step 1 helpppp

total vs absolute erythrocytosis

An increased total RBC mass indicates an absolute erythrocytosis; a normal RBC mass indicates a relative erythrocytosis

goiter assoc w

most commonly associated imbalance is hypothyroidism

thyroid

placenta

PTU and methimazole cross

TSH does not

aging effects on lung:

____ elastin

____ chest wall stiffness

____ FVC

____ TLC

____ total system compliance

____ WOB

____ physiologic dead space

____ A-a gradient

____ VQ mismatch

____ PaO2

____ PaCO2

dec elastin

inc chest wall stiffness

dec FVC

normal TLC

dec total system compliance

inc WOB

inc physiologic dead space

inc A-a gradient

inc VQ mismatch

dec PaO2

no change PaCO2

In response to LV pressure overload (eg, prolonged systemic hypertension), there is upregulation of genes encoding for

contractile proteins of the cardiac sarcomere, including beta-myosin heavy chain

additional contractile fibers are added in parallel to increase the contractile strength of the LV wall

LV pressure overload (eg, prolonged systemic hypertension)

additional contractile fibers are added in

parallel to increase the contractile strength of the LV wall

When ADH levels are high (eg, dehydration), the ____ is highly permeable to water

collecting duct

prox tubule mech

water is passively reabsorbed along with active transport of solutes into the interstitium

PCT osm

isoosmotic with plasma

abs electrolytes and water passively

desc LOH mech

permeable to water, but not solutes

water moves down its concentration gradient from the lumen into the highly osmotic medulla

fluid in the lumen becomes hypertonic

tubular fluid will be the most concentrated at the

bottom of the loop of Henle where interstitial osmolality is the greatest

asc LOH mech

impermeable to water

electrolytes are actively resorbed by the Na⁺/K⁺/2Cl^- cotransporter, causing the osmolarity of the tubular fluid to decrease and become hypotonic

asc LOH osm

hypotonic

dct mech

Reabsorption of solutes continues to occur in the distal convoluted tubule through the action of the NaCl symporter

early distal convoluted tubule is impermeable to water

tubular fluid increases in hypotonicity

dct mech

inc hypotonicity

collecting ducts mech

water permeability of the collecting ducts depends on the presence of ADH

+ADH —> collecting ducts are impermeable to water, solutes continue to be removed —> very dilute urine

where does water permeability of the collecting ducts depends on the presence of ADH

collecting duct

aging

____ RV

____ TLC

____ FVC

____ FEV1

____ diffusing capacity

inc RV

norm TLC

dec FVC

dec FEV1

dec diffusing capacity

cardiac cycle graph

AL, PL, SV on graph??

Although lactogenesis may begin during the second trimester, lactation is suppressed due to the high

progesterone levels inhibiting the binding of prolactin to receptors on breast alveolar cells

Ventilation is lowest in the

apex and highest in the base

same as perf

Perfusion is lowest in the

apex and highest in the base

same as vent

V/Q ratio is lowest at the

base and highest at the apex

Intrapleural negative pressure peaks at

maximal inspiration at a value of approximately -8 cm H₂O.  During passive expiration the chest wall relaxes and the respiratory system returns to its equilibrium position, in which intrapleural pressure is approximately -5 cm H₂O

preg

____ CO

____ BV

____ RBF
____ GFR
____ GBM perm
____ renal protein resorption

inc CO

inc BV

inc RBF
inc GFR
inc GBM perm
dec renal protein resorption

Cardiac tissue conduction velocity

hep A

cellular rxn

• CD8⁺ lymphocytes & NK cell response; upregulation of IFN-γ

• Microscopic: mononuclear periportal infiltrates, ballooning degeneration of hepatocytes, focal necrosis

hep a

microscopic

• mononuclear periportal infiltrates, ballooning degeneration of hepatocytes, focal necrosis

mallory bodies

ALD

____ infiltration is characteristic of autoimmune hepatitis

Lymphoplasmacytic

COX inhibitor constrict aff or eff arteriole

aff

Time after myocardial infarction

0-4 hrs

minimal change

Time after myocardial infarction

4-12 hrs

early coagulation necrosis, edema, hemorrhage, wavy fibers

Time after myocardial infarction

12-24 hrs

coagulation necrosis and marginal contraction band necrosis

Time after myocardial infarction

1 to 5 days

coagulation necrosis and neutrophilic infiltrate

Time after myocardial infarction

5 to 10 days

macrophage phagocytosis of dead cells

Time after myocardial infarction

10 to 14 days

granulation tissue and neovascularization

Time after myocardial infarction

2 weeks to 2 months

collagen deposition / scar formation

portal htn effect on spleen

splenic vein is part of the portal circulation, any condition that causes portal hypertension can lead to splenomegaly with congestive hypersplenism. 

