Swallowing + Saliva Flashcards Preview

GI Physiology > Swallowing + Saliva > Flashcards

Flashcards in Swallowing + Saliva Deck (36):
1

Which receptors are stimulated by food or drink?

Pressure receptors in the walls of the pharynx

2

Name the pharyngeal constrictor muscles.

Superior constrictor
Middle constrictor
Inferior constrictor

3

Which nerve supplies the pharyngeal constrictor muscles?

Pharyngeal branch of vagus nerve

4

Which nerve supplies the nasopharynx?

Maxillary nerve (V2 of trigeminal nerve)

5

Which nerve supplies the oropharynx?

Glossopharyngeal nerve

6

Which nerve supplies the laryngopharynx?

Vagus nerve

7

How many stages are there to swallowing? Which ones are voluntary and involuntary?

Stage 1: Voluntary
Stage 2: Involuntary
Stage 3: Involuntary

8

Describe stage 1 of swallowing.

1. Food is compresses against roof of mouth and pushed towards oropharynx by tongue
2. Buccinator and supra hyoid muscles allow chewing of food

9

Describe stage 2 of swallowing.

1. Nasopharynx is closed off by soft palate - helps to form bolus of food
2. Swallowing centre inhibits respiration, raises larynx and closes the glottis - prevents food from entering trachea. Epiglottis covers glottis.
3. Pharynx is shortened and widened by elevation of the hyoid bone

10

What type of muscle surrounds the upper 1/3 of the oesophagus?

Skeletal

11

What type of muscle surrounds the lower 2/3 of the oesophagus?

Smooth

12

Describe stage 3 of swallowing.

1. Pharyngeal constrictor muscles contract to drive the bolus of food down the oesophagus
2. Upper oesophageal sphincter relaxes to let in food. Once food has passed, sphincter closes, glottis opens and breathing resumes
3. Peristaltic waves move food down the oesophagus into the stomach - each wave takes 9 seconds to move food to stomach
4. Lower oesophageal sphincter remains open and relaxed throughout swallowing

13

What is the gag reflex?

The reflex elevation of the pharynx. Caused by irritation of oropharynx. Reflex arc between glossopharyngeal and vagus nerves.

14

Give 3 functions of saliva.

1. Lubricant for mastication
2. Maintains oral PH at 7.4
3. Releases digestive enzymes (alpha amylase) for starch digestion

15

What is released in the serous secretion of saliva?

Alpha amylase

16

What is released in the mucous secretion of saliva?

Mucins for lubrication of mucosal surfaces

17

Which salivary gland secretes serous solution?

Parotid gland

18

Which salivary glands secrete mucous and serous solution?

Submandibular gland
Sublingual glans (mainly mucous though)

19

List the defences of the oral cavity.

1. The mucosa - physical barrier
2. Salivary glands - saliva washes away food with bacteria
3. Palatine tonsils
4. Salivary glands are surrounded by lymphatic system which contains immune cells

20

Name the two key epithelial tissue of salivary glands.

1. Acinar cells (both serous and mucous)
2. Ducts (intralobular and main excretory)

21

Which nerve provides sympathetic innervation of the parotid gland?

Auriculo-temporal nerve - a branch of the mandibular nerve (a branch of the trigeminal nerve)

22

Which nerve provides parasympathetic innervation of the parotid gland?

Glossopharyngeal nerve

23

Which structures pass through the parotid?

External carotid artery
Retromandibular vein
Facial nerve

24

Which nerve provides sympathetic innervation of the submandibular gland?

Lingual branch of the facial nerve

25

Which nerve provides parasympathetic innervation of the submandibular gland?

Chorda tympani branch of facial nerve

26

Which nerve provides sympathetic innervation of the sublingual gland?

Lingual branch of facial nerve

27

Which nerve provides parasympathetic innervation of the sublingual gland?

Chorda tympani branch of facial nerve

28

Are the minor salivary glands serous or mucous?

They are all mucous apart from the serous glands of von Eber

29

What effect does parasympathetic innervation have on the salivary glands?

Stimulates salivary secretion

30

What effect does sympathetic innervation have on the salivary glands?

Inhibits salivary secretion

31

What is xerostomia?

Dry mouth - caused by cystic fibrosis, Sjorgren's syndrome. Salivary output falls to <50%.

32

What name is given to stones formed from calcium and phosphate ions in the saliva?

Salivary calculi

33

Where are salivary calculi most common?

Submandibular gland

34

What is the clinical term for the tear ducts?

Lacrimal glands

35

What are the consequences of xerostomia?

Bad oral hygiene. Accumulation of plaque. Increased incidence of opportunistic infections
Poor lubrication

36

Which epithelium lines the lower oesophagus?

Simple columnar