Physio/Path Flashcards
MEN 2B
Medullary carcinoma of thyroid, pheochromocytoma, oral and intestinal mucosal neuromas. ret gene.
MEN 2A
Medullary carcinoma of thyroid, pheochromocytoma, parathyroid. ret gene. Medical Physicians Are Parental But Neurotic
MEN1
AD; 3 P’s - parathyroid, pituitary, pancreas. MEN1 gene
Superior Vena Cava syndrome presentation?
Impaired venous return = facial edema and plethora, venous distension distal to obstruction; Lung cancer is most common etiology
Trochlear nerve palsy presents as
Vertical diplopia, most commonly seen when looking towards nose
Histology of hyperplastic arteriosclerosis
Onion-like concentric thickening of walls b/c of laminated SMCs and reduplicated BM’s
Pathophysio of Paget’s disease of bone?
Excessive osteoclastic bone resorption; unknown etio (?paramyxovirus). High Alk phos. Bone pain. Older patient. Inc. risk for osteosarcoma. Characterized by episodes of bone resorption then bone accumulation. (Osteolytic phase, mixed phase, osteosclerotic phase). “Mosaic lines.” “Woven bone.”
Osteoclastic differentiation?
From hematopoietic progenitor cells; RANK-L and M-CSF
Etio of subacute cerebellar degen?
Paraneoplastic often w/ SCLC; AB-mediated! (Anti-Yo, P/Q, Hu)
Blotchy red muscle fibers? (on Gomori trichome stain)
Mitochondrial myopathies - abnl mt accumulate under sarcolemma
Cystic fibrosis - details of CFTR mutation
Chromosome 7; DelF508; ATP-binding cassette transmembrane ione transporter that uses ATP to pump Cl- against gradient out; Hydrates mucosal surfaces, secretion from exocrine pancreas, sweat (hypotonic)
Axonal reaction
Changes in neuronal body after axon severing. Cellular edema, peripheral nucleus, Nissl substance dispersed (central chromatolysis); starts 24-48 h after
Classic triad of reactive arthritis?
Non-GC urethritis, conjuctivitis, and arthritis. HLA-B27 associated. seronegative spondylarthropathies causing sacroiliitis ~20% time.
Most common autoab’s in SLE?
ANA (sensitive). Anti-dsDNA (specific). Anti-Smith (=anti-snRNPs, specific).
Dermatitis herpetiformis
Erythematous, puritic papules, vesicles. B/l, symmetric on extensor surface. Associated with CELIAC disease. Formation of IgA and IgG ab against gliadin, cross-react with reticulin. Immuno will reveal IgA deposits in tips of dermal papillae.
Pseudogout
Calcium pyrophosphate deposition disease. RHOMBOID weak Positive birefringence (blue when parallel and yellow when perpendicular). WBC w/ neutrophilic.
Hematogeneous osteomyelitis affects what area of bone?
Metaphysis of long bones (children) b/c of slow-flowing vasculature. tx = debridement + abx
Carcinogens like arsenic, thorotrast, and PVC can lead to what cancer?
Hepatic angiosarcoma. Express CD31 (epithelial)
MM
Easy fatigability, constipation, back pain, azotemia. Large eosinophilic casts composed of Bence-Jones proteins.
Hypercalcemia associated with cancer usually due to?
Overproduction of parathyroid-hormone-related protein (PTHrP). It’s also an inhibitor of phosphorus reabsorption
Potter sequence
Final pathway from oligohydramnios. True Potter syndrome from b/l renal aplasia. Leads to clubfeet, pulmonary hypoplasia, facies.
Primary hyperparathyroidism
Adenoma in 80-85%, hyperplasia in 10-15%. Inc. renal absorption, inc. GI absorption b/c of 1,25-D, and increased bone resorption via osteoclasts. Bone loss, renal stones, ulcers, psych. Subperiosteal erosions.
Causes of ED
Psychogenic stressors, anxiety/depression, SSRIs, sympathetic blockers, vascular/neuro impairment, GU trauma
Net filtration pressure =
Hydrostatic pressure gradient - oncotic pressure gradient
Coagulation necrosis?
