Transcript Transport Systems in Animals

CIRCULATORY SYSTEM
Part 1
Grade 8 Semester 1
Year 2011-2012
Blood as the Transport Medium
To supply oxygen and glucose, as well as other
substances, large organisms have a specialised
transport system.
This system has 4 parts:
 A medium-blood
 A system of tubes-arteries and veins
 A pump-heart
 Sites of exchange-capillaries

Blood Content
Types of Blood Cells
Cell Type
Appearance
Function
Structure
Red blood Cells
(erythrocytes)
Transport O2 from
lungs
Contain haemoglobin
Have no nucleus
Cells are smalls and flexible
White Blood
Cells
(Phagocytes)
Remove
microorganisms that
invade the body and
might cause infection
by engulfing them.
Irregular shaped nucleus
Enzymes in cytoplasm digest
microorganisms once engulfed
Sensitive cell surface membrane
White Blood
Cells
(Lymphocytes)
Produce antibodies-as
defense against
diseases
Large nucleus contains may
copies of genes for antibody
production
Platelets
Involved in blood
clotting
Can release blood clotting
enzyme
Blood Clotting
Collagen fibers
Platelet
plug
Fibrin clot
Platelet releases chemicals
that make nearby platelets sticky
Clotting factors from:
Platelets
Damaged cells
Plasma (factors include calcium, vitamin K)
Prothrombin
Thrombin
Fibrinogen
Fibrin
5 µm
Red blood cell
Blood Plasma



Our transport medium has watery liquid part that is
called plasma.
Plasma has transport function which carries
dissolved food molecules, waste materials, and
hormones.
Plasma is also able to distribute heat around the
various part of the body.
The Heart





It is a double pump
It contracts (systole)
and relaxes (diastole)
It has 4 chambers
Each chamber pumps
the same volume of
blood
Heart rate/pulse: 72
beats/min
Blood Vessels





The blood flows away from the heart in vessels
called arteries.
The blood flows back towards the heart in vessels
called veins.
Joining the arteries and veins are the capillaries.
Main artery: aorta
Main veins: vena cava
Transverse Section of Vessels
Narrow
central tube
(lumen)



Wide
central tube
(lumen)
Artery: Blood is rich in oxygen (except in the
pulmonary artery); High pressure.
Vein: Blood is low in oxygen (except in the
pulmonary vein); Low pressure; has pocket valve.
Capillary: One cell thick; large surface area
Capillaries
Tissue cell
Capillary
Red
blood
cell
15
Net fluid
movement out
Net fluid
movement in
m
At the arterial end of a
capillary, blood pressure is
greater than osmotic pressure,
and fluid flows out of the
capillary into the interstitial fluid.
At the venule end of a capillary, blood
pressure is less than osmotic
pressure, and fluid flows from the
interstitial fluid into the capillary.
Direction of
blood flow
Blood pressure
Osmotic pressure
Pressure
Capillary
INTERSTITIAL FLUID
Inward flow
Outward flow
Arterial end of capillary
Venule end

The mammalian cardiovascular system
7
Capillaries of
head and
forelimbs
Anterior
vena cava
Pulmonary
artery
Aorta
Pulmonary
artery
9
6
Capillaries
of right lung
Capillaries
of left lung
2
4
3
Pulmonary
vein
5
1
Right atrium
3
11
Left atrium
Pulmonary
vein
10
Left ventricle
Right ventricle
Aorta
Posterior
vena cava
8
Capillaries of
abdominal organs
and hind limbs