BCM Elective Flashcards
What is the function of the middle ear?
To transmit and amplify sound waves from the tympanic membrane to the stapes footplate, thus converting energy from air to fluid of the membranous labyrinth.
Tympanic membrane:
- The 3 layers?
- The area superior of the annulus?
- Inferior?
- Outside/lateral: squamous epithelium
Middle: fibrous layer
Inside/medial: cuboidal epithelium
- Pars flaccida
- Pars tensa
(the incomplete ring is formed by the thickened fibrous layer around the tympanic membrane)
What is the structure medial to the oval window?
Its two components?
What is anterior and posterior to it?
Vestibule, with utricle and saccule
Cochlear is anterior, and semicircular canals are posterior
What is the names of the fluids outside and inside of the membranous labyrinth?
Perilymph and endolymph
What are the 3 semicircular canals?
Superior, posterior and lateral or horizontal
Name and compoments of CN VIII?
Vestibulocochlear nerve
It has the afferent and efferent fibers from both the cochlear and vestibular nerves
Describes the cartilages and bones of the external nose
Cartilages: Lower lateral, upper lateral, septal, lesser alar, lateral nasal (upper nasal)
Bones: nasal, maxillary, frontal

Blood supplies for the external nose?
External carotid branches: external maxillary –> lateral nasal, angular, alar, septal, external nasal
Internal carotid branches: ophthalmic –> anterior ethmoid, posterior ethmoid, and dorsal nasal vessels
Nerve supply to the external nose?
Sensory trigeminal: ophthalmic and maxillary
(Ophthalmic brainches: external nasal, nasociliary and infratrochlear, Maxillary branch: infraorbital)
Motor facial: bucca, zygomatic
What are the structures that make up the internal nose? (Floor, roof and lateral walls)
Floor: hard palate anteriorly, and soft palate at the back
Roof: cribriform plate, with tiny perforations for sensory fibers to go to the oldfactory bulbs
Lateral walls: turbinates
What drains into these nasal meatuses:
Inferior, Middle, Superior, and Spheno-ethmoid recess
**Inferior: **nasolacrimal
**Middle: **maxillary, frontal and anterior ethmoidal sinuses
**Superior: **posterior ethmoid cells
What kind of structures does the nasopharynx house?
Adenoid tissue and orifices of Eustachian tubes
What are the small hair-like columns at the base of the tongue called?
Circumvallate papillae
What is the vallecula (of the oropharynx)?
Vallecula = furrow or depression
The epiglottic vallecula at the base of the tongue
What are palatine tonsils?
Tonsils. They are lymphoid aggreates betwen the mucosal folds created by palatoglossus and palatopharyngeus muscles.
Functions of the larynx?
The voice box, regulator of respiration, cough, valsalva
What are the bony/cartilaginous structures of the larynx?
Hyoid bone, epiglotis, thyroid cartilage, cricoid cartilage, arytenoids
Describe the structure and function of glottis
Glottis are the true vocal folds attached to the thyroid cartilage at the anterior commissure. The vocal folds attach to the arytenoids and are mobile. The arytenoids abduct for inspiration and adduct for phonation, cough and valsalva.
Location of the submandibular gland in relation to floor of mouth muscles?
Which nerve supplies it?
Which nerves run deeps to this gland?
Below the mylohyoid muscle but above the digastric muscle.
Parasympathetic secretory afferents arise from superior salivatory nucleus, leave brainstem with facial nerve, to chorda tympani to lingual nerve.
Lingual and hypoglossal nerves
What are the innervation of the larynx?
Branches of the vagus nerves:
- Superior laryngeal nerve: sensation of glottis and supraglottis, and motor fibers to cricothyroid muscles to tense vocal cords
- Recurrent laryngeal nerve: senstation of subglottis, and motor fibers to intrinsic muscles of the larynx. Note: on the R it travels inferior to the subclavian artery and on the L the aorta
What are the cranial nerves in the neck, and what do they intervate?
CN VII: the marginal mandibular branch dips into the neck to innervate the platysma, stylohyoid, and posterior belly of the digastric
CN X: exits the jugular foramen and travels inferiorly to the carotid sheath, carry the laryngeal and pharyngeal sensory and motor branches
CN XI - spinal accessory nerve : innervates trapezius and sternocleidomastoid muscles
CN XII - hypoglossal nerve : muscle of the tongue
What are the cervical nerves other than the cranial nerves?