Irreversible ischemic injury EXCEPT brain. Tissue arch preserved. But anucleated cells with eosionphilic cytoplasm.
Wilsons Disease
Kayser-Fleischer ring. AR, dec. formation and secretion of ceruloplasmin (Cu can’t get to biliary system for excretion). Damages hepatocytes. Atrophy of basal ganglia. Tx = cu chelators (d-penicillamine and trientine). Neuropsych. Dx = dec. ceruloplasmin. Path - degenerated putamen.
Strawberry hemangiomas
Capillary hemangiomas are benign vascular tumors of childhood appearing early in 1st weeks, growing rapidly, then regressing by 5-8.
Hemochromatosis
HFE encodes HLA I-like molecule that affects Fe absorption. (C282Y).
Drug-induced lupus
Linked to drugs metabolized by N-acetylation in the liver (e.g. hydralazine and procainamide). Acetylator phenotypes associated with genetic disposition.
The major genes in pathogenesis of colon cancer?
APC (to polyp), RAS (to larger polyp), p53 + DCC (to malignancy)
Why is nephrotic syndrome a hypercoagulable state?
Loss of anticoagulation factors, especially anti-thrombin III
Buerger’s disease
Thromboangiitis obliterans - vasculitis of medium and small arteries (e.g. tibial and radial). Segmental! Fibrous. SMOKING.
Path of Temporal arteritis?
Granulomatous inflammation.
Most potent cerebral vasodilator
pCO2. Decreases cerebral vascular resistance -> inc. cerebral perfusion and intracranial pressure. COPD patients have hypercapnia and therefore have increased cerebral circulation
Dietary aflatoxin exposure associated with?
G:C -> T:A in codon 249 of p53 -> HCC risk. Aspergillus toxin in Asia/Africa
Sarcomere
Z to Z. Thick line = M-line. Actin in I-Band attaches at Z-line. Myosin in H-Band attaches at M-line.
Sensitive indicator for apoptosis?
DNA laddering - during karyorrhexis, endonucleases cleave internucleosomal regions -> 180bp fragments.
Sarcomere
Z to Z. Thick line = M-line. Actin in I-Band attaches at Z-line. Myosin in H-Band attaches at M-line. “H&M” “I&Z”
Bcl-2 f(x)?
Prevents cytochrome-c release by binding to and inhibiting Apaf-1, which induces caspace activation. Over-expressed bcl-2 -> tumorigenesis (e.g. follicular lymphoma)
Extrinsic pathway of apoptosis
Two pathways. Ligand receptor (FasL binding to Fas; medullary negative selection). Crosslinking of Fas to FasL leads to binding site formation for death domain-containing adapter protein FADD, which activates caspases. OR cytotoxic release of Granzyme B + perforin.
Fibrinoid necrosis
Vasculitides, malignant hypertension. Appears amorphous and pink on H&E
Gangrenous necrosis
Dry (ischemic coagulative) and wet (infection). Limbs and GI
Liquefactive necrosis
Brain, bacterial abscess. Enzymatic degradation FIRST.
Coagulative necrosis
Heart, liver, kidney (tissues supplied by end-arteries). Inc. binding of acidophilic dye. Proteins denature first, THEN enzymatic degradation. Tissue architecture preserved. Eosinophilic cells.
Liquefactive necrosis
Brain (not much stroma), bacterial abscess. Abscess, CSF-filled spaces. Enzymatic degradation FIRST.
Areas susceptible to hypoxia/ischemia and infarction
Watershed areas (brain, splenic flexure, rectum). Subendocardium (LV). Straight segment of proximal tubule and thick ascending limb. Central vein (liver). HIE affects pyramidal cells of hippocampus and purkinje of cerebellum
Red vs. pale infarct?
Red infarct occurs in tissue with MULTIPLE blood supply (lung, intestine, testicle). Reperfusion injury 2/2 free radicals. Pale infarcts occur in solid organs with single blood supply (heart, kidney, spleen)
Types of shock
Distributive (septic, neurogenic, anaphylactic) - vasodilation, IV fluid NONresponsive, decreased PCWP, decreased TPR, increased CP, inc. venous return. Hypovolemic/cardiogenic - vasoconstriction, bp restored. PCWP high in cardiogenic but LOW in hypovolemic. LOW-output failure (inc. TPR, low CO, and low venous return)
Chromatolysis?
