Chapter 2 – Circulatory System and Other Systems
Tip Sheet
Circulatory System – Also referred to as cardiovascular or vascular system; controls
the steady circulation of blood. Consists of the heart, veins, and capillaries that
distribute blood throughout the body.
a. Heart – Heart is a muscular, conical-shaped organ about the size of a closed fist,
weighs approximately 9 ounces located in the chest cavity.
● Pericardium – Membrane that encloses the heart.
● Resting heart rate – normally beats about 72 to 80 times per minute
b. Chambers and valves of heart interior
● Right and Left Atrium – Also called auricle, upper, thin-walled chambers.
● Right and left ventricle – Lower thick-walled chambers.
● Valves – Allow blood to flow in only one direction
● Atria – When heart contracts and relaxes, the blood flows in, traveling
from the atria to the ventricles; it is then driven out to be distributed
throughout the body.
c. Blood Circulation – The blood is in constant and continuous circulation from
leaving the heart upon returning to the heart.
● Pulmonary circulation – Brings blood from heart to lungs to be
oxygenated or purified
● Systemic or general circulation – carries blood from heart throughout
body and back to heart as follows:
- Blood flows from body into right atrium
- From right atrium, flows through the tricuspid valve into the right
ventricle
- Right ventricle pumps blood to lunges where it releases waste gases
and receives oxygen; blood is then oxygen rich.
- Oxygen-rich blood returns to heart, entering the left atrium.
- From left atrium, blood flows through the mitral valve (also known as
, bicuspid valve) into left ventricle.
- Blood then leaves left ventricle and travels to all body parts. The
tricuspid and bicuspid valves are known as the atrioventricular
valves.
Chapter 2 – Circulatory System and Other Systems
Tip Sheet
d. Blood vessels – Arteries, capillaries, veins are tube-like in construction. They
transport blood to and from the heart and then to various body tissues. ● Arteries
– Thick-walled muscular and elastic tubes that carry pure blood from heart to
capillaries. The largest artery is the aorta.
● Arterioles – Small arteries that deliver blood to the capillaries. ●
Capillaries – Minute, thin-walled vessels that connect smaller arteries to
veins; provide tissues with nourishment and elimination of waste products
● Venules – small vessels that connect capillaries to the veins; they collect
blood from capillaries and drain it into veins.
● Veins – Thin-walled blood vessels; less elastic than arteries. Contain
cup-like valves to prevent back flow, and carry impure blood from
capillaries back to ehart; located closer to outer surface of body than
arteries.
e. The Blood – Nutritive fluid circulating through the circulatory system;
approximately 80% water. Composed of red and white corpuscles, platelets,
plasma, and hemoglobin.
● Sticky, salty fluid
● Normal temperature of 98.6 degrees. F
● Makes up 1/20 of body weight
● About 8-10 pints in body.
● Bright red in arteries
● Dark red in veins (except pulmonary) – Color change due to exchange of
carbon dioxide and oxygen as blood passes through lungs and circulates
through body.
Tip Sheet
Circulatory System – Also referred to as cardiovascular or vascular system; controls
the steady circulation of blood. Consists of the heart, veins, and capillaries that
distribute blood throughout the body.
a. Heart – Heart is a muscular, conical-shaped organ about the size of a closed fist,
weighs approximately 9 ounces located in the chest cavity.
● Pericardium – Membrane that encloses the heart.
● Resting heart rate – normally beats about 72 to 80 times per minute
b. Chambers and valves of heart interior
● Right and Left Atrium – Also called auricle, upper, thin-walled chambers.
● Right and left ventricle – Lower thick-walled chambers.
● Valves – Allow blood to flow in only one direction
● Atria – When heart contracts and relaxes, the blood flows in, traveling
from the atria to the ventricles; it is then driven out to be distributed
throughout the body.
c. Blood Circulation – The blood is in constant and continuous circulation from
leaving the heart upon returning to the heart.
● Pulmonary circulation – Brings blood from heart to lungs to be
oxygenated or purified
● Systemic or general circulation – carries blood from heart throughout
body and back to heart as follows:
- Blood flows from body into right atrium
- From right atrium, flows through the tricuspid valve into the right
ventricle
- Right ventricle pumps blood to lunges where it releases waste gases
and receives oxygen; blood is then oxygen rich.
- Oxygen-rich blood returns to heart, entering the left atrium.
- From left atrium, blood flows through the mitral valve (also known as
, bicuspid valve) into left ventricle.
- Blood then leaves left ventricle and travels to all body parts. The
tricuspid and bicuspid valves are known as the atrioventricular
valves.
Chapter 2 – Circulatory System and Other Systems
Tip Sheet
d. Blood vessels – Arteries, capillaries, veins are tube-like in construction. They
transport blood to and from the heart and then to various body tissues. ● Arteries
– Thick-walled muscular and elastic tubes that carry pure blood from heart to
capillaries. The largest artery is the aorta.
● Arterioles – Small arteries that deliver blood to the capillaries. ●
Capillaries – Minute, thin-walled vessels that connect smaller arteries to
veins; provide tissues with nourishment and elimination of waste products
● Venules – small vessels that connect capillaries to the veins; they collect
blood from capillaries and drain it into veins.
● Veins – Thin-walled blood vessels; less elastic than arteries. Contain
cup-like valves to prevent back flow, and carry impure blood from
capillaries back to ehart; located closer to outer surface of body than
arteries.
e. The Blood – Nutritive fluid circulating through the circulatory system;
approximately 80% water. Composed of red and white corpuscles, platelets,
plasma, and hemoglobin.
● Sticky, salty fluid
● Normal temperature of 98.6 degrees. F
● Makes up 1/20 of body weight
● About 8-10 pints in body.
● Bright red in arteries
● Dark red in veins (except pulmonary) – Color change due to exchange of
carbon dioxide and oxygen as blood passes through lungs and circulates
through body.
