Transcript Chapter 12 Transport in Organisms

When do Organisms need
Transport Systems?
 We need TRANSPORT when
2 cells are far from each other
materials needed to be moved from
one place to another
huge sum of substances to be moved
Why do Organisms need
Transport Systems?
ensure a continual supply of nutrients,
oxygen and other useful materials for
metabolism and removal of toxic waste
products produced by metabolism
small animal can undergo this by
diffusion but large animal cannot,
they need a transport system
Blood Components
blood = plasma
+
blood cells
(straw-coloured fluid) (corpuscles)
blood cells include red blood cell
(erythrocytes), white blood cells (leucocytes )
and blood platelets where red blood cells are
the most numerous blood cells and give blood
the red colour
Separation of blood
Blood components can be separated by
centrifuge
A Centrifuge for
separation
Plasma
Blood cells
Composition of
Mammalian Blood
Whole Blood
Plasma
(55% by volume)
90 % Water
Blood Cell
(45% by volume)
White
Blood Cell
10% Dissolved
Substances Phagocytes
Red
Blood Cell
Platelets
Lymphocytes
Blood Plasma
Plasma is approximately 55% by volume and
contains
WATER
(as a solvent)
SOLUBLE SUBSTANCES
 hormones
 protein
 mineral salts
 gases
 dissolved food substances
 metabolic wastes
Blood Cells
Platelets
White Blood Cell
Red Blood Cell
Red Blood Cells
(red corpuscles, erythrocytes)
 form within bone marrow
 short life span with about 120 days
 old red blood cells are destroyed in
liver & spleen
 they have no nuclei when mature
- it increases the space to carry
haemoglobin
 they have biconcave disc shape
- which provides large surface area to
diffuse oxygen
 possess of haemoglobin
– haemoglobin is an iron-containing
compound and its presence is responsible
for the colour of red blood cell
– enable red blood cell to carry oxygen from
lungs to all parts of the body
Red blood cells
Transport of Oxygen
haemoglobin has a high affinity for oxygen
when the concentration of oxygen is high
In lung
Oxygen + haemoglobin
oxyhaemoglobin
In tissue
change of haemoglobin to oxyhaemoglobin is
accompanied by the colour change from
purplish red to bright red
Transport of Carbon Dioxide
CO2
(from tissue)
CO2 + H2O
CO2
(in bloodstream)
enzyme
+
H2CO3
carbonic acid
HCO3
(In red blood cell)
(in plasma)
H
+ HCO3
hydrogencarbonate ion
To Test a Sample of Blood
Plasma (chicken/pig/ox)
for glucose
supernatant
Fehling’s
solutions A
and B
centrifuge
chicken blood
boiling
water
Name the supernatant obtained after centrifugation.
Ans: It is plasma.
supernatant
Fehling’s
solutions A
and B
centrifuge
chicken blood
boiling
water
What does the precipitate in the centrifuge tube
consist of ?
Ans: The precipitate contains blood cells.
supernatant
Fehling’s
solutions A
and B
centrifuge
chicken blood
boiling
water
What happens to the supernatant when it is heated with
Fehling’s solutions A and B ?
Ans: The supernatant forms an orange precipitate.
White Blood Cells (white
corpuscles, leucocytes)
larger than red blood cells
and irregular in shape
White blood cells
prominent nucleus
no haemoglobin
kill germs, defend against
disease
Red blood cells
two main kinds of white blood
cells: phagocytes and lymphocytes
White Blood Cells
- Phagocytes
made in bone marrow but different from the
place where red blood cells are made
irregularly shaped nucleus
move like Amoeba
can squeeze out through the walls of
capillaries into the surrounding tissues
engulf dead cells or pathogens
White Blood Cells
- Lymphocytes
made in bone marrow, then migrate to
lymph nodes
large nucleus which nearly fills up the
cells
produce antibodies to attack germs by
reaction with their surfaces and often cause
them to clump together
produce antitoxins to neutralize the toxins
secreted by germs
Platelets
(thrombocytes)
platelets are not cells
fragments budded off from specialized
cells in bone marrow
smaller than other blood cells
life-span is about 5 to 9 days
agent for initializing blood clotting
Blood Clotting
when platelets are damaged in an injury, it
releases a chemical substance which starts
a chain of reactions
results: fibrinogen
fibrin
fibrin acts like a net, trapping blood cells
and plugging the wound so bleeding stops
serum are yellowish fluid which is
plasma without fibrinogen
clot dries up and harden to form a scab
when new skin formed
under the scab, it loosens
and comes off
The clotting of blood
(plasma protein)
Functions of Blood
It acts as a transport medium for oxygen,
carbon dioxide, food, urea, hormones,
antibodies and heat
It contains white blood cells and platelets for
body defense against infection
It helps in maintaining body temperature
constant
In emergencies an injured
person may die...
