Heart and Circulation Flashcards
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What are the functions of the cardiovascular system?
- transport of nutrients, oxygen and hormones throughout the body and removal of metabolic waste
- protection of the body by white blood cells, antibodies and complement proteins that circulate in the blood and defend the body against foreign microbes and toxins. (Clotting agents are also present that protect the body from loss of blood)
- regulation of body temperature, fluid pH, and water content of cells
What is the arterial system?
the vessels that carry blood around the body
What is microcirculation?
Where transfer of nutrients, waste and water occurs - capillaries, arterioles, venules
What is the function of the heart?
pumps blood around the cardiovascular system
What are the two circuits in the cardiovascular system?
- Pulmonary - carries deoxygenated blood away from the right ventricle of the heart to the lungs and returns oxygenated blood to the left atrium of the heart
- systemic - carries blood away from heart and delivers to tissues and organs, then returns blood back to heart - distinct form pulmonary circuit
Where does the functional aspect of the cardiovascular system occur?
In the capillaries where the exchange of gasses and nutrients occurs
Where is most blood in the heart found?
the left side
What side of the heart has higher muscle mass and why?
left side because it is used to pump blood around the body
What lines the walls of the heart
squamous epithelial cells
How does contraction work?
atria contract just before ventricles
What organ regulated blood volume? Why is blood volume important? What adds resistance to blood pressure?
the kidneys and to maintain blood pressure
arteries add pressure
What is the location of the heart?
lies centrally in the chest, between the lungs and pleura, in the middle mediastenum
What surrounds the heart?
pericardial sac of fibrous tissue that is lined by a serous, slippery membrane that secretes a small amount of lubricating fluid - mesothelial layers - allows free movement
What is the front of the heart called?
sternocostal surface
Where are the auricles found?
anterior surface of the outer walls of the atria
What is the function of the auricles?
increase the volume of blood the heart can hold
What is the bottom of the heart called?
diaphragmatic surface (mainly left ventricle)
How does deoxygenated blood return to the heart?
vena cavae (superior and inferior) (veins) into the right atrium
What valve lies between the right atrium and right ventricle?
tricuspid valve
Where does blood go from the right ventricle?
pulmonary trunk where it divides into right and left pulmonary arteries to the lungs where blood is oxygenated (pulmonary circulation)
How does blood return from the lungs?
via the left and right, superior and inferior pulmonary veins to the left atrium
What valve lies between the left atrium and left ventricle?
mitral/bicuspid valve
Where does blood go from the left ventricle?
aorta which pumps blood around the body
What lines all blood vessels?
endothelial cells
What is the coronary sinus?
a collection of veinsjoined together to form a large vessel that collects blood from the heart muscle (myocardium). It delivers deoxygenated blood to the right atrium, as do the superior and inferior vena cavae. It is present in all mammals, including humans.
What enters the right atrium?
deoxygenated blood via the superior and inferior vena cava and coronary sinus
What is the fossa ovals?
vestige of the foramen ovale which is a shunt in embryo that allows oxygenated foetal blood (coming from mother) to bypass non ventilated foetal lungs
What nodes are present in the right atrium?
Sino-atrial node and atrio-ventricular node
What is also known as the natural pace maker of the heart?
the Sino-atrial node - electrically conductive tissue that generates action potential spontaneously
What does the left atrium consist of?
left and right pulmonary veins (superior and inferior)
left auricle (receives blood from pulmonary veins
no nodes
What are papillary muscles?
muscles located in the ventricles, they attach to the cusps of antrioventricular valves to prevent prolapse of the valves on systesol - along with tendinous cords
What is laminar blood flow?
the normal condition for blood flow throughout most of the circulatory system
What ensures laminar blood flow into the pulmonary trunk and aorta?
smooth ventricle walls near its outflow
What is systole?
when ventricles contract
What is diastole
when ventricles relax
Where does the heart receive its blood supply from?
coronary arteries (left and right)
What controls the speed of the S-A node (pacemaker)?
the autonomic nervous system
What is the Bundle of His?
part of the electrical conduction system of the heart, that transmits impulses from the atrioventricular node, located at the inferior end of the interatrial septum, to the ventricles of the heart. - it is the only route in which conduction can pass from the AV node - it continues into the right and left bundle branches that spread conduction through each ventricle
Where does the wave of conduction (and contraction) in the heart occur?
passes from Sino-atrial node (SA node) through the atria to the atrioventricular node (AV node)
