Cardiovascular System Intro

The molecular process necessary to keeps cells alive is called

diffusion

diffusion

allows oxygen and nutrients to enter cells and waste to leave

Why is the cardiovascular system necessary for humans?

Diffusion alone is too slow for large organisms. The cardiovascular system moves substances quickly over long distances

Larger surface area =

increase diffusion efficiency

• cells get nutrients and remove waste faster

three main functions of the cardiovascular system?

1. Gas exchange

2. Energy balance

3. Osmoregulation & Communication

Gas exchange

delivers oxygen for cellular respiration and removes carbon dioxide

Energy balance

• delivers nutrients for digestion and absorption

• removes waste products to excretory organs

Osmoregulation & Communication

carries water, ions, and hormones

three main components of the cardiovascular system

1. Circulatory fluid (blood) - carries gases and nutrients

2. Tubes. (blood vessels) - arteries→capillaries→veins

3. Muscular pump (heart) - moves blood

What are the three types of blood vessels ?

• arteries

• capillaries

• veins

Function of arteries

carry blood away from the heart, branching into smaller arterioles and capillaries

Function of capillaries

infiltrate tissues and organs allowing diffusion of molecules into cells

Function of veins

Merge into veins/venules to carry blood towards the heart

What is the normal path of blood flow through the vessels?

heart→arteries→arterioles→capillaries→venules→veins→heart

Where is the heart located?

thoracic cavity, between the lungs

• posterior to the sternum

• anterior to the vertebral column

• superior of the diaphragm

What are the four chambers of the heart?

• Two atria (upper chambers)

• Two ventricles (lower chambers)

Atria are upper chambers of the heart that

receive blood returning to the heart

Right atrium

low-oxygen blood returns from systematic circuit

Left atrium

high-oxygen blood returns from pulmonary circuit

Ventricles are lower chambers that

pump blood out of the heart

Right ventricle

sends low-oxygen blood to pulmonary circuit

Left ventricle

sends high-oxygen blood to systemic circuit

Two types of circulatory circuits

• pulmonary circuit

• systematic circuit

make up the “double circulation”

pulmonary circuit

right heart pumps blood to lungs for oxygenation

• chambers involved: right atrium and right ventricle

systemic circuit

left heart pumps oxygenated blood to organs/tissues

• chambers involved: left atrium and left ventricle

Pulmonary circuit carries

deoxygenated blood to lungs and returns oxygenated blood to the heart

Systemic circuit delivers

oxygenated blood to the organs/tissues and returns deoxygenated blood to the heart