Cell body processes following axonal injury reflective of increased protein synthesis to repair. Round cellular swelling, displacement of nucleus to periphery, dispersion of Nissl substance throughout
Types of shock
Distributive (septic, neurogenic, anaphylactic) - vasodilation, IV fluid NONresponsive, decreased PCWP, decreased TPR, increased CP, inc. venous return. Hypovolemic/cardiogenic - vasoconstriction, bp restored. PCWP high in cardiogenic b/c of incomplete emptying but LOW in hypovolemic. LOW-output failure (inc. TPR, low CO, and low venous return)
Where does extravasation typically occur?
Post-capillary venules
Leukocyte extravasation
Margination and rolling (E-selectin, P-selectin; Sialyl-Lewis). Tight-bdining (ICAM-1, VCAM-1; integrins [LFA, Mac, VLA]). Diapedesis (PECAM-1). Migration (Chemotactic products include IL-8, C5a, LTB4, kallikrein, PLT-activating factor)
Free radical injury
Initiated via radiation, metabolism of drugs, redox rxns, NO, transition metals, oxidative burst. Damage cells via lipid per oxidation, protein mod, and DNA breakage. Eliminated by enzymes (catalase, superoxide dismutase, glutathione peroxidase), decay, and antioxidants (ACE). Path - retinopathy of prematurity, bronchopulmonary dysplasia, CCl4 -> liver necrosis, acetaminophen overdose, iron overdose, reperfusion injury (superoxide)
Sequelae of inhalation injury?
Chemical tracheobronchitis, edema, and pneumonia
Two pathologic scar formation types
Hypertrophic - increased collagen synthesis, parallel arrangement, but confined to borders of wound, and don’t recur often after resection. Keloid scars are HIGH collagen synthesis with disorganized arrangement, extending beyond border and frequently recurring.
PDGF
Secreted by activated platelets and macrophages. Induces vascular remodeling, SMC migration, fibroblast growth -> collagen synthesis
FGF
Stimulates angiogenesis
EGF
Epidermal growth factor. Stimulates cell growth via tyrosine kinases.
FGF
Stimulates angiogenesis. Fibroblast growth factor is NOT for fibrosis but for angiogenesis.
Metalloproteinases
Tissue remodeling
Three phases of wound healing
Inflammatory (plt, neutrophils, macrophages - clot formation, inc. vessel permeability w/ migration. macrophage clean-up by dy 2). Proliferative (2-3 dy, fibroblasts, myofibroblasts, endothelial cells, keratinocytes, macrophages. Deposition of GRANULATION tissue and collagen, angiogenesis, epithelial cell, clot dissolution, wound contraction). Remodeling phase (1 wk, FIBROBLASTS, Type III replaced by type I to increase tensile strength, which returns to 70-80% by 3 mo).
Granuloma formation
Th1 cells secrete IFN-gamma activating macrophages. TNF-alpha from macrophages induce and maintain. Anti-TNF drugs can 2ndarily cause disseminated disease. Bartonella, Churg-Strauss, Crohn, Francisella, Fungal, Wegener, Listeria, M. leprae/tuberculosis, Treponema, Sarcoidosis, Schistosomiasis
Exudate vs. Transudate
Exudate is cellular, protein rich, sg>1.020, 2/2 lymphatic obstruction, inflammation/infection, or malignancy. Transudate is hypo cellular, protein-poor, sg<1.012, 2/2 inc. hydrostatic pressure, dec oncotic pressure, Na+ retention
ESR
Products of inflammation coat RBC -> aggregation -> falling faster
ESR up vs. ESR down.
Up - anemias, infections, inflammation, cancer, pregnancy, autoimmune. Down - Sickle cell, Polycythemia (diluting the aggregates), CHF (unk. mech)
Fe poisoning?
Mech is peroxidation of membrane lipids. Symptoms include nausea, vomiting, gastric bleeding, lethargy. Chronically causes metabolic acidosis and warring -> GI obstruction. Tx = chelation (IV deferoxamine) and dialysis
Amyloidosis histopath?
