NBME 16 Flashcards
Cystic fibrosis is due to a defect in what
protein structure of the ATP gated Cl- channel
What is the cellular process for muscle atrophy
polyubiquitination
Our body goes through arteriolar vasoconstriction to do what?
MAMMALS IN A COLD ENVIRONMENT
Vasoconstriction also occurs in superficial blood vessels of warm-blooded animals when their ambient environment is cold; this process diverts the flow of heated blood to the center of the animal, preventing the loss of heat.
What does central venous pressure represent?
pressure in the thoracic vena cava near the right atrium (therefore CVP and right atrial pressure are essentially the same)
- it is a major determinant of the filling pressure and therefore the preload of the right ventricle, which regulates stroke volume
What causes hemochromatosis?
- recessive mutation HFE gene C282Y which is a point missense mutation changing cysteine to tyrosine
- this results in abnormal iron sensing and increase intestinal absorption
- can also be secondary to chronic transfusion therapy like in beta-thalassemia major
A 45 year old man is admitted because of CHF. 2 relatives died of dilated cardiopathy and cirrhosis. PE shows hyperpigmentation and elevated glucose. What is the cause?
hemochromatosis
Presents in patients after age 40 when total body iron >20g. Women show signs later because they lose iron through menstruation. Classic triad is: DIABETES, CIRRHOSIS, SKIN PIGMENTATION (BRONZE DIABETES)
In addition to cirrhosis, diabetes, skin pigmentation, what can patients with hemochromatosis present with?
- classically restrictive cardiomyopathy but also dilated cardiomyopathy (reversible)
- hypogonadism
- arthropathy (calcium pyrophosphate deposition especially in MCP joints)
- HCC is common cause of death
How is hemochromatosis treated?
- repeated phlebotomy
- chelation with deferasirox, deferoxamine, oral deferiprone
What are neuroendocrine tumors?
Group of neoplasms originating from Kulchitsky and enterochromaffin-like cells.
Occur in various organs: 1. thyroid: medullary carcinoma 2. Lungs: small cell carcinoma 3. pancreas: islet cell tumor 4. adrenals: pheochromocytoma
Cells contain amine precursor uptake decarboxylase (APUD) and
secrete different hormones (eg, 5-HIAA, neuron-specific enolase [NSE], chromogranin A
What is the MOA of hydralazine?
increased cGMP to cuase smooth muscle relaxation
Vasodilates arterioles > veins; afterload reduction
What is hydralazine used for?
- Severe hypertension (particularly acute), 2. HF (with organic nitrate).
Safe to use during pregnancy.
Frequently coadministered with a β-blocker to prevent reflex tachycardia
What are the SE of hydralazine?
Compensatory tachycardia (contraindicated in angina/CAD)
fluid retention, headache, angina.
Lupus-like syndrome.
Non-selective α-blockers
- phenoxybenzamine
2. Phentolamine
α-1-selective-blockers
prazosin
terazosin
doxazosin
tamsulosin
- zosin ending
α-2-selective-blockers
mirtazapine
β1-selective blockers [β1>β2]
acebutolol (partial agonist) atenolol betaxolol bisoprolol esmolol metoprolol
- SELECTIVE ANTAGONIST MOSTLY GO FROM A to M
nonselective β blockers [β1=β2]
nadolol
pindolol (partial agonist)
propranolol
timolol
Nonselective α1 and β-blocker
carvedilol
labetalol
MOA of Nebivolol
cardioselective β1-blocking with stimulating β3- receptors (activate NOS synthase in vasculature and decreases SVR)
What is cystic hygroma associated with?
Turner syndrome.
What is tracheomalacia?
Tracheal cartilage is soft so that the trachea partially collapses when the person breathes out
can be congenital, compression from vascular rings or acquired during infection
What does the SMA supply
Distal duodenum to proximal 2/3 of transverse
colon
[midgut]
What does the celiac artery supply
Pharynx (vagus nerve only) and lower esophagus
(celiac artery only) to proximal duodenum;
liver, gallbladder, pancreas, spleen (mesoderm)
What does the IMA supply
Distal 1/3 of transverse colon to upper portion of
rectum
The greater curvature of the stomach is supplied by which two arteries?
The right gastro-omental artery supplies the inferior part of the greater curvature.
The left gastro-omental artery supplies the superior part of the Greater Curvature.
