uWorld 27 Flashcards

1
Q

what is the motor and sensory innervation of the tibial nerve

A

Motor:
foot PLANTAR FLEXION (gastrocnemius, soleus, planters muscles)
INVERION (tibialis posterior muscle)
TOE FLEXION (flexor digitorum longs, flexor hallucis longus muscles)

sensory: plantar foot
lateral 4 toes (posterior tibial nerve)

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2
Q

how does tibial nerve injury (at the popliteal fossa- deep penetrating trauma, knee surgery) often present

A

calcaneovalgus position (dorsiflexed and everted)

if tarsal tunnel may cause sensory loss over the sole with intrinsic foot muscle weakness (plantar flexion and inversion remain intact)

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3
Q

the femoral nerve dos what motor and sensort

A

motor:
leg flexion at the hip
leg extension at the knee

sensory:
medial leg (saphenous nerve)
anterior thigh (femoral nerve)
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4
Q

the superficial peroneal nerve does what motor and sensory

A

motor:
foot EVERSION

sensory:
dorsal surface (top) of foot
anterolateral leg

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5
Q

the deep peroneal nerve dos what motor and sensory

A

motor:
foot dorsiflexion
toe extension

sensory:
between first and second toes

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6
Q

what is the T LOOP of the tRNA

A

contents T(psi)C sequence that is necessary for BINDING of tRNA to RIBOSOMES

refers to the presence of ribothymidine, pseudouridine, and cytidine residues

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7
Q

what is the D LOOP of tRNA

A

facilitates correct tRNA recognition by the proper AMINOACYL tRNA SYNTEHTASE (with the acceptor stem and anticodon loop)

contains dihydrouridine residues (modified bases)

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8
Q

what is the ANTICODON loop of tRNA

A

contains sequences that are complementary to the mRNA codon

during translation, the RIBOSOME complex SELECTS the proper tRNA based SOLEY on its ANTICODON SEQUENCE

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9
Q

what is the ACCEPTOR STEM of tRNA

A

created through the base parking of the 5’-terminal nucleotides with the 3’terminal nucleotides

has the CCA at the 3’ end, with the amino acid bound to the 3’ terminal hydroxyl group

helps mediate correct tRNA recognition by the proper aminoacyl tRNA synthetase

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10
Q

if a patient has decreased breath sounds, hemithroax opacification on one side (right), and deviation of the trachea toward the opacified side are suggestive of what

A

COLLAPSED LUNG due to BRONCHIAL OBSTRUCTION

complete collapse of a lung usually occurs following obstruction of a MAINSTEM BRONCHUS (central lung tumors in smokers)

alveolar collapse (atelectasis) which causes TRACHEA to DEVIATE TOWARD SIDE of LESION

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11
Q

when does one see COMPLETELY OPACIFIED HEMITHROAX w/ tracheal deviation TOWARD the effected lung

A

mainstream bronchus lesion causing ATELECTEASIS

loss of radiolucent air combined with shifting of organs into the hemithroax

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12
Q

bilateral fluffy appearing infiltrates in the lungs are typically seen when

A

pulmonary edema (fluid in alveolar species)

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13
Q

when does one see COMPLETELY OPACIFIED HEMITHROAX w/ tracheal deviation AWAY FROM the effected lung

A

large pleural effusion

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14
Q

what are the two main enzymes of the non oxidative reaction of the HMP shunt

A

transketolase (two carbon group transfer) w/ TPP substrate
transaldolase (three carbon transfer)

can synthesize ribose from fructose-6-phosphate

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15
Q

what does the HMP shunt produce from one molecule of glucose

A

five-carbon sugar, two molecules of NADPH and CO2

two reactions:
oxidative (irreversible)
non-oxidative (reversible)

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16
Q

the oxidative portion of the HMP shunt primarily occurs where

A

tissues active in reductive biosynthesis
fatty avid and steroid synthesis
CYP450 pathway
generation fo superoxide in phagocytes

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17
Q

what enzymes are necessary for the oxidative part of the HMP shunt

A

GLUCOSE-6-PHOSPHATE DEHYDROGENASE (RATE LIMITING): glucose-6-phosphate to 6-phosphogluconate

