Adaptations for transport(animals).

Question 1

Open circulatory system.

Answer 1

Blood bathes organs
Returns slowly to heart
Little control over direction of flow
Blood not in blood vessels.

Question 2

Closed circulatory system.

Answer 2

Blood in vessels
Flow=rapid and controlled direction
Organs bathed by tissue fluid from capillaries.

Question 3

Single circulatory system.

Answer 3

Blood passes through heart once in each circulation.

Question 4

Double circulatory system.

Answer 4

Blood passes through the heart twice in each circulation
Once in pulmonary(lung)
Then in systemic(body) circulation.

Question 5

Insect circulatory systems.

Answer 5

Open
Dorsal tube shaped heart
No resp pigment due to lack of resp gases because of tracheal gas exchange system.
Gases not carried in blood.

Question 6

Earthworms circulatory systems.

Answer 6

Closed system
5 pseudo hearts
Haemoglobin carries gases in blood
Vascularisation.

Question 7

Closed system advantages.

Answer 7

Maintains blood pressure
Blood supply to different organs can vary
Lower volumes of transport fluids required.

Question 8

Fish circulatory systems.

Answer 8

Closed, single
Blood pumped to gills and oxygenated there
Moves around in body tissues
Lower pressure and slower flow around body.

Question 9

Mammals circulatory systems.

Answer 9

Closed, double
High blood pressure=quick O2 delivery
Low pressure prevents hydro static pressure forcing tissue fluid into alveoli(would decrease efficiency).

Question 10

Double circulatory system advantages.

Answer 10

Maintains blood pressure around body
Uptake of O2 and delivery of O2 and nutrients is more efficient
Pressure can differ in pulmonary and systemic.

Question 11

The mammalian heart chambers.

Answer 11

Left and right atrium
Left and right ventricle.

Question 12

Structures in heart and functions.

Answer 12

Left atrium-receieves ox blood from lungs
Right ventricle-thinner wall, less pressure needed
Bicuspid(mitral)-prevents backflow into left atrium when ventricles contracts
Tricuspid(atrioventricular) valve-pressure of contraction opens it, closes to prevent backflow
Pulmonary vein-return ox blood from lungs to left atrium
Superior Vena cava-returns de-ox blood to heart
Semi-lunar(pulmonary) valve-prevent backflow
Aorta-carries ox blood from left vent to body
Pulmonary artery-takes de-ox blood from right vent to lungs
Apex-bottom of heart
Septum-divides ox(left0 and de-ox(right) sides
Inferior vena cava.

Question 13

Pathway of blood around body.

Answer 13

Pulmonary vein
Left atrium
Left ventricle
Aorta
Vena cava
Right atrium
Right ventricle
Pulmonary artery
Lungs.

Question 14

Pathway of blood through vessels.

Answer 14

Heart arteries arterioles capillaries venules veins heart.

Question 15

Arteries function and structure.

Answer 15

Carry oxygenated blood from heart to tissue(high pressure).
Thick muscular wall
Elastic tissue
Narrow lumen
Tunica externa, tunica media, endothelium, tunica intima, lumen.

Question 16

Veins function and structure.

Answer 16

Carry deoxygenated blood towards the heart(low pressure).
Same structure as arteries
Thin walls
Valves
Less muscular and less elastic tissue.

Question 17

Capillaries function and structure.

Answer 17

Large network through tissues
Connect arterioles to venules
One cell thick(short diff path)
Narrow
Numerous and highly branched.

Question 18

The cardiac cycle.

Answer 18

Atrial systole:
-Atrial contract, pressure opens AV valve, blood flows into ventricles.
Ventricular systole:
-Ventricles contract, AV valve closes(vent pressure higher than in atria), semi lunar valves open,blood flows to arteries.
Ventricular diastole:
-Vent muscles relax, semi lunar valve closes.
Diastole:
-Heart muscles relax, atria fills from vena cava and pulmonary veins.

Question 19

How the heart contracts.

Answer 19

Sinoatrial node sends waves of excitation across atria=contract
Connective tissue prevents waves passing to vents
Waves pass to AV node
Delay to allow atria to complete contraction
AV node transmits impulses down bundle of his–>apex
Impulses travel up purkinje fibres=vents contract from bottom up.

Question 20

ECG characteristics.

Answer 20

P wave- depolarisation of atria(atrial systole)
QRS wave- depolarisation of ventricles(ventricular systole)
T wave- re polarisation of ventricles(ventricular diastole).

Question 21

What is plasma?

Answer 21

Main part of blood
Carries red blood cells
Proteins, nutrients, mineral ions, hormones, dissolved gases, waste.

Question 22

Haemoglobin role.

Answer 22

O2 molecules bind to haem groups
Released where they are needed.

Question 23

Effect of partial pressure on O2-hB binding.

Answer 23

High partial pressure=O2 associates to form oxyhaemoglobin
Low partial pressure=O2 disassociates to form deoxyhaemoglobin.

Question 24

Shape of oxygen dissociation curves.

Answer 24

Sigmoidal(S)
first O2 binds=shape changes for 2nd and 3rd to bind easier
3rd changes shape=hard for 4th O2 molecule

Question 25

Foetal haemoglobin ox diss curve.

Answer 25

Higher affinity for O2
2 diff sub units that allow O2 to bind more readily
Moves whole curve to left
Enables fetus to get O2 from mother’s blood
O2 sat is greater at same partial pressure.

Question 26

CO2 transport and effect on partial pressure.

Answer 26

In aqeous sol in plasma
As hydrogen carbinate ions
As carbaminohaemoglobin in blood
High CO2 pp=Lower affinity for O2 of Hb=less efficient at loading it.
Moves to right(bohr effect).

Question 27

Chloride shift process.

Answer 27

CO2 diffuses to RBC
CO2 combines w/ H2O catalysed by carbonic anhydrase=carbonic acid
C acid dissociates into H+ and HCO3- diffuse out of RBC to plasma
Cl- fac diff to RBC(maintain electrochemical neutrality)- chloride shift
H+ bind to oxyHb, reduces O2 affinity(bohr effect)#
O2 released from Hb
O2 diffuses from RBC to plasma and body cells.

Question 28

Tissue fluid formation.