2 The Cardiovascular System or Circulatory System TodayThe Cardiovascular System or Circulatory System
3 Today We will aim to learn to: Identify what the cardiovascular system is,What makes up the CV systemThe different elements and functions of the CV system,And how they work during exercise.
4 The Circulatory System What is the Cardiovascular or circulatory system?It is the blood, which is pumped round the body by the heart, which flows along tubes called blood vessels.So what makes up the Circulatory system?The HeartThe BloodThe Blood Vessels
5 Functions of the CV system The circulatory system has several functions these are:It is the body’s transport system.Takes O2 and food to every cell in the body.Removes CO2 and other waste products from every cell.Carries Hormones to different parts of the body.Maintains Temperature and fluid levels in the body.Prevents infections from invading organism and germs.
6 The circulatory system Opposite is a simple plan of the Cardiovascular system. It shows the heart and 4 main blood vessels.Can you identify what is what?
7 The circulatory system What do you notice about the circulatory system?The heart is divided into 2 parts. Each part is a pump, so the heart is a double pump in a double circulatory system.
8 The circulatory system The right side of the heart pumps the blood (de-oxygenated blood) to the lungs to pick up oxygen.The left side of the heart pumps the oxygenated blood around the rest of the body.
9 The circulatory system The heart has large tubes to carry blood from the heart to lungs and body and vice versa.These are called:Blood vessels
10 How Blood is carried around your body Your heart pumps blood at HIGH pressure into your body.The blood carries OXYGEN to your cells and eventually back to your HEART through various different sized blood vessels.These blood vessels also vary in function and are divided into 3 types.These 3 types are:ArteriesCapillariesVeins
11 How is blood carried around your body Every time your heart beats, it pumps blood at high pressure into:Arteries – These push blood into …..Arterioles -Which are smaller than arteries. These branch into……
12 Blood around the bodyCapillaries – Which are tiny tubes that allow the transfer of food and oxygen to our cells.Venules – Which are larger than capillaries and carry de-oxygenated blood from our cells.Veins – These are larger than venules and carry all de-oxygenated blood back to the heart.
13 Structure of blood vessels There are three types:ArteriesCarry Oxygenated blood away from our heart under high pressure.The walls are the thickest of all 3 blood vessels.Inner walls are smooth and elastic, made of involuntary muscle.The bloods high pressure stretches the inner walls as it is forced through.Walls contract forcing blood towards the Capillaries.Largest Artery is the AORTA, coming straight from the heart.
14 Structure of blood vessels Arterioles:Arteries branch into smaller tubes called arterioles.These connect arteries to capillaries.Capillaries:Arterioles branch into these.Walls are so thin (1 cell thick) so food and O2 can pass into body cells and tissues.So CO2 and waste products can pass into Blood Stream.
15 Structure of blood vessels Venules:Blood then flows into these vessels after it has given up it’s oxygen (it is now dull red / de-oxygenated).Venules connect capillaries to veins.Veins:Carry De-oxygenated blood back to the heart, muscle contractions / valves prevent backflow of bloodLargest Vein is the VENA CAVA.Larger than arteries, so BP is lower.Look similar to arteries, but larger inner tube to get blood back to heart as fast as possible. BP is lower so blood is flowing slower.
16 Valves and Veins Why do Veins have Valves? To keep blood flowing in one direction.To stop blood flowing backwards.Many Veins are near muscles of your arms and legs.As muscles contract it pushes the blood towards the heart through next valve.
17 Arteries and VeinsIf the Aorta and Vena cava carry blood to and from the heart from the body, what do we call the tubes that carry the blood to and from the lungs?The Pulmonary artery – carries blood from the heart to the lungs to pick up oxygen, it’s the only artery that carries de-oxygenated blood.The Pulmonary vein – carries oxygenated blood from the lungs to the heart.
19 The circulatory system and exercise During exercise there are certain changes that the circulatory system goes through to adapt to exercise.Can you guess what changes the circulatory system goes through?
20 The circulatory system and exercise The changes that occur are:During exercise cell respiration increases, so CO2 levels in the blood increase.More CO2 passes out of the blood and more O2 passes into it.Blood flow increases, so more O2 reaches the working muscles.
21 The circulatory system and exercise Blood gets shunted from where it is less needed to where the action is. E.g. from the stomach to the legs.This happens by blood vessels widening (Vasodilation) and constricting (Vasoconstriction) at different points.Exercise generates heat. So the blood gets hotter. More blood is shunted close to the skin to cool down. This makes the skin redden.
22 Today We have learnt: What the Cardiovascular system is made up off. The functions of the CV system.The name of the major blood vessels.How blood is transported around the body.How the CV system responds with exercise.