Digestive System

Question 1

What are the universal building blocks of food?

Answer 1

Amino acids and monosaccharides

Question 2

What are the 4 things that happens to food in our digestive tract?

Answer 2

Ingestion of nutrients in food, digestion of large molecules into small ones, absorption of nutrients into cells of digestive tract then into blood and defecation or elimination of undigested residue

Question 3

What are the 2 anatomical divisions of the digestive system?

Answer 3

Digestive tract and accessory organs

Question 4

What makes up the digestive tract?

Answer 4

Oral cavity, pharynx, oesophagus, stomach, small intestine and large intestine

Question 5

What makes up the accessory organs?

Answer 5

Teeth, tongue, salivary glass, liver, gall, bladder and pancreas

Question 6

What is gastroenterology?

Answer 6

Study of stomach and intestines

Question 7

What is proctology?

Answer 7

Study of rectum and anus

Question 8

What are the 3 steps of digestion?

Answer 8

Mechanical processing
Chemical breakdown
Secretion

Question 9

What is mechanical processing?

Answer 9

Tearing and crushing with teeth
Squashing and compaction by tongue
Swirling, mixing and churning of stomach and intestines

Question 10

How does chemical breakdown happen?

Answer 10

By digestive enzymes

Question 11

What does secretion involve?

Answer 11

Release of water, acids, enzymes, buffers and salts by GU tract and glandular organs

Question 12

What makes the submucosa layer different to mucosa layer?

Answer 12

It has larger bv, lv, distensibility and elasticity and makes up submucosa plexus nerve network

Question 13

What is the muscularis externa layer of GI tract wall?

Answer 13

Major SMC coat made up of both circular MC to decrease diameter and longitudinal MC to propulse/ mix

Question 14

What is serosa membrane of GI tract wall?

Answer 14

Membrane that lines body cavity and is no open to external surface

Question 15

What are the structural variations in muscularis externa?

Answer 15

Stomach contains additional internal oblique muscle layer

Upper oesophagus and sphincters of anus consists of skeletal muscle fibres

Question 16

What are the structural variations in serosa layer?

Answer 16

It is continuous with mesentery in most places and mesentery suspends digestive organs from inner wall of abdominal cavity

Question 17

What are the 3 major types of glands associated with GI tract?

Answer 17

Unicellular mucous glands in mucosa
Multicellular glands in mucosa and submucosa
Multicellular accessory glands outside GI

Question 18

What are functions of mouth?

Answer 18

Ingestion 
Taste and other sensory responses to food
Mastication 
Chemical digestion
Deglutition
Speech 
Respiration

Question 19

Where are intrinsic salivary glands found?

Answer 19

Dispersed amid oral tissues. Found in lingual, labial and buccal

Question 20

What do intrinsic salivary glands do?

Answer 20

They produce small amounts of saliva whether you eat or not

Question 21

What is saliva secreted from intrinsic salivary glands made up of?

Answer 21

Lingual lipase and lysozymes that moisten mouth and inhibit bacteria

Question 22

Where are extrinsic salivary glands found?

Answer 22

Outside of mucosa

Question 23

What are the 3 pairs that make up the extrinsic salivary glands?

Answer 23

Submandibular, parotid and sublingual

Question 24

What do sublingual extrinsic salivary glands produce?

Answer 24

Salivary mucus and thinner fluid made up of amylase and electrolytes

Question 25

What is saliva made up of?

Answer 25

99. 4% water
100. 6% electrolytes, buffers to keep pH around 7, glycoproteins, antibodies that control bacteria , enzymes and waste products

Question 26

What does lysozyme in saliva do?

Answer 26

It is antibacterial

Question 27

What does amylase in saliva do?

Answer 27

Turns polysaccharides into disaccharides

Question 28

What controls salivary secretion?

Answer 28

Constant stimulation by parasympathetic nerve endings working from a trigger reflex when there is an object in that mouth

Question 29

What is formed when stomach begins chemical digestion of proteins and small amounts of fat?

Answer 29

Chyme

Question 30

Where does most digestion occur?

Answer 30

In small intestine

Question 31

What are the 4 regions of the stomach?

Answer 31

Cardiac, fundus, body and pyloric sphincter

Question 32

What are all portions of the stomach lines by?

Answer 32

Simple columnar epithelium producing a carpet of protective mucus