6-phosphogluconate dehydrogenase: 6-phosphogluconate to ribulose-5-phosphate

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18
Q

what does enolase do

A

convers 2-phosphoglycerate to phosphoenolpyruvate in glycolysis

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19
Q

why does aconite do

A

catalyzes isomerization of citrate to isocitrate in the TCA cycle

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20
Q

what treatment is being researched for AR SCID

A

RETROVIRAL VECTORS to “INFECT” patient STEM CELL with the GENE CODING for ADENOSINE DEAMINASE

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21
Q

what bug is associated with fever, headache, and diplopia in immunocompromised people and found in DAIRY (milk, soft cheeses, and ice cream) as well as raw fruits and processed meats

A

LISTERIA

significant disease in patients with CELL-MEDIATED immunodeficiency

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22
Q

what happens to 2,3-BPG after chronic high altitude adaptation

A

an organophosphate created in erythrocytes during glycolysis

increase levels of 2,3-BPG decrease hemoglobin O2 affinity , allowing the release of more O2 in the peripheral tissues

curve shifts RIGHT

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23
Q

what happens O2 curve in exercise, severe anemia, and hypoventilation

A

shifts RIGHT

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24
Q

what is a CROSS-SECTIONAL study

A

PREVALENCE STUDY

“SNAPSHOT” design that is inexpensive and easy to perform

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25
what happens to cortisol levels in response to stressful situations (infections, surgery) in patients on chronic glucocorticoid therapy
it CANNOT RISE (the adrenal is atrophied) can result in RELATIVE GLUCOCORTICOID DEFICIENCY even when the patient's baseline glucocorticoid regime is maintained can precipitate HYPOTENSION/SHOCK- a higher STRESS DOSE is needed if this happens
26
what is a rare complication that can happen on first dose of ACE inhibitors
FIRST-DOSE HYPOTENSION happens in patients with high plasma RENIN levels like in VOLUME DEPLETION (from DIURETIC USE) or HEART FAILURE prevent this by starting therapy at low doses and slowly titrated upward as needed
27
in a patient with albuminuria why are they started on an ACE inhibitor
to treat early diabetic neuropathy
28
what are the etiologies of hypoxemia in a patient with a NORMAL Aa gradient (5-15 mmHg)
HYPOVENTILATION (obesity hypoventialtion syndrome, neuromuscular disorders LOW INSPIRED FRACTION OF AIR (high altitude)
29
what are the etiologies of hypoxemia in a patient with a ELEVATED Aa gradient (over 15mmHg)
RIGHT-to-LEFT SHUNT (cardiac septal defects, pulmonary edema) VENTIALTION/PERFUSION MISMATCH (PE, COPD) IMPAIRED DIFFUSION (interstitial lung disease)
30
what is seen in OBESITY HYPOVENTILATION SYNDROME
increase CO2 production due to increased mass and surface area sleep-disordered breathing reduced lung volumes and compliance chronic fatigue, dyspnea, difficulty concentrating, evidence of hypoventilation (PaCO2 over 45 while awake)
31
what cells are responsible for synthesizing the structurally important collagen isoforms and extracellular matrix of a atherosclerotic plaque
vascular smooth muscle cells (VSMCs)
32
who is renal blood flow calculated
first calculate renal PLASMA flow using PAH: RPF = (Urine PAH)*(urine flow rate)/(Plasma PAH) renal blood flow: RBF = RPF/(1-hematocrit)
33
when placing a chest tube into the 4th or 5th intercostal space in the anterior axillary or MIDAXILLARY line what does the tube traverse
SERRATUS ANTERIOR muscle intercostal (external, internal, innermost) muscles parietal pleura
34
what does serrates anterior do
originated from ribs 1-8 and inserts along the entire length of the medial scapular border 3 parts: superior, intermediate, inferior infer part of muscle facilitates ARM ELEVATION by PULLING lower end of SCAPULA forward (SCAPULAR ROTATION) all 3 parts help with respiration by lifting the ribs when the shoulder grille is FIXED
35
what does pectorals major do
adduct and internally rotate the humerus arises from anterior clavicle, sternum, costal cartilages, and aponeurosis of the external oblique muscle attaches to lateral lip of bicipital groove of the humerus
36
