Oral Esophageal Physio - Pernuske

Question 1

What are some of the secretions in saliva? (7)

Answer 1

1. Water
2. Digestive Enzymes: salivary α-amylase (ptyalin), lingual lipase, RNAase, DNAase
3. Mucins
4. Defense molecules: Lysozyme, secretory immunoglobulin (IgA), lactoferrin, peroxidase, defensins
5. Epidermal and nerve growth factors.
6. Bicarbonate
7. Sex hormones

Question 2

Composition and volume of saliva in glands?
Parotid
Submandibular
Sublingual

Answer 2

Composition of saliva is slightly different from each of the glands
Parotid – entirely serous, watery (25% volume)
Submandibular- mixed (70% volume)
Sublingual – mainly mucous (5% volume)

Question 3

What is the difference between serous and mucous secretion?

Answer 3

Serous (watery, amylase)

Mucous (mucin) cells contain serous demilunes

Question 4

Why is saliva alkaline?

Answer 4

Neutralize acidic emesis and low pH from bacteria undergoing fermentation.

Question 5

What are some ions that are secreted by salivary duct cells?

Answer 5

Salivary duct cells secrete K+, HCO3-, Ca++, Mg++, phosphate to prevent demineralization of the tooth enamel and are impermeable to water

Question 6

Describe the roles of parasympathetic and sympathetic activation in saliva production. What nerves are involved? What NTs are involved?

Answer 6

Parasympathetic (glossopharyngeal and facial): acts through VIP and acetylcholine on muscarinic receptors to increase secretion of watery saliva.

Sympathetic (cervical sympathetic chain) acts through norepinephrine on β1- and α1 adrenergic receptors to secretion of viscous saliva

Question 7

What are some factors that inhibit saliva production?

Answer 7

Sleep, fatigue, and fear.

Question 8

What are the functions of salivary amylase and lingual lipase?

Answer 8

Salivary amylase: activated by Cl- in saliva and hydrolyzes alpha-1,4 glycosidic linkages in starch. Active until acid penetrates the bolus.

Lingual lipase: breaks down triglycerides

Question 9

What are some causes of too little salivary secretions?

Answer 9

• SjÖgren syndrome- autoimmune disorder that destroys exocrine glands
• Many medications: muscarinic antagonists (antidepressants and opiate analgesics)
• Secondary to head and neck radiation
• Dehydration due to diarrhea, vomiting, fever, diuretics
• Sialolithiasis (submandibular)
• Nerve damage related to injury or diabetes
• Postmenopausal hyposalivation

Question 10

Consequences of dry mouth?

Answer 10

Increased likelihood of opportunistic infections
Halitosis due to production of hydrogen sulfide by bacteria and accumulation of dead cells
Decrease in oral pH leads to tooth decay
Decrease in taste
Problems with speech
Dysphagia> Malnutrition

Question 11

Treatment for dry mouth?

Answer 11

Gum, artificial saliva, switch medicines
Parasympathomimetics (pilocarpine)
stimulate flow but also cause hypotension,
respiratory distress, and gastrointestinal disorder

Question 12

A patient is tested for dry mouth. How are they tested and what is the normal threshold level of saliva production?

Answer 12

Sialometry
(Stimulate with citric acid)
Normal >1 mL/min
Sialochemistry

Question 13

Mucosal mechanoreceptors transmit message through [ ] and [ ] nerves to the medullary swallowing center in the brain stem.

Answer 13

Mucosal mechanoreceptors transmit message through glossopharyngeal and vagus nerves to the medullary swallowing center in the brain stem.

Question 14

Somatic nerves cause contraction (Ach- nicotinic) of striated muscles in the [ ].

Answer 14

Somatic nerves cause contraction (Ach- nicotinic) of striated muscles in the UES and top third of the esophagus

Question 15

Autonomic nerves regulate smooth muscle in the bottom two thirds of esophagus - Ach on [ ] and [ ].

Answer 15

Autonomic nerves regulate smooth muscle in the bottom two thirds-
Ach on nicotinic and muscarinic

Question 16

Relaxation of cricopharyngeal muscle leads to what and how is it innervated?

Answer 16

Relaxation of cricopharyngeal muscle
(innervated by vagus CN. X)
leads to opening of distal pharynx and
upper esophageal sphincter.

Question 17

Mechanoreceptors sense distension or changes in pH leading to contraction [NT] above and relaxation [NT] below.

Answer 17

Mechanoreceptors sense distension or changes in pH leading to contraction (ACh) above and relaxation (NO/VIP) below.

Question 18

Secondary peristalsis is restricted to what type of muscle? What is it caused by?

Answer 18

Secondary Peristalsis- restricted to smooth muscle, elicited by distension of GI tract or acid in the esophagus
-enteric neurons produce a very strong peristaltic wave starting just above the obstruction

Question 19

With respect to force and speed, how are larger or colder boluses propelled?

Answer 19

Larger or colder boluses are propelled with greater force but more slowly.

Question 20

What is the connection between the vagus and the lower esophageal sphincter?

Answer 20

Control of the Lower Esophageal Sphincter: depends on enteric plexus neurons-closed between swallows due to cholinergic neurotransmission-relaxed during swallows due to NO and VIP neurotransmission
Vagal tone releases ACh to contract (close) LES.

Question 21

Causes of GERD? (4)

Answer 21

Causes of GERD: Obesity, Pregnancy (increased progesterone), Eructation, and Hiatal Hernia (diaphragmatic hiatus widens with age)

Question 22

What is achalasia?

Answer 22

Achalasia- failure of lower esophageal sphincter to relax and in some cases lack of proximal peristalsis

Question 23

What does venouse drainage of the esophagus form? Where does it drain to?

What is a key portal HTN pathological finding?

Answer 23

Venous drainage of esophagus forms a submucosal venous plexus that drains directly into systemic circulation
The plexus anastomoses with veins in the stomach that drain into hepatic portal system.
During portal hypertension gastric blood diverts to form varices.