Transcript The Heart

Circulation
Read Chapter 31
1. Blood
Blood carries to the cells
Oxygen produced by R______________
Nutrients processed by D_____________
Blood carries away waste materials from the cells
Carbon dioxide taken to the L_______
Urea, taken to the K_________
Blood also transports
Hormones
(molecules that regulate the
function of tissue or organs)
Enzymes
(molecules that catalysis reactions)
Antibodies
(protein that are on B-cells and
attach to & kill foreign bodies)
What is blood made up of?
Plasma, mostly water. carries dissolved
molecules & plasma proteins for clotting
Red blood cells transport O2 in
hemoglobin, no nucleus, can’t repair them
selves. Have a 120 day life-span
•White blood cells, defend body against
invaders
The shape of blood cells
Blood clotting
When plasma comes into contact with tissue it reacts to
produce a protein (fibrin) which clump together to form a mesh
which traps red blood cells & platelets to form a clot.
The Cardiovascular System
This is the Heart & blood vessels
The Blood vessels:
Arteries
Carries blood away from heart to the body. Thick ,
tough elastic walls to withstand high pressure
Veins Carries blood to the heart from the body. Have larger
passageways.
Capillaries
Very fine blood vessels where exchange of
substances between the blood & cells occurs.
Most molecules leave capillaries by diffusion or bulk flow. Fluids
renter the capillaries by osmosis
Pulmonary vein
Blood moves from _________ To _______________
Pulmonary artery
Blood moves from _________ To _______________
Aorta
Blood moves from _________ To _______________
Superior vena cava
Blood moves from _________ To _______________
Inferior vena cava
Blood moves from _________ To _______________
The Heart
The heart has evolved from the simple two chambered heart in fish
to the three chambered heart in amphibians to our four chambered
heart.
Disadvantages of the fish heart
Not enough power to make blood flow fast after the gills
Advantages of our heart
More efficient
Higher pressure
Higher metabolic rate & so higher levels of activity
Relatively constant body temperature
Structure of the Heart
The interior of the Heart is divided into 4 chambers
Right atrium Deoxygenated blood from the body enters here via
the superior & inferior veins.
Left atrium Oxygenated blood returning from the lungs enters
here via the pulmonary vein.
Right ventriclePropels deoxygenated blood through the pulmonary
arteries to the capillaries of the lungs
Left ventricle Propels oxygenated blood through the aorta to the
capillaries in body tissue
Valves Stop back flow of blood between the chambers & also back
into the blood vessels during contraction
The atria are thin walled so they can expand to take in blood &
both contract at the same time to push blood through the valves
into the ventricles.
The ventricles contract simultaneously, this closes the valves
preventing back flow
The healthy heart of an adult beats 70 times a minute at rest