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  1. Rough ER function
    synthesis of secretory, membrane bound, and lysosomal proteins. 

    Protein modification, folding, transfer of those same proteins

    Well developed in protein secreting cells (i.e. enzyme secreting pancreatic cells)
  2. Ribosome function
    Synthesize proteins used in the cytosol and cellular organelles
  3. Smooth ER
    Synthesis of steroid hormones and drug detoxification occurs in the SER

    Function in lipid synthesis, carbohydrate metabolism
  4. Potter syndrome
    pulmonary hypoplasia, limb deformities, characteristic facies (suborbital creases, depressed nasal tip, low-set ears, and retrognathia) as a result of oligohydramnios

    oligohydramnios - deficiency of amniotic fluid

    occurs in fetuses with bilat renal agenesis --> lack of fetal urine causes oligohydramnios

    Amniotic fluid is required for proper lung development
  5. Maternal hyperglycemia
    Causes of maternal hyperglycemia: gestational diabetes

    Complications: increased still birth rates, macrosomia (big baby syndrome), post natal hypoglycemia in infant
  6. Placenta previa
    Placenta implants over cervical os

    common cause of vaginal bleeding during pregnancy
  7. Maternal megaloblastic anemia
    Can be due to deficiency of Vit B12 or folate

    Folate deficiency during first trimester is associated with neural tube defects
  8. Splitting 
    unconscious belief that people are either wholly good or wholly bad

    Hallmark of borderline personality disorder
  9. Meckel diverticulum
    failure of obliteration of the omphalomesenteric duct. 

    Presentation: Lower GI bleeding, RLQ pain

    contains ectopic gastric mucosa which produces acid, causing ulceration (possibly) and bleeding

    Dx: 99mmTc-pertechnetate scan
  10. Hirschsprung disease
    failure of neural crest migration into the bowel wall

    intestinal obstruction in the first few days of life
  11. Incidence
    number of new cases of a disease per year / total population at risk
  12. Renal angiomyolipoma
    benign tumor composed of blood vessels, smooth muscle, and fat

    Bilateral renal angiomyolipomas are associated with tuberosclerosis (autosomal dominant condition)

    Associated with cortical tubers and subendymal hamartomas

    Hamartomas - benign growth of a tissue; resembles a neoplasm, but is not. Same tissue, doesn't grow faster
  13. Female Gametogenesis
    Primary oocytes develop in female embryos by the fifth month of gestation.

    At this point they are arrested in prophase of meiosis I

    Menstrual cycle hormones stimulate the primary oocyte to resume meiosis

    Secondary oocytes are arrested in metaphase of meiosis II and are released during ovulation

    The secondary oocyte remains in metaphase of meiosis II until fertilization
  14. Aspirin

    irreversibly inhibits COX1 and COX2

    COX2 is an inducible enzyme that is undetectable in most tissue except during inflammation
  15. Actin Filaments in myocytes
    Actin filaments are anchored to the Z line of the sarcomere

    Z line lies in the center regions of the I band

    Image Upload 1
  16. Benzodiazepines in depression and anxiety
    benzos are sometimes used during the SSRI initiation period if there is a significant increase in anxiety related sx

    Triazolam is a benzo that is helpful in treating insomnia in patients who need to be aware during the day due to it's short half life
  17. Kinesin
    a microtubule associated ATP motor protein that does anterograde transport of NT containing vesicles down axons to synaptic terminals
  18. Tetrodotoxin
    pufferfish associated neurotoxin (from microogranisms associated with the fish)

    binds voltage gate sodium channels in nerve and cardiac tissue preventing depolarization
  19. Neuron Action Potential
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  20. Deficiency of the Complement membrane attack complex
    MAC (C5b-C9)

    results in recurrent Neisseria infections

    • Neisseria is a common cause of bacterial meningitis
    • Presentation:
    • -fever
    • -chills
    • -altered mentation
    • -petechial rash affecting palms and soles (vasculitis)
  21. Pure T cell dysfunction
    ie: DiGeorge syndrome (thymic hypoplasia)

    pure T cell lymphopenia

    Recurrent viral and fungal infections
  22. Chronic Granulomatous Disease
    • X linked
    • NADPH oxidase deficiency
    • deficient intracellular killing

