Heston Step 1 Flashcards
Depending on oxygen availability, what two pathways do cells use to produce energy?
Anaerobic glycolysis and Oxidative Phosphorylation
when does anaerobic glycolysis occur?
occurs in oxygen poor states; coverts glucose to pyruvate to lactate in the cytosol which is excreted from the cell.
when does Oxidative Phosphorylation occur?
Occurs in oxygen rich states; moves pyruvate from the cytosol to the mitochondria where it is converted to acetyl-coa and runs through the tricarboxylic acid cycle
where do stem cells and cancer cells generate most of their energy?
Anaerobic glycolysis; despite the presence of adequate oxygen (Warburg effect)
what is the Warburg effect?
cells produce more lactate than a normal terminally differentiated cells (stem and cancer cells) as almost all the glucose is converted to lactate and excreted
symptoms of tuberculosis?
cough, hemoptysis, night sweats, fever, weight loss , chess pain
what is silicosis?
occupational lung disease caused by inhalation of crystalline silica and characterized by multiple rounded nodules in the upper lobes. patients may develop calcification of the rim of hillier lymph nodes (eggshell calcification)
silicosis and impaired macrophage function
silicosis is associated with increased risk of mycobacterial infections, particularly mycobacterium tuberculosis, due to impaired macrophage function
what can cystic fibrosis cause?
recurrent pulmonary infections due to impaired pathogen clearance. (impaired mucociliary clearance0
what is sickle cell disease (SCD)?
autosomal recessive disorder caused by the predominance of hemoglobin S, causing red blood cells to sickle. hemolyze and cause vascular obstruction. (offspring of carrier parents have a 3/4 chance of inheriting at least 1 mutated allele)
symptoms of sickle cell disease?
anemia, swelling (hands and feet), pain episodes, frequent infections, delayed growth, Vision problems
unaffected parents of an affected sickle cell offspring means?
both parents are carriers and the probability of inheriting each of the three possible genotypes (AA, Aa,aa) is determined using a Punnett square (75% chance of being affected)
verrucuos, skin colored genital lesions are most consistent with?
condylomata acuminatum (anogenital warts)
Cause of condylomata acuminatum?
HPV (human papillomarvirus) most common sexually transmitted disease
What kind of cells does HPV affect?
basal epithelial cells; predilection for stratified squamous epithelium, found in the anal canal, vagina and cervix. those same cells are found in the vocal chords
how can infants be affected by HPV?
infants can acquire papillomatosis via passage through the birth canal of mothers infected by the virus. (warty growths on the true vocal chords can lead to weak cry hoarseness and stridor
the presence of “Gowers Sign” (use of hands to rise from squat or from chair to compensate proximal weakness) and calf enlargement in a boy age 2-5 is classic for?
DMD ( Duchenne muscular dystrophy )
structural component of skeletal muscle fibers that provides mechanical stability to the sarcolemma
Dystrophin
what does dystrophin do?
links a component of the cytoskeleton (actin) to transmembrane proteins that are connected to the extracellular matrix
frameshift mutations
deletions that are not a multiple of 3 change the reading frame. which results in non functional proteins and severe clinical manifestations of DMD (Duchenne muscular dystrophy)
pregnancy of twins with different sexes can only occur in? and why?
Dizygotic twins; due to the fertilization of 2 oocytes by two different sperm.
dizygotic twins are almost always?
diachorionic & diamnotic (because they have two separate chorions and amnions
what are the longterm changes in gas exchange in the lungs
The alveolar arterial (A-a) oxygen gradient progressively widens over decades which causes the arterial partial pressure (PaO2) to fall but the carbon dioxide (PaCO2) does not change
acute compartment syndrome (ACS)
pressure in the fascia compartment rises causing severe pain and tissue ischemia after long bone fractures, crush injury or thermal injury
Most common site for ACS (acute compartment. syndrome)
anterior compartment of the leg which includes extensor muscles, anterior tibial artery and deep perineal (fibular) nerve; can cause decreased sensation in the first and second toes
legionella pneumonia (gram negative rod)
fever, headaches, diarrea. sputum gram stain shows many neutrophilis but few to no organisms.
