The Cardiovascular System

The Cardiovascular System• It is also known as the circulatory system• This system consists of:

• The heart & lungs

• Blood vessels

• The lymphatic system

Words to Know• Cardiac/Coronary – Regarding the heart• Artery – A blood vessel that carries blood away from

the heart• Vein – A blood vessel which carries blood towards

the heart• Capillary – The smallest blood vessels that are only

1 cell wide

The Main Function• The main function of the

cardiovascular system is to circulate nutrients, gases, blood cells and hormones to and from cells in the body

Other important functions• Temperature Control

• The body to direct blood to increase the flow to capillaries, causing us to ‘flush.’ This cools the blood that is near the surface.

• Immune Defense• White blood cells are carried throughout the body.

Other important functions• Removal of wastes, such as:

• CO2• Urea• Lactic Acid

• Regulation of pH• Coagulation to form clots to repair wounds (both

internal and external)

The Three Loops•Pulmonary •Systemic •Coronary

Pulmonary• A circulatory system

in which blood exits the heart to the lungs to get oxygenated, and then back to the heart.

Systemic• A circulatory system that

sends oxygenated blood from the heart, throughout the body and carries oxygen-poor blood back to the heart.

Coronary• A circulatory system

which supplies oxygenated blood just to the heart.

Blood Vessels

There are 3 types of blood vessels

• Arteries:• Arteries take oxygen-rich blood from the heart• They become smaller and smaller as they leave the heart

to become arterioles

• Veins• Veins take oxygen-poor blood to the heart• They become bigger and bigger as they get closer to heart• Start off as venuoles

• Capillaries• The smallest vessels; they are only one cell thick• They are found in between arterioles and venuoles

What is Blood?

Blood

• Blood is a specialized tissue that

delivers necessary substances to the

body’s cells (nutrients and oxygen)

while transporting waste products

away from those same cells.

Ingredients• Plasma• Red Blood Cells (RBCs)• White Blood Cells (WBCs)• Platelets

Plasma• Plasma is the fluid in which the other nutrients and

cells are suspended• Also called extracellular fluid, since it is found

outside all cells• Plasma is about 93% water and contains dissolved

nutrients, gases, proteins, glucose, hormones, minerals, and other things

• It makes up about 55% of blood

Red blood Cells• RBCs are the most common type of blood cells

(that’s why blood looks red!)• Their main function is to carry oxygen throughout

the body• RBC cytoplasm is rich in hemoglobin, which

causes O2 to bond and makes the cell red

• Upon reaching maturity, RBCs become anucleated (they spit out their nuclei); this makes room for more O2

White Blood Cells• WBCs are the cells of the immune system, fighting

both internal and external enemies• They are found in the blood and in the lymph• There is typically a small amount in the blood. If you

have a high WBC count, that indicates an infection or disease

• There are 5 different types of white blood cells

Platelets• Are not cells! They are small cell fragments that

contain growth factors• They are found only in mammals (except for few

other non-mammalian species)• Too many platelets can cause blood clots• Too few can lead to excessive bleeding

Fun Facts• The average adult’s body has 5 liters

• 1.3 gallons• 2.5 Two-liters

• It takes 30-60 seconds for one drop of blood to circulate through the body!

• They say blood is thicker than water… its true – thanks to all the cells suspended in it.

• Carbon monoxide irreversibly binds to hemoglobin so that there is less available for oxygen to bind to. This can lead to suffocation and anemia.