Physiology of Mouth, pharynx and oesophagus Flashcards Preview

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Flashcards in Physiology of Mouth, pharynx and oesophagus Deck (22)
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1

What are the functions of saliva?

Lubricates food for swallowing
Helps with taste
Digestion (starch and lipids)
Protects oral cavity (destroy bacteria, alkaline environment)

2

How much saliva is produced each day?

800 - 1500ml each day

3

What is the pH range for saliva?

pH 6.2 - 8.0

4

Is saliva hypotonic or hypertonic?

Hypotonic

5

If a solution has high osmolarity/osmolality, does it have high or low concentration?

High concentration

6

What ions is saliva composed of?

High [K+], [HCO3-] and [Ca2+] (relative to plasma)
Low [Na+] and [Cl-] (relative to plasma)
thiocynate ions (antibacterial)

7

What enzymes is saliva composed of?

Digestive enzymes – salivary α-amylase, lingual lipase
Antibacterial agents – thiocynate ions, proteolytic enzymes (e.g. lysozyme), antibodies

8

What is the difference between serous and mucous saliva?

Serous - has enzymes
Mucous - no enzymes

9

Describe the structure of salivary glands.

Bunch of grapes appearance
Initial secretion by acini (lined by acinar cells). Ducts (lined by duct cells) modify this secretion. Myoepithelial cells contract to eject saliva

10

What modifications happen at the ducts for saliva production?

Absorption of Na and Cl from saliva
Secretion of K and HCO3 into saliva
Ductal cells impermeable to water, so saliva is hypotonic

11

What occurs in primary secretion of saliva production?

Isotonic ultrafiltrate from plasma diffuses through acinar cells.
Mixes with enzymes or mucins and drains into ducts

12

What type of saliva is highly modified (resting or stimulated)?

Resting - very hypotonic and neutral pH. Slaiva flow rate is lower and so more time for ductal modification

13

Which ion is selectively stimulated when saliva production is stimulated?

HCO3 - (increases with increasing flow rate)

14

What is xerostomia?

Dry mouth

15

What are some causes of xerostomia?

dehydration, side effects, radiation therapy, Sjögren’s syndrome (autoimmune destruction of salivary and lacrimal glands)

16

What are the 5 taste classifications?

Sweet, sour, bitter, salty and umami

17

What kind of receptors are taste receptor cells?

Chemoreceptors

18

What is the lower oesophageal sphincter? and its function?

Physiological sphincter at the gastro-oesophageal junction
Prevents reflux of gastric contents into the oesophagus
Higher resting basal tone

19

What 4 components form the 'physological sphincter' (Lower oesophageal sphincter)

Right crus of diaphragm
Acute angle of oesophagus entering stomach
Mucosal folds at the junction
+ve intra-abdominal pressure

20

What are the three phases of swallowing?

Oral, pharyngeal and oesophageal

21

What happens in the pharyngeal phase of swallowing?

Soft palate elevates – blocks of nasopharynx
Respiration inhibited
Glottis closes
Larynx elevates
Epiglottis tilts to cover opening of larynx

22

What type of clinician can assess dysphagia?

Speech and language therapists (SALT)