What supplies the lesser curvature of the stomach?
The inferior part is supplied by the right gastric artery, which comes from the Hepatic artery, a branch of the Common Hepatic artery.
The superior part, and the cardia, are supplied by the left gastric artery, which is a direct branch from the Celiac Trunk
Mechanisms of C. Diff colitis
Toxin A, an enterotoxin,
binds to brush border of gut and alters fluid
secretion
Toxin B, a cytotoxin, disrupts cytoskeleton via actin depolymerization. Both
toxins lead to diarrhea- watery but occasionally bloody
A 4-month old boy is diagnosed with a rare autosomal recessive skeletal dysplasia involving abnormal endochondral bone formation. Genetic analysis shows null mutations in a gene for a protein that controls the traffic of vesicles into the golgi complex. EM of this patient’s cells will most likely show which of the following findings?
dilated rough endoplasmic reticulum
assuming since things can’t get moved from the RER to golgi so it gets stuck in the Golgi
What is Cyclin D1 associated with?
mantle cell lymphoma
Which drug reversibly inhibits dihydroorotate dehydrogenase, preventing pyrimidine synthesis. Suppresses
T-cell proliferation
Leflunomide
- used for Rheumatoid arthritis, psoriatic arthritis.
How is NAPQI, the toxic metabolite of Tynelol normally inactivated?
inactivated by conjugation with glutathione
in general the majority of Tynelol is excreted in bile after glucuronidation
Which class of chemotherapy drugs causes peripheral neuropathy?
microtubule inhibitors
When would you use clomiphene?
Used to treat infertility due
to anovulation (eg, PCOS). May cause hot flashes, ovarian enlargement, multiple simultaneous
pregnancies, visual disturbances.
What is the cause of urticaria?
Mast cell degranulation. Macrophages produce IL-1, IL-6, TNF-alpha
Which drug is a derivative of Jimsonweed and causes anti-cholinergic symptoms?
atropine
How would you treat atropine poisoning?
physostigmine [indirect agonist- anticholinesterase]
What is carbachol used for?
Copies Ach- Constricts pupil and relieves intraocular
pressure in open-angle glaucoma
Uses of pilocarpine
- muscarinic receptor (M3) found on the iris sphincter muscle, causing the muscle to contract -resulting in pupil constriction (miosis)
- Pilocarpine also acts on the ciliary muscle and causes it to contract. When the ciliary muscle contracts, it opens the trabecular meshwork through increased tension on the scleral spur. This action facilitates the rate that aqueous humor leaves the eye to decrease intraocular pressure
What is Peutz-Jeghers
syndrome?
PATHGNOMIC for hyperpigmented lip
- Autosomal dominant syndrome featuring numerous hamartomas throughout GI tract, along with
hyperpigmented mouth, lips, hands, genitalia. - Associated with increased risk of breast and GI cancers (eg,
colorectal, stomach, small bowel, pancreatic)
What are the characteristics of Gardner syndrome?
FAP + osseous and soft tissue tumors, congenital hypertrophy of retinal pigment epithelium,
impacted/supernumerary teeth.
Common culprits of acute prostatis
Common bacteria are Escherichia coli, Klebsiella, Proteus, Pseudomonas, Enterobacter, Enterococcus, Serratia, and Staphylococcus aureus.
What is special about Ureaplasma Urealyticum
like mycoplasma it has no cell wall
What are the antibodies for celiac disease?
- IgA anti-tissue
transglutaminase (IgA tTG) - anti-endomysial
- anti-deamidated gliadin peptide antibodies
Histology shows loss of villi and increased number of intraepithelial lymphocytes
celiac disease
small intestine histology shows noncaseating granulomas in bowel wall and serosa
Crohn Disease
small intestine histology shows macrophages containing Periodic acid-schiff positive bacilli in lamina propria
Whipple disease
First line for Schizophrenia-
atypical anytipsychotics
What does enkephalin mediate?
nociception
What causes bacillary angiomatosis
Bartonella Henselae
which cancer produces PTHrP and elevated calcium
non-small cell lung cancer- squamous cell carcinoma
Urine 5-hydroxyindeoleacetic acid is what
serotonin’s main metabolite
testing is most frequently performed for the diagnosis of carcinoid tumors of the enterochromaffin (Kultschitzsky) cells of the small intestine, which release large amounts of serotonin
What murmur is most likely heard in Marfan’s
decrescendo diastolic murmur in the aortic area- aortic regurgitation OR late systolic with mitral valve prolapse
Where do you see hyaluronate
- part of the ECM
- parts of synovial fluid
What murmur are you likely to hear - mitral/ tricuspid regurgitation?