    Recurrent infections with catalase positive organisms (Staph)
  23. Too much IgA production
    -increased risk of disseminated infection in young adults infected with N. meningitidis

    -IgA attaches to bacteria and blocks IgM and IgG which would induce C' mediated lysis
  24. Neural Tube Defects
    -failure of neural tube to close in 4th week of gestation

    -most commonly in anterior or posterior neuropores

    -folic acid supplementation in early pregnancy decreases risk

    Meningocele and menigomyelocele present as cystic masses in lower spine region covered with skin, maybe a tuft of hair present

    -Elevated acetylcholinesterase and alpha-fetoprotein on amniocentesis
  25. Opioid Tolerance
    -exact mechanism unknown

    -activation of NMDA receptors by glutamate is believed to enhance morphine tolerance by phosphorylation of opioid Rs and increasing NO levels

    -NMDA blockers like ketamine decrease morhpine tolerance
  26. Ataxia-telangiectasia
    • -autosomal recessive disorder
    • -defect in DNA repair genes

    -DNA is hypersensitive to ionizing radiation

    • Manifestation:
    • -cerebellar ataxia
    • -oculocutaneous telangiectasias
    • -repeated sinopulm infections
    • -increased incidence of malignancy
  27. Craniopharyngiomas
    -calcified cystic tumors

    -arise from remnants of Rathke's pouch (embryonic precursor to anterior pituitary)

    • Presentation:
    • -HA
    • -growth failure
    • -bitemporal hemianopia
  28. Axonal Conduction: Length Constant
    measure of how far along an axon an electrical impulse can propagate

    -low length constant reduces the distance an impulse can travel

    -myelin increases the length constant

  29. Axonal Conduction: Summation
    -additive effects of multiple postsynaptic potentials on a target neuron's membrane potential

    ***can occur anywhere BUT the axon

    Temporal summation: sequential impulses from the same neuron over time

    Spatial summation: simultaneous impulses from several different neurons
  30. Axonal Conduction: Time Constant
    -time it takes for a change in membrane potential to achieve 63% of the new follow

    -lower time constants allow for quicker changes in membrane potential --> increased conduction speed

    -myelination reduces the time constant

  31. Bilirubin and bile acid
    Bilirubin is synthesized (mostly) in the spleen by phagocytic cells metabolizing hemoglobin from old RBCs.

    Splenic vein feeds the unconjugated bilirubin into the portal vein, where ~20% is taken up by hepatocytes per pass

    Conjugated bilirubin in the blood is only found bc of small, normal reflux from hepatocytes.

    • Nl ranges
    • -Total bilirubin is <1.2mg/dL
    • -direct (conjugated) is <0.2mg/dL
    • -indirect (unconjugated) is the difference

    -Most bile acid is recycled from the intestine (via sodium-coupled bile acid transporter in the ileum); only 10% is from new synthesis
  32. Cell to cell junctional complex
    zona occludens

    • Junctional complex relies on homotypic interactions between E-cadherin proteins on adjacent cells
    • -Forms the zona adherens, which are then activated to initiate formation of the zona occludens and desmosomes

    Gap junctions are formed by Connexin; NOT part of a junctional complex

    Desmoglein is a cadherin specific to demsosomes; lack of this protein would affect only desmosome formation
  33. SLE (lupus)
    • Systemic lupus erythematous
    • -pt must meet 4 of 11 criteria
    • 1. malar rash
    • 2. photosensitivity
    • 3. anemia
    • 4. hematologic disorders....
    • x. arthritis