Venous congestion causes apparent expansion of the red pulp of the spleen, which is composed of blood-filled sinuses and cords lined by reticuloendothelial-type cells

Venous congestion causes apparent expansion of the _____ of the spleen, which is composed of blood-filled sinuses and cords lined by reticuloendothelial-type cells

red pulp

VHL

mutation

• Mutation in the VHL tumor suppressor gene on chromosome 3

• Autosomal dominant inheritance

VHL gene is a

tumor suppressor

VHL

triad

• Cerebellar & retinal hemangioblastomas

• Pheochromocytoma

• Renal cell carcinoma (clear cell subtype)

AD

deposition of

• Beta-amyloid plaques: excess beta amyloid forms insoluble fibrils that accumulate into extracellular amyloid plaques

• Neurofibrillary tangles: aggregates of hyperphosphorylated tau protein form intracellular tangled clumps

Tau is a protein associated with neuronal

microtubules

The formation of a platelet plug (primary hemostasis) is essential for preventing bleeding after damage to vascular endothelium; it occurs in 3 steps:

• Platelet adhesion takes place via von Willebrand factor acting as a connector that binds platelets to underlying collagen

• Platelets become activated and secrete multiple substances, including adenosine diphosphate, ionized calcium, and fibrinogen, from their alpha and delta (dense) granules.

• Thromboxane A2 is released and acts as a vasoconstrictor and potent stimulator of platelet aggregation.  Adenosine diphosphate also stimulates platelet aggregation

• Thromboxane A2 is released and acts as a

• vasoconstrictor and potent stimulator of platelet aggregation.  Adenosine diphosphate also stimulates platelet aggregation

prostacyclin acts locally to

inhibit platelet aggregation and adhesion to the vascular endothelium and to cause vasodilation

Jervell and Lange-Nielsen syndrome

inher

AR

Jervell and Lange-Nielsen syndrome

characterized by

profound bilateral sensorineural hearing loss and congenital long QT syndrome, which predisposes individuals to syncope and sudden cardiac death

Jervell and Lange-Nielsen syndrome

occurs secondary to mutations in genes (eg, KCNQ1, KCNE1) that encode the

alpha and beta subunits of voltage-gated potassium channels

Activation of the renin-angiotensin-aldosterone system (RAAS) leads to elevated levels of angiotensin II (ATII), a potent vasoconstrictor that stimulates the release of aldosterone and

endothelin 1

Vasopressin (antidiuretic hormone) is released by the

posterior pituitary

Glutamate-induced excitotoxicity

steps:

• Ischemic glutamate release:  Within minutes of focal cerebral ischemia, neurons depolarize because of ATP depletion —> exocytosis of glutamate-containing vesicles

• NMDA receptor activation:  Glutamate NMDA receptor is activated, increasing the conductance of cations and causing depolarization (and additional glutamate release)

• Intracellular calcium overload:  Opening of the NMDA receptors —> calcium influx into the cell —> mitochondrial dysfunction, free radical formation, and calcium-dependent protease activation.

• Neuron death:  The neuron suffers energetic failure (mitochondrial dysfunction) and macromolecule damage (eg, membrane lipid peroxidation, DNA cleavage).  The neuron ultimately dies, ruptures, and releases more glutamate

eggshell calcification") containing fluid and budding cells that will eventually become daughter cysts

echinococcal

When infection occurs, echinococcal larvae implant within the

capillaries, triggering an inflammatory reaction involving monocytes and eosinophils

echinococcal cyst

mgmt

Depending on the size of the cyst, surgery and adjunctive chemotherapy (eg, albendazole) are the treatment of choice for symptomatic patients.  Cyst manipulation (eg, surgery, aspiration) should be performed with caution, as spilling of cyst contents can cause anaphylactic shock

hepatic cyst —> anaphylactic shock

echinococcal

CRC

cancer w/i mucosa

stage 0 (polyp)

CRC

cancer infiltrates submucosa

stage i

CRC

infiltrates muscularis

stage II

CRC

infiltrates serosa

stage III

CRC

spread to lymph and other organs

stage IV

single most important risk factor for the development of intimal tears leading to aortic dissection

htn

Reye syndrome

pathophys

mitochondrial toxicity

In the liver, impaired fatty acid oxidation by mitochondria leads to fat deposition in hepatocytes (ie, hepatic steatosis), hepatomegaly, and acute liver failure.  In turn, excess ammonia accumulates due to hepatic dysfunction (eg, reduced urea cycle activity), causing diffuse astrocyte swelling and cerebral edema (eg, vomiting, confusion, lethargy)