the lateral epicondyle serves as the primary attachment point for what muscles
EXTENSOR CARPI RADIALIS BREVIS (ECRB) EXTENSOR DIGITORUM both involved in WRIST EXTENSION lateral epicondylitis aka tennis elbow is pain over the lateral epicondyle of the humerus due to antiofibrotic tendinosis of the ECRB tendon
37
what muscles flex the forearm
biceps brachii brachialis brachioradialis
38
L2 radiculopathy leads to what
sensory loss: upper anteromedial thigh | weakness: hip flexion (ILIOPSOAS)
39
L3 radiculopathy leads to what
sensory loss: lower anteromedial thigh | weakness: hip flexion (iliopsoas), hp adduction, knee extension (quads)
40
L4 radiculopathy leads to what
sensory loss: lower anterolateral thigh, knee, medial calf and medial foot weakness: hip adduction, knee extension (quadriceps), PATELLAR REFLEX
41
L5 radiculopathy leads to what
sensory loss: buttocks, posterolateral thigh, anterolateral leg, DORSAL FOOT weakness: foot dorsiflexion and inversion (tibialis anterior), foot eversion (peroneus), toe extension (extensor digitorum brevis)
42
S1 radiculopathy leads to what
sensory loss: buttocks, posterior thigh and calf, lateral foot weakness: hip extension (gluteus maximus), knee flexion (hamstrings), foot plantar flexion (gastrocnemius), ACHILLES REFLEX
43
what are two causes of radiculopathy and how do they differ (if we are talking about say L5-S1 radiculopathy)
SPINAL FORAMINA STENOSIS:affects the UPPER nerve root that is actually exiting at that level (since the roots exit below) - so L5 would be affected if L5-S1 neural foramen were affected HERNIATED DISC: affects the LOWER nerve root - so S1 would be affected if L5-S1 disc were to herniate
44
how does Strep Viridans work
ADHEREs to tooth enamel and to FIBRIN-PLATELET aggregates on damaged heart valves due to their ability to produce INSOLUBLE EXTRACELLULAR POLYSACCHARIDES (aka DEXTRANS) using sucrose as a substrate this colonization of host surfaces contributes to their ability to cause infections
45
angiotensin-II, oxytocin, and vascular vasopressin (V1) receptors all work through what mechanism
Gq
46
why is oxalate absorption in creased in Crohns
calcium normally binds oxalate in the bowel to form insoluble salts that promote oxalate excretion in Crohns calcium binds LIPIDS instead and cannot complex oxalate OXALTE ABSORPTION is thus INCREASED, promoting formation of OXALATE KIDNEY STONES (enteric oxaluria)
47
what causes avascular necrosis (osteonecrosis)
THOMBOTI/EMBOLIC OCCLUSION (SICKLE CELL, BENDs) GLUCOCORTICOIDS vascular inflammation/injury (vasculitis, radiation) alcohol abuse traumatic fracture
48
what clinical presentation is seen with osteonecrosis (avascular necrosis)
pain on weight bearing DECREASED RANGE of MOTION wedge-shaped or geographic zone of necrosis articular cartilage is viable but may be distorted or detached from underlying bone necrosis of surrounding adipocytes dead bony trabecular with empty lacunae
49
prior MI is associated with lower risk of ventricular free wall rupture, why?
myocardial fibrosis at the site of infarction | development of collateral circulation
50
what is the TATA box
promoter region located 25 bases UPSTREAM from the beginning of the CODING REGION
51
when does gene transcription begin
when RNA POLYMERASE II attaches to one of the promoter regions in a process that requires general TRANSCRIPTION FACTORS
52
in eukaryotes translation initiation requires what
both ribosomal units (60S and 40S) with their associated rRNA, mRNA, initiation factors, initiator tRNA charged with methionine, and GTP
53
what is adiponectin
cytokine secreted by fat tissue that increases the number of insulin-responsive adipocytes and regulates fatty acid oxidation increased by PPAR-gamma via thiazolidinediones (glitters)
54
what does nedocromil do
mast cell degranulation inhibitor (along with CROMOLYN)
55
long term glucocorticoid use stimulates anabolism where and catabolism where
anabolism- LIVER (stimulation of GLUCONEOGENESIS and upregulate the synthesis of key gluconeogenic enzymes (PEPCK, G-6-phosphatase), increase in GLYCOGEN RESERVES via expression of glycogen synthase) catabolism- peripheral in the SKELETAL MSUCLE (antagonizing the action of insulin)- provides substrates for gluconeogenesis and glycogenesis in the liver can manifest as: muscle weakness (glucocorticoid myopathy) lipolytic and antilipolyic, altered fat distribution (central obesity, hypertrophy of dorsocervical fat pad) increased appetite and caloric intake HYPERGLYCEMIA (gluconeogenesis and insulin antagonism)
