Biology Topic 6 - Transport in Humans

diffusion

the net movement of particles from an area of high concentration to an area of low concentration

plasma

liquid part of blood that carries the blood cells around the body

white blood cell

cell created in bone marrow to destroy microorganisms, produce antibodies and give immunity

red blood cell

(erythrocyte) to transport oxygen via haemoglobin

platelets

cell fragments that release chemicals to make blood clot

heart septum

separates left and right sides of the heart; separates oxygenated and deoxygenated blood, making the heart efficient

pulmonary

to do with lungs

hepatic

to do with liver

renal

to do with kidneys

single circulatory system

blood is pumped from the heart to the gas exchange organ and then directly to the rest of the body

double circulatory system

blood is pumped from the heart to the gas exchange organ, back to the heart and then to the rest of the body

oxygen debt

the volume of oxygen needed to completely oxidise the lactate that builds up during anaerobic respiration

arteries

carry oxygenated blood away from the heart to the organs of the body

veins

carry deoxygenated blood from organs back towards the heart

capillaries

carry blood through organs, bringing the blood close to every cell in the organ

coronary artery

how blood reaches the cardiac muscle and it carries blood to capillaries that supply the heart muscle with oxygen and nutrients

coronary vein

returns blood to the right atrium

phagocytes

perform phagocytosis (ingest microorganisms)

lymphocytes

produce antibodies which stick to surface antigens and destroy the pathogen

primary immune response

the production of antibodies following the first exposure to a foreign antigen

immunity

when the pathogen is quickly dealt with due to memory cells reproducin and producing antibodies

memory cells

lymphocytes that do not immediately get involved in killing microorganisms

fibrinogen

soluble plasma protein

fibrin

insoluble fibres that trap RBCs

secondary immune response

faster and more effective response where the number of antibodies in the blood quickly rises, killing microorganisms before there are enough to cause disease

phagocytosis

phagocytes ingesting microorganisms

pseudopodia

extensions of phagocyte cytoplasm to enclose microorganisms

antigens

chemical markers on the surfaces of pathogens

cardiac muscle

can contract and relax continuously without becoming fatigued; has its own blood supply (coronary blood vessels)

valves

to prevent the backflow of blood

Why don’t unicellular organisms have a transport system?

High SA:V; materials can easily move around the cell

Why do multicellular organisms have a transport system?

Low SA:V; materials cannot reach all parts of the organism

Organs in human circulatory system

heart

blood vessels

blood

What two circulations are in a double circulatory system?

Pulmonary circulation

Systemic circulation

Why do humans have a double circulatory system?

To maintain high blood pressure so blood can pump against gravity and blood can travel quickly to all the organs

Composition of blood

plasma; WBC; RBC; platelets

When does heart rate increase?

Exercise

Adrenaline (stressed/angry/afraid)

When does heart rate decrease?

Sleep

Medulla

part of brain that receives and sends impulses to change heart rate

Veins qualities

blood is under lower pressure than arteries

contain valves

large lumen

thinner walls

Lumen

central cavity in veins/arteries

Capillaries qualities

thin wall to allow for transfer of substances between blood and cell

Arteries qualities

blood is under high pressure

walls can stretch and recoil

small lumen

thick wall

Risk factors of CHD

heredity

high blood pressure

diet

smoking

stress

lack of exercise

Why is the wall of the LV thicker than the right?

blood from the LV is pumped to the rest of the body, so it needs higher pressure; blood from RV is just pumped to lungs

Why are the walls of atria thin?

allows them to stretch as they receive blood; only a small force needed to move blood from atria to ventricles

What do antibodies do when attached to antigens?

cause pathogens to stick together

act as labels

cause pathogens to burst open

neutralise toxins

artificial immunity

becoming immune to a disease without actually contracting the disease

Plasma function

carries dissolved nutrients; hormones; CO2; urea

distributes heat around the body

Adaptations of RBCs

contain haemoglobin

no nucleus

biconcave shape

high SA:V

thin shape

What does clotting do?

prevents further blood loss

prevents entry of microorganisms

Agents in vaccines

weakened strain of microorg

dead microorg

antigen

genetically engineered harmless bacteria