Biology Topic 1 Flashcards
What happens as the size of an organism increases
Surface area of volume ratio decreases
Diffusion distance increases
Metabolic rate increases
Why is the fusion alone insufficient for multicellular organisms?
As it will take too long for raw material to reach every cell in the organism due to high energy requirements
What is the use and features of a mass transport system?
Use the raw materials in bulk to the body cells
They require:
A medium to the substance in
A network to move through
A controlled direction to or from where the substance is supposed to be
Maintain speed to ensure that the substance is moved quickly
Why is water polar?
Oxygen atom has a slightly negative charge and the hydrogen atom has a slightly positive charge making it a dipole
What is a dipole?
A molecule with an uneven distribution of electrons which causes it to have a partial charge
How are hydrogen bonds formed?
The slightly negative oxygen atom of one water molecule is attracted to the slightly positive hydrogen atom of another molecule
What are three properties of water that can be attributed to its dipole?
Good solvent
Cohesion and adhesion
Thermoregulatory
How is water a good solvent and why? What is the importance?
When an ionic molecule is added to water
The slightly negative oxygen atom surrounds the positive ions
And the slightly positive hydrogen surround the negative ions
Allows water to transport substances around the body and allowed reactions to take place in aqueous solutions
What are the features of cohesion and adhesion and what is the importance?
Hydrogen bonding allows water molecules to attract each other(cohesion)
Hydon bonding allows water molecules to attract other substances (adhesion)
Allows for water molecules and dissolve substances to move around the body easily
What are features of thermal regulatory properties? what is the importance?
Water has a high specific heat capacity
This is because there are lots of hydrogen bond to break
Which require a lot of energy
This prevents rapid temperature changes from occurring inside the body
This provides stable conditions for reactions to happen
What features of the arteries?
Transport blood away from the heart at high pressures
Has lots of collagen to withstand high pressures and avoid ruptures
Lots of smooth muscle to constrict and contract the lumen to maintain pressure
Lots of elastic fibres to recoil the lumen back to its original size to maintain pressure
Highly folded endothelium wall to withstand pressure and smooth to reduce friction for efficient blood flow
What are features of the vein?
To transport blood towards the heart at low pressures the
They have a large lumen with thin walls
Low amount of collagen, elastic fibres and smooth muscle
Veins have valves to prevent backflow to ensure blood goes into direction
What are features of the capillary?
Allow substances to be exchanged between the blood and the tissue
Has a thin wall for gas exchange
Blood is transported at low pressures
Small lumen
What is the pulmonary circuit?
The heart pumps blood to the lungs where gas exchange takes place. The blood is oxygenated and carbon dioxide is removed.
What is the systemic circuit?
Blood is pumped to the rest of the body
Oxygen and other nutrients diffuse into tissues while the blood receives carbon dioxide and other waste products
Why is the left ventricle thicker than the right?
The left ventricle needs to pump blood to the rest of the body
The left ventricle contains more muscle to have a stronger contracting force to transport the blood a greater distance
How does blood move through the heart?
Body
Right Atrium
AVV
Right Ventricle
SL
Pulmonary Artery
Lungs
Pulmonary Veins
Left Atrium
AVV
Left Ventricle
SL
Aorta
Body
What is the cardiac cycle
The series of events in one heartbeat
What happens in Atrial Systole
Atria walls contract
Volume decreases
Pressure increases
When pressure is greater in the atria than ventricle, atrial ventricular valves open
Forced into the ventricles
Ventricles are in diastole
What happens in ventricular?
Ventricles contract
Volume decreases
Pressure increases
When pressure in the ventricles is greater than the pressure in the atrium, atrial ventricular valves close
When pressure is greater in the ventricles than it is in the aorta or pulmonary artery, semi lunar valves open
What happens in cardiac diastole
The atria and ventricles are both relaxed
AV and SL valves are closed
Blood flows into the atria
AV valves open(A Pressure> V Pressure)
Blood flows passively into the ventricles
Cycle begins again
Draw a cardiac cycle graph
When does atrial systole, ventricular systole and cardiac diastole happen on a cardiac cycle graph?
AS- before AVV Close
VS- After AVV close and SL Closes
CD- After SL Closes
How to calculate heart rate
60 divided by time to complete one cycle