Congo red stain, which shows apple green birefringence under polarized light.
AL amyloidosis
Primary. Deposition of Ig Light chains. Plasma cell or MM disorder. Nephrotic, restrictive cardio/arrhythmia, easy bruising, hepatomegaly, neuropathy
AA amyloidosis
Secondary. Chronic conditions like RA, IBD, spondyloarthropathy, inf. Amyloid A.
Dialysis-related amyloidosis
B2-microglubulin fibrils. ESRD or long-term dialysis.
Heritable amyloidosis
Transthyretin (TTR or prealbumin) gene mut -> ATTR neurologic/cardiac
Age-related (senile) systemic amyloidosis
Deposition of normal TTR (Transthyretin) in myocardium and other sites
Organ-specific amyloidosis
Alzheimer’s is most important. 2/2 to amyloid precursor protein (APP) cleaved to amyloid-B protein. Islet amyloid polypeptide in DMT2.
Lipofuscin
Yellow-brown “wear and tear” formed by oxidation/polymerization of old organellar membranes.
Neoplastic cells invade basement membrane how?
Collagenases and hydrolases (metalloproteinases)
P-glycoprotein
Multidrug resistance protein 1 (MDR1) expressed to pump out chemotherapeutic agents
Metaplasia vs. dysplasia
Metaplasia is change of adult cell type often 2/2 irritation. While dysplasia is abnormal growth with loss of cellular orientation, shape, and size
Anaplasia vs. neoplasia
anaplasia is loss of STRUCTURE (differentiation and function). Neoplasia is clonal proliferation that is uncontrolled and excessive.
Desmoplasia
Fibrous tissue formation in response to neoplasm. Irreversible.
Carcinoma vs. sarcoma
Epithelial vs. mesechyma. Carcinomas tend to spread lymphaticlly (but not RCC, HCC, follicular carcinoma of thyroid, and choriocarcinoma). Sarcomas tend to spread hametogenously
Muscle tumor nomenclature
Leiomyoma (smooth) and rhabdomyoma (striated) vs. leiomyosarcoma and rhabdomyosarcoma
Cachexia mediators
TNF-alpha, IL-6, and IFN-gamma
Acanthosis nigricans ~ malignancy?
Visceral esp. stomach
Cushing syndrome ~ malignancy?
SCLC
Down syndrome ~ malignancy?
ALL and AML
Paget disease of bone ~ malignancy?
Secondary osteosarcoma and fibrosarcoma
Polycythemia ~ malignancy?
RCC, HCC
SIADH ~ malignancy?
SCLC
Tuberous sclerosis ~ malignancy?
Giant cell astrocytoma, renal angiomyolupoma, cardiac rhabdomyoma
myc genes associated with what tumors?
c-myc w/ Burkitt. L-myc with Lung. N-myc with neuroblastoma. Transcription factor. Myc? CBiscuit. L for lung. N for neuroblastoma.
Pancreatic cancer genes?
CPD4/SMAD4
Tumor marker alpha-fetoprotein for?
HCC, hepatoblastoma, yolk sac tumor, testicular ca, mixed germ cell tumor
B-hCG marker for?
Hydatiform moles, Choriocarcinomas, testicular
CEA
Non-specific but used for breast, colon, and pancreatic cancer.
S100 marker
Neural crest (melanoma, neural, schwannomas, Langerhans cell histiocytosis)
TRAP marker?
Tartrate-Resistant Acid Phosphate for Hairy cell leukemia
Calcitonin is tumor marker for?
Medullary thyroid carcinoma
EBV associated with what malignancies?
Burkitt, Hodgkin, nasopharyngeal carcinoma, and CNS lymphoma in immunocompromised pts
Liver carcinogens?
Alfatoxins (Aspergillus, HCC), Arsenic (Angiosarcoma), CarbonCl4 (centrilobular necrosis/fatty change), EtOH (HCC), Vinyl chloride (angiosarcoma)
Lung carcinogens?
Arsenic, asbestosis (Bronchogenic carcinoma > mesothelioma), cigarette (squamous cell and small cell), radon
Nitrosamines?
