Transport in animals
8.1 Transport systems in muliticellular animals
Specialised transport systems are
needed because:
The metabolism demands of most multicellular
animals are high(they need lots of oxygen
and food, they produce lots of waste
products) So diffusion over the long distances
is not enough to supply the quantities needed
The surface area to volume ratio get smaller as
multicellular organisms get bigger so not only
do the diffusion distances get bigger but the
amount of surface area available to observe all
of move substances becomes relatively smaller
Molecules such as hormones or enzymes
may be made in one place but needed in
another
Food will be digested in one organ system but
needs go be transported to every cell for use in
Type your text
respiration and other aspects of cell metabolism
Waste products of metabolism need to be removed
from the cells and transported to excretory organs
Types of circulatory system
Features of a most circulatory systems
They have a liquid transport medium that
circulates around the system(blood)
They have vessels that carry the transport
medium
They have pumping mechanism to move the fluid
around the system
,Mass transport system: when substances
are transported in a mass of lead with a
mechanism for moving the fluid on the body
Open circulatory systems
Few vessels to contain the transport medium
It is pumped straight from the heart into the body
cavity of an animal which is called the haemocoel.
Transport medium
is under low pressure
It comes into direct
contact with the
tissues and cells
This is the exchange takes place between the
transport medium and the cells. The transport
medium returns to the heart through an open-
ended vessel
These Open ended so glitchy systems are found
mainly in invertebrate eg insects
Insect blood is Gas exchange
called haemolymph takes place in
the tracheal
systems
Which doesnt carry
oxygen or co2
Transports food and
nitrogenous waste
products And the
cells involved in
defence against
disease
The body cavity split by a membrane and the heart
extends along the length of the thorax and abdomen of
insect. The haemolymph circulates but steep diffusion
gradient cannot be maintained for efficient diffusion. The
amount of haemolymph flowing to particular tissue cannot
be very to meet changing demands.
, Closed circulatory system
Blood is enclosed in blood vessels and does not come
directly into contact with the cells of the body
The heart pumps The blood around the body
under pressure and relatively quickly and the
blood returns directly to the heart
Substances leave and enter the blood by diffusion
through the walls of the blood vessels
Amount of blood flowing to
particular tissue can be adjusted by
widening in there in the blood
vessels
Single closed circulatory systems
The blood flows through the heart and is pumped out to
travel all around the body before returning to the heart
Blood travels only one through the
heart for each complete circulation of
the body
Blood passes through two sets of capillaries before
it returns to the heart
In the first one, eight exchanges oxygen and
carbon dioxide
In the second set of capillaries, in the different
organ systems, substances are exchanged between
the blood in the cells.
As a result of passing through these T-shirts are very
narrow vessels, the blood pressure in the system
drops considerably so the blood returns to the heart
quite slowly.
This limited efficiency of the closest
sensitivity levels of animals with
single circulation tends to be
relatively low
8.1 Transport systems in muliticellular animals
Specialised transport systems are
needed because:
The metabolism demands of most multicellular
animals are high(they need lots of oxygen
and food, they produce lots of waste
products) So diffusion over the long distances
is not enough to supply the quantities needed
The surface area to volume ratio get smaller as
multicellular organisms get bigger so not only
do the diffusion distances get bigger but the
amount of surface area available to observe all
of move substances becomes relatively smaller
Molecules such as hormones or enzymes
may be made in one place but needed in
another
Food will be digested in one organ system but
needs go be transported to every cell for use in
Type your text
respiration and other aspects of cell metabolism
Waste products of metabolism need to be removed
from the cells and transported to excretory organs
Types of circulatory system
Features of a most circulatory systems
They have a liquid transport medium that
circulates around the system(blood)
They have vessels that carry the transport
medium
They have pumping mechanism to move the fluid
around the system
,Mass transport system: when substances
are transported in a mass of lead with a
mechanism for moving the fluid on the body
Open circulatory systems
Few vessels to contain the transport medium
It is pumped straight from the heart into the body
cavity of an animal which is called the haemocoel.
Transport medium
is under low pressure
It comes into direct
contact with the
tissues and cells
This is the exchange takes place between the
transport medium and the cells. The transport
medium returns to the heart through an open-
ended vessel
These Open ended so glitchy systems are found
mainly in invertebrate eg insects
Insect blood is Gas exchange
called haemolymph takes place in
the tracheal
systems
Which doesnt carry
oxygen or co2
Transports food and
nitrogenous waste
products And the
cells involved in
defence against
disease
The body cavity split by a membrane and the heart
extends along the length of the thorax and abdomen of
insect. The haemolymph circulates but steep diffusion
gradient cannot be maintained for efficient diffusion. The
amount of haemolymph flowing to particular tissue cannot
be very to meet changing demands.
, Closed circulatory system
Blood is enclosed in blood vessels and does not come
directly into contact with the cells of the body
The heart pumps The blood around the body
under pressure and relatively quickly and the
blood returns directly to the heart
Substances leave and enter the blood by diffusion
through the walls of the blood vessels
Amount of blood flowing to
particular tissue can be adjusted by
widening in there in the blood
vessels
Single closed circulatory systems
The blood flows through the heart and is pumped out to
travel all around the body before returning to the heart
Blood travels only one through the
heart for each complete circulation of
the body
Blood passes through two sets of capillaries before
it returns to the heart
In the first one, eight exchanges oxygen and
carbon dioxide
In the second set of capillaries, in the different
organ systems, substances are exchanged between
the blood in the cells.
As a result of passing through these T-shirts are very
narrow vessels, the blood pressure in the system
drops considerably so the blood returns to the heart
quite slowly.
This limited efficiency of the closest
sensitivity levels of animals with
single circulation tends to be
relatively low
