Module 8 + 9: Digestive / Metabolism

Question 1

Four basic layers of the GI tract?

Answer 1

Mucosa Submucosa Muscularis Externa Serosa

Question 2

Three components of the mucosa layer?

Answer 2

Muscosal epithelium Lamina propria (connective tissue) Muscularis mucosae

Question 3

How is stomach surface area increased?

Answer 3

By invaginations called gastric glands

Question 4

What are the lymphoid tissues of the gut called

Answer 4

Peyer’s patches

Question 5

What is the muscularis externa?

Answer 5

Consists of two layers of smooth muscle Contains the myenteric plexus of the enteric nervous system

Question 6

What is the submucosa

Answer 6

Connective tissue Contains blood and lymphatic vessels Contains the submucosal plexus of the enteric nervous system

Question 7

What is the serosa?

Answer 7

Continuation of the peritoneal membrane, which forms sheets of mesentery

Question 8

What are the two types of GI contractions?

Answer 8

Tonic and phasic

Question 9

What are tonic contractions?

Answer 9

Sustained for minutes of hours Keep bolus from moving backward

Question 10

Where do tonic contractions occur?

Answer 10

They occur in some smooth muscle sphincters and the anterior portion of the stomach

Question 11

What are phasic contractions?

Answer 11

Quick contractions

Question 12

Where do phasic contractions occur?

Answer 12

In the posterior region of the stomach and in the small intestine

Question 13

Two types of phasic contractions?

Answer 13

Peristalsis and segmentation

Question 14

What are peristaltic contractions?

Answer 14

Responsible for forward movement

Question 15

What are segmental contractions?

Answer 15

Responsible for mixing

Question 16

What parts of the GI tract are under voluntary control?

Answer 16

Ingestion/swallowing and defecation

Question 17

Order of food to faeces?

Answer 17

Food -> Chyme - > faeces

Question 18

Mechanical and chemical stimuli that provoke digestive activity?

Answer 18

Stretch (distention) Changes in osmolarity and pH Presence of substrate and end products of digestion

Question 19

What are short reflexes in the enteric nervous system? What do they respond to?

Answer 19

Respond to stimuli in GI tract; mediated by enteric nerve plexuses

Question 20

What are long reflexes in the enteric nervous system? What do they respond to?

Answer 20

Parasympathetic system enhances digestion, sympathetic system inhibits. Respond to stimuli arising in or out of the gut, most notably the autonomic nervous system

Question 21

What is the site of aldosterone action?

Answer 21

The distal tubule

Question 22

Seven main functions of the oral cavity?

Answer 22

Ingestion Mastication Lubrication Limited digestion Phonation Ventilation Detection/protection of pathogens

Question 23

Three functional compartments of the stomach?

Answer 23

Fundus Body Antrum

Question 24

What is the fundus?

Answer 24

A dome-shaped region beneath the diaphragm. It is the cardiac region of the stomach.

Question 25

What is the body of the stomach comprised of?

Answer 25

Many gastric glands

Question 26

What is the antrum?

Answer 26

Lower part of the stomach

Question 27

What does the antrum terminate at?

Answer 27

The pyloric sphincter

Question 28

What does the antrum continue into?

Answer 28

The duodenum

Question 29

Three functions of the stomach?

Answer 29

Storage Digestion Defence

Question 30

Two phases of the stomach?

Answer 30

Cephalic and gastric phase

Question 31

What is the cephalic phase

Answer 31

Sigh, smell, taste and thought of food trigger LONG reflexes via vagus nerve. Serves to prepare stomach for food.

Question 32

What is the gastric phase?

Answer 32

Presence of food triggers short reflexes via enteric plexus. Distension of gut wall and presence of peptides and amino acids in the gastric lumen activate endocrine cells and enteric neurons.

Question 33

Six types of secretory cells in the stomach?

Answer 33

Exocrine: Mucous Parietal Chief Endocrine: Enterochromaffin-like (ECL) D-cells G-cells

Question 34

What is the acid-resistant bacterium of the stomach that causes reflux?

Answer 34

Helicobacter pylori

Question 35

What does hydrogen chloride active in the body? What does this do?

Answer 35

It activates pepsiongen - converts it to active pepsin.

Question 36

How is gastric secretion regulated?

Answer 36

Neural control - ACh and Gastrin-releasing peptide (GRP) Or hormonally - Enterochromaffin-like (ECL) cells, G cells and D cells

Question 37

How does ACh regulate gastric secretion?

Answer 37

ACh is released by intrinsic nerve plexuses within the stomach, under the control of short local reflexes and vagal stimulation

Question 38

How does ECL regulate gastric secretion?

Answer 38

It secretes histamine among the parietal and chief cells

Question 39

How do G cells regulate gastric secretion?

Answer 39

By secreting gastrin into the bloodsteam

Question 40

How do D cell regulate gastric secretion?

