Circulatory System The circulatory system is responsible for the delivery of nutrients and for the removal of waste products from the body cells. All other systems depend on its efficient function.

Circulatory System Functions – Circulate blood to all parts of the body – Transport water, oxygen and nutrients to cells – Transports wastes, including carbon dioxide away from the cells – Helps maintain correct body temperature – Helps fight disease

Circulatory System The circulatory System has three main elements, these are: 1.The Heart 2.The blood vessels 3.The blood

Circulatory System The Heart – The heart is a muscular pump designed to pump blood through the circulatory system – It has 4 chambers – 2 atria and 2 ventricles. – The atria are the upper chambers which receive blood – The ventricles are the lower chambers which pump blood

Circulatory System The Heart – Features It is located in the centre of the chest between the two lungs and is protected by the ribs An adult heart is about the size of a large fist At rest, the average adult heart pumps at about 70 beats per minute At maximum work, heart rate can be more than 200 beats per minute At maximum work, the heart may be circulating up to 35litres of blood in a minute, or about 4 buckets-full.

Circulatory System Blood Vessels – The network of blood vessels which caryy blood to all parts of our body is also referred to as the vascular system. – There are 3 types of blood vessels. 1. Arteries 2. Capillaries 3. Veins

Circulatory System Arteries – Carry Oxygen enriched blood away from the heart to the rest of the body. – The aorta is the largest artery in the body. – We can measure our heart rate (H/R) by feeling the pulse of each beat as blood is pumped through your arteries. – The 2 most common spots to find your pulse are your neck (carotid pulse) and your wrist (radial pulse) – Bleeding from an artery may be recognised in two ways 1. the blood spurts out with each heart beat 2. The blood is a bright red colour because it is rich in oxygen

Circulatory System Factors which affect resting heart rate – Gender – males usually have a lower resting heart rate than females – Temperature – as it gets hotter, your H/R gets higher – Eating – Your H/R increases after meals – Laughing – increases your H/R – Smoking – increases your H/R – Body Position – H/R is higher standing than it is when you are sitting or lying down.

Circulatory System Capillaries – Are the smallest blood vessel and are the site of exchange of waste and nutrients between the blood and body cells. – Long term exercise can increase the number of capillaries supplying blood to your muscles, this allows for an increase in oxygen supply to your muscles and a more rapid removal of wastes.

Circulatory System Veins – Blood is no longer surging or pulsing by the time it reaches the veins. – Carries blood with low levels of Oxygen, as the oxygen has already been used by the muscles to create energy. – Have one way valves which stop blood flowing backwards – Muscle contract to help the veins move the blood back up the body to the heart and lungs.

Circulatory System After exercise it is important to keep moving as the muscle in your legs help to move the blood up and back to your heart allowing for removal of waste created by your muscles.

Circulatory System Blood – Blood is the only tissue in the body which is a liquid. Blood cells make up 45% of the blood volume, while plasma makes up the other 55%. There are three types of blood cells – 1. Red Cells – 2. White Cells – 3. Platelets

Circulatory System Red Cells – Make up 99% of all blood cells – Carry oxygen and carbon dioxide to and from the cells and muscles – Are produced in bone marrow – Have a life span of about 4 months

Circulatory System White blood cells – Exist in the body in a ratio of 1 to every 700 Red blood cells – Come in a variety of size and shapes. – Are generally larger than red blood cells – Have a life span of only a few days

Circulatory System Platelets – Are the cells which cause blood to clot when a blood vessel is damaged – Are smaller than red blood cells – Are produced in the bone marrow

Circulatory System Plasma – Is a clear yellowish fluid, in which the blood cells are suspended. – Regular exercise causes the amount of blood in your body to increase

Circulatory System Haemoglobin – Is the substance in red blood cells to which the oxygen attaches and gives the blood its bright red colour