How can we save his life?
Blood Transfusion
Any criteria for Blood Transfusion?
Donor’s blood and recipient’s blood must be
compatible, otherwise, agglutination will
occur which will block the blood vessels
Blood Grouping
a person’s blood group determined by the
protein present on the surface of red blood
cells called antigens
there are two different antigens called antigen
A and antigen B. For a person in group A
contains antigen A
in human, there are mainly four different blood
groups called A, B, AB and O
in plasma, there may contain antibodies
known as anti-A and anti-B. They will react
with certain red blood cells which contain the
wrong antigen
The ABO Blood Group
Type B
Type AB
Antigen A
Antigen B
Antigens A and B
Antibody A
Neither
antibody A and
B
Red blood
cell
Type A
Antibody B
Type O
Neither antigen
A or B
Antibodies A
and B
Human Blood Groups
Blood Antigen Antibodies Recipient
Group (RBC) (Plasma)
A
A
Anti-B
A & AB
B
B
Anti-A
B & AB
AB
A&B
NO
AB only
O
NO
Both anti-A
& anti-B
ALL
Agglutination Reaction
A
Type A blood of
donor
Type B antibody in type A
blood of recipient
No agglutination
B
Type A blood of
donor
Type A antibody in type B
blood of recipient
Agglutination
Human Blood Groups
Donor
A
Recipient
B
Agglutination
AB = universal
recipient
O = universal
donor
Blood Vessels
there are three main kinds of vessels:
arteries, veins and capillaries
arteries carry blood away from the heart
while veins carry blood towards the heart
Blood Circulation
Vein
Artery
Heart
Venule
Capillary
Arteriole
Blood Vessels
Artery
Vein
Artery

wall of arteries are thick
and supported with
muscles and elastic fibres
Artery
Vein
• Blood pressure is much lower in vein as
blood has flowed slowly through the
capillaries before entering the vein
• vein has larger lumen and
thinner walls than artery
Vein
valves present to prevent
backflow of blood and ensure
that it flows towards the heart
Valve closed
blood can’t
flow back
Valve open
blood can flow
return of blood to heart is aided by
contraction of body muscles as they
squeeze the blood along the vein
Blood squeezed
towards heart
Muscle contracted
Valves closed
Prevent back-flow
Differences between
Arteries and Veins
Arteries
Veins
Direction of
carry blood away
return blood to the
blood flow
from the heart
heart
thick wall made up
thin wall made up
of muscles and
of muscles and
elastic fibres
elastic fibres
Differences between
Arteries and Veins
Arteries
blood flows with
pulse
Veins
blood flows steadily
with no pulse
Differences between
Arteries and Veins
Lumen
Arteries
Veins
small
large
Differences between
Arteries and Veins
Arteries
Location
deep inside
the body
Veins
close to the
surface
Demonstration of
Venous Flow in
the Fore Arm
A
B
X
vein
elbow joint
C
D
S
R
Y
finger Y
squeezing
finger X pressing
blood
down on R
towards S
finger Y removed
finger X still
pressing down on R
both fingers are
removed
What structure in the vein is indicated by the appearance
of the bulge at S shown in diagram C ?
Ans: The valve in the vein.
A
B
X
vein
elbow joint
C
D
S
R
Y
finger Y
squeezing
finger X pressing
blood
down on R
towards S
finger Y removed
finger X still
pressing down on R
both fingers are
removed
What is the purpose of tying the arm with a piece of
rubber tubing ?
Ans: This makes the vein more conspicuous.
