Transcript 7th Circulatory System

The Circulatory
System
Primary Function
The function of the circulatory system
is to transport nutrients and oxygen
(O2) to cells around the body and to
remove wastes including carbon
dioxide (CO2).
 The fluid part of this system is the
blood.

Three Pathways
1.
Coronary circulation
is the flow of blood
to and from the
heart.
- If this circulation is
blocked= Heart
Attack
Cont. Three Pathways
2. Pulmonary circulation is the flow
of blood to and from the lungs to
gather oxygen.
Cont. Three Pathways
3. Systemic circulation
is the flow of blood
to and from all
other organs and
tissues of the body.
(EXCEPT those
previously
mentioned)
The Heart

Heart is a muscular organ that pumps
blood to lungs and other parts of the
body.
Atria-P Atrium- S
Upper chamber
2 of each
Ventricles – Lower
chamber
A total of 4 chambers
Structure of Heart

Four chambers
– Two upper (Atria)
 Right atrium
 Left atrium
– Two lower
(Ventricles)
 Right Ventricle
 Left Ventricle
Valves separate the top
and bottom
chambers and
prevents blood
from flowing
backwards. (one
way)
Cont. The Heart
Septum- seputm
wall that
SEPARATES the
left side of the
heart that
contains oxygen
from the right
side of the that
does not.
Your Blood Vessels:
Pathway of Circulation

3 types of blood vessels
– Arteries
– Veins
– Capillaries
Artery (Arteries):
carry blood Away from heart
– Large
– Thick- Muscular walled
– Oxygenated blood

Exception Pulmonary Artery
– Carried under great pressure
Veins:
Carry blood to the heart
–
Carries blood that contains
waste and CO2

–
–
Exception pulmonary vein
Blood not under much
pressure
Valves to prevent much
gravity pull
Varicose Veins
Damaged Valves in Veins
Artery vs. Vein
Capillaries:
tiny blood vessels that connect
arteries to veins
–
–
–
–
Smallest vessel
Microscopic
Walls one cell thick
Nutrients and gases
diffuse here
Some Important Vessels
Aorta- Largest
artery which
sends
oxygenated
blood from the
heart to the
rest of the
body.
Pulmonary
artery – carries
blood from the
heart to the
lungs to get
oxygen
Some Important Vessels
Superior vena
cava- major vein
that carries
unoxgenated
blood from the
UPPER parts of
the body.
Inferior vena
cava- major vein
that carries
unoxgenated
blood from the
LOWER parts of
the body.
Pulmonary
vein – carries
oxygenated
blood from the
lungs back to
the heart
Capillaries of head and arms
Superior vena
cava
Aorta
Pulmonary artery
Pulmonary vein
Capillaries of right
lung
Capillaries of left
lung
Inferior vena cava
Capillaries of abdominal
organs and legs
Functions of Blood:
Function:
1. Carries Oxygen (O2) to cells (from lungs)
and Carbon dioxide (CO2) away
2. Carries nutrients to cells from the
digestive system
3. Carries wastes to kidneys
4. Blood cells fight infection White Blood
Cells (WBC’s) and help heal wounds

The Blood
Plasma- liquid part
of the blood mostly
water, some
nutrients, minerals,
hormones etc.
 Body contains 4-6 L
 Consists of

– Red Blood Cells
– White blood cells and
platelets
Red Blood Cells (RBC’s)Erythrocytes


contain hemoglobin, chemical
that carry O2 and CO2
RBC are produced in red
bone marrow of
–
–
–
–
ribs,
humerus,
femur,
sternum, and other long bones
White Blood Cells (WBC’S)Leukocytes

fight bacteria and
viruses; can enter
tissues to destroy
invaders and absorb
dead cells

Attack foreign
substances

Less abundant
Large cells

Platelets
Platelets- irregularly shaped
fragements that release fibrin to
help clot blood.
 Produced in bone marrow
 Fibrin (sticky network of protein
fibers)

– Form a web trapping blood cells
Blood Clotting
Platelets stick to the
wound fibrin form a
sticky net which traps
blood cells and forms
a clot (hardens to
form a scab).
 Skin cells repair skin
under the scab and
the body reabsorbs
the clot.

Your Heart: The Vital Pump
At REST, the heart
pumps about 5
QUARTS of blood a
minute.
 During EXTREME
EXERTION (exercise)
it can pump 40 quarts
a minute.