Reye syndrome

what accumulates

ammonia

Prolonged elevation of systemic blood pressure causes the renal arterioles to undergo compensatory

medial hypertrophy and fibrointimal proliferation.  Endothelial damage leads to deposition of plasma proteins and basement membrane material in the arteriolar walls (hyaline arteriolosclerosis)

The classic presentation of an acute pulmonary embolism is

acute-onset chest pain and shortness of breath that may be accompanied by syncope or near-syncope.  Patients usually have tachycardia, tachypnea, jugular venous distension, and clear lungs

PEEP helps treat ARDS by

opening collapsed alveoli to reduce intrapulmonary shunting and increase FRC back to near-normal levels

ARDS + PEEP

Increasing FRC minimizes the time spent below closing capacity and in doing so decreases

ventilation-perfusion mismatching

how is prostate cancer graded

Gleason

lowest Gleason grade of 1 is assigned to well-differentiated tumors; these tumors resemble normal prostatic tissue and are generally arranged into small, well-formed, closely packed glands.  In contrast, the highest Gleason grade of 5 is assigned to poorly differentiated tumors; these tumors do not resemble normal prostatic tissue and are generally arranged into sheets of invasive cells with no glandular elements

higher the Gleason score, the higher the risk of spread outside of the prostate

hereditary hemochromatosis

skin

hyperpig

hereditary hemochromatosis

msk

• Arthritis (particularly 2nd & 3rd MCP joints)

• Chondrocalcinosis

hereditary hemochromatosis

GI

• Elevated liver enzymes, hepatomegaly (early)

• Cirrhosis & hepatocellular carcinoma (late)

hereditary hemochromatosis

endocrine

• Diabetes mellitus

• Hypopituitarism (eg, secondary hypogonadism, hypothyroidism)

hereditary hemochromatosis

cardiac

• Restrictive or dilated cardiomyopathy

• Conduction abnormalities

hereditary hemochromatosis

neuro

none

Patients with advanced heart failure may exhibit Cheyne-Stokes breathing, a cyclic breathing pattern in which apnea is followed by gradually increasing then decreasing tidal volumes (crescendo-decrescendo) until the next apneic period

17a-hydroxylase

fcn

pregnenolone —> 17-hydroxypregnenolone

progesterone —> 17-hydroxyprogesterone

21a-hydroxylase

fcn

progesterone —> 11-deoxycorticosterone

17-hydroxyprogesterone —> 11-deoxycortisol

17a-hydroxy def —>

inc mineralocorticoids

dec glucocorticoids

dec androgens

21a def —>

dec mineralo

dec gluco

inc androgens

buildup 17-OHP

CREST vs sys sclerosis abs

Anti-centromere: CREST

Anti-DNA topoisomerase I (Scl-70): sys scler

____ involving the breast, axilla, or upper extremity classically occur after treatment of breast cancer due to either radiation exposure (resulting in lymph node sclerosis) or extensive lymph node dissection causing chronic lymphedema

Angiosarcomas

10 years after breast cancer treatment, with the lymphatic arm or axilla developing firm, purple nodules or a poorly healing eschar that rapidly enlarges and coalesces

Angiosarcomas

respiratory mucosa vs sweat ducts

intestinal and respiratory epithelia:

• CFTR channel secretes chloride ions into the lumen

• tonic inhibitory effect on the opening of the ENaC, which decreases sodium reabsorption into the cell

• keep mucosa hydrated

sweat ducts:

• CFTR channel functioning is reversed in sweat ducts

• CFTR reduces the salt content of sweat by reabsorbing luminal chloride

• stimulating ENaC to increase sodium absorption from the lumen into the cells

• produce sweat concentrated in sodium and chloride

nasal transepithelial potential difference test

saline solution is applied to the nose

patients with CF have increased sodium absorption via the ENaC, sodium is absorbed intracellularly but chloride in the saline solution is retained in the lumen

higher relative amounts of negatively charged chloride on the epithelial surface result in a more negative transepithelial voltage difference

Aschoff body

interstitial myocardial granuloma

pathognomonic for ARF-related myocarditis

replaced by fibrous scar tissue, leading to chronic mitral valve stenosis and regurgitation

_____ myocarditis produces a predominantly lymphocytic interstitial infiltrate with focal necrosis of myocytes

no aschoff bodies

viral

amastigotes in myocardial fibers

chagas

Patients with AVNRT have 2 distinct AV nodal conduction pathways:

a fast pathway with a long refractory period and a slow pathway with a short refractory period

impulse may travel back up the fast pathway, creating a reentrant circuit with rapid conduction of impulses to the ventricles

mean corpuscular volume (MCV) is generally _____ in hereditary spherocytosis

normal to low

abruptio placentae

pain___

painFUL

struvite stone

made of

Mg ammonium phos