A
B
X
vein
elbow joint
C
D
S
R
Y
finger Y
squeezing
finger X pressing
blood
down on R
towards S
finger Y removed
finger X still
pressing down on R
both fingers are
removed
With reference to the steps shown, explain why the part of
the vein between R and S has disappeared ?
Ans: Since
In step
On
thethere
other
B, finger
are
hand,
valves
Y squeezes
finger
at Xpoint
isthe
still
S,vein
blood
pressing
towards
is down
point
S. Blood
on
prevented
point in
R which
from
this segment
flowing
prevents
back
is blood
therefore
… flowing
pushed
into R.
along …
A
B
X
vein
elbow joint
C
D
S
R
Y
finger Y
squeezing
finger X pressing
blood
down on R
towards S
finger Y removed
finger X still
pressing down on R
both fingers are
removed
Why is it necessary to take the rubber tubing away as soon
as the demonstration has been completed ?
Ans: It is because we need to restore the normal blood
flow for the arm as soon as possible.
Capillaries
It is the smallest blood vessels
It is the site of exchange (by diffusion)
Thin wall (one cell)
Nutrients
Diffusion
O2
CO2
Waste
Adaptation of Capillary
 It has many branches
to increase the surface area for diffusion of
materials like glucose, amino acids, water,
carbon dioxide, oxygen, mineral salts and
metabolic wastes between blood and tissue
cells
 It has thin wall (only one-cell thick)
to decrease the diffusion distance for
exchange of materials between blood and
tissue cells
Exchange of Materials
It is carried out by diffusion through the whole
length of capillaries
(B.P. > O.P.)
(O.P. > B.P.)
substance pressed out
to the tissue cells
O.P.= osmotic
pressure
B.P.= blood
pressure
O.P.
substances diffused into
the blood capillary
O.P.
B.P.
arteriole end
B.P.
blood flow
venule end
Heart
located inside the thorax, between the
lungs
enclosed by the pericardium
the wall of heart is made of cardiac
muscle and it works days and nights
throughout one’s life
oxygen and nutrients are supplied to
heart through coronary arteries while
wastes are carried away by coronary
veins
Structure of Heart
the heart is divided into right and left halves
internally by a central wall or partition called
septum
heart is divided into four chambers with the
two chambers at the top of heart are auricles
and the two down at the bottom called
ventricles
Heart-Auricles (Atrium)
walls are relatively thin
right auricles receives deoxygenated blood
from the venae cavae (superior vena cava and
inferior vena cava) which collect blood from all
parts of the body except lungs
left auricle receives oxygenated blood from the
pulmonary veins which come from the lungs
Direction of Blood Flow
from Auricles to Ventricles
Right
Superior
vena cava
Right auricle
(atrium)
Inferior
vena cava
Right ventricle
Left
Pulmonary
veins
Left auricle
(atrium)
Left ventricle
Heart-Ventricles
have thicker and more muscular walls than the
auricles
right ventricle pumps deoxygenated blood to
the lungs via the pulmonary artery
left ventricles pumps oxygenated blood into
the aorta which takes the blood around the
body
right ventricle pumps blood to the lungs,
which lie very close to the heart but left
ventricle needs to pump blood all around the
body
 left ventricle has a thicker wall of muscles
Heart-Valves
 prevent blood from flowing backwards,
ensuring blood flows through the heart in only
one direction
 there are three types of valve present in heart,
they are : Tricuspid valve, Bicuspid valve and
Semilunar valves
Tricuspid valve
-valve on the right hand side lying between
the right auricle and right ventricle has three
parts
Bicuspid valve
- it situates at the left hand side lying between
the left auricle and left ventricle is made up of
two parts
 REMARKS: chordae tendineae (heart tendon)
are attached between the two
valves above and the muscular
walls of the ventricles to prevent
the one-way valves from being
turned inside out
Semilunar valves
-situated at the entrances of the aorta and
the pulmonary artery. They are pocketshaped valves to prevent the backflow of
blood into the ventricles
Blood Flow from Ventricles
to Other parts of the Body
To left lung
To right lung
Pulmonary
arteries
Venae cavae
Semilunar
valves
Tricuspid Septum
valve
Ventricles
To head
Aorta
To body
Pulmonary
veins
Articles
Bicuspid
valve
Heart tendon
- prevent valves
to turn inside out
Cardiac muscle
Examination of a
Pig’s Heart
pulmonary
artery
right
auricle
right ventricle
first cut pulmonary artery
second cut
aorta
right
auricle
left
auricle
left ventricle
third cut
left
auricle
left auricle
open
heart tendon
Why do the ventricles have thicker walls than the
auricles ?
