Digestive system

Question 1

What are the components of the digestive system?

Answer 1

mouth, pharynx, oesophagus, stomach, small intestines, large intestines and anus.

Question 2

What accessory organs does the D.S have?

Answer 2

salivary glands, teeth, liver, gallbladder and pancreas.

Question 3

What is the function of the D.S

Answer 3

• Physical and chemical breakdown of food
  ● Absorption of nutrients
  ● Elimination of waste

Question 4

What is the alimentary canal?

Answer 4

-Continuous hollow tube
-Approximately 30 ft long in cadavers
-Food is always considered external
-Tissues similar along length of canal with slight modifications to aid digestion (mechanical/chemical)
-Goes all the way through the body

Question 5

What are the two layers of muscle in the alimentary canal?

Answer 5

Two layers of mostly smooth (involuntary) muscle: —Inner circular layer and Outer longitudinal layer –

Question 6

what is peristalsis and what causes it?

Answer 6

The mixing and pushing of contents along, and waves of contraction causes this.

Question 7

What acts as valves in the alimentary canal?

Answer 7

-Sphincters of thickened circular muscle at points to act as valves.

Question 8

What is the purpose of the mouth/pharynx?

Answer 8

starts the process of chemical and mechanical digestion. Mixing food with enzymes and making food swallowable.

Question 9

What are the mouths/ oral cavity boundaries?

Answer 9

Anteriorly – lips, posteriorly – oropharyngeal isthmus, laterally – cheeks / buccal surfaces (buccinators muscle), Superiorly – palate (hard/soft), Inferiorly - tongue and floor

Question 10

What is the floor of the mouth?

Answer 10

Formed by mylohyoid and geniohyoid muscles (mandible to hyoid). U-shaped diaphragm. Supports tongue

Question 11

What is the hard palate of the mouth?

Answer 11

Anterior 2⁄3. Made of Maxilla and palatine bones.

Question 12

what is the soft palate of the mouth?

Answer 12

Posterior 1⁄3. Mobile muscular fold. Uvula – fold of muscle; saliva, speech, gag reflex

Question 13

What is the tongue and its function?

Answer 13

Accessory organ. Functions in mastication (mechanical breakdown of chewing), swallowing, speech and taste. Base attached to hyoid bone and to floor by lingual frenulum. Skeletal muscle fibres (intrinsic and extrinsic).

Question 14

what does mastication mean?

Answer 14

(mechanical breakdown of chewing),

Question 15

whats the function of teeth?

Answer 15

Accessory organ. Functions in mastication and speech

Question 16

Whats the function of the salivary glands?

Answer 16

Accessory organs. Three bilateral pairs of glands which release saliva into mouth through ducts. Parotid, submandibular and sublingual – release enzymes to form chemical break down of food.

Question 17

What are the 3 parts of the pharynx?

Answer 17

Nasopharynx, oropharynx and laryngopharynx.

Question 18

What is the purpose of the oespohagus?

Answer 18

Purpose - transports food/chyme from mouth to stomach. Resistant to damage
Muscular tube
Begins distally to mouth (oropharynx) around C6
Hardwearing

Question 19

What is the structure of the oesophagus?

Answer 19

Approximately 25cm long and 2cm in diameter
Lies in midline posteriorly to trachea and anteriorly to spine
Passes through diaphragm posterior to central tendon at level of T10 (oesophageal hiatus)

Question 20

what is the purpose of the stomach?

Answer 20

Purpose: mix/ pummel food into chyme (further product of food). Supports further mechanical and chemical digestion

Question 21

what is the regional anatomy of the stomach?

Answer 21

Position, Below diaphragm, left upper quadrant or left hypochondriac region and epigastrum.

Question 22

what are the different sections of the stomach ?

Answer 22

Greater (lateral, convex) and lesser (medial, concave) curvature

Question 23

What is the gross anatomy of the stomach?

Answer 23

• Superiorly, cardia connecting oesophagus to stomach. Cardiac notch. Fundus often demonstrated with gas in.
• Main body - largest section
• Pylorus, inferior, pyloric antrum (superior) and pyloric canal (inferior). Pylorus continuous with duodenum.

Question 24

what is the S.I and what is its purpose?

Answer 24

Muscular tube stretching from pyloric sphincter to ileocaecal sphincter at large intestine
Longest section of digestive tract
Purpose: prepare food so that it can be absorbed through the cells in the body- GI Tract.

Question 25

What are the 3 divisions of the S.I?

Answer 25

Duodenum (5%) Jejunum (40%) Ileum (55%)