Cervical plexus - C1-4 : ansa cervicalis innervates strap muscles. Also branches of phrenic nerve and sensory components
Phrenic nerve - C3-5
Branchial plexus - C5-T1
Posterior rami - to posterior muscles and skin
Cervical sympathetic chain - travels in carotid sheath
What are the arteries in the neck?
Internal carotid
External carotid - branches:
Superior thyroid, Ascending pharyngeal, Lingual, Facial, Occipital, Post-auricular, Superficial temporal, Internal maxillary
Thyrocervical trunk
Vertebral artery
Which embryonic structure gives rise to parathyroid gland?
Branchial pouches, III makes inferior gland and IV the superior
Name the lymph node group around the pyramidal thyroid lobe
Delphian lymph node group
Name the most posterior extension of the lateral thyroid lobes
Tubercle of Zuckerkandl
Which cell secretes calcitonin?
Parafollicular cells of thyroid
What is Plummer’s disease?
Toxic multinodular goiter
What kind of cancers Multiple Endocrine Neoplasm presents with?
MEN 1: pituitary adenoma, parathyroid hyperplasia, pancreatic tumor
MEN 2a: parathyroid hyperplasia, medullary thyroid cancer, pheochromocytoma
MEN 2b: mucosal neuroma, medullary thyroid cancer, phenochromocytoma (and Marfanoid body habitus)
What are the 5 thyroid carcinomas in descending order of frequency?
- Papillary carcinoma - 70%
- Follicular carcinoma - 10%
- Medullary carcinoma - 5%
- Hurthle cell carcinoma - 2%
- Undifferentiated carcinoma - 1%
What are some associated conditions of pt with papillary thyroid adenocarcinoma?
Past Hx of neck radiation
Has Gardner syndrome
What is an associated histologic finding of papillary thyroid adenocarcinoma?
Spreading route and speed?
10-yr survival rate?
Psammoma bodies
Lymphatics, slowly
95%
What is an option for post-op treatment of papillary thyroid adenocarcinoma?
131I at ablative doses. Uptake can also be used for looking up and treat mets
What are the 5 F’s of follicular thyroid adenocarcinoma?
- Female dominant (3:1 ratio)
- Far-away metastasis, hematogenous to bones
- FNA is NOT useful because tissue structure is needed for Dx
- Favorable prognosis (10-year survival rate of 85%)
- Post-op 131I scan and/or treatment
How is Hurthle cell cancer different from regular follicular thyroid adenocarcinoma?
Even though they come from follicular cells, they don’t take up 131I, and they spread through lymphatic route more than hematogenous
What are the 6 M’s for medullary cancer?
MEN II
aMyloid
Median lymph node dissection
Modified neck dissection if lateral nodes are positive
Medium 10-year survival rate of 50%
Minimal 131I uptake
What is the most common cause of hyperthyroidism?
Graves’ disease, in which antibodies stimuating TSH receptor circulates and cause secretion of thyroid hormones
What is the ratio of F:M in Graves’ disease?
6:1
Which specific physical finding is found with Graves’ disease?
Exophthalmos
What are the treatments for Grave’s disease?
- Medical blockade: iodine, propanolol, propylthiouracil (PTU), methimazole, Lugol’s solution of KI
- Radioactive ablation
- Surgial resection: bilateral subtotal thyroidectomy
What is the major complication for radioiodide or surgery for Graves’ disease?
Hypothyroidism
Mechanism of action for PropylThioUracil?
- Blocking peroxidase oxidation of iodide to iodine, thus inhibits incorportation of iodine into T4/T3
- Inhibits peripheral conversion of T4 into T3
Mechnism of action for methimazole?
Blocks peroxidase oxidation of iodine into iodine, thus inhibits incorporation of iodine to T4/T3
What is Pemberton’s sign?
A large goiter causes plethora of head when arms are raised
What are the signs and causes of acute thyroiditis?
Painful, swollen thyroid, F, erythema of overlying skin, dysphagia
Bacteria - Staph or Strep, usually associated with a fistula or anatomic variant
What is the signs and cause of subacute thyroiditis?
Swelling, tenderness following URI
Viral infection –> thus only supportive care (NSAID, steroids)
What is De Quervain’s thyroiditis?