Ans: It is because ventricles need to pump blood
to other parts of the body.
pulmonary
artery
right
auricle
right ventricle
first cut pulmonary artery
second cut
aorta
right
auricle
left
auricle
left ventricle
third cut
left
auricle
left auricle
open
heart tendon
Which ventricle has a thicker wall than the other ? What is
the reason for this difference ?
Ans: Left ventricle. As it needs to pump blood all around the
body but right ventricle pumps blood to lungs which
lie close to heart.
pulmonary
artery
right
auricle
right ventricle
first cut pulmonary artery
second cut
aorta
right
auricle
left
auricle
left ventricle
third cut
left
auricle
left auricle
open
heart tendon
What are the structures separating the auricles and
ventricles ?
Ans: It is septum.
pulmonary
artery
right
auricle
right ventricle
first cut pulmonary artery
second cut
aorta
right
auricle
left
auricle
left ventricle
third cut
left
auricle
left auricle
open
heart tendon
Why is it necessary to have the chordae tendineae ?
Ans: It is used to prevent the one-way valves from
being turned inside out.
pulmonary
artery
right
auricle
right ventricle
first cut pulmonary artery
second cut
aorta
right
auricle
left
auricle
left ventricle
third cut
left
auricle
left auricle
open
heart tendon
What is the function of the coronary artery ?
Ans: It is used to supply nutrients and oxygen to
the heart.
Heart Attack
 cardiac muscle differs from other kinds of
muscle as it is able to contract repeatedly
without getting tired
 coronary arteries are branches from aorta
which supply nutrients and oxygen to the
cardiac muscle
 coronary heart disease is the slow down of
the flow of blood through coronary arteries
which is caused by the deposition of a fatty
substance called cholesterol on the inside
wall of these arteries, making them narrower
and rougher
 heart attack is a result of blocking coronary
arteries so cardiac muscle cannot obtain
oxygen or nutrients from blood and die as a
result, the person may die
 excess animal fat in the diet, smoking, high
blood pressure, lack of exercise and stress
may lead to heart attacks
Heart Beat
 as cardiac muscle in its walls contracts and
relaxes, heart beats
 systole is the time when cardiac muscle
contracts and the heart becomes smaller which
squeezes blood out
 diastole is the time when cardiac muscle
relaxes and the heart becomes larger which
allow blood to flow into the auricles and
ventricles
 it consists of auricular systole, ventricular
systole and diastole
 Auricular systole
- it is about 0.1 second in duration
- contraction of the two auricles, squeezing
blood into the ventricles
 Ventricular systole
- it is about 0.3 second in duration
- contraction of the two ventricles
- tricuspid and bicuspid valves are forced to close
by the pressure of the blood, producing the
first heart sound “lub”
- semilunar valves are forced open by the
pressure of the blood, so blood is forced out
of the ventricles into the arteries
 Diastole
- it is about 0.4 second in duration
- all four chambers relax
- blood pressure in the ventricles decreases
and this causes the closure of the semilunar
valves, producing the second heart sound
“dup”
 Cardiac cycle is the duration between
one contraction of the auricles and the
next and it is about 0.8 seconds
pulmonary
circulation
lungs
Blood Circulation
in Man
heart
In one complete circulation,
blood flows through heart
twice but flow through the
body once only
systemic
circulation
consists of two circuits:
pulmonary circulation and
systemic circulation
body
Pulmonary Circulation
Venae cavae
Tissue
Deoxygenated
blood
Left ventricle
Right
auricle
Left
auricle
Right
ventricle
Pulmonary
vein
Lung
Oxygenated
blood
Systemic Circulation
 contraction of left ventricle pumps
oxygenated blood out of the heart via
aorta to all parts of the body (except lungs)
 exchange of materials occurs when blood
flows through the capillaries and become
deoxygenated
 finally, blood is collected by the venae cavae
which drains them into the right auricle of the
heart
Lymphatic System
Tissue fluid
- fluid formed when the high blood pressure at
the arterial end of a capillary forces fluid out
through it but red blood cells, platelets and
plasma proteins stay back in the bloodstream
- used to bath the cells and keeps them in
the right condition and provides a
medium for exchange of materials
between blood and cells
Lymph
- excess tissue fluid which cannot be returned
to the capillaries by osmosis but drained into
lymph capillaries
- lymph capillaries are colourless vessels
present in the tissues and it will join up to
form large lymph vessels
- lymph vessels carry lymph to subclavian
veins which empty into the heart through the
superior vena cava
- lymphatic vessels contain valves, which help to
keep the lymph flowing in the right direction
- contraction of skeletal muscles also aids the
flow of lymph
Lymph nodes (lymph glands)
- situated on the way from the tissue to the
subclavian veins
Lymph nodes
- made up of tiny spaces like a sponge and
lymph is filtered through these spaces
before it can continue to return to the
bloodstream
- contain large numbers of white blood cells to
destroy bacteria and toxin in lymph
Functions of Lymphatic System
– to return excess tissue fluid to blood
system
– as a medium for material exchange
between capillaries and tissue cells
- fats are absorbed by lacteals which join
the lymphatic system so it transport
absorbed fats
- the lymph node filters the lymph, it also
produce lymphocytes which make
antibodies
Functions of Transport System
in Angiosperms
 carries water and mineral salts from the
roots to the mesophyll cells of the leaves
for photosynthesis by xylem
carries foods made in the leaves by
photosynthesis to other cells of the plant
by phloem
 xylem and phloem are together called
vascular bundles
Arrangement of Conducting
Tissues in Angiosperms
 in root
- close to central position in which xylem
is found in the centre in a star-like
arrangement and phloem lies between
the radial arms of the xylem
- to resist the strong pulling force
from the wind blowing the shoot
 in stem
- close to the epidermis where the
conducting tissues are arranged in a
ring near the outside edge, with phloem
lying outside and xylem inside
- to resist the strong bending force
produced by wind
 in leaves
- vascular bundles are often called veins in
which xylem lies above the phloem
Xylem
 consists of long tubular vessels
 each vessel is made up of many dead cells
which are hollow and joined end to end
 the end walls of the cells have disappeared
and so a long and open tube is formed
 xylem vessels run from the root, through the
stem and finally branch out into every leaf of
the plant
xylem vessels contain no cytoplasm or
nuclei
to prevent xylem from collapsing, they have
thick cell walls made of cellulose and
strengthened by rings of a woody
substance called lignin
Phloem
 made up of tube cells called sieve tubes
which are living cells joined end to end by
perforated horizontal walls called sieve plate
 the perforations allow dissolved substances
to flow through them so food made in the
leaves can be carried to other parts of the
plant
 sieve tubes contain cytoplasm but no
nuclei and they do not have lignin in
their
cell walls
 each sieve tube has a companion cell next
to it but this companion cell does not have
nucleus and contain many other organelles
Comparison between
Sieve Tubes and Vessels
Sieve Tubes
living cells
smaller diameter
walls relatively thin,
flexible, composed of
cellulose
Vessels
dead cells
larger diameter
walls relatively thick,
hard, strengthened by
rings of lignin
Comparison between
Sieve Tubes and Vessels
Sieve Tubes
the lumens of mature
cells are filled with
cytoplasm
end walls of adjacent
sieve tubes from
sieve plates
Vessels
the lumens of
mature cells are
empty
end walls of adjacent
vessels cells
break down
Upward Transportation of Water
and Mineral Salts
• root pressure
• capillarity
• by transpiration pull
Transpiration Pull
 most of the water rising up in the xylem of
the stem is pulled up by this
 during transpiration, water is continually
removed from the top of xylem vessels to
supply cells in the leaves so pressure at
the top of xylem reduces and water flows
up
Transport of Organic Nutrients
 translocation is the process of transporting
the manufactured carbohydrates in
photosynthesis via phloem from the leaves
to other parts of the plant
~ End ~