Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI Week 1 - WLB > Oral & Esophageal Physiology - A.Prunuske > Flashcards

Oral & Esophageal Physiology - A.Prunuske Flashcards

1
Q

What is the function of saliva production?

A
  • Digestive:
    • -Contains amylase => initiates digestion of Carbs
    • -Lipase
    • -Swallowing
    • -Bolus formation
  • Protective:
    • -contains IgA => antimicrobial actions
    • -Lubrication
    • -Cleansing
    • -Dilution
  • Other:
    • -Speech
    • -Excretion
    • -Grooming
    • -Thermoregulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What glands contribute to saliva production?

A
  • Salivary glands:
    • Serous (watery, amylase)
    • Mucous (mucin) cells contain serous demilunes
    • Secreted by lobulated exocrine gland
    • Acinus and ionic content modified by duct cells.
    • Parotid – entirely serous, watery (25% volume)
    • Submandibular- mixed (70% volume)
    • Sublingual – mainly mucous (5% volume)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the causes of too little saliva production?

A
  • -Sjrogren’s 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 (blocked submandibular gland)
  • -Nerve damage related to injury or diabetes
    • Postmenopausal hyposalivation
  • -Cystic fibrosis
  • -Methamphetamines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the consequences of too little saliva production?

A
  • -Dry mouth
  • -Difficulty swallowing
  • -Increased likelihood of opportunistic infections
  • -Halitosis (bad breath) => 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 (swallowing issues) => Malnutrition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What processes of digestion occur in the oral cavity?

A
  • -Mastication- mechanical digestion by teeth and tongue
  • -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
  • -Salivary enzymes increased during pancreatic insufficiency and in neonates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the main muscles of the Lips?

A

Obiularis ori

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the main muscles of the Cheek?

A

Buccinator - positioning of the food in the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the main muscles of Mastication?

A

Masseter and Temporalis (raise mandible)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the main muscles of Opening the jaw and grinding?

A

Pterygoid Muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the main nerve that innervates the muscles of chewing?

A

Trigeminal Nerve (CN V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 7 secretions contained in Saliva?

A
  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
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How much saliva does a typical human produce per day?

A

Total 1.5 L/ day and myoepithelial cells control flow rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why is saliva an alkaline solution?

A
  • -If you vomit or reflux acid from the stomach, it will neutralize it.
  • -Neutralize acid produced by bacteria.
  • -Salivary duct cells secrete K+, HCO3-, Ca++, Mg++, phosphate to prevent demineralization of the tooth enamel and are impermeable to water
  • -When food is consumed, carbohydrates are fermented by bacteria producing lactic acid (pH of oral cavity 6.3).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What regulates saliva production?

A
  • Salivatory nucleus of medulla interprets external stimuli.
  • Parasympathetic (glossopharyngeal and facial): acts through VIP (vasoactive inhibitory protein) 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
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What external stimuli stop saliva production?

A
  • -Fear
  • -Fatigue
  • -Sleep
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the primary (5) elementary qualities are detectable by taste buds?

A
  • Salty, sour, sweet, bitter, umami.
  • Myth that certain regions of tongue detect certain elements.
  • Taste buds are made up of taste cells and support cells joined near the apical surface by tight junctions.
17
Q

What kind of sensory receptors are located on the tongue?

A
  • Taste, Pain, and Temperature receptors
  • Taste ligands bind to receptors activating G-proteins and secondary messengers release neurotransmitters onto primary sensory neurons.
  • Taste signals to nucleus tractus solitarius leading to gastric acid secretion.
18
Q

What processes of absorption occur in the oral cavity?

A
  • -Little nutrient absorption
  • -Buccal and sublingual absorption of drugs (glyceryl trinitrate), avoids hepatic first-pass metabolism
19
Q

What is Xerostomia?

A

subjective sensation of dryness of the oral mucosa

20
Q

How do you measure saliva production?

A
  • Sialometry:
    • Collect baseline saliva, then => Stimulate with citric acid
    • (Normal >1 mL/min)
    • Sialochemistry
21
Q

How do you treat/manage inadequate saliva production?

A
  • -Gum, artificial saliva, switch medicines
  • -Parasympathomimetics (pilocarpine) => stimulate flow
    • but also cause hypotension, respiratory distress, and gastrointestinal disorder
22
Q

When does Swalloing or Deglutition occur?