Smoked foods -> stomach -> gastric ca risk
Small cell lung carcinoma paraneoplastic syndromes?
Cushing syndrome (ACTH), SIADH (ADH), Lambert-Eaton (presynaptic Ca2+ Ab)
Hypercalcemia 2/2 to paraneoplastic syndrome?
Calcitriol (Hodgkin lymphoma) or PTHrP (squamous cell lung ca, RCC, breast cancer)
Polcythemia 2/2 to paraneoplastic syndrome?
EPO. RCC, thymoma, hemangioblastoma, HCC, leiomyoma, pheochromocytoma
Psammomma bodies
Laminated, concentric, calcified spherules. FOUR things. PSaMM - Papillary carcinoma of thyroid, serous papillary cysadenocarcinoma of ovary, meningioma, malignant mesothelioma
Brain metastases
Lung > breast > GU > osteosarcoma > melanoma > GI. 50% of brain tumors are metastases. Tend to be found at gray/white matter junction and well-circumscribed.
Liver metastases
Colon»_space; stomach > pancreas.
Bone metastases
Prostate and breast > lung > thyroid. Prediliction for axial. Prostate = blastic. Breast = lytic and blastic.
Melanoma genes
BRAF - often V600E mutation (valine -> glutamate)
SLE endocarditis?
Libman-Sacks endocarditis occurring in up to 25% of SLE patients causing small cardiac vegetations on either side of valve -> fibrotic thickening
HBV path?
Cytoplasm is filled with spheres and tubules of HBsAg -> finely granular, eosinophilc appearance; “ground glass.”
Acute neuronal injury vs. axonal reaction
Transiet severe insult (red neuron) -> shrinkage of body, pyknosis, loss of Nissl, eosinophilic.
Psoriasis biopsy
Hyperkeratosis, aconthosis, rete ridge elongation, mitotic activity above basal cell, and reduced/absence stratum granulosom.
Glomangioma
Very tender, small (mm) red-blue lesion under nail bed, originating from SMC that control thermoregulatory f(x) of dermal glomus bodies (neurovasc organs, which shunts blood away from finger-tips with cold).
Churg-Strauss
Idiopathic systemic vasculitis associated with adult-onset asthma, eosinophilia, pANCA, neuropathy, paranasal sinus abnormalities
Proto-oncogenes?
Ras, N-myc, ERB-B1/2, TGF-alpha, sis (astrocytoma, osteosarcoma), abl (CML, ALL)
Anti-oncogenes?
BRCA-1/2, NF-1, APC/beta-catenin, DCC, p53, Rb, WT-1
Osler-Weber-Rendu syndrome
Hereditary hemorrhagic telangectasia. AD inheritance of telangiectasis of skin and mucous membranes. Ruptures causing epistaxis, GI bleeding, and hematuria.
Malignant hyperthermia
Hyperthermia and and muscle rigidity. Can occur after administration of inhaled anesthetics and/or succinylcholine to genetically susceptible. Tx = dantrolene which blocks ryanodine receptors to prevent Ca+ release into cytoplasm of skeletal muscle fibers.
Fulminant ARF?
Only 1% of patients. Death from severe myocarditis.
Melanoma embryological origin?
Neural crest cell
Where are the stratified squamous epithelium from esophagus up?
Oropharynx, laryngopharynx, anterior epiglottis, upper half of posterior epiglottis, TRUE vocal cords. Rest is pseudo stratified, columnar, mucus-secreting epithelium
T-tubules?
Invaginanations of the muscle cell membrane. One T-tubule contacts two terminal cisterns forming triad at junction of A-band and I-band. RAPID depolarization of sarcolemma (dihydropyridine voltage-gated Ca+) to SR (ryanodine)
Li-Fraumeni syndrome
p53 AD. Tumors of breast, brain, and adrenal cortex are common.
RAS
GTP-binding protein. Cholangiocarcinoma, pancreatic adenocarcinoma. Proto-oncogene (1-hit gain of function)
ERBB1/EGFR
RTK. Lung adenocarcinoma. proto-oncogene
ERBB2=HER2
RTK. Breast cancer. Proto-oncogene
BRAF
RAS signal transduction. Hairy cell leukemia, melanoma. Proto-oncogene.
