Transport in animals

Question 1

State 5 reasons why animals need specialised transport systems

Answer 1

high metabolism
small SA : V ratio –> large diffusion distances
products ( e.g. hormones, enzymes) made in one area but needed in another
food must be transported to every cell
waste products must be removed

Question 2

describe how diffusion distance, SA, volume, SA:V ratio vary with increasing organism size

Answer 2

as organism size increases:

• SA:V ratio decreases
• diffusion distance increases
• SA increases but volume increases at a faster rate

Question 3

how is the level of activity related to needs for oxygen and glucose

Answer 3

increased activity = higher needs for oxygen and glucose

Question 4

define diffusion

Answer 4

net passive movement of substances from an area of high concentration to low concentration (down a concentration gradient)

Question 5

define circulatory system

Answer 5

the transport system in an animal

Question 6

define open circulatory system

Answer 6

a circulatory system with a heart but that doesn’t contain the transport medium (transport medium flows freely)

Question 7

define closed circulatory system

Answer 7

where the blood is enclosed in blood vessels and doesn’t come into direct contact with cells

Question 8

define haemolymph

Answer 8

insect blood. it doesn’t carry oxygen or carbon dioxide. it transports food, nitrogenous waste, cells involved in defense

Question 9

define single circulatory system

Answer 9

the blood travels once through the heart for a complete circulation
eg
heart –> gills , oxygenated –> cells, deoxygenated –> heart

Question 10

define double circulatory system

Answer 10

2 separate circulation systems:

1) deoxygenated blood is pumped from the body, through the heart and to the lungs
2) oxygenated blood is pumped from the lungs, through the heart and to the body

Question 11

define pulmonary circulation

Answer 11

the part of the double circulatory system that takes deoxygenated blood to the lungs, oxygenates it and takes it back to the heart

Question 12

define systematic circulation

Answer 12

the part of the double circulatory system that takes the oxygenated blood around the body, and the deoxygenated blood back to the heart

Question 13

draw a diagram showing both a single closed circulatory system and a double closed circulatory system

Answer 13

do it now

Question 14

an example of animals with:

open circulatory system
closed single circulatory system
closed double circulatory system

Answer 14

open circulatory:
insects

closed single:
fish

closed double:
mammals

Question 15

similarities and differences between open and closed systems

Answer 15

similarities
- mass transport

differences

• haemolymph vs blood
• open vs closed
• in contact with cells vs not
• no o2 or co2 vs carries o2 and co2

Question 16

advantages and disadvantages of open / closed systems

Answer 16

advantages disadvantages
open less vulnerable to pressure
amount of haemolymph can’t be varied
closed high pressure
amount of blood can be varied
more efficient

Question 17

similarities and differences between single and double circulatory systems

Answer 17

similarities
closed
blood

differences
through heart once vs twice
low pressure returning to heart vs high pressure

Question 18

advantages and disadvantages of single and double circulatory systems

Answer 18

advantages disadvantages
single low pressure limits efficiency
double more efficient
copes with higher demand

Question 19

differences between pulmonary and systemic circulation

Answer 19

pulmonary

• heart to lungs
• oxygenated
• lungs to heart

systemic

• heart to body
• deoxygenated
• body to heart

Question 20

list the sequence of blood vessel types from the heart

Answer 20

• artery
• arteriole
• capillary
• venule
• vein

Question 21

state the anatomical layers in arteries veins and capillaries

• state the components of each layer
• state properties and function of each layer

Answer 21

tunica intima
epithelial cells
- smooth, thin lining

tunica media
smooth muscle tissue -
contracts and relaxes to change size of lumen

elastic fibres - elastin
stretch and recoil

tunica externa
collagen - protein
- structural support
- maintains shape

Question 22

compare proportions of each layer in artery, capillary, vein and state function

width of wall 
muscle layer
elastic layer
inner surface
valves
size of lumen
pressure

Answer 22

artery capillary vein
width of wall thick very thin thin
muscle layer thick none thin
elastic layer thick none thin
inner surface folded epithelium// endothelial cells // smooth endothelium
valves no no yes - semi lunar
size of lumen small tiny large
pressure high falling low

Question 23

structure of capilliaries

function of capillaries and how they’re adapted

Answer 23

wall = single epithelial cell thick
lumen = single RBC thick

link arterioles to venules
wide junctions between cells to allow fluid to pass out

Question 24

explain how structure of veins adapts them to function

explain how valves work

Answer 24

blood pressure is low so semi lunar valves prevent back flow
wide lumen and smooth epithelial cells to allow blood to flow easily

valves open when blood flows towards heart, and close when blood starts to flow backwards
valves in arms and legs are between muscles, so when the contract they force the valves to open.
breathing forces blood in the chest to the heart

these act against gravity

Question 25

describe processes of vasoconstriction, vasodilation

- explain how this affects blood flow through capillaries

Answer 25

vasoconstriction:

• blood vessel constrics
• prevents blood flowing into capillary bed

vasodilation:

• arteriole relaxes
• blood flows into capillary bed

Question 26

list components of blood and the bloods functions

Answer 26

plasma

• glucose - storage compounds
• amino acids
• hormones
• ions
• plasma proteins - albumin, fibrinogen,

red blood cells -oxygen to respiring cells
white blood cells - immune response
platelets (megakaryocytes) - damaged areas

also - pH buffer
- maintains temperature

Question 27

define blood plasma

Answer 27

yellow liquid that makes up 50% blood and transports solutes and molecules

Question 28

define tissue fluid

Answer 28

tissue that surrounds the cells of multicellular animals

it contains glucose, amino acids, hormones, ions, some white blood cells

Question 29

define lymph

Answer 29

modified tissue that is collected in the lymph system

Question 30

table comparing contents of lymph, tissue fluid and blood plasma

RBC     
WBC            
glucose               
plasma protein         
amino acids           
fatty acids           
hormones           
oxygen                
carbon dioxide

Answer 30

blood plasma tissue fluid lymph
RBC yes no no
WBC yes some some
glucose yes less no
plasma protein yes no no
amino acids yes less no
fatty acids some no yes
hormones yes yes less
oxygen yes less no
carbon dioxide no yes yes

Question 31

define hydrostatic pressure

Answer 31

pressure created by an enclosed area - pressure against the walls

Question 32

describe oncotic pressure

Answer 32

the tendency of tissue fluid to move back into blood vessels by osmosis

Question 33

describe filtration pressure

Answer 33

the overall pressure of hydrostatic vs oncotic pressure

Question 34

describe how the blood / hydrostatic pressure varies over circulatory system

Answer 34

blood pressure:
highest in arteries, falling in arterioles, low in capillaries, venules and veins

hydrostatic pressure:
high at arteriole end of capillary
oncotic pressure higher at venule end so filtration pressure is high enough to draw tissue fluid back in