Heart Anatomy Flashcards
Why does the hear function as a dual pump?
It pumps blood through the pulmonary and the systemic circuits.
two main chambers of the heart
atria and ventricles
Pulmonary circuit
- carries blood to and from the lungs
- right ventricle is the pump
systemic circuit
- transports blood to and from the body tissues
- left ventricle is the pump
general orientation of the heart
lies on the diaphragm, posterior to the sternum, in the mediastinum
Base
posterior and superior surface of the heart
Apex
- anterior and inferior, points to the left hip
- level of the fifth left intercostal space
Mediastinum is located in:
Located within the thoracic cavity
Subdivisions of the mediastinum
Superior Mediastinum
Inferior Mediastinum
- Superior
- Inferior
- ->Anterior
- -> Middle: pericardium and heart
- -> Posterior
3 layers of the pericardium
- Fibrous pericardium
- Serous pericardium
- -> Parietal layer
- -> visceral layer
Pericardial cavity
contains serous fluid
Pericardium functions
- prevents undesired movements
- prevents overfilling of the heart
- reduces friction
Pericarditis
-inflammation of pericardium
three major layers of the heart wall
epicardium
myocardium
endocardium
what kinds of tissues make up the epicardium
simple squamous epithelium
arreolar connective tissue and fat
what does the myocardium consist of
- cardiac muscle
- bulk of the heart wall
- myocardial infarctions occur here
what layer of the pericardium is present in the epicardium
visceral layer of the serous pericardium
endocardium consists of:
arreolar connective tissue and endothelium
what does the endocardium do
lines the heart chambers and covers the valves
what vessels transport oxygen-poor blood to the right atrium
superior vena cava
inferior vena cava
coronary sinus
what are the conducting nodes
sinoatrial node and the atrioventricular node
what supports the right AV valve
the papillary muscles and the chord tendinae
left atrium
receives oxygen-rich blood from the lungs through pulmonary veins
left ventricle
pump of the systemic circuit: ejects oxygen-rich blood into the aorta
which heart chamber is the most muscular
left ventricle: wall is three times thicker than the right ventricle
Valves structure
- composed of dense connective tissue
- 2 or 3 cusps
Valves function
- permit passage of blood in one direction
- permit back flow of blood
Right AV valve location
inferior portion of the body of the sternum
Left AV valve location
left fifth intercostal space
Pulmonary semilunar valve
second left intercostal space
aortic semilunar valve
second right intercostal space
Lub sound
closure of the AV valves
Dub sound
closure of the semilunar valves
Fibrous skeleton
connective tissue located between the atria and th ventricles
Functions of the fibrous skeleton
- separates the atria and the ventricles(structurally and electrically
- anchors heart valves
- framework for cardiac muscle attachment
chambers and major vessels that carry oxygen-poor blood
coronary veins coronary sinus superior vena cava inferior vena cava right atrium right ventricle pulmonary trunk pulmonary arteries
oxygen-rich blood
pulmonary veins left atrium left ventricle aorta coronary arteries
Blood flow through the heart
Systemic veins superior and inferior venae cavae right atrium right atrioventricular valve right ventricle pulmonary semilunar valve pulmonary trunk and arteries gas exchange in the lungs pulmonary veins left atrium left atrioventricular valve left ventricle aortic semilunar valve aorta systemic arteries gas and nutrient exchange in peripheral tissues
Branches of right coronary artery
posterior interventricular artery
right marginal artery
Branches of left coronary artery
circumflex artery
anterior interventricular artery
myocardial infarction
commonly called a heart attack
caused by blockage of a coronary artery
-most commonly the left anterior interventricular artery: which is also called the left anterior descending artery
what causes the heart muscle to die
lack of blood flow to a region of the myocardium can cause heart muscle to die because of lack of oxygen