    • Libman-Sacks endocarditis can affect pts with SLE
    • -small, granular vegetations consisting of fibrin develop on either side of the leaflets of the mitral and aortic valves.
    • -fragments may detach, resulting in embolism
    • -healing leads to distortion of valve leaflets and resultant insufficiency or stenosis
  34. Endocarditis
    Classic signs
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  35. Testicular hydrocele
    Processus vaginalis is an evagination of the parietal peritoneum of the abdomen that descends through the inguinal canal

    The distal end normally remains patent as the tunica vaginalis, the remainder fuses and becomes fibrous

    Incomplete fusion leads to cystic structure (hydrocele) of the spermatic cord
  36. Spermatic cord
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  37. Horner's syndrome
    ipsilateral ptosis, miosis, anhydrosis

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  38. Heteroplasmy
    • -characteristic of mitochondrial diseases
    • -exclusively maternal inheritance

    -variable severity

    • -random distribution of normal and mutated mitochondria between daughter cells during mitosis
    • --> some cells may have perfectly healthy mitochondria while others contain affected genes
  39. Important Mitochondrial Syndromes
    1. Leber hereditary optic neuropathy (bilateral vision loss)

    2. Myoclonic epilepsy with ragged-red fibers (myoclonic seizures and myopathy associated with exercise)

    3. Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes MELAS (seizure disorder, stroke-like episodes, increased serum lactate levels post exercise and at rest)
  40. Mode
    -more resistant to outliers

    -the most commonly observed data point
  41. Haversian System in bone
    • -osteocytes have long intracanalicular processes that extend through the ossified bone matrix
    • -these processes send signals and exchange nutrients/waste products with the osteocytes within the neighboring lamellae via gap junctions.
    • -osteocytes can sense mechanical stresses and send signals to modulate the activity of surface osteoblasts --> regulate bony remodeling
  42. Valproare
    -increases risk of neural tube defects

    -inhibits folic acid absorption
  43. Kallmann Syndrome
    -absence of GnRH secretory neurons in hypothalamus due to defect of migration from olfactory placode

    • -central hypongonadism
    • -anosmia

    -often present with delayed puberty
  44. PPV and NPV
    -depend on disease prevalence in the population

    -sensitivity and specificity do not depend on prevalence of disease in population
  45. Pre-eclampsia
    • Triad:
    • -HTN
    • -Proteinuria
    • -edema

    <10% of pregnancies

    Onset after 20th week of gestation

    Cause unknown, poor placental perfusion thought to contribute

    Release of inflammatory factors from hypoxic placenta cause damage to the endothelium

    • May progress to HELLP Syndrome:
    • -Hemolytic anemia
    • -Elevated Liver enzymes
    • -Low Platelets
  46. CML
    • -translocation 9;22 (Philadelphia chromosome)
    • -leads to BCR-Abl fusion protein
    • -constituitive tyrosine kinase activity
    • -Imatinib tx (TKI)
  47. NSCLC Genetics
    • -some have chromosomal rearrangement that leads to fusion gene btwn EML4 (echinoderm microtubule associated protein like 4) and ALK
    • -constituitively active tyrosine kinase (like CML)
  48. Psuedomonas Toxin
    • Exotoxin A:
    • -ribosylates and inactivates EF2
    • -inhibits host cell prot synth --> cell death

    Acts similar to diptheria toxin
  49. Diphtheria Infection
    -respiratory infection that  can cause severe myocarditis and heart failure

    -sx: severe pharyngitis with exudates, cervical lymphadenopathy

    -diphtheria toxin = exotoxin that inhibits EF2 (no prot synth and cell death)
  50. Autosomal Dominant Polycystic Kidney Disease
    • -manifests in patients 40-50 years old
    • -enlarged kidneys, HTN, renal failure

    -In newborns: kidneys are normal sized and cysts are too small to be detected on U/S
  51. Porphyria
    -enzyme deficiencies in early steps of porphyrin synthesis --> Abd pain, neuropsych, W/O photosensitivity

