Oral and esp PHYS-Prunske Flashcards
Define Achalasia
failure of lower esophageal sphincter to relax
define Aspiration
inhalation of oropharnygeal or gastric contents into the respiratory track
Define Gastroesophageal Reflux Disease
heartburn due to inappropriate closure of lower esophageal sphincter allowing stomach contents to reflux into the esophagus
Define Deglutition
swallowing
DEfine Dysgeusia, results from?
distorted ability to taste, can be due to infection, aging, and nutritional deficiencies
Define Dysphagia
difficulty swallowing
Define Halitosis
bad breath
Define Manometry
test to measure pressure in GI tract
Define Mastication
chewing
Define Xerostomia
dry mouth-sign of sjorerns sydrome
Saliva is secreted by what?
Acinus
Saliva contains…
- Water
2. Digestive Enzymes: salivary α-amylase (ptyalin), lingual lipase, RNAase, DNAase
3. Mucins lubricate and protect oral mucosa - Defense molecules: Lysozyme, IgA, lactoferrin, peroxidase, defensins
5. Epidermal and nerve growth factors. - Bicarbonate-BASIC PH!
7. Sex steroids
Why do we think saliva may have endocrine (besides just exocrine) functions as well?
some salivary substances are also secreted into the blood
What controls the flow rate of saliva?
myoepithelial cells- they contract to control flow!
What is the salvia compostion of the parotid gland?
entirely serous (25% volume),
What is the salvia compostion of the Submandibular gland
mixed (70% volume)
What is the salvia composition of the sublinguial gland
mainly mucous (5% volume)
Where are the minor salivary glands?
in lips, cheek, and tongue
At fast flow rates what does the saliva represent?
saliva resembles plasma with higher HCO3 so Na high, CL high, K low
At slow flow rates what does saliva represent
the duct have time to make significant changes in ionic concentration but do not alter volume as ducts are impermeable to water.
Is the inhibitition of the salivary glands during sleep, fear, and fatigue due to sympathetics
No
What is the pathway of the parasympathetic pathway with the otic ganglion?
(distention, esophagitis, vomiting, or taste, smell ect)-salivary gland of the mediually-parasympathetics-otic ganglion releases ACH-parotid
What is the pathway of the parasympathetic pathway with the submandibular gland
(distention, esophagitis, vomiting, or taste, smell ect)-salivary gland of the mediually-parasympathetics-submandibular ganglion releases AcH-submandiulbar gland
Do you have secretions even with an empty mouth>
yes
Again whats the most important regulatory element of salivary secretion?
Parasypmathetics,
What does the paraysmpathetics NS act though?
through VIP and acetylcholine on muscarinic receptors to increase secretion of watery saliva.
What is the result of the parasympathetics
Increase volume of salivary secretion at the acinus
Increases secretion of enzymes and mucus
Increases the rate of bicarbonate secretion within the ducts
Stimulates glandular metabolism and growth
Increases blood flow to the gland (bradykinin)!!!
What does the sympathetic NS act though?
NE on B1 and alpha1 receptors to increase secretion of VISCOUS salivia
What are the actions of the SNS in regards to the
Stimulates secretion of enzymes and mucus
Stimulates glandular metabolism and growth
Stimulates contraction of myofibroblasts
Constricts blood vessels, decreases blood flow resulting in viscous saliva.
Where is salivary amylase found? what is it activated by?
oral cavity! CL in salvia and hydrolyzes -1,4 glycosidic linkages in starch. Active until acid penetrates the bolus in the stomach
Why is salvary amalyse important in neonates
they have decreased pancretic insufficiency
What does lingual lipase do?
breaks down triglycerides in the oral cavity
Where do taste cells and support cells join?
Near apical surface by tight junctions
What is the path of taste ligands?
They bind to receptor G protien, activate secondary messengers, release neurotransmitters onto primary sensory neurons
Taste perception goes to what in the brain?
nucleus tractus solitarius leading to gastric acid secretion
Whats important about Buccal and sublingual absorption of drugs
avoids first-pass metabolism, potential vaccine
Reasons for too little salivia production aka Xerostoma?
- SjÖgren syndrome- autoimmune disorder that destroys exocrine glands
- Many medications: muscarinic antagonists, decongestants, and antihistamines
- Secondary to head and neck radiation
- Dehydration due to diarrhea, vomiting, fever, diuretics
- Sialolithiasis (submandibular)
- Nerve damage related to injury or diabetes
- Postmenopausal hyposalivation
What are some consequnces of dry mouth?
Increased likelihood of opportunistic infections (mumps parotid gland)
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>Poor nutrition
Treat dry mouth?
muscarinic agonist
Gum, artificial saliva, switch medicines
Parasympathomimetics like pilocarpine
stimulate flow but also cause hypotension,
respiratory distress, and gastrointestinal disorder
A small bolus can be swallowed involuntarily or voluntarily?
