1. Cardiovascular System- Heart Structure

cardiovascular system

includes heart and blood vessels

heart

pumps blood throughout the body

base of heart

higher than apex

apex of heart

bottom of heart poitning down

arterties

carry oxygenated blood away from the heart

veins

carry deoxygenated blood toward the heart

capillaries

tiny vessels where gases, nutrients, and wastes are exchanged between blood and tissues

pulmonary circuit

deoxygenated blood to the lungs to unload CO2 and pick up O2

systemic

oxygenated blood and nutrients to the body’s cells and removes wastes

left side of heart →

body

right side of heart →

lungs

pericardium (pericardial sac)

encloses the heart and proximal ends of large blood vessels

pericardium consists of

firbous, parietal, visceral, and pericardial cavity

wall of heart layers

epicardium, myocardium, endocardium

epicardium

outermost, connective tissue, blood capillaries, adipose tissue

myocardium

cardiac muscle tissue, heart contracts

endocardium

connective tissue, cardiac muscle fibers (purkinje fibers)

atria

upper chambers, receive blood, thin walls

ventricles

lower chambers, force blood out of heart, thick walls

interatrial septum

thin wall separating right and left atria

interventricular septum

separates right and left ventricles

right atrium

receives blood from superior and inferior vena cavae and coronary sinus

tricuspid valve

separates right atrium and right ventricle

chordae tendinae

fibrous strings attached to cusps of tricuspid and mitral valves to papillary muscles in wall of heart

right ventricle

blood leaves through pulmonary trunk to the lungs

pulmonary valve

base of trunk and has 3 cusps, separates right ventricle from pulmonary trunk

left atrium

receives blood from lungs through pulmonary veins

mitral valve (bicuspid valve)

separates left atrium and left ventricle

aorta

blood leaves left ventricle

aortic valve

three cusps at base, allows blood to leave when left ventricle contracts

heart skeleton

rings of connective tissue around pulmonary trunk and aorta at proximal ends, provides attachments for heart valves, prevents outlets of atria and ventricles from dilating during contraction

blood supply to heart

left and right coronary arteries, first two branches of the aorta

posterior interventricular artery

supplies posterior ventricles

right marginal branch

supplies right atrium and ventricle

circumflex branch

supplies left atrium and ventricle

anterior inter ventricular (left anterior descending) artery

supplies walls of ventricles

cardiac veins

drain blood from myocardium, paths lie parallel to those of coronary arteries

coronary sinus

enlarged vein into which other cardiac veins drain, drains into right atrium