7/14 Flashcards
what is nondisjunction
failure of chromosome pairs to separate properly during division.
failure of homologous chromosomes to separate during meiosis 1:
mom giving 24; the extra one is DIFFERENT
this is where 2 X’s go into one cell and 0 X’s in another
failure of sister chromatids to separate during meiosis 2 or mitosis:
mom giving 24; the extra one is IDENTICAL
this is where both I’s of the same X go into once circle
what is 1st vs zero order kinetics
1st order:
a constant proportion of drug is metabolized per unit of time
the amount metabolized changes based on the serum concentration- increases as the dosing is increased
zero order:
constant amount of drug is metabolized per unit of time
independent of serum levels- rate does not increase with increasing dose (you’ve saturated your converting enzyme)
what are the cells in Graft vs Host disease
Graft T cell sensitization against host MHC antigens
donor T cells from the graft migrate to host tissues, recognize host MHC antigens as foreign, and activate CD4 and CD8 T cells to destroy host cells.
what should you think if they give Marfan’s sounding story but you’re supposed to go somewhere else
Homocystinuria
what is structurally similar to bisphosphonates
pyrophosphate
what do bisphosphonates do
disrupt osteoclast function by attaching to hydroxyappetite binding sites on the bony surfaces
what’s the mutation in sickle cell
valine replaces glutamic acid in 6th position of the beta-globin chain of Hb
what do miRNAs and siRNAs do
they’re small, noncoding RNA molecules that post-transcriptionally regulate protein expression.
they degrade or inactivate target mRNA, which leads to decreased translation into proteins
what is Ehlers Danlos pathophysiology
defect in Type 3 collagen synthesis, giving you hyper-flexible joints and skin with easy bruising/scarring
what are the collagen types matched with
Type 1 = bONE
(defect in osteogenesis imperfecta)
Type 2 = carTWOlage
Type 3 = “threE D” Reticulin, blood vessels
(Ehlers Danlos and easy bruising)
Type 4 = “under the floor” basement membranes, basement lamina, and lens
where are ribosomes made
nucleolus, the really dense circular area inside the nucleus
what is the urachus
remnant of the allantois that connects the bladder with the yolk sac during fetal development
what happens if the urachus does not obliterate at birth
patent urachus, which can facilitate discharge of urine from the umbilicus
what is Leukocyte Adhesion Deficiency
decreased expression of neutrophil cell-surface adhesion proteins, beta-2 integrins
how does LAD present
neutrophils fail to migrate towards infected sites
there’s delayed separation of the umbilical cord, omphalitis, and leukocytosis!!
what is Meckel diverticulum
failure of obliteration of the Vitelline duct.
how does tricuspid regurgitation present
a holosystolic murmur that increases with inspiration
what happens to the heart during inspiration
intrathoracic pressure drops,
so more blood returns to the heart
RV stroke volume increases (more venous return)
the drop in intrathoracic pressure also increases pulmonary vessel capacity,
leading to a transient decrease in LV venous return.
as a result, a Tricuspid regurg murmur would increase in intensity during inspiration
(MR or VSD would decrease/stay the same)
what can kill cels with decreased or absent MHC class I proteins on their surfaces
Natural Killer cells
virus-infected or tumor cells lack MHC class I
what specifically do NK cells express and not express
Do not express:
CD4, CD8, or CD3
Do express:
CD16, CD56
what is special about NK cells
do not require thymus for maturation, and they’re present in a-thymic patients
have no antigen-specific activities
do not require exposure to antigen for activation
do no possess antigen memory ability
what are NK cells activated by
Interferon-gamma and IL-12
how do NK cells function to kill other cells
they are large lymphoid cells that have perforin granules, which produce holes in target cell membranes; and granzymes, which induce target cell apoptosis
how do you treat ADHD
stimulants
they increase availability of NE and DA and block reuptake at synapses
how does Fragile X present
CCG repeats on FMR1 gene
eXtra large jaw, ears, face, and macroorchidism, maybe not noticeable until puberty
mild intellectual disability
how does fetal alcohol syndrome present
facial dysmorphisms:
short palpebral fissures (eyes)
indistinct philtrum (nose-lip groove)
thin vermillion border (upper lip)
poor growth
how does Klinefelter syndrome present
47 XXY Males
tall gynecomastia female hips female hair distribution small, firm testes (Cryptorchidism) mild intellectual disability
decreased testosterone by fibrotic testes causes infertility
what is group A strep’s major virulence factor
Protein M
it inhibits phagocytosis and complement activation, mediates bacterial adherence, and is the target of type-specific humoral immunity to Strep pyogenes
(Hyaluronic acid is on Strep pyo’s capsule and cannot be distinguished from humans, so it cannot be immunogenic)
what is Plummer Vinson Syndrome
Iron deficiency anemia plus esophageal webs/dysphagia and a shiny red tongue 2/2 papillae atrophy
“imagine a spider under your sink licking (tongue) the pipes (iron/metal)”
what are 2 weird findings with Iron deficiency anemia
koilonychia (spoon shaped nails)
shiny red tongue
