4 chambers of the heart
~22 atria (upper chambers for blood storage)
2 ventricles (lower chambers, for pumping action. One has higher pump pressure and one has lower pump pressure).Heart size:
~3-varies with body size
- lies in thoracic cavity
-Average size: 14 cm long, 9 cm wide.Heart Location:
~6-Posterior to the sternum
-Medial to the lungs
-Anterior to the vertebral column.
-The base lies beneath the 2nd rib.
-The apex lies at the 5th intercostal space
-it lays just above the diaphragmCoverings of the heart include:
~4Pericardium
- Fibrous pericardium
-Parietal pericardium
-Visceral pericardiumFibrous pericardiumtough outer layer of the pericardium that surrounds double-layered serous membraneParietal pericardium
~2-Deep to fibrous pericardium
-Outer layer of serous membrane.Visceral pericardium
~3-Inner layer of serous membrane
-attached to surface of heart
-also called the epicardium.The heart wall has 3 distinct layers:
~3epicardium, myocardium, endocardiumEpicardium function
~2-aka visceral pericardium
-Forms a protective outer covering; secretes serous fluidMyocardium function
~2-middle muscle part; thickest part
-Contracts to pump blood from the heart chambersendocardium functionForms a protective inner lining of the chambers and valvesRight atrium:
~5-Receives blood returning from
-the superior vena cava
-inferior vena cava
- coronary sinus
-pumps blood to right ventricle.superior and inferior vena cavareturn blood, which is low in oxygen from tissuescoronary sinusdrains venous blood into the right atrium from the myocardium of the heartRight ventricle:
~2-receives blood from the right atrium
- pumps blood to lungs.Left atrium:
~2-Receives blood from the pulmonary veins
-pumps blood to left ventricle.Left ventricle:
~2-Receives blood from the left atrium
-pumps blood to systemic circuit.Tricuspid Valve location and function
~2location : Right atrioventricular orifice
function: Prevents blood from moving from the right ventricle into the right atrium during ventricular contractionPulmonary Valve Location and Function:
~2Location: Entrance to pulmonary trunk
Function: Prevents blood from moving from the pulmonary trunk into the right ventricle during ventricular relaxationMitral Valve Location and Function:
~2Location: Left atrioventricular orifice
Function: Prevents blood from moving from the left ventricle into the left atrium during ventricular contractionAortic Valve Location and Function:
~2Location: Entrance to aorta
Function: Prevents blood from moving from the aorta into the left ventricle during ventricular relaxationWhen the ventricles are contracting, the valves that led to the Atria are what?
~2-they are closed and they stay closed
-they are closed so that when the blood pumps the only place it can go is to the right atria to pulmonary valve and left atria to the aortic valve.the skeleton of the heart: (an extra note)Rings of dense connective tissue surround origins of pulmonary trunk and aorta, and orifices between atria and ventricles.
Provide attachments for heart valves and muscle fibers Prevent excess dilation of heart chambers during contraction
These rings, along with other fibrous masses in the interventricular septum, make up the skeleton of the heart.The left and right coronary arteries:
~2-supply blood to the tissues of the heart
-The coronary arteries are first 2 branches of the aorta.
