Transcript Cardiovascular System and Heart Health

Cardiovascular system
Function
1. Transports blood (which contains
nutrients, hormones, and gases)
2. Gas Exchange
3. Helps maintain
constant body
temperature
Central Organ
• The Heart - muscular organ that pumps
blood through a network of blood
vessels
– Myocardium- major portion of the heart
– Pericardium- a thick membranous
enclosure that protects the heart
Heart Anatomy
• A septum (wall) vertically divides into two
sides
• Right- pumps blood to the lungs
• Left- pumps blood to the other parts of the
body
• Upper chambers- atrium
• Lower chambers- ventricles
Heart Valves
• Valves- Flap of tissue that open in only
one direction. Valves prevent blood
from flowing backwards.
Flow of Blood in the Heart
• Coming from the body,
blood is deoxygenated (low O2, rich in carbon
dioxide)
enters the:
1. Superior and Inferior Vena Cava
2. Into the Right atrium
3. To the Right Ventricle
4. Through the Pulmonary arteries
5. To the capillaries of the lungs
to exchange CO2 for O2
Flow of Blood in the Heart
6. From the lungs - the blood is rich in O2
7. Through the pulmonary veins
into the Left Atrium
8. To the Left Ventricle
9. Through the Aorta
to the rest of the body
Blood Vessels
•
Vast network that keep the blood flowing in
one direction
1. Arteries and arterioles- carry blood away
from the heart.
Arteries are large, muscular vessels. They
are strong and elastic which allow them to
stretch as blood enters from the heart.
Arterioles are smaller and less muscular
in size and turn into capillaries
Blood Vessels
2. Capillaries – tiny blood vessels in networks
that allows exchange of material through
diffusion, between blood and cells in tissue
3. Veinuoles- small blood vessels that carry
deoxygenated blood away from the
capillaries. They turn into veins.
4. Veins- large blood vessels that carry
deoxygenated blood to the heart. Veins
have valves which prevents blood from
flowing backwards.
Two Cardiovascular Pathways
1. Pulmonary Circulation – blood that travels
between the right side of the heart and
lungs. Carbon dioxide diffuses out of the
capillaries and oxygen diffuses in.
2. Systemic Circulation – oxygenated blood
that travels between the left side of the
heart and all parts of the body except the
lungs.
Cardiovascular System
End Part 1
Cardiovascular System and
Heart Health
Control of the Heartbeat
• Muscle cells of the heart contract in
waves so that when the first cells are
stimulated they in turn stimulate
neighboring cells to contract.
Phases of the Heartbeat
1. Systole- occurs when the chambers contract
2. Diastole- occurs when the chambers relax
• Heart Beat - The closing of the two heart
valves results in the “lub dub” sound.
Pulse
• Pulse- series of pressure waves within
an artery caused by the contractions of
the left ventricle. When the ventricles
contract, blood surges through the
arteries and the elastic walls expand
and stretch.
Blood Pressure
• The pressure against a blood vessel wall,
usually measured in an artery in the arm
• systolic pressure: highest pressure during
blood ejection from the heart
• diastolic pressure: lowest pressure when the
ventricles relax
The End of Part 2