Pathoma - USMLE Step 1 QUESTIONS
AND VERIFIED CORRECT ANSWERS
GRADED A+ LATEST 100%
GUARANTEED PASS
Mechanisms of Action of Atrophy - CORRECT ANSWER-Apoptosis - programmed cell death
(decrease in cell number)
Ubiquitin Protein Degradation-->Decrease in cell size by ubiquitin tagging cells for death.
Autophagy of cell components (vacuoles fuse with lysosomes) --> decrease in cell number
Example of Metaplasia - CORRECT ANSWER-Barret's Esophagous
What's an exception of metaplasia that doesn't increase the risk of cancer? - CORRECT
ANSWER-Apocrine Metaplasia (exocrine gland breast cancer)
What is dysplasia? - CORRECT ANSWER-Disorders cell growth --> proliferation of precancerous
cells
* REVERSIBLE if you remove stressor*
,Difference between dysplasia and cancer? - CORRECT ANSWER-- Dysplasia is reversible if you
remove the stressor
- Cancer is irreversible even if you remove stressor
What are streak ovaries? What genetic disease is it common in? - CORRECT ANSWER-Streak
Ovaries are smaller, atrophied, fibrous streaky looking ovaries due to hypoplasia (decrease cell
number in embryogenesis).
- Occurs in Turner's Syndrome (XO) where ovaries develop early but lack of 2nd X chromosome
leads to accelerated loss of oocytes
- Lead to early menopause even before having a period
What type of cell is highly susceptible to ischemic injury? What type of cell is more resistant to
hypoxia? - CORRECT ANSWER-- Easily affected by hypoxia are neuronal cells (can only last 3-5
mins w/o oxygen)
- Skeletal muscle is more resistant
What are causes of hypoxia? - CORRECT ANSWER-1) Ischemia: decreased blood flow through an
organ
2) hypoxemia: low oxygen in blood (PaO2 <60, SaO2 < 90)
3) decreased 02 carrying capacity: Hb dysfunction
Causes of Ischemia? - CORRECT ANSWER-1) Decrease arterial perfusion (blockage ex:
arthlesclerosis)
2) decreased venous drainage (back up of flow: Ex: Budd-Chiari Syndrome
,3) Shock: decreased perfusion of organs due to hypotension
Bud-Chiari Syndrome - CORRECT ANSWER-thrombosis of hepatic vein therefore blood no longer
gets to the liver = infarction of liver parenchyma
What is the most common cause of Budd-Chiari Syndrome? - CORRECT ANSWER-Polycythemia
Vera: high RBC number due to overproduction of EPO/RBC, making the blood thick, viscous,
slow flowing.
- leading to thrombosis/ clotting which can occur in the hepatic vein
-->Budd- Chiari Syndrome
another cause is lupus = which makes blood hypercoa guable
Causes of Hypoxemia - CORRECT ANSWER-1) High altitude: decreased Fi 02 (available oxygen in
the air)= less PA02 (02 in blood)
2) Hyperventilation: increase C02 in blood leads to less PA02 in blood (ex: COPD air trapped in
lung)
3) Diffusion defect: Thickened diffusion barrier prevent s02 from being pushed into cells (ex:
interstitial pulmonary fibrosis)
4) VQ mismatch: blood bypasses oxygenated lungs (circulation problems --> RIGHT to LEFT
shunt)
or
Oxygenated air can't reach blood (ventilation problems --> atelectasis)
Causes of decreased 02 carrying capacity - CORRECT ANSWER-Due to HB dysfunction
, 1) Anemia: decrease in 02 carried in blood (Pa02 & Sa02 normal)
2) CO poisoning (smoke from fire, exhaust from cars, gas heaters)
- CO binds HB more strongly than 02 and doesn't let go
- Pa02 normal but Sa02 decreased
3) Methemoglobinemia: Iron in heme is oxidized to Fe3+ (instead of Fe2+) which can't bind 02
Signs of CO (Carbon monoxide) poisoning - CORRECT ANSWER--Cherry red appearance on skin
(HB so tightly bound reflects red in skin, but technically person is hypoxic b/c they aren't binding
as much 02 as they need to)
- Early sign = headache
- Late sign= confusion, coma & death
Methemoglobinemia definition and Signs/Symptoms - CORRECT ANSWER-Iron in heme is
oxidized to Fe3+ (instead of Fe2+) which can't bind 02 = hb has decreased 02 carrying capacity
- signs: cyanosis + chocolate color blood
- pa02 normal Sa02 decreased
-seen in oxidant stressors (sulfa & nitrate drugs) and newborns
- treat: IV methylene blue (converts Fe3+ to Fe2+), vitamin C, Cimetidine
How does low ATP disrupt cell function? - CORRECT ANSWER-It disrupts:
- Na-K pump (na & water build up)
AND VERIFIED CORRECT ANSWERS
GRADED A+ LATEST 100%
GUARANTEED PASS
Mechanisms of Action of Atrophy - CORRECT ANSWER-Apoptosis - programmed cell death
(decrease in cell number)
Ubiquitin Protein Degradation-->Decrease in cell size by ubiquitin tagging cells for death.
