Transcript You`ve Got to Have Heart…

You’ve Gotta Have Heart…
a brief overview of the heart
and circulatory system
The Three Major Parts of the
Circulatory System
• Blood
– complex mixture of cells and fluids
• Blood Vessels
– tubes to carry the blood
• Heart
– muscle to pump the blood
Blood Vessels
• Arteries
– bring blood from the heart to body tissues and
organs
– thick walls hold up under high pressure
• Veins
– bring blood back to the heart from body tissues
and organs
– contain valves to prevent backflow of blood
• Capillaries
– -Exchange gases and water (via diffusion)
– very tiny vessels (as small as one cell thick!)
– can branch off from:
• small arteries (arterioles)
• small veins (venules)
The Pathways of Blood
• Pulmonary Pathway
– oxygen poor blood pumped from the heart to
the lungs
– oxygenation occurs in the lungs
• oxygen diffuses in
• carbon dioxide diffuses out
– oxygenated blood returns to the heart
• Systemic Pathway
– oxygen rich blood pumped from the heart to
the rest of the body
– makes three major “stops” along the way:
• digestive system
• cells in the body
• kidneys
Systemic “Stops”
• Digestive System
– nutrients absorbed through diffusion
in capillaries and sent throughout
body
• Cells in the Body
– blood drops off oxygen and nutrients
(so the cells can do their jobs)
– blood picks up carbon dioxide and
urea (the waste products of
metabolism)
• Kidneys
– remove urea, some water, and some
salts for later excretion as urine
The Heart
superior vena cava
aorta
pulmonary
artery
pulmonary
artery
right atrium
pulmonary
veins
left atrium
right ventricle
inferior vena cava
left ventricle
Blood Flow
HEART  Aorta  arteries  arterioles 
capillaries  venules  veins  vena cava
heart  lungs