Both, involuntary reflex is initiated by mucosal mechanoreceptors but can be overridden voluntarily (swallow pill) but subsequent events are involuntary.
What nerves transmit the mucosal mechanoreceprot signal? Where do they go?
glossopharyngeal (CN 9) and vagus nerves to the medullary swallowing center in the brain stem
What regulates contraction in the upper 1/3 of the esophagus
Somatic nerves cause contraction (Ach- nicotinic) of striated muscles in the UES and top third of the esophagus
What regulates contraction in the lower 2/3 of the esophagus
Autonomic nerves regulate smooth muscle- Ach on nicotinic and muscarinic
Why are the spincters closed in the esophagus usually?
because of the low pressure environment, to prevent air and gastric contents from entering
Whats the purpose of the nasopharynx?
prevent bolus from entering the nasal cavity
Whats the purpose of the oropharynx?
contraction propels bolus into esophagus
Whats the purpse of the Hypopharynx/Laryngopharynx
relax, segregate food and air
How long does the Oral and pharyngeal phases take
less than 1 sec
What action of the tongue triggers the swallowing reflex?
the tongue contacting the hard palate pushes the bolus against the soft palate-SWALLOW
Is peristalsis necessary to move a liquid bolus?
yes
what happens to breathing when you swallow?
it stops also the Longitudinal muscles of posterior pharynx contract Epiglottis folds down to prevent material fromentering the trachea. Relaxation of cricopharyngeal muscle leads to opening of distal pharynx and upper esophageal sphincter.
What is the most common kind of diverticulum>
Zenker
What can lead to Dysphagi?/Odynophagia
structural abnormalities (esophageal cancer or diverticula) functional abnormalities (stroke leading to neural disorder)
What bad things can happen from Dysphagia/Odynophagia
aspriration, malnutrition
What happens to the pressure in the esophaus during swallowing?
Before swallowing, sphincter pressures are higher than atmospheric and fall during a swallow, ssophageal pressure increases as the peristaltic wave sweeps down the esophagus
about 10 sec
distention or change in pH causes mechanorectoprs to do what?
either contract via ACh or relax via NO/VIP
What is different about cold boluses moving through?
propelled with greater force but more slowly
What controls esophageal peritstalsis?
long and short reflexes-para and enteric neuron
The circular muscles in the esophagus constrict where in regards to the bolus? What binds and activates them?
UPSTREAM from the bolus ( AcH) and relax down steam (NO) Vagal efferents
The relaxation and constriction of the longitudinal muscles is the same or different as the circular muscles in the esophagus?
Different-opposite of the circular muscles- constricts downstream and relaxes upstream
What happens when a bolus gets stuck?
Secondary peristalsis
What kind of muscle participates in secondary peristatlsis?
smooth muscle only
What is the cause of secondary peristatlsis? What nerves respond?
elicited by distension of esophagus or acid in the esophagus, enteric neurons produce a very strong peristaltic wave starting just above the obstruction
Retrograde movements require what to be relaxed?
UES and LES, but thats it!
What are diffuse esophageal spasms
uncoordinated contractions can cause the regurgitation of food or liquids
What is a nutcracker esophagus
painful contractions
What does the control of LES depend on?
ENTERIC PLEXUS neurons, closed b/t swallows due to AcH, relaxed durign swallows due to NO and VIP
What are some factors that increase tone in the LES?
protien, ACH, phenyephrine, 5HT, gastrin, substance P, motilin, neuropeptide Y, ect
What is Gastro-Esophageal Reflux Disease (GERD)
reflux of acidic gastric contents into the esophagus due to relaxation of lower esophageal sphincter
Whats the mild reflex of GERD feel like?
heartburn
Whats severe reflux of GERD feel like?
REAL BAD- get epithelial erosion, Barrett’s esophagus
TX of GERD?
Elevation of bed, change in diet?, Proton pump inhibitors and antacids
What are some contributing factors to GERD
Obesity, Pregnancy (increased progesterone), Eructation, and Hiatal Hernia
How does belching/eructation contribute to GERD?
swallowed air builds up in the stomach opens LES, larynx rises to prevent aspiration, diaphragm decends, increase abdominal pressure and decreased chest pressure, air moves from stomach to esophagus and opens up UES
Excessive belching may be related to?
Unconsciously walling air=aerophagia
What is Achalasia
failure of the LES to relax, get regurgitation, dysphagia of solids
What cells are lost due to achalasia?
MYENTERIC gangilon cells- lack of NO synthase
What would you see on an barium X-ray for a patient who had achalsia?
“birds beak”
