Cardiovascular Physiology Lecture 2 Flashcards
What are the four valves in the heart?
- Atrioventricular (AV) valves - between atria and ventricles
- Bicuspid (mitral): between L Atrium and L ventricle
- tricuspid: between R Atrium and R ventricle
- Semilunar (arterial) valves - between the ventricles and there arteries into which the ventricles pump
- aortic valve
- pulmonary valve
What are valves made of?
What are the flaps called?
Made of fibrous tissue (collagen) covered by endothelium
The valve flaps are also called leaflets or cusps
What are valve rings?
What the valves attach to
Made of cartilage
How do the valves open and close?
Passively: due to differences in pressure or pressure gradients (do not require muscle)
What happens to the atrioventricular valves when the pressure in the atria exceeds the pressure in the ventricle?
AV valves open
What is the funciton of the AV valves?
Prevent backflow of blood into the atria as the ventricles contract
What are the chordae tendineae?
Tendinous-type tissue that extend from edges of each leaflet to papillary muscle.
What are papillary muscles?
Do they contract?
Cone-shaped muscles
- contraction of papillary muscles causes the chordae tendineae to become taut
- holds valve in closed postion
What is the Cardiac skeleton?
Fibrous skeleton of the heart
What is the cardiac skeleton made of?
Dense connective tissue
What is included in the cardiac skeleton?
- Heart valve rings
- dense connective tissue between the heart valves
What are three functions of the cardiac skeleton?
- physically separates the atria from the ventricles
- electrically inactive and blocks the direct spread of electrical impulses from the atria to the ventricles
- Provides support for the heart, providing a point of attachment for the valves leaflets and cardiac muscle
What is coronary circulation?
Part of the systemic circulatory system that supplies blood to and provides drainage from the tissues of the heart
Where do the coronary arteries originate?
Coronary arteries originate at aortic sinuses at base of ascending aorta
Supply blood to the heart
What is the aortic sinus?
Dilation or “out-pocketing” of the ascending aorta; site where the left and right coronary arteries originate
Where do the cardiac veins empty?
Coronary sinus
- collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart
What is systole?
Ventricular contraction
What is diastole?
Ventricular relaxation
Blood flow almost ceases when the heart is ______ and peaks while the heart is ______
Blood flow almost ceases when the heart is contracted (systole) and peaks while the heart is relaxed (diastole)
What causes coronary artery disease?
Atherosclerosis of the coronary arteries.
atherosclerosis = condition where arteries become hardened and narrow due to plaque in the walls