transport in animals snap revise

Question 1

why is there a need for transport systems in animals

Answer 1

all living cells need a constant supply of oxygen and nutrients- respiration occurs to produce ATP
-nutrients need to be moved around

Question 2

what’s an exchange surface in humans

Answer 2

the lungs

Question 3

factors requiring an organism to have a transport system

Answer 3

• size- big= large diffusion distance
• surface area to vol ratio- big= small sa:vol
• level of metabolic activity

Question 4

features of a good transport system and what they might have

Answer 4

• a fluid medium running through them
• a pump to create the pressure for circulation
  -exchange surfaces for substances to enter and exit
  might have:
  -vessels or tubes
  -two circuits

Question 5

what are open circulatory systems

Answer 5

ones in which blood is not always held in vessels

Question 6

what has open circulatory systems

Answer 6

insects

Question 7

two disadvantages of open circulatory systems

Answer 7

• blood pressure remains low= slow flow of blood

- circulation is affected by body movements

Question 8

what are closed circulatory systems

Answer 8

are ones which the blood is held in vessels

Question 9

what separate fluid does organisms with closed circulatory systems have

Answer 9

tissue fluid

Question 10

two key advantages of closed circulatory systems

Answer 10

+ blood pressure in vessels can be high and circulation is rapid
+ circulation is not affected by any body movements.

Question 11

what are single circulatory systems

Answer 11

ones which the blood flows through the heart once for each circuit of the body

Question 12

compare the pressure of single circulatory systems and double circulatory systems

Answer 12

double has a higher pressure

Question 13

why do fish have single circulatory systems

Answer 13

• counter current flow maintains a large diffusion gradient for exchange in the gills
• most fish are exothermic and the water is thermally insulating

Question 14

whats a double circulatory systems

Answer 14

ones which the blood flows twice for every circuit of the body

Question 15

talk about the pressure in double circulatory systems

Answer 15

• pressure to the lungs is low (pulmonary circuit)

- pressure to the body is high (systemic)

Question 16

whats tissue fluid

Answer 16

extracellular fluid which bathes the cells of most tissues

Question 17

state the circulatory system that a fish has

Answer 17

closed single

Question 18

explain why larger organisms need transport systems rather than relying on diffusion

Answer 18

• large organisms ahve a small surface area to vol ratio. This means some tissues are too far for molecules to be exchanged fast enough. Transport systems ensure that even tissues far away from the organisms surface can exchange molecules rapidly

Question 19

describe features of the mammalian circulatory system that makes it well suited for transport

Answer 19

• blood plasma acts as a fluid transport medium which moves molecules easily throughout the body
• blood vessels ensure that blood is transported where its required
• the heart pumps the blood ensuring that it circulates the body; this means tissues can undergo exchange continuously. Mammals have systemic and pulmonary circuits. This maximises gas exchange at the alveoli in the lungs which have surfaces specialised for exchange

Question 20

suggest why some animals require complex transport systems with reference to activity

Answer 20

more metabolically active animals require faster exchange of gasses at the tissue as well as a faster supply of glucose for respiration. complex transport systems allow for faster and more efficient transport of molecules like oxygen and glucose for respiring tissues

Question 21

what does transporting blood in vessels allow for

Answer 21

allows for it to be pumped at high pressure delivering nutrients and removing waste efficiently

Question 22

what are the 5 vessels in the circulatory system

Answer 22

• arteries
• arterioles
• capillaries
• venules
• veins

Question 23

what do all blood vessels have

Answer 23

a smooth thin inner layer of cells called endothelium

Question 24

what do the arteries do

Answer 24

carry blood away from the heart at high pressure

Question 25

state the arrangement of arteries

Answer 25

- to cope with high pressure, artery walls are very thick | - artery walls have thick layers of elastic tissue and smooth muscle encased in a thick outer layer of collagen

Question 26

state the general things abt arterioles

Answer 26

- simmilar structure to arteries but are smaller and have relatively thinner muscle and elastic layers - contraction of the smooth muscle constricts the arteriole and is used to control the flow of blood through the body

Question 27

state the general things abt capillaries

Answer 27

- capillaries have very thin walls consisting of just a single celled layer of endothelium - the lumen of the capillaries is very narrow and can squeeze red blood cells against the endothelium to improve transfer of oxygen

Question 28

what do veins do

Answer 28

carry low pressure blood back to the heart

Question 29

state the arrangement of veins

Answer 29

- vein walls are not thick and the lumen is very wide to maximise blood flow - veins have valves to ensure the low pressure blood only flows in the right direction

Question 30

state the general things abt venules

Answer 30

- smaller than veins and lack valves | - they deliver blood from the capillary beds to the veins

Question 31

functions of the blood

Answer 31

- carries substances in the circulatory system - forms part of the immune system - the blood carries hormones around the body as part of cellular communication - distributes heat around the body

Question 32

what is the fluid component of the blood called

Answer 32

blood plasma

Question 33

why is the blood plasma important

Answer 33

the blood plasma holds dissolved gasses and organic molecules and provides a fluid medium for the blood cells

Question 34

whats the most common type of cell found in blood

Answer 34

erythrocytes- red blood cells

Question 35

what are other cells found in blood apart from RBCs

Answer 35

- leucocytes- white blood cells | - blood platelets- tiny fragments of other blood cells that are involved in clotting process

Question 36

in what type of circulatory system is body tissue bathed in blood

Answer 36

open circulatory systems

Question 37

in what type of circulatory system is body tissue bathed in tissue fluid

Answer 37

closed circulatory systems

Question 38

what is tissue fluid used to exchange

Answer 38

exchange nutrients and gasses between cells of the body in the circulatory system

Question 39

how is tissue fluid slightly different to blood

Answer 39

tissue fluid contains the same nutrients that blood contains but without most blood cells and proteins

Question 40

where is tissue fluid formed

Answer 40

at the arterial end of a capillary bed

Question 41

how is tissue fluid formed

Answer 41

high hydrostatic pressure in the blood forces blood plasma through the capillary endothelium into the existing tissue fluid (high hydrostatic pressure at arterial end and low at venous end) -this force is resisted by oncotic pressure in the tissue fluid but this force is weaker (doesn't want things out the blood) The hydrostatic pressure will always have a greater influence than the oncotic so fluid always ends up leaking out from the blood to the tissue fluid from capillaries

Question 42

how is tissue fluid returned to the blood

Answer 42

- oncotic pressure in the tissue fluid remains constant throughout the capillary bed - at the venous end of the capillary bed, the hydrostatic pressure is much lower - tissue fluid containing waste products of metabolism travels back into the blood forming blood plasma

Question 43

what forms at the arteriole end of the capillary

Answer 43

tissue fluid ( here hydrostatic pressure outweighs the oncotic pressure)

Question 44

what forms at the venous end of the capillary

Answer 44

low hydrostatic pressure so fluid moves from the tissue into the blood so the blood can take away co2 and waste( here hydrostatic pressure doesn't outweigh the oncotic pressure)

Question 45

whats the lymphatic system

Answer 45

a network of vessels and organs that help maintain the internal fluid environment of the body as well as transporting some proteins and fats

Question 46

what does too much tissue fluid go to

Answer 46

some drains into lymph capillaries that are part of the lymphatic system

Question 47

what does the lymphatic system transport lymph to

Answer 47

transports lympth aroun the body