Answer 18

Roof of mouth, swallowing

Question 19

Features of the oesophagus

Answer 19

muscular tube, ‘pierces’ diaphragm, located posterior to trachea

Question 20

Features of the stomach

Answer 20

Most dilated part of alimentary canal
J-shaped
2 openings, 2 curvatures & 2 surfaces

Question 21

What does the cardial orifice link to?

Answer 21

Oesophagus

Question 22

What does the pyloric orifice link to?

Answer 22

Small intestine

Question 23

What does the wall of the stomach include?

Answer 23

Pyloric & cardial sphincters

Question 24

3-layered muscle in the wall of the stomach

Answer 24

1) Longitudinal
2) Circular
3) Oblique (slant)

Question 25

What takes place in the small intestine?

Answer 25

Digestion & absorption

Question 26

3 main regions in the small intestine

Answer 26

1) Duodenum 2) Jejunum 3) Ileum

Question 27

Small intestine extend from the 1)... to the 2)...

Answer 27

1) Pylorus of stomach 2) Ileocaecal junction

Question 28

What space does the duodenum lie in?

Answer 28

Retroperitoneal space

Question 29

4 parts of the duodenum

Answer 29

1) Superior 2) Descending 3) Horizontal 4) Ascending

Question 30

What opens in the duodenum?

Answer 30

Duct from the pancreas + gall bladder, bringing in bile & pancreative juices

Question 31

Where does the duodenum end?

Answer 31

Duodenal-jejunal junction

Question 32

Role of the jejunum + ileum

Answer 32

Absorption

Question 33

What does jejunum+ileum have that contributes to the large SA?

Answer 33

Villi + microvilli

Question 34

Where does jejunum + ileum extends for?

Answer 34

Duodenal-jejunal junction to the ileocaecal junction

Question 35

4 parts of the large intestine

Answer 35

1) ascending 2) transverse 3) descending 4) sigmoid

Question 36

Space of the ascending & descending part?

Answer 36

Retroperitoneal space

Question 37

Role of the small intestine

Answer 37

Reabsorb water, form faeces and expel faeces

Question 38

What is the action of the large intestine controlled by?

Answer 38

Sphincters in the rectum

Question 39

What is the superior mesenteric artery?

Answer 39

Major artery of the abdomen; supplies arterial blood to midgut organs

Question 40

4 major branches in the superior mesenteric artery

Answer 40

1) Jejunal & ileal branches 2) Middle colic 3) Right colic 4) Ileocaecal

Question 41

What is the inferior mesenteric artery?

Answer 41

Supplies arterial blood to the hingut organs

Question 42

3 major branches in the inferior mesenteric artery

Answer 42

1) Left colic 2) Sigmoid 3) Superior rectal

Question 43

Nerves involved in sympathetic innervation

Answer 43

1) Splanchnic nerves 2) Symp trunk & ganglia

Question 44

Nerves involved in parasympathetic innervation

Answer 44

1) Vagus nerve 2) Pelvic splanchnic nerves