Section 8 - Exchange And Transport In Animals Flashcards
What do all chemical reactions in your body produce?
Waste
What must happens to the waste that is created from chemical reactions in your body?
It must be excreted so it doesn’t caused problems
What do your kidneys remove?
Urea
What is urea?
A poison produced by breaking down amino acids
What do your lungs get rid of?
Carbon dioxide produced from aerobic respiration
What is needed for aerobic respiration?
Oxygen and glucose
What is needed to produce new substances for your body?
Molecules (glucose and amino acids) and mineral ions
How do many substances move into and out of the body?
By diffusion
What adaptations does your body have to allow particles to diffuse quickly through the surfaces they move?
The surfaces are thin / have a large surface area
Why does a substance being thin help particles to diffuse quickly?
So that particles do not have to diffuse very far
Why does a surface having a large surface area help particles to diffuse quickly?
So that there is more room for particles to diffuse
What are small blood vessels called?
Capillaries
How are capillaries adapted to be thin?
They are just one cell thick
Which way to oxygen particles move through a capillary?
They diffuse out of the capillary
Which way do glucose molecules move through a capillary?
They diffuse out the capillary
What does the continual flow of blood through a capillary maintain?
The concentration gradient
Which way do the carbon dioxide molecules more through the concentration gradient in the capillary?
They move down the concentration gradient
Why do multicellular organisms have transport systems?
Because it would take too long for materials to diffuse through cells on the outside of each tissue to reach the cells on the inside
How is blood transported to and from cells in a human?
A fine network of capillaries in the circulatory system
What is the circulatory system?
The system that moves blood through the body
What organs/things make up the circulatory system?
The heart, veins, capillaries and arteries
How does a larger surface area help a cell transport things?
A substance can diffuse into (and out of) it in a certain time
What happens if a cell’s volume is too big?
The cell cannot fill up with all the materials it needs quick enough
What is the equation to work out the surface area:volume ratio?
Surface area / volume
If the surface area:volume ratio is larger, what does that tell you about the surface area?
That something has more surface area per unit volume
What happens to a cell’s SA:V ratio if the cell gets bigger?
The ratio gets smaller
What does it mean when a SA:V ratio is too small?
The cell cannot get enough raw materials fats enough
Do organs that move substances into and out of the body have a large or small surface area:volume ratio?
A large SA:V ratio
How come lungs have such a large surface area compared to volume?
They are packed with alveoli, which increase the surface area
How does the lungs having a large surface area help it to do its process?
It increases the speed and amount of gas exchange
Name 3 adaptions that alveoli have to increase the rate of gas exchange
Millions of alveoli / very thin walls / good blood supply
How does the alveoli having a thin wall help increase the rate of gas exchange?
The diffusion path is very short
Does the alveolus have a higher concentration of oxygen or carbon dioxide than the blood?
A higher concentration of oxygen (which then flows into the blood, oxygenating it
When blood enters from the rest of the body, does it have a higher concentration of oxygen or carbon dioxide?
A higher concentration of carbon dioxide
By oxygen being rapidly removed after diffusing into the blood, what does this do to the concentration gradient?
Insures it is as steep as possible
How does breathing increase the rate of diffusion?
Brings in fresh oxygen and takes carbon dioxide away quicker, making the concentration gradient higher for these gases
Does oxygen have a net movement into or out of the alveoli to the blood?
Net movement into the blood
In the circulatory system which where does the blood flow into from the heart?
Arteries
What do arteries divide into?
Capillaries
What does blood return to the heart in?
Veins
What are adaptations of the vein?
Wide tube / thin, flexible wall
What is the purpose of the veins?
To carry blood back into the heart
Where are the capillaries found?
In tissues
What is the purpose of arteries?
To take blood away form the heart
What are the adaptations for arteries?
Narrow tube and a thick layer of elastic and muscle fibres
What pressure are arteries under?
A high pressure, generated by the heart
What pressure are veins under?
Lower pressure than the blood in the arteries
What is the function of capillaries?
To allow food and oxygen to diffuse into the cells whilst waste is diffused from the cells
What do veins have that arteries don’t that allows them to keep moving blood in the correct direction?
Valves
Why do arteries need thick walls?
To withstand the sudden increase of pressure when the heart squirts blood into them
Why do arteries have a thick layer of elastic fibres and muscle fibres?
Because the pressure from th blood makes the, stretch
What does the stretch in your arteries create?
A wave, that you feel as your pulse
What makes blood flow in the arteries smoother?
Stretching and contracting (contracts after the stretching of the muscle and elastic fibres)