Set 16 Flashcards
Describe the flow of blood into and out of the thyroid gland.
External carotid artery gives rise to the superior thyroid artery
The thyrocervical trunk gives rise to the inferior thyroid artery
Venous drainage: superior thyroid vein, middle thyroid vein and inferior thyroid vein
A 30-year-old man is undergoing the Schilling test to investigate his B12 deficiency. What must be present in the enteric system in order for vitamin B12 to be absorbed?
Intrinsic factor - produced by parietal cells in the stomach
B12/IF complex is absorbed in the terminal ileum
The part of the brain responsible for attention and alertness has been implicated in schizophrenia, PTSD, Parkinson disease, narcolepsy, progressive supranuclear palsy, depression, and ADHD. What part of the brain is this? (Hint: Lesion results in coma.)
Reticular activating system (midbrain)
What is the definition of first-degree heart block? What are the symptoms of first-degree heart block?
PR interval is prolonged (>200 msec - five little boxes or one big box). Benign and asymptomatic. No treatment required.
What are the main differences between delirium and dementia? Which is more commonly reversible?
Delirium: waxing and waning level of consciousness with acute onset; rapid decrease in attention span and level of arousal. Characterized by disorganized thinking, hallucinations (often visual), illusions, misperceptions, disturbances in sleep-wake cycle, cognitive dysfunction. EEG abnormal. Usually secondary to other illness (e.g., CNS disease, infection, trauma, substance abuse/withdrawal, metabolic/electrolyte disturbances, hemorrhage, urinary/fecal retention. Usually reversible.
Dementia: gradual decrease in intellectual ability or “cognition” without affecting level of consciousness. Characterized by memory deficits, aphasia, apraxia, agnosia, loss of abstract thought, behavior/personality changes, impaired judgement. A patient with dementia can develop delirium (e.g., a patient with AD who develops pneumonia is at increased risk for dementia). EEG usually normal. Not associated with acute onset. Usually irreversible.
What potentially fatal autoimmune skin disorder is caused by IgG antibodies against desmosomes? What is the difference between a desmosome and a hemidesmosome?
Desmosome (macula adherens) structural support via keratin interactions (connects cells to cells). Autoantibodies —> pemphigus vulgaris
Hemidesmosome connects keratin in basal cells to underlying basement membrane (cells to basement membrane). Autoantibodies —> bullous pemphigoid (hemidesmosomes are down “bullow”)
What is the classic presentation of granuloma annulare?
Asymptomatic. Non-scaly, slightly erythematous annular plaque. Borders are thick, rope-like and irregular with well-defined edges. Thick rope-like border helps distinguish from ringworm or dermatophyte fungal infection (generally flat borders). Starts small and grows outward. Lesions are usually localized to the wrists, ankles, or dorsal hands/feet (palms and soles usually not affected)
A 66-year-old man is involved in a motorcycle accident and suffers a head injury that leaves him in a coma. Prior to this injury the man met with his lawyer to write out specific instructions in case an event like this happened. What are these instructions called?
Living will - written advance directive
An 18-year-old man is brought to your office for delayed onset of puberty. Physical exam confirms a small penis and testicles for his age, as well as lack of facial, pubic, and underarm hair. The patient also reveals that he has never been able to smell. What is the likely diagnosis?
Kallman syndrome - failure to complete puberty; a form of hypogonadotropic hypogonadism. Defective migration of GnRH cells and formation of olfactory bulb; decreased synthesis of GnRH in the hypothalamus; anosmia; decreased GnRH, FSH, LH, testosterone and infertility (low sperm count in males; amenorrhea in females) - lack of secondary sex characteristics
A 45-year-old woman who has been taking prednisone for control of rheumatoid arthritis symptoms has recently been diagnosed with Cushing syndrome. Other than exogenous steroids, what else can cause Cushing syndrome? How does the level of ACTH help differentiate the etiology?
Causes: primary adrenal adenma, hyperplasia or carcinoma. ACTH secreting pituitary adenoma, paraneoplastic ACTH secretion (small cell lung cancer, bronchial carcinoids).
Serum ACTH - if decreased suspect adrenal tumor. If increased distinguish between Cushing disease and ectopic ACTH with high-dose 8 mg dexamethasone suppression test and CRH stimulation test. Ectopic secretion will not decrease with dexamethasone because the source is resistant to negative feedback; ectopic secretion will not increase with CRH because pituitary ACTH is suppressed.
