Cardiovascular system (aka.
circulatory system): Consists of the
heart, blood vessels, and blood.
The cardiovascular system carries needed substances
to cells and carries waste products away from cells. In
addition, blood contains cells that fight disease.
Delivering Needed
Materials=substances
(oxygen, glucose) are
carried by blood.
Removing Waste
Products=picks up waste
from cells (carbon
dioxide)
Heart: Hollow, muscular
organism that pumps blood
throughout the body.
Each time the heart beats,
it pushes blood through the
blood vessel of the
cardiovascular system.
Heart Parts:
Atrium: Two
upper chambers
that receives
blood that comes
from the heart.
Ventricle: Every Atrium has a
Ventricle underneath that pumps
the blood out of the heart. ATRIA
separates ventricles and valves.
Valve: A flap of tissue that prevents
blood from flowing backwards and
makes it travel the right direction
so that it can travel away from
heart to the large blood vessels.
Functions:
Heart: Heart muscle relaxes and fills with
blood. Heart muscles contract and pumps
blood forward. When heart relaxes again and
blood flows into chamber. Atria contracts,
heart in contracts, goes through valve to
ventricles..."LUB". Ventricles contract and
blood gets into the blood vessels. Valves,
ventricles, and blood vessel closes... "DUP"
Pacemaker: group of heart cells that
sends out signals that causes the
heart to contract and relax. Changes
depending on how much oxygen the
body needs. Excercising=more
oxygen, more pumping... Sitting in
chair=less oxygen, normal pumping.
Blood Vessels
Arteries: The thickest vessel
and carries rich blood or a
lot of oxygen. 3 layers: Layer
of epithelial, smooth muscle,
and connective muscle.
Flexible to handle enormous
blood pressure.
Can feel pulse by touching the artery and
arteries contract and relax as blood is
being pumped. Muscles relax=bigger
opening. Arteries go to digestive organs
and become narrower, and decreases the
blood flow towards organs.
Capillary: Smallest vessel
with only a layer of epithelial
cells. Materials are
exchanged between blood
and the body's cells. oxygen
and glucose pass through.
Cellular waste pass through
the capillary vessel and are
picked up by blood cells.
Veins: After blood moves through
capillaries, it enters into larger
blood vessels which carry blood
back to the heart. The walls of
veins are like arteries, but walls
are thinner. Near skeletal muscles
to make blood flow. Larger veins
have their own valves to keep
blood going towards heart.
Breathing movements also cause
blood to flow.
Blood Pressure: Cause the the contraction and
relaxation of the ventricles. Farther from
ventricles, the less force. Measured by a
sphygmomanometer, goes around upper arm,
artery is stopped quickly then released. The
sphygmomanometer measure first the blood
pressure while ventricles contract, then again as
the ventricle relaxes. Make fraction of contraction
of relaxation of the ventricles.
Blood: Made up of plasma,
red blood cells, white blood
cells, and platelets.
Plasma: Liquid part of blood. 90%
is water, 10% dissolved material.
Carries nutrients, glucose, fats,
vitamins, and minerals. Carries
chemical messengers the direct
body's activities. Cell waste is
carried away by plasma. Carries
carbon dioxide=cell waste.
Red blood cells: Take oxygen from the
lungs and deliver it to cells all over
the body. Looks like a disk pinched-in.
Flexible to fit through vessels and
heart. Hemoglobin is an
iron-containing protein that binds
and releases oxygen. Live up to 120
days, die and reproduce 2 million/sec.
No nucleus and can't reproduce
themselves. Bone marrow makes red
and white blood cells.
White Blood Cells: Produced
by bone marrow. The body's
disease fighters that
recognize and others kill the
bacteria/virus. 1 white blood
cell/500-1,000 red blood cell.
Have nucleus and can live for
months and years.
Platelets: Cell fragments that form blood clots.
When vessel is cut, platelets collect and stick
to the vessel and release a chemical, chain
reaction. Produces the protein called fibrin.
Blood clot=platelets, blood cells, and fibrin.
Lymphatic System: Network of veinlike vessels that
returns fluids to the bloodstream. (blood immune
system)
Lymph: Liquid that leaks out of blood
vessels. Travels in one direction. Get
filtered by lymph nodes where bacteria
is trapped and killed by white blood
cells. Then lymph is returned to blood.