Flashcards in #4 3/8 Deck (82)
histology of true vocal folds
stratified squamous epithelium
- regions of respiratory tract with ciliated, pseudostratified, columnar, mucus-secreting epithelium
- regions with stratified squamous epithelium
- paranasal sinus, nasopharynx, most of larynx (including false cords), tracheobronchial tree
- oropharynx, laryngopharynx, anterior epiglottis, upper half of posterior epiglottis, true vocal cords
HIV fusion depends on...
(1) host cell CD4 + CCR5 and (2) HIV gp120
Nef and Tat HIV gene
Tat: role in viral replication
Nef: decreases expression of MHC class I on surface of expressed cells
When does tetrology of fallot present w/ cyanosis?
when pulmonic stenosis results in enough pulmonary HTN to turn VSD into a right-to-left shunt
Endocardiac cushion defects result in
defects in atrioventricular septum (left-to-right shunt, initially asymptomatic, but can have Eisenmenger syndrome later on
3 major cyanotic diseases caused by abnormal migration of neural crest cells...
tetralogy of fallot (anterior misalignment of aorticopulmonary septum), transposition of great vessels, truncus arteriosus
(3) mitochondrial myopathy (blotchy red muscle fibers on Gomori trichrome stain)
(1) myoclonic epilepsy w/ ragged red fibers [MERRF] (2) leber optic neuropathy [blindness] (3) mitochondrial encephalopathy w/ stroke-like episodes and lactic acidosis (MELAS)
ragged red bc abnormal mitochondria deposit under sarcolemma
Inheritance of cystic fibrosis
autosomal recessive (chr. 7)
fertility w/ cystic fibrosis
most men are infertile, but not sterile
human multidrug resistance (MDR1) gene
codes for P-glycoprotein, a transmembrane ATP-dependent efflux (esp good for hydrophobic agents like anthracyclines)
prevents influx as well as increases efflux
What precipitates sickling in HbS?
low oxygen, increased acidity, low volume (dehydration) [valine instead of glutamate at 6th AA position in beta subunit
hemoglobin M disease
mutation in heme binding pocket of alpha or beta chain; most common mutation replaces histidine in the heme binding pocket with tyrosine, results in the formation of an iron phenolate complex that resists the reduction of iron to the ferrous state --> methemoglobin
lipid loss in nephrotic syndrome under microscopy
polarized light -> oval fat bodies have maltese cross appearance
high altitude acclimatization process
inspired partial pressure (pO2) falls from 150 to 86mmHg, resulting from PaO2 of 60mmHg or less. hypoxemia stimulates carotid & aortic body chemoreceptors --> increased ventilatory drive --> hyperventilation and respiration alkalosis (increased pH, decreased CO2, low O2). drop in bicarb within 48 hours. within hours, increased EPO. see increased RBC 10-14 days. also, increased capillary density, myoglobin concentration, mitochondria
describe osteoclasts in paget's disease of the bone
very large, can have up to 100 nuclei (normal 2-5). will be tartrate-resistant acid phosphatase positive (like all osteoclasts)
factors important for osteoclastic differentiation
(1) M-CSF (macrophage colony-stimulating factor) and (2) RANK-L (receptor for activated nuclear factor kappa beta-ligand)
typical presentation of Paget's disease of bone
older gentleman, pain and deformity in a bony area and hearing loss (conductive problem w/ bone) . potentially caused by paramyxovirus infxn of osteoclasts
fibroblast growth factor on bone
increase bone formation, stimulate osteoblast. neurovascularization and wound healing
TGF-beta on bone formation
increases replication of osteoblast precursors and increased formation of mature osteoblasts. increase collagen synthesis. stimulate osteoclast apoptosis; decrease bone resorption
insulin-like growth factor on bone formation
IGF-1 increases osteoblast replication and collagen synth. decreases collagen degradation; inhibits MMP-13. anabolic
osteocalcin in bone formation
non-collagenous protein secreted by osteoblast. marker of bone formation. limits bone mineralization.
factors that stimulate osteoblasts
FGF, TGF-Beta, IGF-I
pulsus paradoxus (definition, detection, pathophysiology)
decrease in systolic BP greater than 10mmHg on inspiration. korotkoff sound first heard on expiration, then later on all phases of respiration.
caused by IMPAIRED expansion in PERICARDIAL space
normally, inspiration increases venous return --> increased volume of right heart, which expands into pericardial space.
when impaired expansion (acute cardiac tamponade, constrictive pericarditis, severe obstructive lung disease, restrictive cardiomyopathy)
here: increased RV volume pushes interventricular septum to left, reducing left heart diastolic volume & stroke volume --> decreases systolic BP.
the only ss DNA virus (non-enveloped)
s. aureus, listeria monocytogenes, s. pyogenes, s. agalactiae
listeria monocyogenes characterestics
- tumbling motility at 22 deg (immobile at 37)
- can multiply at 4 deg (refrigeration)
- only gram positive with LPS!
intracellular evasion strategies of Salmonella & Mycobacterium
- block fusion of phagolysosome with lysosome
- tuberculosis also blocks phagolysosome acidification