Autophagy of cell components (vacuoles fuse with lysosomes) --> decrease in cell number
Example of Metaplasia - CORRECT ANSWER-Barret's Esophagous
What's an exception of metaplasia that doesn't increase the risk of cancer? - CORRECT
ANSWER-Apocrine Metaplasia (exocrine gland breast cancer)
What is dysplasia? - CORRECT ANSWER-Disorders cell growth --> proliferation of precancerous
cells
* REVERSIBLE if you remove stressor*
,Difference between dysplasia and cancer? - CORRECT ANSWER-- Dysplasia is reversible if you
remove the stressor
- Cancer is irreversible even if you remove stressor
What are streak ovaries? What genetic disease is it common in? - CORRECT ANSWER-Streak
Ovaries are smaller, atrophied, fibrous streaky looking ovaries due to hypoplasia (decrease cell
number in embryogenesis).
- Occurs in Turner's Syndrome (XO) where ovaries develop early but lack of 2nd X chromosome
leads to accelerated loss of oocytes
- Lead to early menopause even before having a period
What type of cell is highly susceptible to ischemic injury? What type of cell is more resistant to
hypoxia? - CORRECT ANSWER-- Easily affected by hypoxia are neuronal cells (can only last 3-5
mins w/o oxygen)
- Skeletal muscle is more resistant
What are causes of hypoxia? - CORRECT ANSWER-1) Ischemia: decreased blood flow through an
organ
2) hypoxemia: low oxygen in blood (PaO2 <60, SaO2 < 90)
3) decreased 02 carrying capacity: Hb dysfunction
Causes of Ischemia? - CORRECT ANSWER-1) Decrease arterial perfusion (blockage ex:
arthlesclerosis)
2) decreased venous drainage (back up of flow: Ex: Budd-Chiari Syndrome
,3) Shock: decreased perfusion of organs due to hypotension
Bud-Chiari Syndrome - CORRECT ANSWER-thrombosis of hepatic vein therefore blood no longer
gets to the liver = infarction of liver parenchyma
What is the most common cause of Budd-Chiari Syndrome? - CORRECT ANSWER-Polycythemia
Vera: high RBC number due to overproduction of EPO/RBC, making the blood thick, viscous,
slow flowing.
- leading to thrombosis/ clotting which can occur in the hepatic vein
-->Budd- Chiari Syndrome
another cause is lupus = which makes blood hypercoa guable
Causes of Hypoxemia - CORRECT ANSWER-1) High altitude: decreased Fi 02 (available oxygen in
the air)= less PA02 (02 in blood)
2) Hyperventilation: increase C02 in blood leads to less PA02 in blood (ex: COPD air trapped in
lung)
3) Diffusion defect: Thickened diffusion barrier prevent s02 from being pushed into cells (ex:
interstitial pulmonary fibrosis)
4) VQ mismatch: blood bypasses oxygenated lungs (circulation problems --> RIGHT to LEFT
shunt)
or
Oxygenated air can't reach blood (ventilation problems --> atelectasis)
Causes of decreased 02 carrying capacity - CORRECT ANSWER-Due to HB dysfunction
, 1) Anemia: decrease in 02 carried in blood (Pa02 & Sa02 normal)
2) CO poisoning (smoke from fire, exhaust from cars, gas heaters)
- CO binds HB more strongly than 02 and doesn't let go
- Pa02 normal but Sa02 decreased
3) Methemoglobinemia: Iron in heme is oxidized to Fe3+ (instead of Fe2+) which can't bind 02
Signs of CO (Carbon monoxide) poisoning - CORRECT ANSWER--Cherry red appearance on skin
(HB so tightly bound reflects red in skin, but technically person is hypoxic b/c they aren't binding
as much 02 as they need to)
- Early sign = headache
- Late sign= confusion, coma & death
Methemoglobinemia definition and Signs/Symptoms - CORRECT ANSWER-Iron in heme is
oxidized to Fe3+ (instead of Fe2+) which can't bind 02 = hb has decreased 02 carrying capacity
- signs: cyanosis + chocolate color blood
- pa02 normal Sa02 decreased
-seen in oxidant stressors (sulfa & nitrate drugs) and newborns
- treat: IV methylene blue (converts Fe3+ to Fe2+), vitamin C, Cimetidine
How does low ATP disrupt cell function? - CORRECT ANSWER-It disrupts:
- Na-K pump (na & water build up)
