Physiology

Question 1

4 functions of the digestive system

Answer 1

Digestion
Absorption
Secretion
Motility

Question 2

Four layers of the GI tract

Answer 2

Mucosa
Submucosa
Muscularis externa
Serosa/adventitia

Question 3

3 layers of mucosa

Answer 3

Epithelium
Lamina propria
Muscularis mucosae

Question 4

2 types of epithelium and where they are found

Answer 4

Stratified squamous - mouth, oesophagus, anal canal

Simple columnar - stomach, small and large intestines

Question 5

Submucosa

Answer 5

Thick irregular connective tissue

Question 6

Serosa

Answer 6

Connective tissue layer surrounding intraperitoneal organs

Question 7

Adventitia

Answer 7

Connective tissue layer surrounding retroperitoneal organs

Question 8

Two laters of muscularis externa

Answer 8

Inner - circular

Outer - longitudinal

Question 9

What make up the ENS?

Answer 9

Submucosal plexus

Myenteric plexus

Question 10

Parasympathetic control is via which nerve?

Answer 10

Vagus nerve

Question 11

Sympathetic control is via which nerve?

Answer 11

Splanchnic nerve

Question 12

Effect of parasympathetic control

Answer 12

Increase secretion and motility

Question 13

Effect of sympathetic control

Answer 13

Decrease secretion and motility

Question 14

Arterial supply

Answer 14

Splenic
Celiac trunk
Superior and inferior mesenteric

Question 15

Venous drainage

Answer 15

Gastric
Splenic
Superior and inferior mesenteric
Hepatic portal vein

Question 16

Where does all venous drainage of the GI pass before returning to the heart?

Answer 16

Liver

Question 17

3 monosaccharides absorbed by the body

Answer 17

Glucose, galactose and fructose

Question 18

Monosaccharides that make up laltose

Answer 18

Glucose and galactose

Question 19

Monosaccharides that make up sucrose

Answer 19

Glucose and fructose

Question 20

Monosaccharides that make up maltose

Answer 20

Glucose and glucose

Question 21

3 types of polysaccharides

Answer 21

Starch, cellulose and glycogen

Question 22

Bond type in starch

Answer 22

Alpha-1,4 glycosidic bonds

Question 23

Plant glucose storage type

Answer 23

Starch and cellulose

Question 24

Bond type in cellulose

Answer 24

Beta-1,4 glycosidic bonds

Question 25

How is cellulose broken down in vertebrates

Answer 25

Bacteria in colon expresses cellulase that hydrolysis cellulose

Question 26

Animals glucose storage type

Answer 26

Glycogen

Question 27

Bond type in glycogen

Answer 27

Alpha-1,4 glycosidic bonds

Question 28

2 types of membranes in SI epithelial cells

Answer 28

Basolateral membrane - sides and bottom | Apical membrane - surface (brush border)

Question 29

Transporters involved in glucose and galactose absorption

Answer 29

SGLT-1 - sodium glucose coupled transporter Na/KATPase GLUT-2

Question 30

Transporters involved in fructose absorption

Answer 30

GLUT-5 | GLUT-2

Question 31

Enzymes that break down proteins and peptides

Answer 31

Proteases and peptidases

Question 32

Endopeptidases

Answer 32

Act on interior amino acids of proteins

Question 33

Exopeptidases

Answer 33

Act on terminal amino acids of proteins (amino and carboxy)

Question 34

Transporters involved in amino acid absorption

Answer 34

SAAT1 - sodium amino acid coupled transporter Na/KATPase Amino acid carrier

Question 35

Transporters involved in di/tripeptide absorption

Answer 35

PepT1 - hydrogen di/tripeptide coupled transporter NHE3 Na/KATPase Unknown di/tripeptide transporter

Question 36

Fat is found in the form of

Answer 36

Triacylglycerol

Question 37

Triacylglycerol is broken down by

Answer 37

Lipase

Question 38

Triacylglycerol is broken down into

Answer 38

Monoglyceride + 2 fatty acids

Question 39

Function of emulsifying agent

Answer 39

Prevents small droplets of fat reforming into large droplets of fat

Question 40

Emulsification

Answer 40

Breaking down large droplets of fat into smaller droplets

Question 41

Why does emulsification of fat globules occur?

Answer 41

To increase surface area for lipase to act on

Question 42

Chylomicrons contains

Answer 42

Phospholipids, cholesterol and fat-soluble vitamins

Question 43

Chylomicrons

Answer 43

Extracellular fat droplets

Question 44

Water soluble vitamins

Answer 44

B group C Folic acid

Question 45

Fat soluble vitamins

Answer 45

A, D, E, K

Question 46

How is vitamin B12 absorbed

Answer 46

Binding to intrinsic factor

Question 47

Vitamin B12 deficiency leads to

Answer 47

Pernicious anaemia

Question 48

Iron is transported into duodenal enterocytes via?

