GI! Flashcards
Why are the salivary ducts important?
- they can become obstructed causing pain
- parotid gland secretes mucus and amylase
- submandibular and sublingual glands are more serous fluid
Why are the sublingual veins important clinically?
sublingual meds absorbs here
What is the anatomical importance of the uvula?
it closes off the nasopharynx
- if the uvula is surgically removed, food can reflux into the nasopharynx
What is the anatomical importance of teh anterior and posterior arches (palatoglosssal and palatopharyngeal) surrounding the palatine tonsil?
Accidentally removing them can cause speech impediments
Which salivary duct becomes obstructed most often
Stensen’s duct is the most frequent salivary gland to have stones (parotid)
Why is Stensen’s duct (parotid) the most frequent gland to have stones?
The incidence of stones has been increasing as more people have become more and more dehydrated
- also, salivary amylase is produced here and in the pancreas - the blood levels of amylase reflect the concentrations provided by both glands
What structure are involved in cleft palate?
upper lip, soft and hard palate
how does cleft palate result in malnutrition?
cleft palate creates a condition where breathing and chewing cannot occur at the same time so decreased amounts are taken in
What are the anatomical parts of the tooth?
Cusps - elevations present on the occlusal surface of the crown Alveolus - tooth socket Gomphosis (dento-alveolar joint) Clinical crown Anatomical Crown
What is the different between the clinical crown and the anatomical crown?
abscesses can never be adequately treated with a bx
Why is the different between the slinical and anatomical crown of the teeth important?
provides the explanation why dentists say it is so important to floss (you need to clean around the hidden anatomical crown)
Some teeth have variable number of roots. Why is this important?
The dentist might miss one during a root canal
- tooth morphology is important because the loss of certain teeth means that you have to alter the diet of individuals (ex. no molars for grinding = “soft mechanical diet”)
What are the dental formulas for deciduous and permanent teeth?
Deciduous Teeth: (approx. 6 mos after birth) Inciser(I)2, Canine(C)1, Premolar(0), Molar(M)2 x4 = 20 teeth
Permanent Teeth (approx 6 y/o): 2I, 1C, 2P, 3M x 4 = 32 teeth
Which branch of which nerve does the dentist block?
V3: the mandibular division of the trigeminal nerve
Why, when the dentist numbs your gums, does your tongue numb?
And why does your tongue not work well afterward?
- blocking the mandibular branch will also block part of the tongue
- V 3 is mixed, both sensory and some motor
What is a T&A, and what structures are involved?
There are 3 tonsils
- 2 (adenoids and palatine) were removed in the past
- Now, mostly just the palatine tonsils are removed surgically
Where is the epiglottis and what does it do?
What can happen to it?
The epiglottis is attached to the tongue, and gaits food into the esophagus keeping it from going down the trachea
–> it can become infected: epiglottis
What are the 5 types of chemoreceptors found in the tongue?
Sweet - sugars
Sour - acids (citric, lactic)
Salty - salts (NaCl, NaI, KCl)
Bitter - complex organic molecules; aspirin
Umami - “savory; meaty; brothy” amino acids (MSG - derivec from glutamic acid)
Why is tasting bitter important?
Bitter tastes are often poisons - explains why people have a strong reaction not to swallow bitter
What do filiform papillae do?
Touch, pain, temperature
What are the different types of tongue papillae?
Filiform
Fungiform
Circumvaliate
Foliate
What do fungiform papillae do? Where are they found?
contain one or more taste buds
- anterior part of the tongue (pink dots)
What do circumvallate papillae do? Where are they found?
distributed in the shape of an inverted V near the back of the tongue
What do folate papillae do? where are they found?
In smalll trenches on the sides of the posterior tongue.
Which nerve innervates the pharyngeal constrictor muscles?
CNX
Which nerve innervates the Upper esophageal sphincter?
CNX
Why was the uvula removed?
Did it work?
We believed that snoring was causing obstructive sleep apnea, so we started surgically removing the uvula, which we thought was causing the obstruction
- It cured the snoring, not the sleep apnea
What causes cavities (carries)?
metabolic byproducts of bacteria
- lactic acid (ex)
What is xerostomia and what role does it play in the development of carries?
Dry mouth
Decreases circulating IgA
What is periodontitis?
infection of the aveolar socket (formerly known as pyorrhea); extension of gingivitis
What is a Waldeyer’s ring and what does it do?
A network of lymphatic tissue that acts as the first line of defense against inhaled or ingested pathogens
Which taste receptors are membrane channels?
Salt: Na+ channel Sour: H+ channel Sweet: 2nd Mess (cAMP) Bitter: 2nd Mess (IP3) Umami: 2nd Mess * ALL result in Ca+ release, which trigger transmitter release
Which CN provides motor innervation to the tongue? Why is this important?
CN XII (hypoglossal) When trying to localize the site of a tumor or strike, the cranial nerves are examined If the tongue deviates during the exam, it indicated the location at which the stroke or tumor is acting (the nucleus or nerve root of CN XII)
Which never innervate the posterior pharynx and why is it important?
CN IX
It is used to test the gag reflex, say after a stroke
What type of cells line the nasopharynx?
Respiratory Tract: Lined by ciliated mucus membrane (Pseudostratified columnar ciliated epithelium with goblet cells)
Air flow: lined with cilia!
Different areas have different linings - impt bc they indicate which types of tumors are likely to be present
squamous cells - squamous cell carcinoma
columnar cells - adenocarcinoma
Squamous cell carcinomas are likely to form in the oropharynx, why?
Lined with squamous epithelium (non-keratinizing stratified squamous epithelium)
What structures “close” the airway so that food does not travel to the lungs?
the epiglottis
What is stomatitis?
an inflammation of the mucus membrane of any of the structures in the mouth (buccal mucosa, gums, tongue, lips, throat or palate)
- can be caused by poor oral hygiene, dietary protein deficiency, poorly fitted dentures, burns from hot food or drinks, toxic plants, of infections/allergic reactions that affect the entire body
What causes thrush?
oral candida
Where can candida be found?
Anywhere in the oral cavity and esophagus (and other places not covered in GI)
What 2 things are needed for the Lower Esophageal Sphincter to function properly?
inner circular esophageal muscle
loop of diaphragm around esophagus
Why does the LES not work well when there is a hiatal hernia?
because part of its function depends upon the diaphragm circling around it
What structure drains the foregut, midgut and hindgut?
the portal vein
Cirrhosis causes portal hypertension (HTN) - what is the significance of this condition?
Blood can’t get through the liver effectively, so it shunts it through the Azygous and Hemiazygous veins in order to get it back to the heart.
- Blood also backs up into other structures like the esophageal veins, causing esophageal varices
What drains the majority of the esophagus?
azygous and hemiazygous veins