Blood Components
Transports (O2, CO2, wastes, nutrients, heat, hormones)
Regulates (pH, body temperature)
Protects (against blood loss, disease)
The functions of blood
Points anteriorly, inferiorly, and to the left
Apex of heart
In 2 superior atria, small pouch extensions that allow each atrium to hold more blood
Auricles
Muscular ridges on wall of atrium
Pectinate muscles
Pulmonary trunk splits into these left and right vessels
Pulmonary arteries
Erythrocytes (red)
Leukocytes (white)
Two types of blood cells
Points posteriorly, superiorly, and to the right
Base of heart
Thin inner layer, gives smooth lining to heart chambers
Endocardium
Remnant of foramen ovalis in fetal heart, usually closes within 6 months of birth
Fossa ovalis
Similar structure to right version, receives oxygenated blood from lungs via pulmonary veins
Left atrium
No nucleus, contain hemoglobin, live for 120 days
Erythrocytes (RBC)
Surrounds heart, has 2 layers with pericardial fluid between, prevents overstretching of heart, protects & anchors, reduces friction while heart contracts
Pericardium
Heart located here, between sternum & vertebral column
Mediastinum
Right atrium contracts, blood passes through here into the right ventricle
Atrioventricular valve (tricuspid valve)
Blood passes to the left ventricle through here
Left atrioventricular valve (bicuspid or mitral valve)
Leukocytes (WBC)
Outermost thin, slippery layer (continuous with inner pericardial layer)
Epicardium
Receives deoxygenated blood from 3 major veins
Right atrium
Muscular ridges inside the ventricle, anchor flaps of the tricuspid valve
Chordae tendinae
Forms apex of heart; similar to the right version, but the myocardium is much thicker
Left ventricle
Watery plasma (water, proteins, other solutes), formed elements (cells and cell fragments)
Components of blood
Muscular layer, responsible for pumping
Myocardium
3 major veins that enter the right atrium
Superior vena cava, inferior vena cava, coronary sinus (on the exterior of heart)
Blood exits right ventricle through here, then enters the pulmonary trunk
Pulmonary semi-lunar valve
Blood exits left ventricle through here and goes into the ascending aorta
Aortic semi-lunar valve