Grand tour of the Alimentary system

Question 1

List the four main functions of the digestive system

Answer 1

1. digestion
2. secretion
3. absorption
4. motility

Question 2

digestion

Answer 2

large molecules to small molecules

Question 3

secretion

Answer 3

create an aqueous environment + enzymes

Question 4

absorption

Answer 4

into blood

Question 5

motility

Answer 5

moves everything along

Question 6

what kind of circuit is the digestive system described as

Answer 6

series - can’t miss the liver

Question 7

how many pairs of salivary glands are there

Answer 7

3 pairs = 6 in total

Question 8

name the different salivary glands

Answer 8

1. parotid - largest
2. sublingual - up under tongue
3. submandibular - under jaw line

Question 9

main function - mouth

Answer 9

foodstuffs broken down by chewing - saliva added as lubricant

Question 10

main function - oesophagus

Answer 10

conduit between mouth and stomach - can also move food against gravity

Question 11

main function - stomach

Answer 11

Digestion of proteins, foodstuffs reduced to liquid form, storage, sterilisation (due to HCL content)

Question 12

main function - pancreas

Answer 12

Digestive enzymes for digestion of fats, carbohydrates and proteins

Question 13

main function - liver

Answer 13

Bile salts for digestion/absorption of fats in small intestine

Question 14

main function - gallbladder

Answer 14

Stores and concentrates bile

Question 15

main function - small intestine

Answer 15

Final stages of chemical digestion and nutrient absorption

Question 16

main function - large intestine

Answer 16

Water absorption, bacterial fermentation and formation of faeces

Question 17

main function - bile salts

Answer 17

emulsify fats – allow for absorption

*water follows sodium in absorption

Question 18

general structure of the alimentary canal

Answer 18

continuous hollow tube (varying diameter)

oesophagus-rectum = ~8m

Question 19

What are the 4 layers go the alimentary canal (in to out)

Answer 19

1. mucosa
2. submucosa
3. musclularis externa
4. serosa/adventitia

Question 20

What are the three layers of the mucosa (in to out)

Answer 20

1. epithelium
2. lamina propria
3. muscularis mucosae

Question 21

What are the only two places where the submucosa contains glands

Answer 21

oesophagus (glands secrete mucous) and duodenum (glands secrete bicarbonate)

Question 22

what is and what comprises the enteric nervous system

Answer 22

1. nervous system for independant control of gut function

2. made up of submucosal plexus + myenteric plexus

Question 23

stratified squamous epithelium found

Answer 23

mouth, oesophagus, anal canal

Question 24

simple columnar epithelium found

Answer 24

stomach, small intestine, large intestine

Question 25

main epithelium functions

Answer 25

1. barrier separating lumen of alimentary canal from body 2. synthesis and secretion of digestive enzymes, hormones, mucus 3. absorbs products of digestion

Question 26

lamina propria structure/function

Answer 26

1. loose connective tissue | 2. contains glands, blood vessels and lymph vessels

Question 27

muscularis mucosae structure

Answer 27

thin smooth muscle layer

Question 28

submucosa structure/function

Answer 28

1. thick irregular connective tissue supports structures | 2. contains neurones, blood vessels and lymphatic vessels

Question 29

what network do submucosal neurones form

Answer 29

Meissners plexus (parasympathetic)

Question 30

Adventitia structure/function

Answer 30

1. connective tissue outer layer of canal | 2. OUTSIDE peritoneal cavity - attaches oesophagus and rectum to surrounding structures

Question 31

Serosa structure/function

Answer 31

1. connective tissue outer later of canal | 2. INSIDE peritoneal cavity - surrounds stomach, small intestine and large intestine

Question 32

Muscularis externa structure/function

Answer 32

1. two concentric thick layers of smooth muscle (Inner circular, outer longitudinal) 2. produce motility (peristalsis, segmentation)

Question 33

What does the inner circular muscle layer do

Answer 33

constircts lumen

Question 34

what does the outer longitudinal muscle layer do

Answer 34

shortens tube

Question 35

What plexus is found between the circular and longitudinal muscle layers

Answer 35

myenteric Auerbacks plexus

Question 36

Autonomic control

Answer 36

Long (parasympathetic) and short (ENS) reflexes

Question 37

Parasympathetic control

Answer 37

1. via vagus nerve (X) EXCEPT salivation (VII,IX) 2. always STIMULATORY to gut function: Increased secretion and motility

Question 38

Sympathetic control

Answer 38

1. via splanchnic nerve 2. always INHIBITORY to gut function (expect salivation): Decreased secretion and motility

Question 39

Stomach blood vessels

Answer 39

``` A = celiac trunk V = gastric veins - hepatic portal vein - hepatic vein - IVC ```

Question 40

Pancreas blood vessels

Answer 40

``` A = celiac trunk V = Splenic vein - hepatic portal vein - hepatic vein - IVC ```

Question 41

Liver blood vessels

Answer 41

``` A = celiac trunk V = Hepatic vein - IVC ```

Question 42

Small intestine blood vessels

Answer 42

``` A = superior mesenteric artery V = superior mesenteric vein - hepatic portal vein - hepatic vein - IVC ```

Question 43

Caecum blood vessels

Answer 43

``` A = superior mesenteric artery V = superior mesenteric vein - hepatic portal vein - hepatic vein - IVC ```

Question 44

Ascending colon blood vessels

Answer 44

``` A = superior mesenteric artery V = superior mesenteric vein - hepatic portal vein - hepatic vein - IVC ```

Question 45

Transverse colon blood vessels

Answer 45

``` A = superior mesenteric artery V = superior mesenteric vein - hepatic portal vein - hepatic vein - IVC ```

Question 46

Descending colon blood vessels

Answer 46

``` A = inferior mesenteric artery V = inferior mesenteric vein - hepatic portal vein - hepatic vein - IVC ```

Question 47

Sigmoid colon blood vessels

Answer 47

``` A = inferior mesenteric artery V = inferior mesenteric vein - hepatic portal vein - hepatic vein - IVC ```

Question 48

Rectum blood vessels

Answer 48

``` A = inferior mesenteric artery V = inferior mesenteric vein - hepatic portal vein - hepatic vein - IVC ```