Subacute thyroiditis post URI
What are the 2 types of chronic thyroiditis?
- Hashimoto: firm, rubbery gland, 95% Female, with **lymphocyte invasion, **positive antithyroglobulin and microsomal antibodies
- Riedel: benign inflammatory thyroid enlargement with **fibrosis. **Large, painless thyroid.
What percentage of patients have 5 or 3 parathyroid gland?
5% and 10%
What is the usual position of inferior parathyroid gland?
Posterior and lateral of the thyroid gland, and below the inferior thyroid artery
Where is the most common site for the extra parathyroid gland? Other sites?
Thymus.
Thyroid gland, mediastinum, carotid sheath, tracheoesophageal groove, behind esophagus
What is the blood supply to parathyroid gland?
Inferior thyroid artery in 80% of pts
How does DiGeorge’s syndrome affect parathyroid gland?
There is none in these pts
What is the most common cause of hypercalcemia in outpatients vs inpatients?
Outpt: Hyperparathyroidism vs inpt: cancer
Which cells secret PTH?
Chief cells
What does PTH do?
Increase serum calcium through bone breakdown, GI absorption, kidney resorption
Decrease serum phosphate: decrease kidney resorption, Gi absoprtion
How does vitamin D work?
Increase both calcium and phosphate absorption from GI
Where in the gut is calcium absorbed?
Duodenum and proximal jejunum
Primary vs secondary vs tertiary hyperparathyroidism?
Primary: increased PTH secretion –> high serum Ca low phosphate
Secondary: renal failure/failure of GI to absorb –> Ca wasting/can’t absorb –> low serum Ca
Tertiary: Ca supplement for secondary hyperparathyroidism –> normal Ca level –> but PTH is still high due to unresponsiveness to neg feedback
How do we image parathyroid?
- Open them up during surgery
- Ultrasound
- Sestamibi scan
- 201Technetium-thallium subtraction
- CT/MRI
- venous sampling of PTH
What are the most common causes for primary hyper-parathyroidism? Risk factors?
Adenoma - 85%, Hyperplasia - 10%, Carcinoma - 1%
Irradiation, family history, MEN-I and MEN-IIa
What are some symptoms of primary HPTH?
Stones, bones, groans, and psychiatric overtones
**Stone: **Kidney stones
**Bones: **fracture, bone pain, subperiosteal resorption
Groans: muscle pain and weakness, pancreatitis, gout, constipation
**Psychiatric overtones: **depression, anorexia, anxiety
Other Sx: polydipsia, wt loss, HTN, polyuria, lethargy
What is the 33:1 rule in primary HPTH?
serum Cl to phosphate ratio
What is an x-ray finding for HPTH?
Subperiosteal bone resorption in hand digits
What is another common cause for hypercalcemia without involving the parathyroid?
Familial hypocalciuric hypercalcemia
Differentials of hypercalcemia?
CHIMPANZEES
Calcium overdose, Hyperparathyroidism/Hypocalciuric Hypercalcemia, Immobility/Iatrogenic (thiazide diuretics), Mets, Paget’s disease, Addision disease, Neoplasm, Zollinger-Ellison syndrome, Excessive vit D or A, Sarcoidosis
What is the initial medical treatment of primary HPTH?
Fluids, furosemide
How much parathyroid gland should be saved post-op?
30-40mg
How does parathyroid carcinoma present?
Hypercalcemia, elevated PTH, and palpable neck mass
What is a marker for parathyroid carcinoma?
Human chorionic gonadotrophin
What is hungry bone syndrome?
After resection of parathyroid adenoma, bones who have been derived of Ca aggressively absorb Ca leading to hypocalcemia
Signs and Sx of hypocalcemia?
Perioral tingling, paresthesia, positive Chvostek’s sign, positve Trousseau’s sign
Q-T prolongation
What are the 4 pairs of strap muscles?
Innervation?
Sternohyoid, sternothyroid, thyrohyoid, and omohyoid
All but thyrohyoid: C1-3 - ansa cervicalis
Thyrohyoid: C1 through hypoglossal nerve
What are the fascial layers of the neck?
- Superficial: contains dermis and platysma muscle
- Deep cervical: investing layer (sternocleidomastoid muscle and trapezius), pretracheal layer (visceral and muscular parts), prevertebral layer
- Carotid sheaths