Mouth

Question 1

Composition of saliva

Answer 1

Contains: h2o, na, cl, K, hco3, amylase, bacteriostats

Acinar cells = volume
Duct cells = modification - remove Na/Cl + secrete K/HC03

Saliva is hypotonic + alkaline

Question 2

Functions

Answer 2

Lubrication
Hydration
Protection
Washes teeth
Immune function - IgA, lysozyme 
Maintains an alkaline enviro

Question 3

Control of secretions

Answer 3

Sympathetic:
Decreased production by acinar cells
Decreased BF to glands

Parasympathetic:
Acinar cells = increased secretion
Duct cells = increased secretion of HC03
Increased BF to glands
Contraction of myoepithelium - increased rate of expulsion of saliva
Overall, increased saliva that is more watery in composition

Question 4

Swallowing phases - oral preparation

Answer 4

Food is chewed and manipulated

Question 5

Swallowing phases - oral phase

Answer 5

Tongue propels food posteriorly until pharyngeal swallow is triggered

Question 6

Swallowing phases - pharyngeal phase

Answer 6

Bolus moved to pharynx - pressure Rs activated in anterior pharynx + palate - signals to swallowing centre in medulla - inhibit respiration, close glottis, raise the larynx, relax the upper oesophageal sphincter

Question 7

Swallowing phases - oesophageal phase

Answer 7

Oesophageal peristalsis carries bolus from cricopharyngeal junction (upper oesophageal sphincter) through oesophagus to lower sphincter