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Flashcards in Physiology of Pharynx/Esophagus Deck (18)
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1

Swallowing

Process by which food and water is transported from the mouth to the stomach
- entire process is about half the length of the body

2

Anatomic phases of swallowing

Oral phase
- oral stage (voluntary control)
- pharyngeal stage (autonomic)
- cricopharyngeal stage (seals top of esophagus)
Esophageal phase
- primary peristalsis (triggered by swallowing)
- secondary peristalsis
Gastroesophagel phase

3

Pharynx

- nasopharynx
- oropharynx
- laryngopharynx

4

What two portions of the pharynx are divided by the soft palate

Nasopharynx and oropharynx

5

What are the 4 pathways food can take?

- nasopharynx (bad)
- reguritating
- laryngopharynx (bad)
- oropharynx (good)

6

Functional phases of swallowing

Preparatory phase: licking, chewing (voluntary)
- oral cavity
Transfer phase: getting food from oral cavity to pharynx (fast)
- oral cavity and pharynx (40 cm/sec)
Transport phase (transport food from esophagus to stomach)
- esophagus (3-4 cm/sec)

7

Masticatory and facial muscles

- muscles of mastication: trigeminal nerve (5)
- muscles of facial expression: facial nerve (7)

8

Muscles of the tongue

Hypoglossal nerve (12)

9

Muscles of the pharynx

Cranial nerves (9, 10, 11)
- 9 and 11 only serve the pharynx
- 10 serves all phases of swallowing

10

Muscles of the larynx

Recurrant laryngeal nerve, a branch of vagus (10)

11

Adduction

Closing of the larynx during swallowing
- vagus supplies the pharynx, larynx, and esophagus and both sphincters
- vagus is predominantly involuntary

12

What functional phases of swallowing involve the involuntary swallowing reflex

Transfer and transport phase

13

What nerves are involved in the preparatory phase

5, 7, 12

14

Upper esophageal sphincter

Cricopharyngeal muscle
- striated skeletal muscle
- is a highly tight sphincter, only opens when you need it

15

Lower esophageal sphincter

Not a true sphincter in dogs and cats
- considered a physiological sphincter
- gravity alone will drop food into stomach in dogs and cats due to lateral positioning

16

Species differences of the esophagus

Canine
- straited muscle along entire length
- Ach as neurotransmitter and nicotinic receptors
Feline
- proximal 2/3 striated muscle
- distal 1/3 smooth muscle
- muscarinic and parasympathetic nerve supply, Ach is still receptor

17

Primary peristalsis

Reflex peristaltic contraction wave associated with pharygeal phase of swallowing

18

Secondary peristalsis

Reflex peristaltic contraction wave triggered by residual food in the esophagus