BRCA1&2
DNA repair genes. Breast and ovarian cancer. Tumor suppressor genes
APC/Beta-cetenin
WNT signaling pathway. Colon, gastric, pancreatic ca + FAP. Tumor suppressor
VHL
Ubiqitin ligase component. RCC, VHL. Tumor suppressor gene.
WT1
Urgenital differentiation. Wilms tumor. Tumor suppressor gene.
Pathogenesis of acne
Follicular epidermal hyperproliferation, excessive sebum production, inflammation, Propionibacterim acnes. Androgens promote both follicular epidermal hyperpoliferation AND excessive sebum production. So do EGFR inhibitor and lithium.
Cross-bridge cycle?
ATP binds for DETACHMENT of myosin cross bridge. Hydrolysis to ADP +Pi. Cross-bridge formation IF tropomyosin is OUT of the way (requires Ca+ binding to troponin to remove). Then power stroke.
Morning stiffness
RA morning stiffness improves w/ use and lasts >30 minutes. OA morning stiffness <30 min.
Triad for fat embolism
Acute onset neuro, hypoxemia, and petechial rash
MDR1 gene?
Multi-drug resistance gene. P-glycoprotein - ATP-dependent efflux pump. Tumor cell expression leads to decreased effectiveness of chemo (esp. anthracyclines).
AD diseases
Tuberous sclerosis, Marfan syndrome, Neurofibromatosis, Huntington’s disease, Retinoblastoma, Waardenburg syndrome, Myotonic dystrophy, Familial hypercholestrolemia (LDL receptor defect Type IIa), Adult polycystic kidney disease, von Hippel Lindau, Familial adenomatous polyposis and Peutz Jeghers Syndrome, Hereditory spherocytosis, Achondroplasia, Ehlor’s Danlos (vascular type), Acute intermittent porphyria, HOCM, Von Willebrand Disease, Polydactyly, Osteogenesis Imperfecta (Except Type VII), Hereditary hemorrhagic telengiactasia (Osler-weber-rendu syndrome), Osteopetrosis Type II (Adult type), Hypokalemic Periodic Paralysis
X-linked recessive diseases
Lesch-Nyhan Syndrome, Duchenne Muscular Dystrophy
Hunter’s Disease, Menkes Disease, G6PD Deficiency, Hemophilia A and B, Fabry’s Disease, Wiskott-Aldrich Syndrome, Bruton’s Aggamaglobulinemia, Color Blindness
Complete Androgen Insensitivity, Congenital Aqueductal stenosis (hydrocephalus), Inherited Nephrogenic Diabetes Insipidus
Caudal regression syndrome
Agenesis of sacrum +/- lumbar spine -> flaccid paralysis of legs, dorsiflexed feet contractors, and urinary incontinence. Related to poorly controlled maternal diabetes.
Main function of brown fat?
Heat production. Found in neonates + hibernating animals (b/c susceptible to hypothermia). More mitochondria where e- transport and phosphorylation are uncoupled 2/2 thermogenin.
Sarcoidosis hypercalcemia?
Due to activated MACROPHAGES -> extra-renal formation of 1,25-OH Vitamin D. Suppresses PTH.
Henoch-Schonlein Pupura
Usu. boys 2-10 yrs following viral or strep URI. IgA-mediated vasculitis. GI - hematemesis and bloody diarrhea. Kidney - IgA nephropathy (mesangial proliferation and crescent formation). Skin - palpable purport. Joints - migratory arthralgias and arthritis.
Cystic medial degeneration
Myxomatous changes in media of large arteries characterized by fragmentation of elastic tissue (“basket weave” instead of parallel lines”). Often seen in Marfan syndrome patients.
Major indications for long-term uric acid therapy for gout?
Macroscopic tophaceous deposits, >3 eps/yr, uric acid stones, or gross elevation of serum uric acid. Allopurinol and uricosuric drugs (probenecid & sulfinpyrazone, which should be avoided if nephrolithiasis and only work if good renal flow). Febuxostat is new xanthine oxidase inhibitor.
