innermost layer of the blood vessel
thick medial layer of the blood vessel
tunical externa (adventura)
outer layer of blood vessel
More elastic fibers than smooth muscle, contain 15% of body's blood
Thinner walled, more distensible, controlled by smooth muscle tone, 60% of blood is in veins at any given time.
drain the extra 3liters of capillary outflow a day that is not reabsorbed by the venous system through a pumpless system
mostly water and albumin
Atherosclerosis and aneurysms
Cause vessel weakening from plaque eroding at vessel wall
Thromboangitis obliterans. Small microvascular clots. Pain and tenderness, redness, cyanosis in hands and feets. Smoking is indicated in 95% of cases.
Cold hands and feet followed by rubor. Vasospasm of fingers and toes.
HTN exam for target organ damage
carotids, check abd/femoral bruits
heart and lung auscultation
check legs for pulses and edema
Labs for HTN dx
60-100 bpm, greatly affected by external nervous system. "Normal" pacemaker
40-60 bpm. relays impulse to ventricles. Slows conduction to allow for filling. "Back-up" pacemaker.
20-40 bpm. Large fibers that provide simultaneous conduction to the right and left ventricles. Left side has two branches, right side has one. "last ditch" pacemaker.
Peak of action potential. +52mv.
depolarization, represents QRS complex on ecg.