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Flashcards in animal transport Deck (31)
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1
Q

How are the valves prevented from being forced inside out

A

Valves are attached to the tedinous cords

2
Q

how long does one heat beat last (cardiac cylce)

A

0.7-0.8 seconds

3
Q

what does myogenic muscle mean

A

It contracts and relaxes automatically, it doesnt have to receive impulses from the nerves

4
Q

Describe how changes in ratio have influenced the need for transport systems in plants and animals

A

Small SA:V means the diffusion distance increases and the available SA for diffusion decreases. Organisms with larger volumes have higher energy demands.

5
Q

Define double circulation

A

The blood goes to the heart twice in one cycle around the whole body

6
Q

An advantage of a double circulatory system

A

Maintains a high blood pressure carrying substances faster through the body

7
Q

Why is the wall of the left ventricle thicker than the wall of the right atrium

A

The ventricles need to develop more force to contract to push the blood of the heart around the body, which a longer distance than that required of the atria. The ventricle have more muscle, to push with greater force at a higher pressure.

8
Q

Explain how pressure changes in the heart bring about the closure of the atrioventricular valve

A

During VENTRICULAR SYSTOLE
pressure in VENTRICLES IS HIGHER THAN ATRIA
PRESSURE PUSHES UP AGAINST CUSPS OF THE VALVE AND FORCES IT SHUT

9
Q

How the action of the heart is co-ordinated

A

The SA node acts as a pacemaker and creates an electrical signal, WAVE OF EXCITATION SPREADS OVER THE ATRIA
atria contract
the blood is delayed from passing into the ventricles by the AVN, until all the atria are filled with blood
it travels down the septum by the bundle of hiss and purkyne fibres
reaches apex and stimulates purkyne tissue
ventricles contract
progresses from the apex

10
Q

Type of muscle found in the heart wall and the process that creates pressure in heart

A

cardiac muscle

muscle contraction

11
Q

How is the walls of the artery’s different from that of the vein

A

They contain more collagen
more elastic tissue
no valves

12
Q

How is hydrostatic pressure generated in the heart

A

VENTRICULAR SYSTOLE

13
Q

whY does hydrostatic pressure drop as it moves away from the heart

A

As blood moves further from the heart, the vessel decreases in size from an artery to a capillary
the resistance to blood flow decreases
vessels have a larger lumen

14
Q

What happens to blood plasma when it arrives at the capillary

A

Hydrostatic pressure forces it out of capillary and into extracellular spaces, forming tissue fluid

plasma proteins remain in the capillaries too large to pass through wall

Hydrostatic pressure is greater than water potential

15
Q

Why is fetal oxyhaemoglobin on the left of the curve of adult oxyhaemogloblin

A

1 placenta has low pO2 ;

2 adult (oxy)haemoglobin will, release O2 / dissociate,
(in, low pO2 / placenta) ;

3 fetal haemoglobin has higher affinity for oxygen /
described ;

4 fetal haemoglobin, is (still) able to take up
(some) oxygen, in placenta / at low(er) pO2 ;

16
Q

WHy does the pressure fluctuate as blood flows along the aorta

A

Systole and diastole means contractions increase pressue, and relaxation decreases pressure

17
Q

How does increasing permeability of capillary membrane affect surrounding tissues

A

More plasma proteins through
more WHite blood cells
more tissue fluid formed
increased pressure in surrounding tissues

18
Q

Why is the sino atrial node described as a pacemaker

A

Sets up an electrical impulse that starts a heart beat

19
Q

Why does atrial fibrillation decrease the efficiency of the heat

A

Atria doesn’t beat in a synchronised pattern
chambers are unable to flll properly
heart doesn;t pump right amount of blood at each beat

20
Q

3 ways in whch carbon dioxide is transported

A

5% dissolve in plasma
10% react with haemoglobin, form carbohaemoglobin
85% transported as hydrogen carbonate ions

21
Q

How is CO2 converted in HCO3 ions

A

Co2 enters RBS aand reacts with water to form carbonic acid (H2CO3) catalysed by the enzyme carbonic anhydrase

this dissociates forming HCO3 ions and H ions

22
Q

Why is the chloride shift needed

A

When the negatively charged hydrogen carbonate ions leave, CL- ion replace them to return cell to neutral charge

23
Q

How does CO2 reduce the affinit of haemoglobin for oxygen

A

H ions from dissociation displace the oxygen molecules, if there are more hydrogen ions than more oxygen will be released of Hb

24
Q

WHat is the Bohr SHift

A

The change of shape in the oxyhaemoglobin curve, when CO2 is present
causing the oxyhaemoglobin to release oxugen more readily

25
Q

How can Hb supply more oxygen to actively respiing tissues than those with lower levels of respiration

A

Muscle release more CO2
More carbonic acid forms which dissociates to produce more H ions
more hydrogen ions will cause more oxygen to be released

26
Q

How does an electrocadiogram work

A

It measure the electrical activity in the heart
Sensors are attached to skin
They pick up the electrical activity of the heart onto the skin
and sensors convert it into a trace

27
Q

Why do ventricles contract from apex upwards

A

Blood is spread across ventricles upwards and outwards

Blood is squeezed upwards to the opening of major arteries

28
Q

Elevation in the ST section

A

Heart attack

29
Q

Small unclear P wave

A

Atrial fibrillation

30
Q

Deep S wave

A

Abnormal ventricular hypertrophy (increase in muscle thickness)

31
Q

How does an open circulatory system work

A

Muscular pumping organ under the dorsal
blood from body enter the “heart” through pores called ostia
Heart pumps through peristalisis
Blood pours into cavity