anatomy of the cardiovascular system

components of the cardiovascular system

blood, blood vessels and the heart

components of blood

plasma, rbc, wbc, platelets

blood vessels

arteries (high pressure), veins (low pressure) & capillaries

heart circuits

pulmonary and systemic

pulmonary circuit

carries blood to the lungs for gas exchange and returns it to the heart

systemic circuit

carries oxygenated blood from the heart to the rest of the body and back

overview of the heart

muscular pump, generates blood pressure, regulates blood supply

pericardium

closed sac around the heart; visceral layer (surface of the heart), parietal layer (outer layer, mediastinum), pericardial space between filled with pericardial fluid

heart wall

epicardium (outer layer, visceral pericardium), myocardium (cardiac muscle), endocardium (smooth inner surface of heart chambers)

features of the endocardium

simple squamous epithelium over connective tissue, covers heart valves

chambers of the heart

right atrium, right ventricle, left atrium, left ventricle

blood vessels of the heart

inf & sup vena cava, pulmonary artery, pulmonary vein, aorta

atrio-ventricular valves

found between the atria and the ventricles; tricuspid (right) and mitral (left)

semilunar valves

found between the ventricles and the major arteries; pulmonary (right) and aortic (left)

aorta

carries oxygenated blood from the heart (left ventricle) to the rest of the body

pulmonary artery

carries deoxygenated blood from the heart (right ventricle) to the lungs

vena cava

carries deoxygenated blood from the upper (superior vena cava) and lower (inferior vena cava) body to the heart (right atrium)

pulmonary vein

carries oxygenated blood from the lungs to the heart

tricuspid valve

valve between the right atrium and right ventricle

pulmonary valve

valve between the right ventricle and pulmonary artery

mitral valve

valve between the left atrium and left ventricle

aortic valve

valve between the left ventricle and aorta

transport of blood through the body

(deoxygenated) vena cava > right atrium > right ventricle > pulmonary artery > lungs (oxygenated) > pulmonary veins > left atrium > left ventricle > aorta (deposits oxygen around body & repeats)

function of valves in the heart

prevent the backflow of blood

where to listen for aortic valve

2nd intercostal space, right of the sternum

where to listen for pulmonary valve

2nd intercostal space, left of the sternum

where to listen for the tricuspid valve

5th intercostal space, left of the sternum

where to listen for the mitral valve

5th intercostal space, mid-clavicular line

coronary sulcus

groove that separates atria from ventricles - contains coronary blood vessels

coronary arteries

supply the heart muscle with oxygenated blood, branch of the aorta, run on heart surface

coronary artery disease

partial or complete blockage of branches of the coronary arteries

coronary veins

drain deoxygenated blood from heart muscle into the coronary sinus which empties into the right atrium

what is transported in the blood

O2, CO2, minerals & nutrients, hormones

blood production (hematopoeisis)

occurs in red bone marrow (& lymph tissue for lymphocytes)

basic structure of blood vessels

three layers - tunica interna (inner), tunica media (middle), tunica externa (outer)

tunica interna

one layer of endothelial cells (simple squamous epithelium), prevents platelet aggregation, secretes substances to control diameter of blood vessel

tunica media

smooth muscle & elastic tissue

tunica externa

mainly collagen

arteries

classified as elastic arteries, muscular arteries and arterioles

elastic arteries

largest, nearest the heart, high amount of elastic tissue in tunica media, function: stretch under high pressure during heart contraction and recoil during relaxation to maintain steady blood pressure

muscular arteries

medium-sized, more smooth muscle and less elastic tissue in tunica media, function: receive blood from elastic arteries and distribute to specific organs & body regions

arterioles

smallest, composed of a few layers of smooth muscle, function: regulate blood flow and pressure, leading to the capillaries

capillaries

transfers blood from arterioles to veins, site of exchange between blood and interstitial space, thin walls, blood flows through slowly

veins

thinner walls, less elastic & smooth muscle than arteries; walls are thicker and larger veins closer to the heart, contain valves