Answer 40

By secreting somatostatin in response to acid

Question 41

Three functions of the stomach?

Answer 41

Storage Digestion Defence

Question 42

What does bicarbonate in the stomach do?

Answer 42

Buffers gastric acid to prevent damage to epithelium

Question 43

What does Helicobacter pylori do?

Answer 43

Causes inflammation of the gastric mucosa leading to gastritis

Question 44

How much acid is secreted a day

Answer 44

1-3L

Question 45

How is acid released?

Answer 45

Parietal cells pump H+ into stomach lumen via H+/K+ ATPase

Question 46

What does HCL do in the stomach?

Answer 46

Activates pepsinogen - converts it to active pepsin

Question 47

What are the nueral regulators of gastric secretion?

Answer 47

Acetylcholine and Gastrin-releasing peptide (GRP)

Question 48

What are the hormonal controllers of gastric secretion?

Answer 48

Enterochromaffin-life (ECL) cells, G cells and D cells

Question 49

What percentage of starch does amylase break down?

Answer 49

50%

Question 50

What pH does amylase stop working?

Answer 50

Below 4.5

Question 51

How long does it take pancreatic amylase to convert starch to oligosaccharides and maltose?

Answer 51

10 minutes

Question 52

What complete the digestion of oligosaccharides and maltose to monosaccharides after pancreatic amylase is done?

Answer 52

Brush border enzymes

Question 53

What is pancreatic enzyme secretion triggered by?

Answer 53

Cholecystokinin (CCK) and the vagus nerve

Question 54

What are the exocrine cells of the pancreas?

Answer 54

The acinar and ductal cells

Question 55

What are acinar cells?

Answer 55

Contain zymogen granules with digestive enzymes

Question 56

What are ductal cells?

Answer 56

Epithelial cells in the pancreas that produce alkaline secretion (bicarbonate) and transport all secretions

Question 57

What cells secrete insulin and glucagon into the bloodstream?

Answer 57

Islets of Langerhands

Question 58

Order of SI mucosa?

Answer 58

Plicae, villi and microvilli

Question 59

What is the migrating motor complex?

Answer 59

Contractions that begin in the empty stomach and end in the large intestine. 'Housekeeping" function serves to sweep out food and bacteria from the upper GIT into the colon

Question 60

How many essential vitamins?

Answer 60

13

Question 61

What are the essential vitamins?

Answer 61

4 fat soluble (A, D, E and K) + 9 water soluble

Question 62

What vitamins can body synthesise?

Answer 62

D and K

Question 63

7 major minerals needed in the body?

Answer 63

Potassium Chloride Sodium Calcium Phosphorus Magnesium Sulphur

Question 64

How are vitamins A, D, E and K absorbed?

Answer 64

With fats

Question 65

How are minerals transported in the body?

Answer 65

Usually by active transport

Question 66

What is the large intestine villi like?

Answer 66

Lacks villi, produces mucus to lubricate faeces

Question 67

What does the large intestine secrete?

Answer 67

Bicarbonate

Question 68

What is leptin produced by?

Answer 68

Lipid cells

Question 69

What does leptin do?

Answer 69

Provide information about current energy stores, decreasing feeding behaviour by inhibiting NPY neurons and stimulating POMC neurons

Question 70

What releases neuropeptide Y?

Answer 70

Sympathetic nerve endings

Question 71

How many essential amino acids?

Answer 71

9 out of 20

Question 72

How can adipose tissue be endocrine?

Answer 72

Releasing adipokines, like leptin

Question 73

What molecule does brain depend on?

Answer 73

Glucose

Question 74

How much glucose does brain oxidise a day?

Answer 74

120g

Question 75

What is excess cholesterol in the liver secreted as?

Answer 75

A lipoprotein complex

Question 76

Easy way to remember which between HDL and LDL holds cholesterol?

Answer 76

Complex with more protein is denser

Question 77

What does HDL-C contain that facilitates cholesterol uptake?

Answer 77

Appolipoprotein-A

Question 78

What does LDL-C do?

Answer 78

Bring cholesterol from liver to most cells

Question 79

What does HDL do?

Answer 79

Transport cholesterol out of plasma

Question 80

What is oxidized LDL taken up by? Where to?

Answer 80

Taken up by macrophages into atherosclerotic plaques

Question 81

What is deamination?

Answer 81

The removal of the amino group from an amino acid, creating ammonia and an organic acid

Question 82

What is atherosclerosis?

Answer 82

Atherosclerosis is a disease in which plaque builds up inside your arteries

Question 83

What is TCZ and TNZ?

Answer 83

Themoneutral zone and thermal comfort zone

Question 84

What occurs during the thermal comfort zone?

Answer 84

Shivering thermogenesis

Question 85

What occurs during the thermal neutral zone?

Answer 85

Non-shivering thermogenesis

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