Miscellaneous

Question 1

what is tachyphylactic in terms of drug interactions?

Answer 1

acute decrease in response to a drug after initial/repeated administration

ex) nitrates, niacin, phenylephrine, LSD MDMA

Question 2

how can Wilson disease lead to basal ganglia atrophy?

Answer 2

copper accumulates in the brain (basal ganglia)

Question 3

how can nitroprusside cause cyanide toxicity

Answer 3

nitroprusside is metabolized in body to release nitric oxide and cyanide ions

Question 4

how to treat cyanide toxicity

Answer 4

• sodium nitrite: promotes methemoglobin formation, which combines cyanide to form cyanmethemoglobin
• sodium thiosulfate: serves as sulfur donor to promote hepatic rhodanese-mediated conversion of cyanide to thiocyanate to be excreted in urine
• hydroxocobalamin: binds to cyanide ions and forms cyanocobalamin to be excreted in urine

Question 5

osteocytes are connected to each other through

Answer 5

gap junctions

can sense mechanical stresses and send signals to modulate the activity of surface osteoblasts, so they help regulate bony remodeling

Question 6

mechanism of action of colchicine

Answer 6

inhibits leukocyte migration and phagocytosis by blocking tubulin polymerization

used to treat acute gouty arthritis in those who can’t take NSAIDs (normally the first line treatment)

side effects: nausea and diarrhea

Question 7

how does anterior dislocation of the humerus presents

Answer 7

flattening of the deltoid prominence, protrusion of the acromion, and anterior axillary fullness (due to humeral head’s movement into this location)

injured axillary nerve which innervates deltoid and teres minor muscles and provides sensory innervation of the skin overlying the lateral shoulder

Question 8

1st pharyngeal pouch derivatives

Answer 8

middle ear cavity, eustachian tube, mastoid air cells

Question 9

2nd pharyngeal pouch derivatives

Answer 9

epithelial lining of the palatine tonsil

Question 10

3rd pharyngeal pouch derivatives

Answer 10

dorsal wings–> inferior parathyroids

ventral wings–> thymus

Question 11

4th pharyngeal pouch derivatives

Answer 11

dorsal wings–> superior parathyroids

ventral wings–> ultimobranchial body, parafollicular (C) cells of thyroid

Question 12

what is developmental field defect

Answer 12

multiple malformations that occur secondary to an embryonic disturbance in an adjoining group of cells

initial embryonic disturbance leads to multiple malformations by disrupting the development of adjacent tissues and structures within a particular region

Question 13

what are caspases and what do they do?

Answer 13

proteolytic enzymes that cleave cellular proteins- activated by cytochrome c

apoptosis can occur through either intrinsic (mitochondria-mediated) pathway or the extrinsic (receptor-initiated) pathway

both pathways converge in the activation of caspases

Question 14

lymph nodes of the lower extremities

Answer 14

divided into superficial lymphatic vessels (follow venous system) and the deep lymphatic vessels (follow the arterial system)

superficial divided into medial and lateral tracks
-medial track runs up the superficial inguinal lymph nodes, bypassing the popliteal nodes

lesions on the medial foot cause inguinal lymphadenopathy, whereas lateral lesions are more likely to cause lymphadenopathy in both the popliteal and inguinal areas

Question 15

what is responsible for synthesizing cytosolic proteins

Answer 15

free ribosomes floating in the cytosol- translate proteins found found within the cytosol, nucleosol, peroxisome matrix, and nuclear-encoded mitochondrial proteins

the ribosomes on RER synthesizecell membrane proteins

Question 16

homocystinuria-what is the cause and what happens to the individuals affected by this

Answer 16

cause by cystathionine synthase deficiency

affected individuals have marfanoid habitus, ectopia lentis, and developmental delay

many patients respond dramatically to pyridoxine (vitamin B6) supplementation

Question 17

which are the stop codons

Answer 17

UAA, UAG, UGA

Question 18

duchenne muscular dystrophy is caused by what type of mutation

Answer 18

frameshift mutations (most common) or nonsense mutations in the dystrophin gene that lead to the formation of truncated, defective protein

nonsense mutations introduce premature stop codons int he coding sequence of the mRNA

Question 19

how is isoniazid metabolized

Answer 19

metabolized by acetylation

speed of which a patient is able to acetylate drugs depends on whether they are genetically “fast” or “slow” acetylators

Question 20

what is tuberous sclerosis

Answer 20

autosomal dominant condition characterized by cortical tubers and subependymal hamartomas in the brain, with consequent seizures and cognitive disability, cardiac rhabdomyomas, facial angiofibromas, and leaf-shaped patches of skin lacking pigment (ask-leaf patches)

associated with renal angiomyolipoma (benign tumor composed of blood vessels (angio), smooth muscle (myo), and fat (lipoma)

Question 21

amino acid binding site of tRNA

Answer 21

3’ CCA tail

aminoacyl tRNA synthetase is the enzyme responsible for “loading” the appropriate amino acid to the 3’ terminal hydroxyl group of the CCA tail

Question 22

role of ubiquitin proteasome pathway

Answer 22

breakdown of intracellular proteins, both native and foreign, and helps recycle them into the amino acid building blocks

for immune response–> degrade foreign intracellular proteins and couple them to MHC I to present to CD8+ T-cells.

