CIRCULATORY SYSTEM Three Functions 1 Transport moving O

CIRCULATORY SYSTEM

Three Functions 1. Transport – moving O 2, waste, Co 2 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 O 2 blood around body by arteries and de. O 2 blood back to heart by veins 2 Pulmonary = - Carries de. O 2 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 O 2 blood AWAY from the heart (except pulmonary). Have thick, strong Elastic walls to cope with the pressure VEINS Carry de. O 2 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 O 2 starvation Heart Attacks – Heart stops because of O 2 starvation to heart Angina – Sharp pains in chest = not enough O 2 getting to heart Exercise - Increase BP in short term, but reduces it in long term Stress – Increase in BP