Human Physiology - Chapter 20
Terms in this set (31)
The study of the normal heart and diseases associated with it
Membrane surrounding the heart
Outer layer. Protects the heart and anchors it to the diaphram
Inner double layer. Parietal layer and visceral layer
Between the parietal and visceral layers of the serous pericardium
Fills the potential space and reduces friction between the two membranes
inflammation of the pericardium. Associated bleeding into the pericardial cavity compresses the heart (cardiac tamponade) and is potentially lethal.
Three Layers of the Heart Wall
visceral pericardium. epithelium and connective tissue
Cardiac contractile muslce
Edothelium (continuous with the endothelium of blood vessels) and connective tissue.
Small pouches on the anterior surface of each atrium that slightly increase the volume of each atrium
Grooves that contain blood vessels and fat
a. Receives blood from the superior and inferior vena cava and the coronary sinus
b. Blood passes from the right atrium into the right ventricle through the tricuspid valve.
One of two large vessels (superior and inferior) that return deoxygenated blood to the right atrium of the heart.
A valve that is situated at the opening of the right atrium of the heart into the right ventricle and that resembles the mitral valve in structure but consists of three triangular membranous flaps.
a. The right ventricle forms most of the anterior surface of the heart.
b. Blood passes from the right ventricle to the pulmonary trunk via the pulmonary semilunar valve.
a. The left atrium receives oxygenated blood from the pulmonary veins.
b. Blood passes from the left atrium to the left ventricle through the bicuspid (mitral) valve.
a. The left ventricle forms the apex of the heart.
b. Blood passes from the left ventricle through the aortic semilunar valve into the aorta
___ are thin because they deliver blood to the ventricles
____ are thicker because they pump blood greater distances at higher pressure
Right ventricle walls
thinner than the left because they pump blood into the lungs, which are nearby and offer very little resistance to blood flow
Left ventricle walls
thicker because they pump blood through the body where the resistance to blood flow is greater
o Forms the foundation for which the heart valves attach
o Serves as points of insertion for cardiac muscle bundles
o Prevents overstretching of the valves as blood passes through them
o Acts as an electrical insulator that prevents direct spread of action potentials from the atria to the ventricles
Atrioventricular valves (AV)
• Allow movement of blood from atria ventricles
• Prevent blood flow from the ventricles back into the atria
• Back flow is prevented by the contraction of papillary muscles tightening the chordae tendinae which prevent the valve cusps from everting.
Semilunar valves (SL)
• Three crescent cusps without chordae tendinae each.
• Allow ejection of blood from the ventriclesarteries
• Prevent back flow of blood into the ventricles.
• Semilunar valves open when pressure in the ventricles exceeds the pressure in the arteries.
• Certain infectious diseases, such as rheumatic fever, can damage or destroy heart valves.
Right side of the heart is the pump. It receives deoxygenated blood from the body and sends it to the lungs for oxygenation
Left side of heart is the pump. It receives oxygenated blood from the lungs and sends it to the body
results from partial obstruction of coronary blood flow and can give the symptom of "angina pectoris" A complete obstruction may result in a myocardial infarction (cardiac muscle death)
Flow of blood through the many vessels that pierce the myocardium of the heart
-It delivers oxygenated blood and nutrients to and removes carbon dioxide and wastes from the myocardium.
1. The principal arteries, branching from the ascending aorta and carrying oxygenated blood, are the right and left coronary arteries.
2. Deoxygenated blood returns to the right atrium primarily via the principal vein, the coronary sinus.