saliva and swallowing

Question 1

normal pH of saliva

Answer 1

7.2

Question 2

purpose of saliva

Answer 2

lubrication of chewing, swallowing and speech

oral hygiene - washes away food so bacteria can’t use it - immunity -
solvent for taste

Question 3

what structures pass through the parotid gland?

Answer 3

facial nerve
external carotid
reteromandibular vein

Question 4

what types of glands are
A. parotid
B. sublingual
C. submandibular

Answer 4

A = serous
B = mainly mucous
C = mixed seromucous

Question 5

what are the histological features of a serous gland

Answer 5

dark staining
nucleus in basal third
small central duct

Question 6

what do serous glands secrete

Answer 6

H2O and alpha amylase

Question 7

what are the histological features of mucous glands

Answer 7

pale staining - ‘foamy’
nucleus at base
large central duct

Question 8

what do mucous glands secrete

Answer 8

secrete mucous - H2O and gylcoproteins

Question 9

what innervates the parotid gland

Answer 9

glossopharyngeal

Question 10

what innervates the sublingual and submandibular glands

Answer 10

facial nerve - chorda tympani

Question 11

what are the histological features of the submandibular gland?

Answer 11

both serous and mucous acini

arranged in demi lunes

Question 12

what do intercalated ducts cells look like and what are their function?

Answer 12

• short, narrow and cuboidal

- connects the acini to the striated duct cells

Question 13

what do the striated duct cells look like and what are their function?

Answer 13

-striated at basal end, highly folded into microvilli for active transport of HCO3- against conc gradient into the cell
-have many mitochondria in for the above
Function = absorb Na+ and Cl- from lumen and secrete HCO3- & K+ into the lumen causing the final saliva to be hypotonic

Question 14

There are three stages of swallowing, which are voluntary and which are involuntary?

Answer 14

1. voluntary
2. involuntary
3. involuntary

Question 15

describe the first stage of swallowing.

Answer 15

voluntary
-food is compressed against the roof of the mouth forming a bolus.

-the bolus is moved towards the oropharynx by the action of the tongue

Question 16

describe the second stage of swallowing

Answer 16

involuntary

• the phraynx is shortened and widened by the elevation of the hyoid bone done by the suprahyoida
• the nasopharynx is closed of by the soft palate

Question 17

describe the third stage of swallowing

Answer 17

involuntary

• sequential contraction of the constrictor muscles of the pharynx
• followed by the depression of the hyoid bone and pharynx (everything returns to normal)

Question 18

what is the gag reflex and what causes it to take place?

Answer 18

reflex elevation of the pharynx often followed by vomiting caused by the irritation of the oropharynx

Question 19

what is the reflex arc of the gag reflex?

Answer 19

glossopharyngeal - afferent

vagus - efferent