holosystolic murmur best heard over lower left sternal border and apex
Incidence vs prevalence
incidence= new cases
How is vancomycin different than penicillin?
substitution of d-lactate for d-alanine in peptidoglycan
Frequency of an X-linked recessive disease
in males, carrier in females, disease in females
q- males
2pq- carrier in females
q^2- frequency in disease
Hypertension in pregnancy
Hydralazine, labetalol, methyldopa, nifedipine
What can you not use WPW SVT
Don’t give CCB, Beta blockers, adenosine, digoxin
Theres a faruncle on the patients nasal septum. Which bug is most likely to be isolated
- S Pneumo, epidermidis
- Moraxella- can be opportunistic
- Eikenella corodens- nitrate reducer
- Arcanobacterium
What’s the most common bug in the nasal cavity
- Staph epidermidis
- Corynebacterium
- S. Aureus
- Micrococcus luteus is another Gram positive, spherical, bacterium that also resides in the nose as well as the mouth, skin and upper resipratory tract as an obligate aerobe. M. luteus is normally harmless except for those that have compromised immunities.
Which bugs are most likely to cause upper rectal abscess
There are four types of anorectal abscesses: perianal, ischiorectal, intersphincteric, and supralevator.
Historically, many rectal abscesses are caused by bacteria common in the digestive system, such as E. coli. While this still continues often to be the case, there has recently been an uptick in the causative organism being staphylococcus, as well as the difficult to treat community-acquired methicillin-resistant S. aureus.
Microscopic section of the colon reveals the bottom of a “flask” shaped ulcer
Entameba Histolytica
A 53-year-old man with a long-standing history of allergic rhinitis and asthma presents with uveitis, mild hearing loss, numbness and tingling in his right hand, and diffuse joint pain for the past 10 days. Physical examination shows weak to absent left knee patellar reflexes (right knee reflex strong and intact). Laboratory studies show a markedly elevated eosinophil count. A diagnosis is made, and the patient is treated with cyclophosphamide. Further laboratory studies show elevated serum levels of the most common autoantibody associated with this condition. What structure is primarily targeted by the autoantibodies that are most likely elevated in this patient’s serum?
eosinophil granulomatosis- pANCA
antibodies made against neutrophils
Which Plasmodium species do not respond to chloroquine
P vivax and P ovale
12 y/o presents with 6-month history of difficulty walking and leg pain. PE shows mild atrophy of LE and hammer toes. He walks with high stepping gait. Nerve biopsy would show what?
Charcot–Marie–Tooth disease (CMT); related to the defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath
How is Charcot-Marie inherited?
mostly Autosomal dominant
Which HIV drug ginds gp41 in the virus, inhibiting viral entry?
Enfuviritide
What are the 3 NNRTI’s
Delavirdine
Efavirenz
Nevirapine
Allergies can be given what to relieve symptoms in the short term?
alpha-adrenergic agonists
Mechanism of GVHD
Donor T cells react against host cells
usually presents with rash, diarrhea, and elevate liver enzymes and bilirubin since T cells attack areas rich in lymphocytes
Bacteroides
found in our normal GI tract and rectum
A 66-year-old gentleman presents with chronic weakness and “a few” episodes of hematochezia over the past 3 months. Laboratory work-up reveals only a mild iron deficiency anemia. A colonoscopy is performed and vascular abnormalities are noted in the GI tract.
angiodysplasia
ecthyma gangrenosum is associated with what
Pseudomonas
cytotoxic vs vasogenic edema
During an ischemic stroke, a lack of oxygen and glucose leads to a breakdown of the sodium-calcium pumps on brain cell membranes, which in turn results in a massive buildup of sodium and calcium intracellularly. This causes a rapid uptake of water and subsequent swelling of the cells.[5] It is this swelling of the individual cells of the brain that is seen as the main distinguishing characteristic of cytotoxic edema, as opposed to vasogenic edema, wherein the influx of fluid is typically seen in the interstitial space rather than within the cells themselves
6mo M w/ hx of recurrent upper and lower resp tract infections, hypocalcemia rxed with Ca2+ supplementation, surgical repair of aortic coarctation. PE reveals broad nasal bridge and dysplastic pinnae. Cause of recurrent infections?
