Download Mechanics of Breathing

CIRCULATORY SYSTEM
Three Functions
1. Transport – moving O2, waste, Co2 and
nutrients around the body
2. Body Temperature Control –More blood
near skin cools body quicker. – Why you
look redder after exercise.
3. Protection – Moving antibodies around
body to fight disease and clot blood.
The Heart
The Heart Continued
1. BLOOD ENTERS RIGHT ATRIUM – LITTLE OXYGEN
2. RA PUMPS BLOOD INTO RIGHT VENTRICLE
3. RV PUMPS BLOOD THROUGH PULMONARY ARTERY TO LUNGS PICKING UP
OXYGEN
4. FROM LUNGS, BLOOD GOES TO LEFT ATRIUM THROUGH PULMONARY VEIN
5. LA PUMPS BLOOD INTO LEFT VENTRICLE AND BLOOD LEAVES VIA AORTA
TO REST OF BODY
The flow
The Circulation
• The heart pumps Oxygenated (RED) blood
and de-oxygenated (BLUE) blood around
the body.
The stroke volume is the amount of blood
pumped per beat – you can use this to see
how much is pumped in a minute…
CARDIAC OUTPUT = STROKE VOLUME X HEART RATE
Circulation
• Each blood cell goes twice around the body
= there are 2 circuits
• 1 Systemic =
– Carries O2 blood around body by arteries and
deO2 blood back to heart by veins
2 Pulmonary =
- Carries deO2 blood from heart to lungs
Two Systems
Blood flow
Blood leaves the left side of the heart and travels through arteries
which gradually divide into capillaries. In the capillaries, food
and oxygen are released to the body cells, and carbon dioxide
and other waste products are returned to the bloodstream.The
blood then travels in veins back to the right side of the heart,
and the whole process begins again.
Pressure
• You have a pulse in your body from which
you can see how many times your heart
beats in a minute.
• This pulse comes from the pressure build up
- 2 types of pressure
•
•
1 = SYSTOLIC – PRESSURE OF BLOOD IN ARTERIES WHEN LV CONTRACTS
2 = DIASTOLIC – PRESSURE OF BLOOD IN ARTERIES WHEN LV RELAXES
Blood and its Vessels
The blood in the body has a very important
job. It is carried around the body by three
different types of blood vessels
The Vessels
ARTERIES
Carry O2 blood AWAY from the heart
(except pulmonary). Have thick, strong
Elastic walls to cope with the pressure
VEINS
Carry deO2 blood BACK to heart
(except pulmonary vein). Have thinner
walls = less pressure in blood. Have
valves to stop back flow of blood
CAPPILARIES
Carry food and blood direct to tissues
and takes waste away. Very thin walls.
The Blood itself
• The blood is made up of different things….
•
Red Blood Cells, Platelets (stained purple), a T-Lymphocyte white cell
(stained green), and a Monocyte white cell (stained gold) as seen
through a scanning electron microscope. ©2000 Dennis Kunkel, Ph.D.
•
Red blood cells - look like a donought
contain haemoglobin, a protein that carries oxygen. They have no
nucleus, it takes around 30-40 seconds for its cycle and one cell lasts an
average of 120 days.
•
Whit Blood Cells
Fight against diseases by destroying bacteria by using antibodies,
toxins by using antioxidants and consuming foreign bodies
•
Platelets
Small fragments of cell with no nucleus = helps the blood clot wounds
•
Plasma = carries everything
Including blood cells / digested food (glucose etc) / Waste (urea,
carbon dioxide) and hormones
What affects the blood???
•
•
•
•
•
•
•
Age – BP (blood pressure) increases with age
Gender – Generally higher in men
Strokes – damage to the brain because of O2 starvation
Heart Attacks – Heart stops because of O2 starvation to heart
Angina – Sharp pains in chest = not enough O2 getting to heart
Exercise - Increase BP in short term, but reduces it in long term
Stress – Increase in BP