    -enzyme deficiencies in late steps --> photosensitivity
  52. Observer Bias
    Investigator's decision is affected by prior knowledge of the exposure status
  53. Glucose Transport
    -Glucose transport into most tissues occurs by facilitated diffusion (carrier-mediated transport)

    -glucose moves from areas of high concentration to low concentration with the help of carrier proteins (GLUT)

    -carrier proteins have a preference for D-Glucose (stereoselective)

    • GLUT4:
    • -insulin sensitive transporter
    • -SKM, adipocytes

    • GLUT2:
    • -export of glucose into circulation
    • -iver
    • -small intestine
    • -kidneys
    • -helps control insulin secretion in pancreas
  54. Genetic Causes of Down Syndrome
    Three cytogenetic abnormalities may cause Down Syndrome:

    • 1. Trisomy 21 (95%)
    • -almost always maternal origin

    • 2. Unbalanced Robertsonian Translocations (2-3%)
    • -46 chromosomes
    • -chromosome 21 is attached to another chromosome

    • 3. Mosaicism
    • -patients have two cell lines: one with normal genotype, one with trisomy 21
  55. Respiratory Tract Histology
    • Pseudostratified Columnar mucus-secreting epithelium
    • -nose
    • -paranasal sinuses
    • -nasopharynx
    • -most of larynx
    • -tracheobronchial tree

    • Stratified Squamous Epithelium:
    • -oropharynx
    • -laryngopharynx
    • -anterior epiglottis
    • -upper half of posterior epiglottis
    • -vocal folds (true vocal cords)
  56. Collagen Synthesis
    • 1. Pro a-collagen transcribed into RER
    • 2. Hydroxylation of selected proline and lysine residues
    • 3. Glycosylation of selected lysine residues
    • 4. Assembly of pro a- chains into triple helix
    • 5. Secretion of procollagen into Golgi
    • 6. Extrusion into ECM
    • 7. N- and C-terminal propeptide cleavage by propeptidase --> collagen fibril (water insoluble)
    • 8. Covalent cross links formed btwn collagen fibrils by lysyl oxidase
  57. Ehlers-Danlos Syndrome
    -rare hereditary disorder

    • Sx:
    • -hypermobile joints
    • -fragile, hyperelastic skin
    • -easy bruising (decreased strength of vasculature)

    • Mutations:
    • -lysyl-hydroxylase (cross links fibrils for form mature fiber)
    • -pro-collagen peptidase (cleaves N- and C-termini)

    • Pathophys:
    • -defective cleavage at N- and C- termini yields formation of a more soluble collagen that does not properly cross link with other collagen molecules
  58. Agammaglobulinemia
    • -most commonly X-linked
    • -low levels of circulating B cells
    • -low levels of all Ig (including IgA)
    • -IgA deficiency --> recurrent respiratory infections and persistent giardiasis
    • -B cell markers: CD19, CD20, CD21
  59. Intestinal atresia
    • -distal to duodenum occurs due to vascular accidents in utero
    • -SMA obstruction: Apple peel atresia (blind-ending proximal jejunum with absence of a long lenth of small bowel and dorsal mesentery)
    • -terminal ileum distal to atresia assumes spiral configuration around an ileocolic vessel
  60. Postpartum Mood Disturbances
    • 1. Postpartum Blues
    • -2-3 days
    • -resolves within 10 days
    • -tearfulness, fatigue, depressed affect, irritability
    • -tx: reassurance, watchful waiting

    • 2. Postpartum Depression
    • -lasts 2wks-12months
    • -depressed affect, anxiety, worse at night, poor concentration, decreased libido
    • -tx: antidepressants, psychotherapy

    • 3. Postpartum Psychosis
    • -variable
    • -delusions, confusion, sleep disturbances, unusual behaviour, emotional lability
    • -tx: antipsychotics, antidepressants
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