A
  • -When bolus is small enough (2 cm) an involuntary reflex is initiated by mucosal mechanoreceptors
  • -Can be voluntarily overridden voluntarily (swallow pill) subsequent events are involuntary.
23
Q

How is swallowing coordinated with respiration & speech?

A
  • Central Input:
    • -Mucosal mechanoreceptors transmit message through glossopharyngeal and vagus nerves to the medullary swallowing center in the brain stem
    • -Somatic nerves cause contraction (Ach- nicotinic) of striated muscles in the UES and top third of the esophagus
    • -Autonomic nerves regulate smooth muscle in the bottom two thirds => Ach on nicotinic and muscarinic
24
Q

What happens when swallowing is unsuccessful?

A
  • -Choking: aspirate into trachea, bolus gets stuck
  • -Reflux out nose
25
Q

How does the pharynx assist in Deglutition?

A
  • Nasopharynx- prevent bolus from entering the nasal cavity
  • Oropharynx- contraction propels bolus into esophagus
  • Hypopharynx/Laryngopharynx- relax, segregate food and air
26
Q

Plunging action of the tongue is most important. Damage to which nerve would interfere with this tongue function?

A

Hypoglossal (CN XII)

27
Q

What is the role of the lower esophageal sphincter in swallowing?

A
  • 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
28
Q

What is the neural control of primary peristalsis?

A
  • long and short reflexes- involving parasympathetic nerves and enteric neurons
  • Circular muscles contract upstream of the bolus and relax downstream
    • while longitudinal muscles relax upstream and contract downstream
29
Q

What happens if bolus becomes stuck during primary peristalsis?

A
  • 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
30
Q

What happens with retrograde movements in the esophagus?

A
  • eructation, vomiting, and regurgitation
    • -require relaxation of the upper and lower sphincters, but do not require additional esophageal movements
31
Q

What are the three steps in swallowing?

A
  1. Tongue contacting the hard palate pushes bolus against soft palate triggering swallowing reflex. Soft palate elevates, closingoff the nasopharynx. Larynx moves up and forward. Tonically contracted upperesophageal sphincter
  2. Breathing is inhibited as the bolus passesthe closed airway. Longitudinal muscles of posterior pharynx contract. Epiglottis folds down to prevent material fromentering the trachea. Relaxation of cricopharyngeal muscle (innervated by vagus CN. X) leads to opening of distal pharynx and upper esophageal sphincter.
  3. Food moves downward into the esophagus, propelled by peristaltic waves and aided by gravity.
32
Q

How does sword swallowing work?

A
  • -Need to hyperextend neck
  • -Inhibit pharyngeal reflex
  • -Flip epiglottis
  • -Relax upper and lower esophageal sphincters
33
Q

What condition results when you get significantly increased Lower Esophageal Sphincter?

A

Achalasia (impaired relaxation)

34
Q

What condition results when you get significantly decreased Lower Esophageal Sphincter?

A

GERD

35
Q

What is GERD?

A
  • Gastro-Esophageal Reflux Disease (GERD) - reflux of acidic gastric contents into the esophagus due to relaxation of lower esophageal sphincter.
    • Reflux- normal physiologic process cleared by peristalsis
    • Mild reflux - heartburn
    • Severe reflux - epithelial erosion, Barrett’s esophagus
36
Q

What are some of the potential causes of GERD?

A
  • Obesity
  • Pregnancy (increased progesterone)
  • Eructation
  • Hiatal Hernia (diaphragmatic hiatus widens with age)
37
Q

How do you treat GERD?

A
  • -Elevation of bed
  • -Diet changes
  • -Proton pump inhibitors
  • -Antacids
38
Q

What is Achalasia?

A
  • -Failure of lower esophageal sphincter to relax and in some cases lack of proximal peristalsisregurgitation, dysphagia of solids
  • -Dilation of esophagus and “bird beak” on swallow study
  • -Loss of myenteric ganglion cells
39
Q

How might treating Achalasia with botulinum toxin be an effective strategy?

A

Inhibits ACh stimulation (allows relaxation of LES)

GI Week 1 - WLB (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions