The

function of the

Cardiovascular system

P5/ M2

General function• The main function of the cardiovascular

system is to deliver oxygen and nutrients and remove the waste products of metabolism.

• Each part of system has a specific function in helping to do this.

• Blood– Has a number of functions

• Red blood cells and their haemoglobin attract Oxygen, so it can be carried around in the blood• White blood cells fight infection• Platelets help with clotting if we are injured.

• Blood vessels– Designed to carry the blood. They

are hollow, and vary according to their purpose. • For example, arteries have thick muscular

walls so that they can take the blood at high pressure from the heart, and squeeze it along to the capillaries

• Heart– Pump – It is designed to push blood

out through the arteries. • One ventricle pumps blood to the lungs

to get oxygen• The other pumps blood to the body to

deliver Oxygen and nutrients

Delivery of Oxygen and

Nutrients

The key function of the CV system.– It is essential in football

because....

• Achieves this with the three elements working together. – The heart pumps the blood into the blood

vessels– The blood vessels carry the blood to the body’s

tissues– The blood carries a number of things dissolved

in it. For example:

– Oxygen is carried by the haemoglobin in the red blood cells

– Blood also carries nutrients that it has absorbed in the intestines to the working muscles

» Why is this important to success in football?

Removal of Waste productsThe other key function of

the CV system….

Again all three elements work together to allow this to happen

– The force of the pump from the heart helps to get the blood back

– The blood vessels, particularly the veins use their proximity to muscles and their valves to squeeze the blood back to the heart, without any back flow

– The blood carries the Carbon dioxide back to the lungs to be excreted • It also carries other waste from the metabolic process,

such as water and lactic acid. This is taken back to the kidneys and liver so we can process it and excrete it.

Why is this essential to success in sport, and football in particular?

Thermoregulation

VASODILATION• Effectively during exercise, and when we

are hot, the blood vessels redirect the blood closer to the surface, so that the hear can evaporate. – This is why we go red when we exercise.

• The ability to maintain body temperature within certain boundaries.

VASOCONSTRICTIONWhen we are cold, the blood vessels direct the blood away from the surface of the body, to keep our core temperature stable.- This is why we appear more pale/blue when cold

On the other hand…

If the body gets too hot, capillaries near the surface of the skin widen. Blood is diverted to the skin where the heat can easily radiate away. This is called vasodilation.

Water from the blood is excreted as sweat to cool the body.

Capillaries Sweat gland

If the body gets too cold, capillaries near the surface of the skin get narrower. Blood is diverted away from the skin to limit heat loss. This is called vasoconstriction.Sweating stops.

THERMOREGULATION

EXPLAINED FURTHER…

The effects of Training

Short term effects of exercise on the CV system (10 mins):- Increased HR- Increased Stroke Volume- Increased Cardiac Output- Redistribution of blood to

the working muscles and away from other organs

- Blood vessels in the skin dilate

- Increased blood pressure

Long term effects of exercise (3-5x 20 mins a week):- Decreased HR- Increased Stroke Volume- Heart muscles become

bigger (HYPERTROPHY)- Fall in blood pressure- Increase in Red blood cell

count- Increased size in blood

vessels- Increased blood volume

Describe the Structure and Function of the cardiovascular system Examine the cardiovascular

system and explain how it works and how each part of the system is designed to meet its

function

Structure of the cardiovascular system (which you have to find pictures/ label and describe):

Heart: Atria, Ventricles, Bicuspid valve, Tricuspid valve, Aortic valve, Pulmonary valve, Aorta, Vena cava – (superior and inferior), Pulmonary vein, Pulmonary artery

Blood vessels:Arteries, Arterioles, Capillaries, Veins, Venuoles

Function of the cardiovascular system: 1. Delivery of oxygen and nutrients 2. Removal of waste products3. Thermoregulation (vasodilation and

vasoconstriction of vessels); 4. Function of blood (oxygen transport, clotting, fighting infection)