Transcript Circulatory System

Circulatory System
Functions of Circulatory
System
• Carries oxygen to all cells and removes carbon
dioxide
• Carries waste products of cell activity to
kidneys to be removed
• Transports nutrients from the digestive system
to all cells
• Carries materials that fight infections and heal
wounds
Components of Blood
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Plasma
Red Blood Cells
White Blood Cells
Platelets
Plasma
• Liquid part of blood
• Composed of water and nutrients
• Contains electrolytes
– Electrolytes: chemicals that
allow cells to maintain the
correct electrical voltage
(ex: nerve impulses)
Red Blood Cells
• Most numerous blood cells
• Tiny, flexible cells (allows
them to fit through capillaries)
• No nucleus
• Contains hemoglobin
Hemoglobin
• Hemoglobin contains iron & carries
oxygen in the blood
White Blood Cells
• Fight infection
Platelets
• Small cell fragments that clot the blood when
there are cuts and scrapes
3 types of Blood Vessels
• Arteries
• Veins
• capillaries
Arteries
• Carry blood away from the heart
• Arteries branch into smaller vessels, known as
arterioles
• Arteries have thick walls because the blood is
pumped with strong pressure from the heart
Veins
• Carry blood from the body tissues back to the
heart
• Smallest veins are venules
• Deoxygenated blood is not under much
pressure, so veins have thinner walls than
arteries
Capillaries
• Smallest blood vessels
• One cell thick
• This is the location of exchange of oxygen,
carbon dioxide, wastes, and other nutrients
• Arterioles and venules meet at the capillaries
Heart
• Made of cardiac muscle
• Located under the rib cage
Cardiac Muscle
• Muscle that contracts without nerve
stimulation
Pacemakers
• Special cells in the heart that control the
electrical system of the heart
• Cause the heart to beat by electrical signals
• 2 areas:
– Sinoatrial node
– Atrioventricular node
Heart Chambers
• The human heart
has 4 chambers
– 2 small atria: right
atrium & left atrium
– 2 large ventricles:
right ventricle &
left ventricle
Valves
• Valves allow blood to flow in one direction
only
Tricuspid valve
• separates the right atrium & right ventricle
Mitral valve
• separates the left atrium & the left ventricle
Aortic valve:
• between left ventricle & aorta
Pulmonary valve
• between the right ventricle & pulmonary
artery
Pericardium
• a double walled sac filled
with fluid that protects
the heart
Vena Cava
• Superior Vena Cava
– The higher vein that brings
blood from the head, neck, and
arms to return to the heart
• Inferior Vena Cava
– The lower vein that brings blood
From the rest of the body to the heart
Pulmonary artery
• This artery carries deoxygenated blood from
the heart to the lungs
Pulmonary vein
• This vein brings oxygenated blood from the
lungs to the heart
Aorta
• This is the largest artery in the body
• It has strong muscular walls to withstand the
high pressure with which the left ventricle
pumps the blood
Pulmonary Circulation
• The circulation system that takes blood from
your heart to your lungs and back to your
heart
Systemic Circulation
• The circulation that takes blood from your
heart to your body and back to your heart