Transcript Chapter 22 Circulato..

Circulatory System
Circulation
• In the United States of America, what do we
use to transport goods?
– Roads, railroad tracks, and airline routes.
• Our body has a transportation system too
which we call the circulatory system: where
blood moves through our body.
Circulatory system
• It is made of your heart, blood vessels, and
blood.
• Blood vessels carries blood throughout the
body, which forms a closed circulatory system.
• Closed circulatory system: is where blood
never leaves the blood vessels.
• What other organisms can you name that
have a closed circulatory system?
• Its like a double pump
– Right side pumps blood
to the lungs
– Left side pumps blood to
all other parts of the
body
• Atrium (upper
chambers): receive
blood returning to the
heart
• Ventricle (lower
chambers): pump blood
out of the heart
Heart
Heart Valves
• Each valve in the heart is a thin, strong flap of
tissue that acts like a one-way door
– Tricuspid: valve between the right atrium and right
ventricle
– Bicuspid: valve between the left atrium and the left
ventricle
– Semilunar valves: are found between the ventricles
and the blood vessels
• What is the job of the valves?
– The valves open and close at different times to
prevent blood from flowing backward
Heart Valves
Heartbeat
• What causes the sound of your heartbeat?
– It is caused by the opening and closing of the
valves in the heart.
Blood Vessels
• 3 types of blood vessels:
1. Arteries
2. Veins
3. Capillaries
• They are blood vessels that
carries blood away from the
heart.
• They are thick muscular walls
that are strong and elastic.
• Each time the heat beats,
blood is pushed through the
heart under high pressure.
– Therefore their strong elastic
walls allows them to stretch
preventing the arteries from
bursting
Arteries
Veins
• They are blood vessels that carry blood to the
heart.
• They are less muscular and their pressure exerted
on veins are less than that of arteries.
Capillaries
• They connect the smallest arteries and veins
together.
• Microscopic blood vessels that are only 1 cell
thick.
Circulatory System Problems
• 1 of the leading causes of death in the US.
1. High blood pressure
•
•
•
Caused by the narrowing of the arteries
Hardening of the arteries
Cholesterol (fatty substance) build up
2. Heart attack
•
•
Caused from narrow artery blockage
If the heart doesn’t get enough blood it begins to die
Circulation
• Pulmonary Circulation: pathway of blood
between the heart and the lungs
Circulation cont.
• Systemic Circulation: pathway of blood
between the heat and the rest of the body.
• Functions:
Blood
– Transportation of materials
– Regulate body temperature
– Maintain chemical balance
– Protection against diseases
Parts of the blood
1.
2.
3.
4.
Plasma
Red blood cells
White blood cells
Platelets
Plasma
• It is the liquid part of the blood, which is made
up of 90% water.
• It carries dissolved vitamins, minerals,
digested nutrients, wastes, and different kinds
of proteins.
Red Blood Cells
• Blood gets its color from 25 trillion red blood
cells.
• Their job is to carry oxygen, which is done so
by a molecule called hemoglobin that is found
on every red blood cell.
• Correction!!!!!!!!!!!
– Blood without oxygen is dark red, but never blue.
White Blood Cells
• They are cells that defend your body against
diseases.
• You have only 1 white blood cell for every
1000 red blood cell
• Phagocytes (white blood cells) surround
bacteria and digest them.
• So why do we get pus when we get a cut?
– Shows that our body is fighting the infection
– Made up of dead white blood cells, bacteria, and
tiny pieces of dead tissue.
White Blood Cells
Platelets
• They are the part of the blood that controls
clotting.
• Clotting: prevention of blood loss
• Platelets sick together at the site of a cut and
basically form a plug.
Blood Groups
• Did you know that not every person’s blood is
the same?
• Four blood types:
1.
2.
3.
4.
A
B
AB
O
Blood Disorders
• Anemia: is a disorder where blood can not carry
normal amounts of O2 to body cells.
• Leukemia: cancer of the blood, where the body
produces millions of abnormal immature white
blood cells.
Lymphatic System