Question 23

presentation of trisomy 18 (Edwards syndrome)

Answer 23

“election age”

micrognathia, prominent occiput (back of head), low-set ears, heart defects, clenched hands with overlapping fingers, renal defects, limited hip abduction, rocker-bottom feet

Question 24

promoter region of transcription in eukaryotic cells

Answer 24

TATA and CAAT boxes located approximately 25 and 75 bases upstream form the transcription start site, respectively

Question 25

primary site for ribosome synthesis and assembly

Answer 25

nucleolus all ribosomal RNA except 5S rRNA is transcribed in the nucleolus

Question 26

body's reaction to high-altitude sickeness

Answer 26

hypobaric hypoxia low barometric pressure so decreased pO2 in air and blood --> tissue hypoxia stimulates peripheral chemoreceptors, causing hyperventilation in an attempt to improve oxygenation --> decreased partial pressure of CO2 (pCO2) and increased pH (respiratory alkalosis) --> renal bicarb excretion to compensates increased pH, decreased pCO2 and pO2

Question 27

drug and volume of distribution

Answer 27

if large molecular weight--> bound extensively to plasma proteins, or highly charged, then drug remaining the plasma compartment and the volume of distribution is usually low (3-5 liters) if small molecular weight, but is hydrophilic, then can distribute into the interstitial fluid compartment outside of blood vessels and intravascular compartment (volume of distribution is limited to a total volume of about 14-16 liters (plasma + interstitial)) small molecular weight and uncharged--> dross cell membranes and reach intracellular compartment have the highest volume of distribution (41 liters)

Question 28

financial arrangement: define capitation

Answer 28

payer (individual, employer, or government entity) pays a fixed, predetermined fee to cover all medical services required by a patient payment structure underlying HMO

Question 29

Beers criteria: common drugs to avoid in older patients

Answer 29

- anticholinergic: first gen antihistamines (diphenhydramine), GI antispasmodics - cardio: alpha-1 blockers, centrally-acting alpha-2 agonists, many antiarrhythmics - CNS: tricyclic, antipsychotics, barbituates, benzo, and other hyponotics - endocrine: long-acting sulfonylureas, sliding-scale insulin - pain: non-selective NSAIDS, and skeletal muscle relaxants

Question 30

drug distribution by organs

Answer 30

after IV administration, highly lipophilic drug will rapidly distribute to organs with high blood flow (brain, liver, kidneys, lungs) then to tissues with lower blood flow (skeletal muscle, fate, and bone)

Question 31

what causes increased ESR?

Answer 31

high levels of circulating fibrinogen cytokines IL-1, IL-6, and TNF-alpha mediate systemic inflammatory response and stimulate hepatic secretion of acute-phase proteins (eg, fibrinogen)

Question 32

function of prokaryotic DNA polymerase

Answer 32

Prokaryotes have 3 types of DNA polymerase: I, II, and III all 3 DNA polymerases are capable of removing mismatched nucleotides via their 3' to 5' exonuclease (proofreading) activity only DNA polymerase I has 5' to 3' exonuclease activity, which is used to remove the RNA primer synthesized by RNA primase

Question 33

how does glycogen degradation synchronized with skeletal muscle contraction

Answer 33

due to release of sarcoplasmic calcium calcium causes activation of phosphorylase kinase, stimulating glycogen phosphorylase to increase glycogenolysis

Question 34

phosphatidylinositol 2nd messenger system

Answer 34

ligand binds to G protein-coupled receptor--> activates phospholipase C, which is broken down into DAG and IP3--> protein kinase C is activated by DAG and calcium--> protein kinase C phosphorylates downstream intracellular proteins to produce its physiologic effects (eg, smooth muscle contraction) IP3 increase intracellular calcium to activate more protein kinase C

Question 35

what characteristic of drugs are more likely to be processed by the liver for metabolism

Answer 35

drugs with more lipophilic properties processed by liver into more polar compounds to be eliminated in bile and urine

