B8 EXCHANGE AND TRANSPORT Flashcards
(37 cards)
Substances needed by body
Oxygen
Glucose
Nutrients
Waste products
Carbon dioxide , urea
Transport
Moving substances around the body
Exchange
Moving substances in and out of our cells
Diffusion.
The way substances move in and out of cells-they diffuse from high to low concentration
Increasing diffusion
High surface area thin surfaces
Surface area: volume ratio
Surface area / volume
Importance of SA : volume ratio
A higher ratio means there is more surface area, so substances can diffuse in and out of cells more quickly
Alveoli
Role- air sacs in lings CO2 and O2 are exchanged
Adaptations- millions of them gives a high surface area good blood supply maintains a high concentration gradient thin walls increase diffusion
Circulatory system
Your heart, arteries, capillaries and veins which work together to pump blood around the body
The role of blood
To carry oxygen and nutrients to our cells and take waste products away
Arteries
Their role is to carry blood away from the heart
There adaptions are thick muscle walls to withstand the high-pressure elastic fibres to stretch as pressure increases during a pulse
Capillaries
Their role is to exchange nutrients and waste between the blood and cells
The adoption of thin walls to increase diffusion many many of them to give a high surface area
Veins
The role is to carry blood towards the heart
Their adaptions off in the walls because pressure is low ,wide because blood is moving slowly valves so blood flows right away
Components of blood
Plasma
red blood cells
white blood cells
Platelets
Plasma
A straw coloured liquid that carries the blood cells and dissolved substances such as urea ,carbon dioxide and glucose
Red blood cells
Erythrocytes
Contain haemoglobin to carry oxygen around the body
White blood cells
Fight pathogens (infections) Many types including Phagocytes - engulf (eat pathogens)
Lymphocyte- produce antibodies to attack pathogens
Platelets
Small fragments of cells that help the blood to clot when you are cut
Heart
A double pump that pumps blood
Right side- to lungs
Left side - around the whole body
Atria
Atriums
The two chambers at the top of the heart
Right : receives blood from body
Left : receives blood from lungs
Ventricles
The two chambers at the bottom of the heart
Right : pumps blood to lungs
Left : pumps blood to body
Valves
Prevent blood from flowing from the ventricles back to the atria
Vena cava
Carries blood from the body into the right atrium
