Biology - Transport in Humans

Name 4 componentes of blood

Red blood cells, white blood cells, plasma and platelets

What is the function of platelets

Platelets are small fragments of cells that are involved in blood clotting

What are 2 benefits of blood clotting?

It prevents the entry of microorganisms and prevents blood loss

How are red blood cells adapted to their function?

Contain haemoglobin to carry oxygen, biconcave shape to maximise surface area and allow them to squeeze through capillaries, no nucleus to maximise space for haemoglobin

What is the purpose of plasma?

Plasma is the liquid part of blood and its purpose is to act as a transport medium to transports CO2, hormones, nutrients and waster products

What is teh function of white blood cells?

White blood cells are involved in phagocytosis and some white blood cells produce anitbodies

What is a pathogen?

a disease-causing microorganism

Give 2 ways that the body can respond to detecting a pathogen

Lymphocytes can produce antibodies that are specific to the antigens of the pathogen and phagocytes engulf the pathogen

How do vaccines work?

Dead/inactive pathogens are injected into the body, the body produces antI odies against the pathogens, memory cells are created to provide long term immunity

Describe the double circulatory system in mammals

The heart pumps blood to the lungs, the oxygenated blood returns to the heart and is then pumped around the body

What is the difference in function between arteries, veins and capillaries ?

Arteries carry blood away from the heart, veins carry blood into the heart and capillaries flow close to tissue for exchange

Describe the structure of arteries

They have thick walls made of muscle and elastic tissue and a small lumen to transport blood under high pressure

describe the structure of capillaries

They have thin walls about one cell thick to allow for easy exchange of substances at the tissues

Describe the structure the veins

Veins have less muscle adn elastic tissue than arteries and they have a larger lumen as the blood is at a lower pressure, they also have valves to prevent back flow

Describe the blood flow through the right side of the heart

Deoxygenated blood flows into the right atrium from the vena cava. This blood passes through the tricuspid valve into the right ventricle. This blood is pumped out fo the heart to the lungs through the right semi-unas valve and into the pulmonary artery

Describe the blood flow through the left side of the heart

Blood enters the left atrium through the pulmonary vein . The blood is then pumped through the bicuspid valve into the left ventricle . The blood is then pumped out through the left semi-lunar valve and into the aorta.

What’s the name of the wall that separates the left and right side of the heart

The septum

What’s the name of the artery that supplies the heart tissue with blood

the coronary artery

What type of muscle is the heart made from?

cardiac muscle

Why is the wall of the left ventricle thicker than the right ventricle?

The left ventricle has to pump blood a further distance around the whole body so the blood needs to be under a higher pressure

What does adrenaline do to the heart rate?

Adrenaline increases the heart rate since it trigger the ‘fight or flight’ reflex

State 2 parts of the body adrenaline effects - other than the heart.

adrenaline dilates your pupils and increases your breathing

Why does heart rate increase during exercise

Your muscles need more energy so we respire more because there is an increase in CO2 levels in your blood which is detected by receptors. This means your brain is signalled to pump more blood, leading to more oxygen arriving at your muscles and more CO2 removed. Your muscles contract more.

What is CHD?

When the artery providing the heart tissue with blood is blocked

What are 3 common risk factors of CHD?

smoking, poor diet and lack of exercise