Ingestion

Question 1

What is ingestion?

Answer 1

The process of taking food into the alimentary tract (gastrointestinal (GI) tract), i.e. eating and drinking.

Question 2

what is the first step of mastication

Answer 2

Food is chewed in the mouth (Mastication)

Question 3

what is the second step of mastication

Answer 3

Mastication involves the use of the teeth, the tongue and the muscles of the cheeks.

Question 4

what is the third step of mastication

Answer 4

Food is mixed with Saliva and chewed to form a soft mass or ‘bolus’

Question 5

what is the fourth step of mastication

Answer 5

Saliva produced by salivary glands

Question 6

what is the fifth step of mastication

Answer 6

Saliva contains enzyme – salivary amylase – initial digestion of carbohydrates – some conversion to disaccharides

Question 7

What are the three pairs of salivary glands?

Answer 7

Parotid Glands
Submandibular Glands
Sublingual Glands

Question 8

What does the salivary glands secrete?

Answer 8

saliva

Question 9

What is the salivary glands comprised of?

Answer 9

water 
mineral salts
salivary amylase (a digestive enzyme) 
mucus 
immunoglobulin
lysozyme.

Question 10

How much approx. to produce of saliva a day?

Answer 10

1500mls

Question 11

What are the three stages of swallowing (deglutition)

Answer 11

Oral stage
pharyngeal stage
oesophageal stage

Question 12

What happens in the oral stage

Answer 12

With the mouth closed the voluntary muscles of the tongue and cheeks push the bolus rearwards to the pharynx.

Question 13

What happens in the pharyngeal stage?

Answer 13

The muscles of the pharynx are stimulated and involuntary contraction propels the bolus into the oesophagus.

Question 14

What happens in the oesophageal stage?

Answer 14

The bolus stimulates a ‘wave of peristalsis’ that pushes the food into the stomach.
Oesophagus – mucous glands produce mucus as lubricant
Lower oesophageal sphincter (cardiac Sphincter) – has greater muscle tone – regulation of entry of food into stomach