T-lymphocyte deficiency. This is DiGeorge
What are the lab findings seen in HyperIgM Syndrome
- Normal or increased IgM.
- very decreased IgG, IgA, IgE.
Failure to make germinal
centers.
Stool occult blood testing has:
low sensitivity
To strengthen infraspinatus and teres minor, what movements should be done against resistance?
lateral rotation
What is the MOA of fish oil?
decreased CLDL production and helps decreased triglyceride
How do fibrates induce HDL synthesis [gemfibrozil, bezafibrate, fenofibrate]
activate PPAR-α to induce HDL synthesis
Which drugs increase the breakdown of LDL?
** STATINS- increases LDL receptors expressed on the liver & inhibits HMG CoA in forming mevalonate. Enhanced LDL receptor expression increases receptor-mediated endocytosis of LDL and thus lowers serum LDL.
** also PCSK9 inhibitors which inactivate LDL-receptor degradation
Which drug inhibits cholesterol uptake?
EZETIMIBE prevents cholesterol absorption at the small intestine brush border
What are the symptoms of hypoglycemia and how would you treat it?
tremor, palpitations, sweating, anxiety, seizure, coma
glucose tablets or glucagon injection if you lose consciousness
What is the renal threshold for glucose excretion?
300 mg/ 100 mL
Which cells are stimulated y gastrin to release H+
parietal cells
https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjrruOT0d3aAhVI5mMKHa-XCeAQjRx6BAgBEAU&url=https%3A%2F%2Fwww.memorangapp.com%2Fflashcards%2F68940%2FGS%2BHE%2B31%2B%2526%2B32%2BGI%2BHistology%2BI%2Band%2BII%2F&psig=AOvVaw3fuOF4Tp4CobuKXGN7fZLB&ust=1525027729621650
Which cells can be seen on histology in the stomach?
starting from lumen to base of the fundic glands:
- surface mucous cell
- mucous neck cell
- parietal cell
- chief cell
- G cell enteroendocrine cell
Both these stomach regions are primarily involved with mucus production and are similar histogically.
cardia & pylorus
A 32-year-old man begins to laugh while eating dinner with his friends. A small particle of food irritates his larynx and provokes him to cough. Which of the following best describes the position of his vocal cords throughout this sequence?
- While Swallowing - Immediately after Laryngeal Irritation - While Coughing
A) Closed closed open
B) Closed open closed
C) Closed open open
D) Open closed closed
E) Open closed open
F) Open open closed
Vocal cords are closed while swallowing. this is the normal position to prevent food from going into the trachea
Immediately after- CLOSED- These is a REFLEX to prevent aspiration of foreign body from going further into trachea
While Coughing its OPEN
- To help expel the foreign body out.
What is the difference in Schwann cell and oligodendrocyte myelination?
Schwann- Each Schwann myelinates 1 PNS axon
Oligodendrocytes- myelinates the CNS. 1 oligo can myelinate many axons!
What is the difference in Schwann cell and oligodendrocyte origin?
Schwann- from the neural crest
Oligo- from neuroectoderm
What diseases have oligodendrocytes injured?
- MS
- progressive multifocal leukoencephalopathy
- leukodystrophies
What diseases have Schwann cells injured?
Guillain Barre
What is a leukemoid reaction?
the patient has an infection which is the definition of leukemoid reaction listen to pathoma on WBC disorders and they explain the differences between leukemia and a normal leukemoid response to infection. Im not sure if leukoclastic response is a real thing but I would imagine it means damage due to increased wbc’s i think an example is leucoclastic vasculitis where neutrophils damage vessels.
male version of Turner syndrome
Noonan syndrome
42-year old woman presents with sudden onset of severe headache. The right pupil is 6mm and nonreactive to light. Adduction of the right eye is impaired. Nuchal rigidity is noted. Cerebral angiography most likely shows an aneurysm in which artery?
