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How much blood does your heart pump in a day? in a year?
- day: 14 000 liters/day
- year: more than 10 million liters/year
Where is the heart located? (2)
- in the mediastinum
- behind sternum, in front of vertebral column, between lungs
which direction does the heart point and what does it sit on?
- heart points to the left
- lying/sits on diaphragm
what are the coverings/sac of the heart called?
what is the function of the fibrous pericardium? (2)
- protects and anchors the heart
- prevents overstretching
what are the two types of pericardium?
- fibrous pericardium
- serous pericardium
What are the two layers in the serous pericardium?
- parietal layer of serous pericardium: fused with fibrous pericardium
- visceral layer of serous pericardium: also called epicardium and it's in direct contact with the heart
what is the serous (pericardial) fluid?
fluid found between parietal and visceral pericardia
what are the 3 layers of the heart wall?
Describe the epicardium.
thin outer layer of heart wall
describe the myocardium.
95% of heart wall that is made of cardiac muscle
describe the endocardium. what is it's function?
- lines the inner chambers of the heart
- minimizes surface friction as blood passes through the heart
what are the 4 chambers in the heart called?
- atria: upper two chambers
- ventricles: lower two chambers
what is the auricle and what's it's function?
- pouch-like structure on the anterior surface of atrium
- helps atria hold a greater volume of blood
what is the function of the atria?
receives blood returning to the heart and push it into the ventricles
what is the function of the ventricles?
receive blood from the atria and pump it into systematic and pulmonary circuit
what are the two ventricles divided by?
divided by the interventricular septum
The right side of the heart pumps blood into the _____________ circuit.
The left side of the heart pumps blood into the _____________ circuit.
What is the function of the right atrium? (2)
- receives deoxygenated blood from the superior and inferior vena cava
- sends blood to right ventricle
what is the function of the right ventricle? (2)
- receives blood from the right atrium
- sends blood to pulmonary circulation (lungs) via the pulmonary trunk
What is the function of the left atrium? (2)
- receives oxygenated blood from the pulmonary circulation (lungs)
- sends blood to left ventricle
what is the function of the left ventricle? (2)
- receives blood from the left atrium
- sends blood to systematic circulation (rest of body) via the aorta
what happens in the pulmonary circuit?
deoxygenated blood is converted to oxygenated blood by the lungs
what are the 3 structures in the pulmonary circuit?
- pulmonary arteries
- capillaries in lungs
- pulmonary veins
compare the myocardial thickness of the atria and ventricles, which is thicker?
compare the myocardial thickness of the right and left ventricles, which is thicker? why?
left ventricle because it pumps blood to the systematic circuit (rest of the body) and therefore need more muscle
What is the function of the atrioventricular valve (AV)? (2)
- separates atria from the ventricles
- prevents backflow of blood from the ventricles into the atria
what are the 2 types of atrioventricular valves and where are they located?
- Tricuspid valve: right AV
- Bicuspid valve: left AV
what are the functions of the semilunar valves? (2)
- allow blood to be pumped into the arteries
- prevent back flow of blood from the arteries into the ventricles
what are the two types of semilunar valves (SL)?
- aortic semilunar valves
- pulmonary semilunar valves
how does the heart valves open?
due to the pressure exerted by the blood
how does the heart valves close?
when papillary muscles contract
where is the papillary muscles located?
in ventricle attached to valve cusps by chordae tendineae
what is the function of the chordae tendineae?
prevent valve cusps from opening into the atrium
where does the sound of the heartbeat come from?
comes primarily from the turbulence in blood flow caused by the closure of the valves
how does the first heart sound (lubb;S1) occur?
blood turbulence associated with the closing of the AV valves soon after ventricular systole begins
how does the second heart sound (dupp; S2) occur?
blood turbulence associated with the closing of the SL valves close to the beginning of the ventricular diastole
Describe the sulci and its function?
grooves on the outside of the heart that separate the chambers
What does sulci contain and why?
contain fat and blood vessels that supply blood to the heart muscle
what is the coronary circulation?
is the circulation of blood in the blood vessels of the cardiac muscle (myocardium)
what is the function of the coronary arteries?
- supply heart cells with fresh nutrients and oxygenbranch of aorta
what is the function of the coronary veins?
- collect waste and deoxygenated blood from cardiac muscle
- drains into a large vein called the coronary sinus
coronary sinus empties into ___________.
what is myocardial ischemia? what are the signs?
- results from reduced blood flow to myocardium which leads to decreased oxygen
- signs= angina pectoris (severe chest pain, chin, neck, and left arm)
what is a myocardial infraction? (2)
- aka heart attack, results from complete blockage of a coronary artery
- tissue dies and is replaced by scar tissue ; heart loses some of its strength