The Circulatory System
Functions of the
Circulatory System
1. Brings blood containing
oxygen, nutrients, and
hormones to cells
2. Transports CO2 and
other wastes away
from cells
Functions Continued
3. Fights infection
4. Regulates body
temperature
5. Helps stabilize pH and
ionic concentration of body
fluids.
Parts of the Circulatory
System
1. Heart
2. Blood
3. Vessels
Arteries
 Veins
 Capillaries

The Heart
1. A muscular pump
2. Moves blood through the body
Aorta
Superior vena
cava
Left pulmonary artery
Left atrium
Right pulmonary
veins
Left pulmonary
veins
Right atrium
Inferior vena cava
Right ventricle
Left ventricle
3. Composed of
four chambers
4. Divided into right
and left halves
5. Made up of
cardiac
muscle cells
Structures of the Heart
Chambers


Atria- (2) upper
chambers
Ventricles- (2) lower
chambers
Pulmonary valve
Left atrium
Aortic valve
Right atrium
Mitral valve
Left ventricle
Tricuspid valve
Septum
Right ventricle
Structures of the Heart

Valves seen from above
Pulmonary
valve
Valves


Prevent backflow of blood
Keep blood moving in one
direction
Pulmonary veins
Tricuspid valve
Right atrium
Chordea tendinea
Mitral valve
Aortic valve
Left atrium
Pulmonary valve
Pathway of Circulation
Nutrients pass into tissues
Waste products filter back
Blood pumped out of
heart into arteries,
which branch into
smaller and smaller
vessels until blood flows
into capillaries
Blood returns to the
heart through the veins
Heart
Capillary
Capillary
network
1. Arteries branch into
smaller and smaller
vessels (arterioles)
2. They eventually
become capillaries,
which supply blood to
all body parts
3. Capillaries merge
into (venuoles) which
join into veins and
carry blood back to the
heart.
Blood Vessels
1. Form a closed circuit
of tubes that carry blood
throughout the body
2. Laid end to end, the
blood vessels in an
average human body
will stretch
approximately 62,000
miles……2.5 times
around the earth
Blood Vessels
3. Have characteristic
features
4. Are distinguished
by size, tissue layers
and direction of blood
flow
Blood Vessels
1. Arteries






Receive blood from
ventricles
Take blood away
from the heart
Usually carry
oxygenated blood
Thickest vessel walls
Connect to capillaries
Aorta is the largest artery
Blood Vessels
2. Veins







Transport blood away from capillaries
Carry blood
toward heart
Take blood to atria
Have valves
Thinner vessel
walls
Usually carry de-oxygenated blood
Vena cava is the largest vein
Blood Vessels
3. Capillaries
Smallest of blood vessels
 Only one cell thick (epithelial cell)
 Connect arteries to veins
 Bring oxygen
and nutrients
to cells
 Removes
CO2, urea,
and other wastes from cells

Blood Vessels

A network of capillaries runs
close to the cells in every part
of the body. The capillaries
have very thin walls which
allows nutrients to diffuse
through into the tissues and
waste products to filter back
into the capillaries.
Capillaries
Artery
Arteriole
capillaries
Venule
Tissue cells
Vein
Blood
1. A circulating
connective
tissue consisting
of several types
of cells
suspended in a
fluid medium
known as
plasma.
Blood
2. Functions of blood:


Supply oxygen to tissues
Supply nutrients to tissues

Removal of wastes from tissues

Immunological functions,
including circulation of white
cells, and detection of foreign
material by antibodies
Blood
Functions of blood continued:
Messenger functions, including transport of
hormones and signaling of tissue
 Coagulation,
part of body's
self-repair
mechanism

Circulatory System Disorders
Heart Disease

Risk factors










Older age
Male gender
Cigarette smoking
High cholesterol
Diabetes
Stress
Obesity
Heredity
Physical inactivity
High blood pressure
Circulatory System Disorders
Hypertension

High Blood Pressure
Makes the heart
and blood
vessels work
harder
Increases the
chance of heart
disease, heart
attack or stroke
Circulatory System Disorders
Heart Attack
acute myocardial infarction
 Interruption of oxygen
supply to the heart
 Causes death of
the heart muscle
 Leading cause of
death in both men
and women

Coronary Blockage
Circulatory System Disorders
Heart Attack

Symptoms









Chest pain
Squeezing or heavy pressure
on chest
Pain that radiates down left
shoulder and arm
Shortness of breath
Nausea or vomiting
Anxiety or Fainting
Lightheadedness - dizziness
Palpitations (feeling like your
heart is beating too fast)
Sweating, which may be
extreme
Circulatory System Disorders
Stroke
Interruption of oxygen supply to the brain
 Caused by:

A clot in an artery
in the brain
 Breakage of an
artery in the brain


Causes brain cells
to be deprived
of oxygen and die
Circulatory System Disorders
Aneurysm



Localized, blood-filled dilation
(bulge) of a blood vessel caused by
disease or weakening of the vessel
wall
Most commonly occur in arteries at
the base of
the brain and
in the aorta
Can burst and
lead to death
at any time