Posterior communicating artery
An otherwise healthy 60-year-old man comes to the physician for a follow-up examination 2 weeks after he was found to have a serum prostate-specific antigen concentration of 5.3 ng/mL (N<4). A biopsy specimen of the prostate shows evidence of adenocarcinoma. A CT scan of the spine shows osteobastic lesions at L1. The patient undergoes bilateral orchiectomy. Five months later, he dies suddenly of a massive myocardial infarction. At autopsy, which of the following microscopic changes in the prostate resulting from the orchiectomy is most likely present?
A) Corpora amylacea B) Edema C) Hypertrophied cells D) Necrosis of the blood vessel walls E) Scattered shrunken cells F) Widespread necrosis
scattered shrunken cells
- Testerone no longer stimulating the prostate
70y F with persistent fever despite IV broad-spectrum abx 3 days post-operation. She has a central venous cathether and a well-healing surgical wound. Gram stain shows 4um elliptical purple budding organisms. Which is the most likely cause?
Candida albicans- Unresponsive to broad spectrum abx, budding pattern, and had white colony formations
What precipitate gout attacks?
Acute attack tends to occur after a large meal with foods rich in purines (eg, red meat, seafood), trauma, surgery, dehydration, diuresis, or alcohol consumption (alcohol metabolites compete for same excretion sites in kidney as uric acid
Which worm can be passed in the stool
Ascaris Lumbricoides- giant roundworm
This is a disease in which eosinophils accumulate in the lung in response to a parasitic infection
Loffler syndrome- cases of eosinophilic pneumonia caused by the parasites Ascaris lumbricoides,[2] Strongyloides stercoralis and the hookworms Ancylostoma duodenale and Necator americanus.
Which parasite is transmitted in undercooked pork?
taenia solium
trichenella spiralis
Which parasite is transmitted in raw shrimp?
anisakiasis [from google but I couldn’t find it in first aid]
A 35 year old woman participate in a study of a new diagnostic test of steroid hormones in saliva. Menses occur at regular 28 day intervals and she has been shown to ovulate on day 14 when her saliva is tested on a particular day of the cycle, laboratory studies show an increased concentration of estradiol and decreased concentration of progesterone. On which of the following days in this patient`s menstrual cycle were these hormones most likely measured? A) Day 1 B) Day 6 c) Day 12 D) Day 18 E) Day 26
Day 12- If her estradiol is increased and progesterone decreased she will most likely ovulate soon, i.e. she is towards the end of the proliferative phase but has not yet ovulated
0 yr old lady brought to er by husband 45 min after he found her unresponsive. She has anxiety disorder trted w/ diazepam. She recently started taking over the counter med for heart burn. she only responds to painful stimuli. interaction with which drug causing this prob?
Cimetidine, the others don’t inhibit P450, which is why she’s had a benzo overdose.
Which drugs do we use to treat HSV
acyclovir
foscarnet for acyclovir resistant HSV
RA that doesn’t respond to prednisone or methotrexate should be given which drugs?
TNF-α inhibitors
A 9-month old boy is brought to the Emergency department by his mother because of severe respiratory distress for 1 hour. His respirations are 80/min. He is at 3rd percentile for lenght and weight. Physical examination shows cyanosis. Despite appropriate measures, the patient dies. Autopsy findings show a ventricular septal defect and persistent truncus arteriosus. Which of the following populations of cells was most likely absent during early fetal cardiac development in this patient?
A) Ectodermal neural crest B) Extraembryonic mesoderm C) Mantle layer neuroblasts D) Mesothelial cells E) Spalnchnopleuric mesoderm
Neural crest cells form the aorticopulmonary septum and endocardial cushions.
Large pulmonary embolism is an example of what
physiologic dead space
What is the ground substance of ECM made up of?
It actually consists of large molecules called glycosoaminoglycans (GAGs) which link together to form even larger molecules called proteoglycans. These molecules are very good at absorbing water, rather like a sponge, such that 90% of the extracellular matrix is made up of water.
What is cartilage made up of?
It is made up of cells called chondroblasts and chondrocytes, (chondro - cartilage) and extracellular matrix, made up about 10% aggrecan, 75% water, and a mix of collagen fibres and other constituents.
3 types of cartilage
Hyaline: Most common - has a glassy appearance (hyalos - is greek for glass).
Fibrocartilage: tendon insertions and invertebral discs: reinforced with parallel bundles of collagen fibres.
Elastic cartilage: external ear and epiglottis: flexible and resilient - has elastic fibres as well as collagen fibres.
