Tri B - Digestive System

Question 1

Describe the 2 sections of the mouth

Answer 1

The vestibule - outside portion
Lips, cheeks, teeth, gums
The mouth cavity - Oropharyngeal isthmus
Pillars of fauces
Palatine tonsils
Bony hard palate, soft palate
Uvula

Question 2

Describe the tongue

Answer 2

Muscular organ, lies in mouth and pharynx
Papillae concerned with sense of taste

Question 3

What is the function of the tongue?

Answer 3

Sense of taste
Speech
Swallowing

Question 4

Describe the salivary glands

Answer 4

3 pairs - Parotid glands
- Submandibular glands
- Sublingual glands
Secrete saliva through ducts into mouth

Question 5

Describe the pharynx

Answer 5

3 portions - oro-, naso-, laryngo-
Only oro- and laryngo- are in digestive system
Epiglottis stops food entering trachea

Question 6

Describe the Oesophagus

Answer 6

Function - propels food to stomach
Fibromuscular tube ~25cm, 2cm diameter
Starts at C6, passes through diaphragm joins stomach at T11

Question 7

Describe the Oesophageal sphincters

Answer 7

Upper sphincter prevents air passing into oesophagus during inhalation
Lower sphincter prevents acid reflux

Question 8

Describe Peristalsis

Answer 8

Muscular wall contracts and relaxes
Peristaltic waves propel food

Question 9

Describe the peritoneum

Answer 9

Closed sac in abdomen, contains small amount of serum
Organs are covered/pushed into it

Question 10

Describe the stomach

Answer 10

Continuous with oesophagus
Joins duodenum at pyloric sphincter
2 curves, fundus, body, pylorus
Internal mucus membrane, folds/rugae, secrete gastric juice

Question 11

Describe the small intestine

Answer 11

~6m long, 2.5cm diameter
Large surface area for absorption
3 parts - duodenum - 25cm
jejunum - 2 meters
ileum - 3 meters

Question 12

Describe the large intestine

Answer 12

1.5m long, 6.5cm diameter
Forms arch over bowel
Attached to posterior abdominal wall by mesocolon
4 Parts - Caecum
Colon - Ascending, transverse, descending, sigmoid
Rectum
Anal canal

Question 13

Describe the haustra of the large intestine

Answer 13

Small pouches caused by sacculation between bands of muscle

Question 14

Describe the pancreas

Answer 14

Pale grey gland
12-15cm long
Head, body and tail
Pancreatic duct - secretes pancreatic juice
Exo/endocrine functions

Question 15

Describe the liver

Answer 15

Largest gland
4 lobes: right, left, caudate, quadrate
Homogenous
Posterior surface - portal fissure
Secretes bile into gallbladder

Question 16

Describe the biliary system

Answer 16

Bile stored in gallbladder
Left and right hepatic ducts join to form common hepatic duct
Hepatic duct joined by cystic duct to form common bile duct
CBD and pancreatic duct meet at duodenal papilla
Bile drains into duodenum

Question 17

What is bile?

Answer 17

Solution secreted by the liver
Contains bile salts, phospholipids, cholesterol
Breaks down food into fatty acids, for digestion