56
what do glucocorticoids do to the skin
``` inhibition of fibroblast proliferation and collagen formation: thinning stria impaired wound healing easy bruising ```
57
how do glucocorticoids decrease bone mass (causing osteoporosis and avascular necrosis)
decreased GI calcium absorption increased renal calcium excretion direct inhibitor of osteoblast activity
58
high levels of what are rewired for spermatogenesis
testosterone | inhibin B
59
how do beta blockers mask hypoglycemia
the neurogenic symptoms of hypoglycemia are caused by SYMPATHOADRENAL ACTIVATION and are mediated via norepi/epi and acetylcholine via sympathetic POSTganglionic fibers symptoms of norepi/epi are tremulousness, palpitations, and anxiety/arousal cholinergic symptoms: sweating, hunger, paresthesias NON-SELECTIVE BETA BLOCKERS will block the norepi/epi mediated compensatory reactions leaving the CHOLINERGIC SYMPTOMS UNAFFECTED blocking beta-2 also stops hepatic gluconeogeneiss, and peripheral glycogenolysis and lipolysis
60
if beta-blocker therapy is needed in a diabetic what is prefered
selective beta-1 blockers | beta-blockers with intrinsic sympathomimetic activity (PINDOLOL, ACEBUTOLOL)
61
what causes the hypervitaminosis D in sarcoidosis
activated MACROPHAGES expression of 1-alpha-hydroxylase this causes 1,25-dihydroxyvitamin D to be produced and increased INTESTINAL ABSORPTION of CALCIUM
62
vimentin (an intermediate filament) is a marker for tumors of what origin
mesenchymal tissue
63
neuron-specific enolase and chromogranin A are markers for what
neuroendocrine tumors
64
what kind of receptor is HER2/neu
EPIDERMAL TRANSDUCTION PATHWAY that control EPITHELIAL GROWTH and DIFFERENTIATION
65
what is derived from surface ectoderm
``` Rathe's pouch (anterior pituitary) lense and cornea inner ear sensory organs olfactory epithelium nasal and coral epithelial linings epidermis salivary, sweat, and mamary glands ```
66
what is derived form neural tube
brain and spinal cord POSITERIOR PITUITRARY PINEAL GLAND RETINA
67
what is derived form the neural crest
``` autonomic, sensory, celiac ganglia schwann cells pia and arachnoid mater aorticopulmonary septum and endocardial cushions branchial arches (bones, cartilage) skull bones melanocytes adrenal medulla ```
68
what is derived from mesoderm
``` muscles (skeletal, cardiac, smooth), connective tissue, bone, and cartilage serosa lining (peritoneum) cardiovascular system blood lymphatic system spleen internal genitalia kidney and ureters adrenal cortex ```
69
what is derived form the endoderm
``` GI tract liver pancreas lungs thymus parathyroids (???) thyroid follicular cells (????) middle ear bladder and urethra ```
70
when do the three germ layers form
GASTRULATION during week 3 go embryogenesis initiated by formation of primitive streak (thickening of epiblast cell layer that appears at caudal end of the embryo and grows cranially)
71
what happens 2 days after gastrulation begins
some epiblast cells migrate cranially though the primitive node (the cephalic end of the primitive streak) to form a midline cellular cord known as the NOTOCORD notochord induces overlying ectoderm cells to differentiate into neuroectoderm and form the neural plate neural plat ogives rise to neural tube and neural crest cells, the rest of the ectoderm becomes the surface ectoderm
72
the notochord becomes what in adults
nucleus pulpous of intervertebral discs
73
what is seen in von Hippel-Lindau
AD disorder HEMANGIOBLASTOMAS in the RETINA and/or CEREBELLUM congenital CYSTS and/or NEOPLASMS of the kidney, liver, and pancreas increased risk for renal cell carcinoma (BILATERAL)
74
what is seen in Sturge-Weber syndrome (encephalotrigeminal angiomatosis)
cutaneous facial angiomas as well as leptomeningeal angiomas skin involvement in V1 and V2 distributions of the trigeminal nerve mental retardation seizures hemiplegia skull radiopacies w/ "TRAM TRACK" calcifications
75
what is seen in tuberous sclerosis
``` AD syndrome kidney, liver, and pancreatic cysts cordial and subependymal HAMARTOMAS cutaneous angiogibromas (adenoma sebaceous) visceral cysts varieties of other hamartomas renal angiomyolipomas cardiac rhabdomyomas SEIZURES ```