Question 36

blotting technique and what substance each detect

Answer 36

northern--> RNA (use single-stranded DNA or RNA (hybridization probe)) southern--> DNA (use ss DNA or RNA (hybridization probe)) western--> protein (antibody probe) southwestern--> DNA-binding protein like transcription factors, nucleases, and histones (dsDNA probe)

Question 37

what is c-Jun

Answer 37

DNA-binding protein nuclear transcription factors that directly bind DNA via a leucine zipper motif

Question 38

effects of different doses of dopamine

Answer 38

low: stimulates D1 receptors in renal and mesenteric vasculature--> vasodilation and increased blood flow to these sites increasing doses--> stimulate beta1 and alpha 1 receptors--> increased cardiac output and eleveated systemic vascular resistance higher dose--> increase in afterload can lead to decreased cardiac output

Question 39

efficacy of drugs

Answer 39

refers to the intrinsic ability of a drug to elicit an effect measure of maximum ceiling of activity (Emax) of a drug with respect to a particular pharmacodynamic end point

Question 40

potency of drug

Answer 40

refers to dose of drug that is required to produce a given effect affected by affinity of drug to receptor and amount of drug that is able to reach the target tissues measure with ED50, lower the greater potency

Question 41

histones

Answer 41

nucleosomes are composed of DNA wrapped around a core of 8 histone proteins (2 molecules each of H2A, H2B, H3, and H4) H1 histone is located outside of this histone core and helps package nucleosomes into more compact structures by binding and linking the DNA between adjacent nucleosomes

Question 42

what are P bodies

Answer 42

distinct foci found within eukaryotic cells that are involved in mRNA regulation and turnover play a role in translation repression and mRNA delay and contain numerous proteins including RNA exonucleases, mRNA decapping enzymes, and constituents involved in mRNA quality control and microRNA-induced mRNA silencing

Question 43

what happens to proteins destined for the lyssome

Answer 43

they require phosphorylation of specific mannose residues to ensure proper transit through Golgi apparatus in the lysosome, they serve as catalysts for degradation of cellular components

Question 44

triple helical conformation of collagen molecules occurs due to simple and repetitive amino acid sequence within each alpha chain with what amino acid in every third amino acid position

Answer 44

glycine | Gly-X-Y

Question 45

common causes of Down syndrome

Answer 45

- meiotic nondisjunction: extra chromosome 21-- based on maternal age - unbalanced translocation: all or part of additional chromosome 21 attached to another chromosome - mosaicism: some (not all) cells have extra copy of chromosome 21 or nondisjunction event in early embryonic life

Question 46

how many half-lives does it take for the drug (metabolized by first-order kinetics) that is given by continuous infusion to reach stead state?

Answer 46

reach steady state in 4-5 half-lives

Question 47

in hyperthyroidism, the upper eyelids are retracted, why?

Answer 47

hyperthyroidism induces increased expression of adrenergic receptors and leads to a hyperadrenergic state excess adrenergic stimulation of the superior tarsal muscle causes increased resting tone and retraction of the lid

Question 48

what is in each of the compartments of the leg

Answer 48

anterior: deep peroneal nerve, anterior tibial artery and veins deep posterior: tibial nerve and peroneal artery and veins lateral: superficial peroneal nerve

Question 49

what is vitamin C used for in the body

Answer 49

necessary for hydroxylatioin of proline and lysine residues during collagen synthesis deficiency--> capillary bleeding, poor wound healing, and periodontal disease in children, bony deformities and subperiosteal hemorrhages

Question 50

what is deficient in alkaptonuria

Answer 50

homogentistic acid dioxygenase can't convert tyrosine to fumarate so accumulation of homogentisic acid leading to black urine color when exposed to air, blue-black pigmentation on the face, and ochronotic arthropathy

Question 51

what is tertiary preventsion

Answer 51

treating an established condition with the goal of minimizing its progression or complications

Question 52

what is health promotion

Answer 52

process of enabling people to increase control over their health and its determinants and thereby improve their health

Question 53

key findings with Patau syndrome (trisomy 13)

Answer 53

"puberty=13" due to secondary to meiotic nondisjunction in mothers of advanced maternal age defective prechordal mesoderm fusion resulting in midline defects (eg, holoprosencephaly, microphthalmia, cleft lip/palate, omphalocele, polydactyly, cutis aplasia, rocker-bottom feet, renal and cardial defects,a dn umbilical hernia/omphalocele

Question 54

when does linkage disequilibrium occur?

Answer 54

occurs with two genetic loci when their respective alleles are inherited together in the same gamete more or less often than expected by chance alone given their corresponding allele frequencies most often occurs when the genes are in close physical proximity on the same chromosome so get crossed over together