Answer 48

DMT1

Question 49

Ferittin

Answer 49

Intracellular iron store

Question 50

Transferrin

Answer 50

What free iron binds to in the blood

Question 51

3 salivary glands

Answer 51

Parotid, submandibular, sublingual

Question 52

Components of saliva

Answer 52

``` Water Mucin Alpha-amylase Electrolytes Lysosome ```

Question 53

Parasympathetic nerves control salivary secretion

Answer 53

Cranial nerves 7 (facial) & 9 (glossopharyngeal)

Question 54

Effect of parasympathetic control on salivary secretion

Answer 54

Profuse watery saliva secretion

Question 55

Effect of sympathetic control on salivary secretion

Answer 55

Viscous salivary secretion of small volume

Question 56

3 layers of stomach muscularis external

Answer 56

Oblique, circular, longitudinal

Question 57

Mucous neck cells secrete

Answer 57

Mucous

Question 58

Chief cells secrete

Answer 58

Pepsinogen

Question 59

Parietal cells secrete

Answer 59

HCl & intrinsic factor

Question 60

4 controls of gastric epithelial proton pump activity

Answer 60

Increase - gastrin, histamine, acetylcholine | Decrease - Prostaglandins

Question 61

3 mechanisms of control of gastric secretion

Answer 61

Neurocrine (vagus/local reflexes) Endocrine (gastrin) Paracrine (histamine)

Question 62

Enterogastrones

Answer 62

Secretin, CCK, GIP (gastric inhibitory peptide)

Question 63

Enterogastrones are release in response to

Answer 63

Acid, hypertonic solutions, fatty acids or monoglycerides in the duodenum

Question 64

Function of enterogastrones

Answer 64

To prevent further acid build up in duodenum

Question 65

Pepsinogen

Answer 65

Zymogen - inactive precursor for pepsin

Question 66

Pepsinogen is activated by

Answer 66

Low pH (<3)

Question 67

What controls the peristaltic rhythm of the stomach?

Answer 67

Pacemaker cells

Question 68

What stimulates bicarbonate production in duodenum?

Answer 68

Presence of acid in duodenum

Question 69

What control the secretion of bicarbonate in the duodenum?

Answer 69

Secretin | Vagal and ENS reflexes

Question 70

What controls gastric motility?

Answer 70

Gastrin | Vagal and ENS reflexes

Question 71

What inhibits gastric motility?

Answer 71

Chyme in duodenum

Question 72

Endocrine portion of pancreas

Answer 72

Islets of Langerhans

Question 73

Exocrine portion of pancreas

Answer 73

Acinar cells

Question 74

Endocrine portion of pancreas secretes to

Answer 74

Circulatory system

Question 75

Exocrine portion of pancreases secretes to

Answer 75

Lumen

Question 76

Exocrine portion of pancreas responsible for

Answer 76

Digestion

Question 77

Acinar cells secrete

Answer 77

Digestive enzymes

Question 78

Duct cells secrete

Answer 78

Bicarbonate

Question 79

Enterokinase is found at

Answer 79

Brush border of duodenal enterocytes

Question 80

Function of enterokinase

Answer 80

Convert trypsinogen to trypsin

Question 81

Pancreatic digestive enzymes

Answer 81

``` Proteases Nucleases Elastases Phospholipases Lipases Alpha-amylase ```

Question 82

Secretion of zymogens from acinar cells stimulated by

Answer 82

CCK

Question 83

CCK released is response to

Answer 83

Fat/amino acids in duodenum

Question 84

Portal triad of liver consists of

Answer 84

Hepatic portal vein, hepatic artery, hepatic duct

Question 85

What are the central veins of hexagonal liver lobules?

Answer 85

Hepatic veins

Question 86

Components of bile

Answer 86

Bile acids, lecithin, cholesterol, bile pigments, toxic metals, bicarbonate

Question 87

Main bile pigment

Answer 87

Bilirubin

Question 88

Bile acid is synthesised from

Answer 88

Cholesterol

Question 89

Bile acid is conjugated with

Answer 89

Taurine and glycine

Question 90

Bile acid in conjugated to from

Answer 90

Bile salts

Question 91

Why is bile acid conjugated?

Answer 91

To increase solubility

Question 92

Gallbladder wall layers

Answer 92

Mucosa, muscularis, serosa (no submucosa)

Question 93

Function of gallbladder

Answer 93

Store and concentrate bile

Question 94

What controls bile secretion?

Answer 94

CCK

Question 95

Function of CCK

Answer 95

Control bile secretion & pancreatic enzyme secretion

Question 96

Crypt cells secrete

Answer 96

Chlorine & water

Question 97

2 types of motility in SI

Answer 97

Segmentation & peristalsis

Question 98

Effect of parasympathetic nerves on segmentation

Answer 98

Increases contraction

Question 99

Effect of sympathetic nerves on segmentation

Answer 99

Decrease contraction

Question 100

Hormone that initiated peristalsis in SI

Answer 100

Motilin

Question 101

Teniae coli

Answer 101

3 bands that run the length of colon

Question 102

Haustra

Answer 102

Pouches of colon formed by contraction of teniae coli

Question 103

Anatomical cause of constipation

Answer 103

Distention of rectum

Question 104

Symptoms of constipation

Answer 104

Headache Nausea Loss of appetite Abdominal distention

Question 105

Causes of diarrhoea

Answer 105

``` Food Stress Viruses Toxins Pathogenic bacteria Protozoans ```

Question 106

Examples of enterotoxigenic bacteria

Answer 106

E. coli | Vibrio cholerae

Question 107

Enterotoxigenic bacteria results in

Answer 107

Increased water in lumen and so profuse water diarrhoea

Question 108

Enterotoxigenic bacteria act by elevating

Answer 108

cAMP cGMP calcium