Cardio-vascular system

Measure your heart beats per minute How many beats per minute should your heart beat at?

The Cardiovascular System? There are two parts to the cardiovascular system Cardio The heart = pumps the blood around the body Vascular The blood vessels divided into veins, = arteries and capillaries

The heart Little larger than a clenched fist Located between the lungs Pumps blood at 60-80 times per minute Average heart beat per day = 100,000 times It takes 1 minute for blood to be pumped around the body The heart is the only place in the body where CARDIAC muscle is found

Function of blood: 3 Functions The body has 4.5 litres of blood Transportation The blood carries OXYGEN AND NUTRIENTS it also carries WASTE Temperature Control BLOOD transfers HEAT around the body Protection Blood carries antibodies

Blood cells Red cells = Make up 40-50% of blood volume Transport oxygen Produced in bone marrow White cells = Make up 1% of blood volume Most are produced in the bone marrow Used to fight infection – they destroy bacteria and viruses Platelets block holes – so these are important in stopping bleeding

Parts of the Heart

Valves right side of the heart separates the auricle and ventricle TRICUSPID Valve right side of the heart separates the auricle and ventricle prevents back flow SEPTUM divides the heart keeps oxy & deoxygenated blood apart BICUSPID Valve Left side of the heart Separates the auricle and ventricle Prevents blood from seeping or flowing back down into the ventricle.

Blood flow through the heart Oxygen rich blood is pumped into the left atrium from the lungs via the pulmonary vein It is then pumped into the left ventricle The blood is pumped from here to the aorta and to the body and muscles The deoxygenated blood passes from the body into the vena cava and back into the right atrium of the heart It is then passed into the right ventricle Passing through the Pulmonary artery the blood is returned to the lungs for oxygen

Deoxygenated blood - blood which contains very little oxygen Oxygenated blood – blood that contains oxygen

Structure and function of blood vessels There are 5 categories: Artery Arteriole Capillary Veins Venules Blood travels through a series of vessels, each varies in structure because of its function.

Arteries Carry blood under high pressure Carry oxygenated blood only Always carry blood away from the heart Thick walls!! Small muscle fibres

Arteries STRUCTURE Thick walls!! Small muscle fibres FUNCTION Always carry blood away from the heart Carry blood under high pressure Carry oxygenated blood only

Capillaries Smallest blood vessels - tiny Gaseous exchange – gases & nutrients swapped Will only allow 1 blood cell through at a time Capillaries are extremely narrow, due to diffusion Remove waste

Capillaries Structure Smallest blood vessels - tiny Capillaries are extremely narrow, due to diffusion Function Gaseous exchange – gases & nutrients swapped Will only allow 1 blood cell through at a time Remove waste

Veins & Venuoles Return blood under LOW pressure to the heart Transport deoxygenated blood Veins also have one way valves to stop back flow Walls contain layers of tissue = thinner and less elastic Small vessels Drain blood from capillaries

Veins & Venuoles STRUCTURE Veins also have one way valves to stop back flow Walls contain layers of tissue = thinner and less elastic Small vessels FUNCTION Return blood under LOW pressure to the heart Transport deoxygenated blood Drain blood from capillaries

Question Describe 4 ways a vein differs from an artery 1 2 3 4

Question Describe 4 ways a vein differs from an artery 1 – One carries oxygenated blood the other deoxygenated blood 2 – one works under high pressure one low pressure 3 – the wall thickness of each 4 - size

One mark for each structure identified, EIGHT required from 1 aorta 2 superior vena cava (accept vena cava) 3 right atrium 4 right ventricle 5 pulmonary artery 6 pulmonary vein 7 left atrium 8 left ventricle

Dysfunction Coronary heart disease

Coronary Artery disease (CAD) One of the arteries becomes blocked or narrow due to fatty deposits Narrowing or blocking means oxygenated blood flow to the heart is reduced Heart muscle begins to die = infarction

Causes - explain Genetics Lifestyle Environment

Diagnosis ECG machine to detect problems with the heart Treatment Change lifestyle Exercise more Cut out smoking, poor diet and alcohol Medication