Download The Circulatory System

The Circulatory System
(Cardiovascular System)
Chapter 16
Three parts of this system are;
1. Heart
2. Blood vessels
3. Blood
Substances travel through the blood from
one part of the body to another. Ex:
 Oxygen
 Glucose
 Disease fighting cells
The Heart
 Made up of cardiac muscle
 Right side and left side
separated by a wall of tissue called
the SEPTUM
 Each side has an upper and lower
chamber
 Upper chamber is the ATRIUM
which receives blood from the heart
 In the right atrium is a pacemaker
(group of heart cells)
 Lower chamber has a right/left
ventricle which pumps blood out of
the heart
 Atria and ventricles are separated
by valves. Valves are also between
ventricles and large blood vessels that
carry blood away from the heart
 Valves are flaps of tissue that
prevent blood from flowing backward
Two Phases of the Heart
P 1- The heart muscle relaxes and fills up
with blood.
P2 – The heart muscle contracts and
pumps blood forward.
 When the heart beats it sounds
like lub-dub during the pumping
phase.
After blood leaves the heart
the blood travels through
the body there are three
types of blood vessels;
1. Arteries – carry blood
AWAY from the heart
2. Capillaries – tiny narrow
vessels that exchange
substances between the blood
and body cells
3. Veins – carry blood BACK
to the heart
Pattern of Blood Flow
Blood flows through the body
like a figure eight (8).
o Loop 1 – blood travels
from the heart to the lungs
and then back to the heart.
o Loop2 – blood is pumped from the
heart throughout the body and then
returns again to the heart.
*Blood travels in one direction.
Loop1
 Blood from the body flows into the
right atrium, it contains little oxygen
but a lot of carbon dioxide. Blood is
DARK red.
 Goes from the right atrium to the
right ventricle.
 Ventricle pumps the oxygen-poor
blood into the artery that leads to the
lungs.
 Blood flows through lungs into
smaller vessels into tiny capillaries.
Loop 2
 Left atrium fills with oxygen-rich
blood coming from the lungs and the
blood moves into the left ventricle
 Left ventricle pumps blood into the
aorta.
 After passing through branching
arteries the blood will flow through
capillaries in different parts of your
body.
 Oxygen moves out of the blood into
body cells.
 At the same time the carbon dioxide
passes from the body cells into the
blood.
 This blood is LOW in oxygen then
flows back to the right atrium through
VEINS completing the second loop.
**The PULSE is caused by the
alternating expansion and relaxation of
the artery wall.
Blood Pressure – blood exerts a force
against the walls of blood vessels. This
is caused by the force with
which the ventricles contract.
Section 2
Blood
Blood is made of 4 components;
1. plasma
2. red blood cells
3. white blood cells
4. platelets
Plasma – liquid part of the blood (water
makes up 90%. The other 10% is
dissolved materials). Plasma carries
nutrients, glucose, fats, vitamins, and
minerals. It also sends chemical
messengers to direct body activities.
Protein molecules give plasma its yellow
color. The three groups of proteins;
1) Regulate the amount of water in
the blood
2) Helps fight disease (white blood
cells.)
3) Interacts with platelets to form
blood clots.
There are 4 blood types;
A B AB
O (Each type is either
negative or positive). The marker
molecule on your red blood cell
determines your blood type.
*Type O is the universal donor.
*Type AB is the universal recipient.
Rh factor – is a protein on the red blood
cell that determines if your blood type is
positive or negative.
Lymphatic System
Blood and fluid that leaks out of
the capillaries into surrounding
tissues has materials that tissue
cells need. After this fluid is
used by the cells it goes through
a drainage system called the
LYMPHATIC SYSTEM.
This system is a network of veinlike
vessels that returns the fluid to the
bloodstream.
LYMPH – once the fluid is inside this
system it is called the lymph. The lymph
consists of water and dissolved materials.
LYMPH NODES – are small knobs of
tissue. They filter lymph, trapping
bacteria and other disease-causing
microorganisms in the fluid. When the
body is fighting infection the lymph
nodes enlarge. They are located near
your arm pits.
Section 3
Cardiovascular Diseases
Atherosclerosis – artery wall thickens
from a build up of fatty materials. It
reduces blood flow in the affected artery.
This can lead to a heart attack because
blood flow to part of the heart muscle is
blocked.
Hypertension - (high blood pressure).
The heart works harder to pump blood
throughout the body. Also could damage
the walls of the blood vessels.