Circulatory or Cardiovascular System: delivers oxygen,
nutrients, and hormones to the various body tissues and
transports waste products to the appropriate waste removal
systems.
Three major parts of the system: the heart, blood vessels and
blood
HEART:
- pericardium: double-walled membrane surrounding
the heart
- epicardium: external layer of the heart
- myocardium: middle and thickest layer of the heart;
the actual heart muscle
- endocardium: inner layer of the heart; lines the heart
chambers and valves
Arteries that serve the heart are known as coronary arteries,
because they resemble a crown. The coronary veins remove
waste products from the myocardium. Coronary veins
remove waste products from the myocardium.
Artery: blood vessel that carries oxygenated blood away
from the heart.
Vein: returns blood to the heart and away from the areas of
the body
Capillaries: single-celled vessels that connect the arteries
and veins. The slower rate of travel of the blood through the
capillaries allows time for diffusion of oxygen, nutrients, and
waste products.
The heart is divided into right and left sides. These sides are
then divided into chambers. Mammals and aviaries have 4chambered hearts. Reptiles have 3 chambers.
All vessels entering the heart enter through the atrium.
Ventricles are the pumping chambers of the heart, and all
vessels leave the heart here.
The narrow tip of the heart is called the apex. The left and
right atria are separated by the septum.
Blood flow through the heart is controlled by valves.
Right atrioventricular valve (right AV valve): this valve
controls the opening between the right atrium and the right
ventricle. Also called the tricuspid valve because it has three
points.
Pulmonary semilunar valve (pulmonary valve):
located between the right ventricle and pulmonary
artery and controls the blood entering the lungs.
This valve is shaped like a half-moon.
Left atrioventricular valve (left AV valve):
controls the opening between the left atrium and
the left ventricle. Also called the bicuspid because it
has to points.
Aortic semilunar valve (aortic valve): located
between the left ventricle and aorta. Controls blood
entering the arteries. Also half-mooned shape.
BLOOD FLOW THROUGH THE
HEART
1)The right atrium receives blood from all tissues
(except the lungs). Blood flows from the right
atrium through the tricuspid valve into the right
ventricle.
2)The right ventricle pumps blood through the
pulmonary semilunar valve and into the
pulmonary artery, which carries it to the lungs.
3)The left atrium receives oxygenated blood from
the lungs through the four pulmonary veins. The
blood flows through the mitral valve into the left
ventricle.
1)The left ventricle receives blood form the left
atrium. From the left ventricle, blood goes out
through the aortic semilunar valve into the aorta
and is pumped to all parts of the body (except the
lungs).
2)Blood is returned to the right atrium, and the
cycle continues.
http://www.khanacademy.org/science/healthcareand-medicine/the-heart/v/meet-the-heart
http://www.khanacademy.org/science/healthcareand-medicine/the-heart/v/flow-through-the-heart
Heartbeat: rate and regularity of the heart rhythm.
Alternating sequence of relaxation and contraction
of the heart chambers.
http://www.khanacademy.org/science/healthcare-and-medicine/theheart/v/lub-dub
http://www.khanacademy.org/science/healthcare-and-medicine/theheart/v/circulatory-system-and-the-heart