Transcript The Circulatory System

The Circulatory System
Function
• It’s main function is Transportation
• Blood is used as a transport vehicle
– transports oxygen, nutrients, cell waste (such
as Carbon dioxide), hormones and antibodies
vital to maintaining homeostasis to and from
cells
Parts of the Circulatory System
• Divided into three major parts:
– The Heart
– The Blood Vessels
– The Blood
The Major Organ-The Heart
• Heart acts as pump
• The heart pumps 60-80 beats per minute
(at rest)
• At REST, the heart pumps about 5
QUARTS of blood a minute.
• During EXTREME EXERTION (exercise) it
can pump 40 quarts a minute.
Structure
• Size of your fist
• Large organ composed of
– cardiac muscle--called myocardium
– Enclosed by a sac –called PERICARDIUM
– rich in mitochondria
– 4 hollow chambers
– Contain valves to keep blood flowing in
ONE direction
The pathway looks like a circle
• The heart, the
lungs, and the
blood vessels
work together
to form the
circle part of
the circulatory
system.
The Chambers
• The heart has 4 hollow chambers
• Upper chambers – atrium receives blood
coming in from the veins
– Left & right Atrium
• Lower chambers - ventricle squeezes
blood out into the arteries
– Left & right ventricle
http://hes.ucf.k12.pa.us/gclaypo/circdia.html
Double Pump
• The two ventricles are responsible for the
pumping action of the heart
• Each chamber pumps blood out of the
heart but to different pathways
• That is why the heart is considered to be a
double pump
3 Kinds of Circulation:
• Pulmonary circulation
• Coronary circulation
• Systemic circulation
Pulmonary Circulation
• Movement of blood from the heart, to the
lungs, and back to the heart again
Pulmonary Circulation Pathway
1. The right Atria receives oxygen poor
blood from the body.
2. blood moves to the right ventricle where
it is pumped out to the lungs via
pulmonary arteries
3. O₂ is exchanged for CO₂
4. Oxygen rich blood now leaves lungs and
returns to the heart
sln.fi.edu/biosci/systems/ pulmonary.html
Systemic Circulation
Supplies nourishment to all of the tissue
located throughout the body , except for
the heart and lungs
THIS IS THE LARGEST PATHWAY OF
THE CIRCULATORY SYSTEM!
Systemic Circulation Pathway
• Oxygen rich blood returning from the lungs
now enters the left atrium
• Moves through the valves to the left
ventricle
• The left ventricle pumps the oxygen rich
blood out the Aorta
• The blood is then carried from aorta to
blood vessels delivering oxygen and
nutrients to ALL tissues of the body
• Blood returns (oxygen poor) back to right
http://users.tpg.com.au/users/amcgann/body/circulatory.html
Coronary Circulation
• Coronary arteries branch immediately off
the aorta and provide blood to the heart
tissue
http://sln.fi.edu/biosci2/systems/
http://sln.fi.edu/biosci/systems/systemic.html
Blood Vessels
Hollow tubes that circulate your blood
• Arteries
• Veins
• Capillaries
Arteries
•
•
•
•
•
•
Carry blood AWAY from the heart
Heart pumps blood
Main artery called the aorta
Aorta divides and branches
Many smaller arteries
Each region of your body has system of
arteries supplying it with fresh, oxygen-rich
blood.
Capillaries
•
•
•
•
Very thin
Only one cell thick
Connect arteries & veins
Food and oxygen released to the body
cells
• Carbon dioxide and other waste products
returned to the bloodstream
Veins
• Carry blood to the heart
• Receive blood from the capillaries
• Transport waste-rich/ oxygen-poor blood
back to the lungs and heart
• Valves are located inside the veins
• Allow blood to move in one direction
http://sln.fi.edu/biosci/systems/circulation.html
How do the nutrients, gases
and such get into and out of
the capillaries?
Overview of Blood Vessels
http://users.tpg.com.au/users/amcgann/body/circulatory.html
Blood composition
• Plasma
• RBC
• WBC
• Platelets
• O₂
• CO₂
• Nutrients
• Antibodies
• Hormones
Blood
• Carries nutrients, water, oxygen and waste
products to and from your body cells.
• Hemoglobin, iron containing molecule
• Loosely picks up oxygen in the lungs
• Loses oxygen in areas low in oxygen
(diffuses)
Blood
•
•
•
•
Hemoglobin carries CO2 also
CO2 is a waste product of cellular work
70% of CO2 combines with water
The rest travels to the lungs
Blood – RBCs
• Red blood cells carry oxygen from the
lungs to all the cells of the body.
• Takes carbon dioxide and transports it
back to the lungs
• About 5,000,000 Red Blood Cells in ONE
drop of blood.
http://hes.ucf.k12.pa.us/gclaypo/circdia.html
Blood – WBCs
• White blood cells protect the body from
germs
• Attack and destroy germs when they enter
the body
scienceu.fsu.edu
www.merck.com/pubs/mmanual_home/
illus/167i2.htm
Blood – Platelets and Plasma
• Platelets are blood cells that help stop
bleeding
• Plasma is the liquid part of the blood
• About half of your blood is made of plasma
• The plasma carries the blood cells
throughout the body
• Plasma is made in the liver.
user.gru.net/clawrence/ vccl/chpt7/plate.htm
SUMMARY
copy and complete the following;
away
Arteries take blood ______ from the heart. The walls of an artery are
muscular
made up of thick _________ walls and elastic fibres. Veins carry blood
towards
capillaries
________ the heart and also have valves. The _________ link arteries
and veins, and have a one cell thick wall. Blood is made up of four main
plasma
things ______, the liquid part of the blood; Red Blood Cells to carry
oxygen
______; White Blood cells to protect the body from disease and
platelets
_________ to help blood clot.
Some Disorders and Diseases
of the Circulatory System
DISORDERS
• ATHEROSCLEROSIS
– Fatty deposits called plaque
– Builds up in walls of arteries
– Obstructs flow
– Also a risk if clot breaks free and blocks flow
elsewhere
Disorders (cont)
• Hypertension
– High blood pressure
– Hearts works harder than necessary
– Increases risk of heart attack or stroke
Disorders (cont)
• Heart Attack
– Atherosclerosis in coronary artery
– Heart muscle begins to die
• Symptoms
– Nausea
– Shortness of breath
– Severe chest pain
IMMEDIATE MEDICAL ATTENTION NECESSARY
Disorders (cont)
• Stroke
– Blood clot gets stuck in blood vessels leading
to brain
– Brain cells die due to lack of oxygen
• Or blood vessel burst
– Can lead to paralysis,
• loss of ability to speak
• death