PNLU - internal anatomy of the heart

pectinate muscles (and where)

small, muscular ridges in the left and right auricle and right atrium

pathway of blood from the aorta

through branches to upper limbs and through brachiocephalic trunk or left common carotid or left subclavian —> thoracic aorta —> pierces the diaphragm

innervation of the heart

does NOT use CNS signals, uses the SA node located of the superior right atria

direction of heart innervation

SA node signal (superior) sent to AV node (posterior) — signal sent to AV bundle/Bundle of His — signal travels down to right and left bundle — signal lands in purkinje fibers

parasympathetic innervation of the heart

inn. by intrinsic ganglia of the vagus nerve to DECREASE HR and contraction force, and constrict coronary arteries

sympathetic innervation of the heart

inn. by cervical and superior thoracic paraveretebral ganglia in the T1-5/6 level to INCREASE HR, contraction force, and coronary arteries’ blood flow

diastole

atria contracting

systole

ventricles contracting and sending blood upwards

left ventricle

myocardium is thicker to account for the larger amount of blood that needs to be sent throughout the body and go against it’s pressure gradient

differences between arteries/arterioles and veins/venules

walls: Aa have thicker walls to receive blood at high pressure

lumen: arteries have smaller lumens to maintain BP

shape: Aa have a more defined, circular shape and Vv have compressed, ovular shapes

elastic fibers: Aa have more elastic fibers

elastic arteries

close to the heart with the thickest walls, containing a high amount of elastic fibers in all three tunics (externa, media, and intima)

muscular artery

contains thick tunica media allowing muscular arteries for vasoconstriction

arteriole

very small artery leading to a capillary with the same three tunics as the larger vessels, that have smaller thickness

capillary

microscopic channel supplying blood to tissues

perfusion

process of blood flowing through the circulatory system to deliver oxygen and nutrients to organs, also removing waste products

varicose veins

disorder of deoxygenated blood accumulating in the veins, causes veins to distend, twist, and become visible on the surface of the skin

arteries characteristics

conducts blood away from the heart, rounded appearance, high pressure, thick wall, high oxygen concentration in systemic arteries and low oxygen concentration in pulmonary arteries, no valves present

veins characteristics

conducts blood toward the heart, irregular/collapsed appearance, low pressure, thin wall, low oxygen concentration in systemic veins, high oxygen concentration in pulmonary veins, valves present in most limbs and in veins inferior to the heart