1-3.
Deoxygenated blood enters the heart
through 3 vessels the superior vena cava, the inferior vena cave and the
coronary sinus.
(The superior vena cava carries blood
from the upper limbs, head and the upper torso. The inferior vena cava carries
blood from the lower limbs, the pelvis and the abdomen. The coronary sinus on
the other hand carries blood from the coronary circulation, which is the
circulation that nourishes the heart wall.)
4. It then enters a chamber called the
Right Atrium.
(The right atrium is small and has thin
muscle lining. It is one of the two receiving chambers of the heart. It is, as
the name suggests, on the right side on the upper area of the heart.)
5. and passes through the tricuspid
valve.
(It is also known as the right
atrioventricular valve. Its main function is to prevent back flow of blood. It is
made up of 3 valves, which look like flaps.)
6. The blood then enters a chamber
called the right ventricle.
(One of the two pumping chambers of the
heart. The muscles are thicker than those you would find on the atria. It is the right lower chamber of the heart)
7. and passes up through the pulmonary semilunar
valve.
(It was named as such because this is
the valve that opens into the pulmonary circuit. It is sometimes referred to as
the pulmonic valve. It also has three cusps. This valve opens during
ventricular systole.)
8. and Pulmonary trunk.
(This is considered as the first vessel
of the pulmonary circuit because it is at this point where the blood makes its
way to the lungs to be oxygenated. It is also known as the main pulmonary artery. It is one of the major vessels of the human
heart.)
9. The area splits into the right and
left pulmonary artery.
(The pulmonary arteries are the only
arteries in the body that carry unoxygenated blood or deoxygenated blood. They
are considered arteries despite this because they carry blood away from the
heart.)
10. Blood then enters the right and left lung where oxygen is picked up.
(As the blood picks up oxygen, it
releases carbon dioxide during respiration. The arteries are divided further
into really small capillaries, which have extremely thin walls.)
11. The oxygenated blood then reenters
the heart through the right and left pulmonary veins.
(Like pulmonary arteries, pulmonary
veins are unique because they are the only veins in the body that carry
oxygenated blood. They are considered as veins because they carry blood towards
the heart.)
12. It enters a chamber called the left
atrium.
(The right atrium is the second of the
two receiving chambers. It differs from the left because on this side of the
heart, it receives oxygenated blood which come from the pulmonary veins.)
13. and passes through the bicuspid
valve.
(Named as such because it has two cusps.
It is also known as the bicuspid aortic valve, the mitral valve or the left
atrioventricular valve. This valve opens during diastole and closes during
systole.)
14. The blood then enters a chamber
called the left ventricle.
(The left ventricle is the second of the
two pumping chambers. It has thicker muscles than the right ventricle because
it has to pump blood all around the body. The right ventricle only has to pump
blood into the lungs.)
15. and pushes up through the aortic
semilunar valve.
(Also known simply as the aortic valve,
it has 3 cusps. It opens as the pressure builds up in the left ventricle. As
the pressure decreases when systole ends, the aortic valve will close. The opening
and closing of the aortic valve makes the second heart sound.)
16.
Blood will then enter the Aorta.
(The aorta is the largest artery in the
human body. It has four sections; ascending aorta, aortic arch, descending
aorta and abdominal aorta. )
17. If it is going to move to the upper
part of the body, blood will exit through the Brachiocephalic trunk,
(The brachiocephalic trunk is the first
and the biggest branch of the aortic arch. It splits into smaller arteries
called the right common carotid artery and the right subclavian artery. It
supplies blood to the right side of the head, neck and right upper limb.)
18. Left common carotid artery.
(This artery is one of the two carotid
arteries. It supplies blood to the left side of the head and the neck. Unlike
the right common carotid artery, it stems directly from the aortic arch.)
19. Left subclavian artery.
(The left subclavian artery supplies
blood to the upper limbs on the left side of the body. It also stems directly
from the aortic arch, unlike its counterpart the right subclavian arteries.
20. If it is going to the lower part of the body,
blood will go through the descending aorta.
(The descending aorta is also called the
thoracic aorta. It continues from the aortic arch. It supplies blood to lower
half of the body. As it leaves the thorax, it becomes the abdominal aorta)