what happens to vasopressin during septic shock?
it is suppressed, vasodilatory mediators overwhelm endogenous vasoconstrictor mechanisms
manifestations od sepsis
Low blood pressure, fever, leukocytes elevated.
what is sepsis?
inflammatory response to infectious pathogen
vasopressin deficiency contributes to unbalanced vasodilation and refractory hypotension causing?
septic shock
The thick white patches seen on this patients tongue are indicative of?
oral thrush (oropharyngeal candidiasis)
Treatment for oropharyngeal candidiasis?
Nystatin (polyene antifungal) it is not absorbed in the gastrointestinal tract
Risk factors of thoracic aortic aneurysm?
above age 60, smoking, hypertension, family history, connective tissue disease (Marfan syndrome)
clinical presentation of thoracic aortic aneurysm?
usually asymptomatic, vague chess or back pain, hoarseness or dysphagia, hemodynamic instability, majority involve ascending aorta.
imaging findings in thoracic aortic aneurysm?
wide mediatinum, large aortic knob, traqueal deviation
what is alkaptonuria?
autosomal recessive disorder caused by deficiency homogentisic acid deoxygenase (metabolizes homogentisic acid into maleylacetoacetate)
symptoms of alkaptonuria?
pigment deposits in connective tissue throughout the body (blue-black deposits) often appear in sclarae, ear, large joints and spine causing motion restriction and significant pain.
urine of these patients turn black when exposed to air because of oxidation of homogentisic acid
major depressive disorder characterization
lasts 2 weeks more or less, has significant function impairment, depressed mood and sidecaps
persistent depressive disorder characteristics
chronic depressed mood that lasts at least two years; has two or more of the following: appetite disturbance, sleep disturbance, low energy, low self esteem, poor concentration, hopelessness
adjustment disorder with depressed mood characteristics
onset within 3 months with identifiable stressor, marked distress &/or functional impairment
avoidant personality disorder characteristics
onset in early adulthood life with pattern of pervasive inhibition, feelings of inadequacy, hypersensitivity to evaluation
chronic fatigue syndrome characteristics
more than 6 moths of significant reduction in activity with the fatigue not relieved by rest, drastic worsening of symptoms after activity, sleep impairment and cognitive impacts (brain fog)
what morphological change occurs due to direct tissue damage from a burn?
histamine and other preformed vasoactive mediators from mast cells release in minutes following a burn which leads to the dilation of superficial skin capillaries
In the heart of an athlete what happens?
maximum cardiac output is increased, left ventricle cavity size is increased but the fraction of ejection stays the same
carcinoembryonic antigen (CEA) is a glycoprotein found in what organs?
embryonic pancreas, liver and intestine
Carcinoembryonic antigen (CEA) levels are elevated in most patients with colon cancer; elevated preoperative levels of CEA are are associated with a worse prognosis and failure to normalize suggests?
A risidual disease
To perform a cricothyrotomy procedure creating an airway through the placement of a tube between the thyroid and cricoid, incisions must be made through which structures?
- Skin
- Superficial cervical Fascia
- investing and petracheal layers of deep cervical fascia.
- Cricothyroid membrane
Symptoms of epiglottitis?
- Childs fever
- respiratory distress ( inspiratory stridor)
- inflamed epiglotis
Epiglotitis is most commonly caused by?
Haemophilus Influenzae type b
What is the major virulence factor of Haemophilus influenza type b (HIB)?
its polycacharide capsule, composed of the polymer cpolyribosylribitol phosphate
azathioprine is a an immunosuppressant used in what cases?
- prevention of organ transplant rejection
- treatment of autoimmune diseases such as rheumatoid arthritis, inflammatory bowel disease and autoimmune hepatitis
Proximal muscle weakness resembling polymyositis, inflammatory skin finding including heliotrope rash in the periorbital area (shown in picture) and cheeks and grotton papules (raised erythematous plaques over the joints and bony prominences of the hand are indicative of what systemic autoimmune disease?
