The Circulatory System

Question 1

What is water?

Answer 1

A solvent

Question 2

What does a solvent do?

Answer 2

Substances dissolve in it

Question 3

Where do most biological reactions take place?

Answer 3

In a solution

Question 4

How can substances be transported more easily?

Answer 4

If dissolved in a solvent

Question 5

Why can water transport all sorts of materials?

Answer 5

It’s a liquid and a solvent

Question 6

What types of materials can water transport?

Answer 6

Glucose and oxygen

Question 7

What’s waters structure?

Answer 7

One molecule of water
One atom of oxygen
Two atoms of hydrogen

Question 8

How does the water molecule and oxygen join to hydrogen molecule?

Answer 8

via electrons

Question 9

What charge of each side of the hydrogen atom have?

Answer 9

Positive

Question 10

What charge does the oxygen atom have?

Answer 10

Negative

Question 11

What type of molecule is water?

Answer 11

Dipolar - positive and negative charge on either side

Question 12

What attraction does the oxygen and hydrogen atom have towards eachother?

Answer 12

Hydrogen bonding

Question 13

What does water being dipolar make it?

Answer 13

Cohesive

Question 14

What does water being cohesive help it do?

Answer 14

Flow and great for transporting substances

Question 15

What does waters dipole nature make it useful for being?

Answer 15

Solvent in living organisms

Question 16

Why do multicellular organisms need mass transport systems?

Answer 16

Diffusion across outer membrane would be too slow because of the large distance the substances have to travel to reach all cells

Question 17

Why do single celled organisms not need mass transport systems?

Answer 17

Materials can diffuse directly across cell membrane

Question 18

What is a mass transport system used for?

Answer 18

Cary raw materials from specialised exchange organs and to remove metabolic water
E.g. in mammals it is the circulatory system

Question 19

Name all the parts of the heart on the right side…

Answer 19

Superior vena cava
Pulmonary artery
Inferior vena cava
Semi-lunar valve
Atrioventricular valve
Right ventricle
Right atrium

Question 20

Name all the parts of the heart on the left side…

Answer 20

Aorta
Pulmonary veins
Semi-lunar valve
Atrioventricular valve
Cords (valve tendons)
Left ventricle
Left atrium

Question 21

What does the left ventricle do?

Answer 21

Thicker more muscular walls than right ventricle due to needing to contract powerfully to pump blood all round the body

Question 22

Why do the ventricles have thicker walls than the atria?

Answer 22

As the need to push blood out of heart whereas atria just need to shunt it a short distance

Question 23

What do the AV valves do?

Answer 23

Link atria to ventricles and stop blood flowing back into atria when ventricles contract
Cords attach atrioventricular valves to ventricles to stop them being forced up into atria when ventricles contract

Question 24

What do the SL valves do?

Answer 24

Link ventricles to pulmonary artery and aorta and stop blood flowing back into heart after ventricles contract

Question 25

What did valves help do?

Answer 25

Help blood flow in 1 direction

Question 26

Name features of artery?

Answer 26

Carry blood from heart to rest of body Thick muscular wall and have elastic tissue to cope with high pressure Endothelium is folded allowing artery to expand (helps cope with high pressure too)

Question 27

Name the features of a vein?

Answer 27

Take blood back to heart Wider lumen Little muscular and elastic tissue as blood is under lower pressure Valves to prevent back flow

Question 28

Name features of a capillary?

Answer 28

Smallest blood vessel Metabolic exchange occurs Networks if capillaries that increase surface area for exchange One cell thick walls Diffusion is efficient

Question 29

What does the cardiac cycle do?

Answer 29

Pumps blood around the body

Question 30

What’s stage 1?

Answer 30

Ventricular diastole Atrial systole

Question 31

What’s stage 2?

Answer 31

Ventricular systole Atrial diastole

Question 32

What’s stage 3?

Answer 32

Cardiac diastole

Question 33

What happens in stage 1? Ventricular diastole and atrial systole…

Answer 33

Ventricles relaxed and atria contract (decreasing vol of chambers but increasing pressure) Blood is pushed into ventricles (slight increase of ventricular pressure and chamber vol as the ventricles receive ejected blood from contracting atria)

Question 34

What happens in stage 2? Ventricular systole and atrial diastole…

Answer 34

Atria relax and ventricles contract decreasing vol and increasing pressure Pressure is higher in ventricles than atria which forces AV valves shut to prevent backflow Pressure in ventricles is also higher than aorta and PA which forces open SL valves and blood forced out into arteries

Question 35

What happens in stage 3? Cardiac cycle…

Answer 35

Ventricles and atria both relax Higher pressure in PA and A closes the SL valves to prevent back flow into ventricles Blood returns to heart and atria fill again due to high pressure in VC and PV atria pressure increases as ventricles relax their pressure falls below pressure of atria and so AV valves open ATRIA CONTRACT AND PROCESS RESTARTS

Question 36

How can you investigate the effect of caffeine in the heart rate if Daphnia?

Answer 36

Make up a range of different solutions of caffeine and a control Transfer one daphnia into glass watch Use pipette and place few drops of first caffeine solution on daphnia Place on stage of microscope and adjust focus so you can see beating heart Count number of heartbeats in 30s then X2 Do this prices 3 times for all solutions Compare results but calculating an average/mean

Question 37

What are 2 ethical issues involved using animals in experiments?

Answer 37

Unethical - Cannot give consent and may be subjected to painful procedures Better to use animals like daphnia and rather than dogs