Pemphigus vulgaris vs. Bullous pemphigoid
Autoab’s against desmosomes vs. hemidesmosome. “Desmond is vulgar.” Ruptured bullae vs. unrupted bullae.
Autoabs against cutaneous basement membrane proteins?
Epidermolysis bullosa acquisita and cicatrical pemphigoid
Pityriasis rosea
Hearld patch (plaque w/ central clearing) followed by ovoid maculpapular rash along skin tension lines (Christmas tree pattern). Unclear etio but perhaps viral?
Cadherins
Transmembrane proteins for adherens junctions and desmosomes. Connect to keratin and actin.
Fibronectin
An ECM protein that binds to integrins to help cells bind to the ECM (collagen IV?)
Nummular eczema
Coin-patch lesions often in setting of xerosis. Harsh soaps.
Tyrosine receptor kinases
Ligand binds. Dimerization of receptor -> autophosphorylation of tyrosine residues -> downstream effects
Hemochromatosis
Often doesn’t present till 40’s because it takes decades of Fe deposition into the dermis for effects to present. AR.
Umbilical vein catheterization
Doesn’t complete close until 1 week. Go from umbilical vein (ligamentum teres) to ductus venosus (bypass liver to IVC; ligamentum venosum).
Mechanisms of therapeutic radiation
(1) DNA ds breaks and (2) formation of free radicals
L-type channel-RyR mechanical coupling?
Refers to how in SKELETAL muscle, depolarization of the membrane leads to coupled release of Ca2+ from sarcoplasmic reticulum via mechanically coupled channels. Does not exist in cardiac muscle, where extracellular Ca2+ influx is required to induce Ca2+ from SR to move out (RyR2 channels).
Calmodulin vs. troponin?
Only in smooth muscle does Ca2+ bind to calmodulin instead of troponin. Calmodulin activates myosin light chain kinase, which phosphorylates myosin and allows it to bind to actin to cause muscle contraction.
Lightning strike sequelae
Peripheral nerve damage, sz, confusion, respiratory arrest, autonomic dysfunction. Lictenberg figures. Rhabdo. Bone fx. comaprtment syndrome. Ruptured TM’s. Cardiac arrest, arrhythmia.
Glutamate-glutamine cycle
In the brain, glutamate used for neurotransmission is taken up by astorcyte from cleft and converted into glutamine (non-active) substance. That is then sent over to the pre-synaptic neuron for change into glutamate.
UVA vs. UVB?
UVB is major cause of sunburns, skin damage, imunosuppression, aging, etc. UVB is 290-320 nm while UVA is 320-400nm. PABA esters block UVB only. Zinc oxide-containing sunscreens protect against both.
Golgi Tendon Organ f(x)?
Monitors and maintains muscle force during contraction. If too much force, will cause sudden muscle relaxation.
Hyaline arteriosclerosis
Thickened walls with pink stained on H&E. Non-malignant hypertension and/or diabetes.
Cystic Fibrosis clinical
Recurrent respiratory infections, malabsorption 2/2 pancreas, azoospermia 2/2 absence of vas deferens b/l
Reye’s syndrome
Children w/ febrile illness treated with salicyclates. Hepatic failure and acute encephalopathy. Microvesicular steatosis.
CA 125
Ovarian cancer tumor marker. NOT CEA.
Von Hippel Lindau disease manifestations
Hemangioblastoma of cerebellum, kidney and pancreas cysts, pheochromocytoma, RCC
What is a hamartoma?
Excessive growth of a tissue NATIVE to organ of involvement. Is NOT hemangioblastoma. IS the usual “coin lesion” on X-ray (cartilage, fat, SMC, clefts of respi. epi)
Eccrine vs. apocrine sweat glands?
Eccrine sweat glands are mostly palms and soles. Apocrine sweat glands secrete into HAIR follicles, innervated by adrenergics and don’t function till puberty. Malodorous 2/2 skin commensal bacteria.
An example of holocrine secretion on the skin?
Sebaceous glands secrete sebum along with dead cells b/c the secretory material comes out of burst cells.
Presbyopia?
Due to denaturation of lens structural proteins -> worsened elasticity = inability to accomodate. In myopics, may lead to paradoxically improved long-distance vision.