Dermatomyositis
- may occur alone or as a pareneoplastic syndrome of underlying malignancy
- most commonly due to underlying adenocarcinoma
- common symptom are “groton papules)
symptoms of general anxiety disorder (GAD)
excessive and chronic worrying, feeling on edge, muscle tension, insomnia
General anxiety disorder is treated with cognitive behavioral psychotherapy and/or antidepressant medication such as?
- Selective serotonin reuptake inhibitors (SSRI’s) such as citalopram 2. serotonin noreprephine reuptake inhibitors (SNRI’s)
first line treatments
why are benzodiazepines such as alprazolam, clonazepam and diazepam considered as second line treatment for General anxiety disorder?
the risk of dependance and tolerance and the potential for rebound and withdrawal syndrome with abrupt discontinuation
chronic kidney disease results in impaired conversion of 25-hydroxyvitamin D to 1,25 dihydroxyvitamin D due to what factors?
- increased levels of FGF23 (growth factor) which inhibits 1-alph-hydroxylase
- limited delivery of 25-hydroxvitamin d to proximal tube cells
- reduced functional renal mass which emits production of 1-alpha-hydroxylase
During an orchiopexy (placement and fixation of testis in scrotum), the malpositioned testis will be pulled through what physiological opening?
superficial inguinal ring which is a physiological opening in the external oblique aponeurosis above the pubic tubercle
Positive anti-HAV Igm indicates?
acute or recent hepatitis A infection, most commonly caused by close contact with an infected person, consuming contaminated food or drinks. outbreaks often occur in vrowded places like health care facilities, prisons or daycare centers
symptoms of Hepatitis A?
loss of appetite, nausea, vomitting, fatigue, fever, abdominal pain . diarrhea
in chronic obstructive pulmonary disease (COPD) (an advanced hypoxic lung disease) vasoconstriction con promote pulmonary hypertension causing what affect on the heart?
increased right ventricle afterload
zolpidem, zaleplon and eszopiclone are hypnotics and examples of what class of drugs?
non-benzodiazepines
Nonbenzodiazepines, like benzodiazepines bind to GABA receptors are the benzodiazepine receptor site where they act as?
GABA agonists
Benzodiazepines produce what effects?
anxiolytic, muscle relaxant and anticonvulsant effects
H pylori is prevalent in what parts of the world?
asia and South America
PUD (peptic ulcer disease) or most patients with duodenal ulcers a have concomitant?
Helicobacter Pylori Infection
treatment and prevention of ulcer reoccurrence require the eradication of H-Pylori infection with the use of what medication?
Combination of antibiotics such as (tetracycline, metronidazole) and proton pump inhibitor such as (omeprazole)
shigella gastroenteritis symptoms?
- abrupt high fever
- abdominal cramping
- stool that starts watery before mucus and blood appears
- left side abdominal tenderness
(stool culture diagnostic)
common causative organisms in bacterial gastroenteritis with bloody diarrhea include?
escherichia coli, shingella and campylobacter
Edema of the proximal trachea causes what sounds upon breathing?
inspiratory trader, barking cough and hoarseness
Symptoms of Croup
rhinorrhea, nasal congestion, barking cough, retractions and inspiratory stridor
Cause of croup?
viral infection caused by the parainfluenza virus, most commonly seen in children ages 6 months to 3 years
respiratory acidosis occurs due to retention of CO2 in the lungs and presents with low pH and high PaCO2
Metabolic acidosis occurs due to depletion of HCO3 and is characterized by?
low pH and low HCO3
pancreatic neuroendocrine tumor symptoms?
epigastric pain, weight loss, jaundice, palpable mass
both functional and nonfunctional pancreatic neuroendocrinic tumors are well circumscribed lesion composed of what type of cells?
uniform tumor cells with organoid architecture (nested, granular, ribbon or pseudorosette arrangement
Wilsons disease
defective copper transporter within hepatocytes, resulting in copper accumulation in the liver, eye, and brain
treatment of Wilsons disease?
