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.

• 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 • 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 • 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.

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?

The other key function of the CV system….

Removal of Waste products

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

• The ability to maintain body temperature within certain boundaries.

•

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. On the other hand…

VASOCONSTRICTION

When 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

Capillaries Sweat gland 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.

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.

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

the cardiovascular system of

Structure

of the cardiovascular

system (which you have to find pictures/

label and describe): Examine the cardiovascular system and

explain

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

function

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 products 3. Thermoregulation

(vasodilation and vasoconstriction of vessels);

4. Function of blood

(oxygen transport, clotting, fighting infection)