2. FUNCTIONS
Transports oxygen and nutrients to the
cells
Transports carbon dioxide and other
waste for elimination from the body
Maintains homeostasis of the body cells
3. 3 MAIN PARTS
1. Heart
2. Blood
3. Blood vessels – arteries and veins***
Veins: carry blood back to the heart
Arteries: carry blood from heart to body tissues (when
you take your pulse, you are checking one of these
sights)
Capillaries: smallest blood vessels that connect the veins
and arteries
4. SIMPLE VS. COMPLEX ANIMALS
Simple animals do NOT have a circulatory
system. The exchange of materials and waste
occur by diffusion across the main body
cavity and cells.
Example: Cnidarians
Complex Animals have either an open or
closed circulatory system.
5. OPEN CIRCULATORY SYSTEM
The heart pumps blood into open-ended
blood vessels.
The blood is pumped from the heart, through
the vessels, and it “bathes” the tissues
Example: Grasshopper (Insects)
6. CLOSED CIRCULATORY SYSTEM
The hearts pumps the blood only through
blood vessels which carry the blood to all the
body tissues and then back to the heart.
Examples: Annelids, Mammals
7. Insect:
Open Circulatory System
Annelid:
Closed Circulatory System
Heartlike
structures
Blood
vessels
Heartlike structure
Small vessels in tissues
Blood
vessels
Hearts
Heart
Sinuses
and organs
Open & Closed Circulatory
Systems
8. Fish has a 2
chambered
heart
Amphibian
has a 3
chambered
heart
Mammal has
a 4
chambered
heart
SINGLE LOOP VS. DOUBLE LOOP SYSTEM
10. 2 CIRCUITS THAT BLOOD TRAVELS
(DOUBLE LOOP SYSTEM)
1. PULMONARY CIRUIT: A short loop where blood
is carried between your heart and lungs. In your
lungs the blood absorbs oxygen and releases
carbon dioxide. Then the oxygenated blood
returns to the heart.***
2. SYSTEMIC CIRCUIT: Carries oxygenated blood
to all other body cells then the blood releases
oxygen to the cells and picks up carbon dioxide
and other wastes and returns to the heart.
Your heart is basically 2 pumps, one for each circuit.
11. Fish has a 2
chambered
heart
Amphibian
has a 3
chambered
heart
Mammal has
a 4
chambered
heart
12. CHARACTERISTICS OF YOUR
HEART
It is about the size of your fist.
It is located beneath the sternum and near the center
of your chest.
It is a hollow organ with thick walls made of cardiac
muscle.
It is surrounded by a double walled sac called the
pericardium.
It has 2 sides separated by a thick wall called a
septum.
It has 4 chambers.
13. Figure 42.5 The mammalian heart: a closer look
Superior
Pulmonary
Tricuspid
Inferior
Aortic
Mitral
Septum
14. PARTS OF THE HEART AND THEIR
FUNCTIONS
The atria (right atrium and left atrium) are at the
top of the heart and the RECEIVE blood.
The Ventricles (right ventricle and left ventricle) are
at the bottom of the heart and the PUMP BLOOD
OUT.
Valves keep the blood moving in the correct
direction.
The right side of the heart carries the deoxygenated
blood.
The left side of the heart carries the oxygenated
blood.
15. Figure 42.4 The mammalian cardiovascular system: an overview
Flow of blood through the heart:
Deoxygenated blood
right atriumright ventricle
pulmonary arterypulmonary
vein
left atriumleft ventricle
aortabody
16. BLOOD PRESSURE
Caused by the force with which the ventricles
contract.
Measured with a sphygmomanometer (blood
pressure cuff)
A healthy adult should have a blood pressure
of 120/80
Top number is systolic pressure, the force felt in
the arteries when the ventricles contract
Bottom number is diastolic pressure, the force felt
in the arteries when the ventricles relax.
17. BLOOD COMPONENTS
55% PLASMA (a straw colored fluid)
45% Blood Cells
Plasma
90% water
10% dissolved minerals
Blood cells
Red blood cells- transport oxygen and get their color from
hemoglobin (an iron containing protein)***
White blood cells- fight disease
Platelets- help in blood clotting