Penicillamine, a copper chelating agent, which causes it to be excreted in urine. common adverse effect is nephrotic syndrome causing proteinuria due to membranous nephropathy
the treatment for patients with gouty arthritis is nonsteroidal anti inflammatory drugs but these medication are contraindicated in patients with what disease?
peptic ulcers
pharmaceutical treatment for patient with acute gout
colchicine; inhibits tubulin polymerization into microtubules
if patients from Southeast Asia have weight loss, cough, apical infiltrate with acid fast bacilli, it raises strong suspicion of what disease?
pulmonary tuberculosis
a learning disorder is characterized by difficulties in what key academic skills?
reading, writing or mathematics
(learning disorders can be the cause of anxiety, stress, emotional outburst, hyperactivity or inattention
newborn patient with bilious emesis, and abdominal distention can be at risk of?
midway malrotation
midgut malrotation can result in narrow mesenteric base that is vulnerable to twisting around the mesenteric artery resulting in?
MIDGUT VOLVULUS
symptoms are low-grade fever, , flank pain, nausea, vomiting
what is the most likely diagnosis
renal infarction: commonly caused by cardioembolitic disease. originating from the left atrium or ventricle
what are common lab abnormalities associated with renal infarction?
elevated lactate dehydrogenase( suggestion cell necrosis, hematuria, mild leukocytosis.
pathology shows sharply demarcated yellow, white wedge shaped infarcts
heart failure causes increased hydrostatic in pulmonary circulation due to backup of blood flow from what failing heart structure?
the left ventricle
“jersey finger” is a rupture of what tendon in the finger?
flexor digitorum profundus
the use of immune suppressing medication such as glucocorticoids can lead to the reactivation of what disease? (commonly known to never reappear)
varicella zoster virus
the rash is congruent with what disease?
Varicella zoster virus
An inflammatory condition that begins in childhood with storm such as dry skin, crusting, itching and dryness is known as?
atopic dermatitis (eczema)
treatment of eczema?
carticosteroids
oral thrush, interstitial pneumonia and severe lymphopenia during the first year of life are consistent with what pathology?
vertical transmission of HIV-1
what medication is used to treat HIV positive mothers giving birth to prevent transmission of HIV?
Antiretroviral therapy (ART)
disease common inn patients with lung transplants?
Cytomegalovirus
Cytomegalovirus is what kind of virus?
enveloped double stranded dna virus
Lynch syndrome (hereditary nonpolyposis colon cancer) is an autosomal dominant disease caused by?
defective DNA mismatch repair
As people are, aortic compliance decreases which causes…
1. systolic pressure to?
2. systolic pressure to?
3. pulse pressure to?
Systolic to increase
systolic to decrease
pulse pressure is the difference between systolic and diastolic so it will also increase
weight bearing exercise helps prevent further bone loss by altering osteocyte (shown in picture) activity through a process known as?
force adaptation
neonate with retinal lesions (chorioretinitis) and hydrocephalus has a placenta containing inflammatory cells, calcifications and crescent shaped organisms consistent with?
congenital toxoplasmosis ( usually contracted by eating undercooked meat)
what landmark with best aid a surgeon in distinguishing between a direct and indirect hernia?
inferior epigastric vessels
Direct inguinal hernias occur due to weakness of what structure?
transversals fascia allowing contents too protrude medial to the inferior epigastric vessels into the hasselbach triangle
Indirect inguinal hernias occur due to?
failure to obliterate processus vaginalis allowing abdominal content to go lateral toward the inferior epigastric vessels and possible through the deep inguinal ring
s2 to s4 nerve roots innervate what structures?
pelvic floor muscles and urinary sphincter
toxoplasma gondii treatment
sulfadiazine plus promethamine (inhibit tetrahydrofolate, a necessary cofactor for purine nucleotide synthesis)
cytokeratin is a commonly used inmunohistochemical marker for what type of tumors?
