High yield concepts

Question 1

Why does verapamil affect smooth muscle and cardiac muscle but not skeletal muscle?

Answer 1

Skeletal muscle does not depend on extracellular calcium influx to cause contraction. The L-type v-gate Ca channel is mechanically linked to the RyR channel resulting in release of Ca from the sarcoplasmic reticulum with little Ca influx from the outside.

Sm. muscle and cardiac muscle both require Ca2+ influx and binding to the RyR to activate sarcoplasmic reticulum release of Ca.

Question 2

Retroperitoneal structures

Answer 2

SAD PUCKER

Suprarenal glands
Aorta and IVC
Duodenum 2nd-4th

Pancreas (except tail)
Ureters 
Colon (descending and ascending)
Kidneys
Esophagus
Rectum

Question 3

4 tumors that secrete EPO

Answer 3

Pheochromocytoma
Renal Cell Carcinoma
Hemangioblastoma
Hepatocellular carcinoma