epithelial derived tumors (cytokeratins are found in almost all epithelial cells)
the most likely pathogenesis of epithelial ovarian cancer is repeated injury and repair to the ovarian surface ( makes epithelial cells susceptible to malignant transformation) in other words “ovulation”… what is the most likely way to reduce the risk of this happening?
use of combined oral contraceptive pills (suppress ovulation)
what do proton pump inhibitors such as omeprazole do in relation to gastroesophageal reflux disease?
they bind to and irreversibly inhibit H+/K+ ATPase activity on parietal cells
the most common germline mutation in breast and ovarian cancer is a defect in the BRCA gene. BRCA1 &2 produce tumor suppressing proteins involved in what process?
repair of double stranded DNA breaks
arginase deficiency symptoms
spastic diplegia, abnormal movements, growth delays in the setting of elevated Arginase levels (urea cycle)
facial pain, headaches, jaw dysfunction and ear muffles hearing are all symptoms of?
temporomandibular disorder (hypersensitivity of the mandibular nerve)
most common finding in posterior cerebral artery stroke?
contralateral homonymous hemianopia with macular sparring due to damage of occipital cortex
contralateral hemisensory loss, due to damage to the thalamus
elevated levels of plasma homocysteine is an independent risk factor for thrombotic events….. homocysteine through remethylation con be converted to?
methionine
light skin/eye color, seizures, musty body odor are suggestive of?
phenylketonuria (autosomal recessive disease)
Phenylketonuria is caused by deficiency of phenylalanine hydroxylase which catalyzes the conversion of phenylalanine to?
tyrosine
adhesion of cells to the extracellular matrix involves integrin mediated binding to?
fibronectin, collagen and laminin
collagen type 1 is found in what parts of the body? (associated disease “osteogenesis imperfect”)
skin, bone, tendons, ligaments, cornea, blood vessels, scar tissue
Collagen type 2 is found in what parts of the body? (associated disease “skeletal dysplasia’s”)
Cartilage, vitreous humor and nuclear pulposes
colagen type 3 is found in what parts of the body?(associated disease “vascular Ehlors Danlos syndrome type 4”)
skin, lungs, intestines, blood vessels, bone marrow, lymphatics and granulation tissuec
collagen type 4 is found in what parts of the body? (associated disease “aport syndrome”)
basement membrane
neurofibromatosis type 1 is an autosomal dominant nuerocutaneous disorder caused by mutation in the NF1 tumor suppressor gene. what are the symptoms?
hyper pigmented macules over the trunk (also soon after birth), elevated intracranial pressure….
cutaneous neurofibrosis manifest during adolescence as multiple raised fleshy tumors and increase in number and size with age…. these are derived from what embryological derivative?
Neural Crest
occlusion of the anterior cerebral artery would have what effect?
the sensory and motor function of collateral leg and foot while predominantly sparing the collateral arm/face
lactate accumulation in the blood leads to?
anion gap metabolic acidosis
acidosis stimulates renal ammonia genesis a process by which renal epithelial cells metabolize _______ which generates ammonium and _______.
glutamine & Bicarbonate
In renal metabolism, _____ is crucial for acid base balance. The kidneys metabolize it to produce ammonium which is excreted in urine thereby eliminating hydrogen ions and reducing blood acidity.
glutamine
phenytoin and other anti epileptic drugs are inducers of cytochrome p-40 enzymes that convert 25 hydroxyvitamin D to 24,25 dihydroxyvitamin D (inactive form) as a result of… there is less 25 hydroxyvitamin d to convert to what?
1, 25 dihydroxyvitamin D (active form) leading to deficiency
any viral infection followed by a bacterial infection is likely caused by what pathogen?
Strep pneumonia
what is leukotriene b4 and what does it do?
it is an aravhidonic acid that os released when there is an infection or any other inflammatory tissue injury.
a patients slow/incomplete gallbladder emptying in response to cholecystokinin stimulation is consistent with what pathology?
Gallbladder hypomotility
the gallbladder function is to absorb water from bile, conditions that cause gallbladder hypomotility results in excessive dehydration of bile causing?
viscous binary sludge
the pathogenesis of this patients 1cm mucosal lesion in the sigmoid colon is a result of of? what is the pathogenesis?
a result of the mutation of the APC tumor suppressor gene (usually the first mutation) Pathogenesis: tubular adenoma
when there is a young lady with underdeveloped ovaries, and the ovarian tissue is replaced with connective tissue what is. the pathology?
turner syndrome
characteristics: Webbed neck, aortic dissection, short stature, broad chest, renal abnormalities
direct factor xa inhibitors have what effect on partial thromboplastin time and thrombin time?
it prolongs them both because its effect takes place in the juncture of both intrinsic and extrinsic pathways
adenovirus infection occurs year round with outbreaks in crowded places, such as dorms, military Baracks and camp dorms, how is this infection transmitted?
via direct contact, fecal oral route, respiratory droplets
constriction of the efferent (outgoing ) arteriole will impede blood flow through the kidney. this is do what to the renal plasma flow but also increase the filtration fraction
decrease
Impaired thermogenesis in relation to preterm infants
neonates are susceptible to hypothermia, they lack the ability to shiver (create heat) newborns have brown adipose tissue (contain mitochondria) that produce heat. in preterm babies, they lack that tissue and as such have impaired thermogenesis. thermogin does not trigger ATP synthesis
what is the superior mesenteric artery syndrome?
gastrointestinal vascular disorder in which the third and final portion of duodenum is compressed between the abdominal aorta and overlying superior mesenteric artery.
learn extra gallop heart sound
here
how does one come to clasiffy superior mesenteric artery syndrome?
lack of intraabdominal fat, states of extreme weightloss (anorexia nerviosa), mesenteric fat depletion, abdominal pain, emesis
symptoms of meralgia paresthatica?
LFCN lateral femoral cutaneous nerve compression
numbness in the lateral thigh above the kneee, pain, paresthesia, but strength is normal because it doesnt contain motor fibers.
decreased sensation of the lateral femoral cutaneous nerve is consistent with what pathology?
meralgia paresthetica
how is filtration fraction calculated?
FF = glomerular filtration rate (GFR) / Renal plasma flow (RPF)
GFR calculated by insulin or creatine clearance
RPF calculated by para-aminohippuric acid
(urine concentration x urine flow rate) / plasma concentration (serum)
then divide GFRb by RPF
signs of post party depression
learn
CREST syndrome
Calcinosis: Calcium deposits under the skin
Raynaud’s phenomenon: Blood vessels in the fingers or toes spasm in response to cold or stress
Esophageal dysmotility: Difficulty swallowing
Sclerodactyly: Skin tightens, causing the fingers to bend
Telangiectasia: Dilated vessels on the skin, such as spider veins, that can appear on the fingers, face, or inside the mouth
unilateral, painful, eczematous rash confined to the nipple and areola; sometimes seen with scaling and ulceration
paget disease of the breast (adenocarcinoma cells)
patients with chronic infections such as HIV develop anemia of chronic disease due to high circulating levels of inflammatory cytokines which causes what problem with iron?
maladaptive changes to iron utilization
what enzyme involved in DNA synthesis catalyzes the formation of RNA?
primase (an RNA polymerase) aslo Uracil is found only in RNA
zidovudine is a nucleoside reverse transcriptase inhibitor that maternal to fetal transmission of HIV during labor. the nucleotides are added to the 3’- hydroxyl group using a ___________ which results in chain termination
phosophodiester bond
what pathology does this MRI show?
cerebral arteriovenous malformation (can lead to aneurysms, headache, seizures; frequent in young children)
smooth muscle cells are responsible for synthesizing the extracellular matrix proteins such as collagen and proteoglycans the form the fibrous cap in mature atheroma/. the buildup of this can lead to?
rupture (heart attack)
