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iGCSE Biology Animal Circulation - Coggle Diagram
iGCSE Biology
Animal Circulation
single circulatory system
:
pumped via gas exchange organ
eg.
fish
double
: pumped to
gas exchange organ
then separately to
rest of body
pulmonary circulation
deoxygenated blood
goes to lungs & returns to heart
systemic circulation
oxygenated blood
circulates through the body
HEART
pump
Cardiac Cycle
Blood enters R & L
atria
via Pulmonary Vein & Vena Cava
Walls of atria contract
forcing open
bicuspid
&
tricuspid
valves and blood
into ventricles
Ventricles contract
forcing bicuspid &
tricuspid valves closed
Ventricles
contract more
forcing semi-lunar valves open
and blood out of
Pulmonary Artery & Aorta
Pressure closes valves
in Pulmonary Artery & Aorta
Restart
Coronary blood supply
Coronary arteries & veins
Coronary arteries
very narrow
Coronary Heart Disease
fatty substances in coronary arteries
heredity
high blood pressure
diet (saturated fat -> cholesterol)
smoking
stress
lack of exercise
Heart Rate
normal 70bpm
increased by hormone
adrenaline
from adrenal gland
controlled by medulla
in brain
CO2 receptors
in aorta & carotid artery
medulla
<> receptors
via
accelerator nerve
&
decelerator nerve
tells '
pacemaker
' cells in
heart to increase/decrease rate
walls made of
cardiac muscle
(mammals)
Oxygen from lungs
CO2 to lungs
Nutrients from gut
Urea from liver to kidneys
Blood Vessels
Arteries
Carry blood away from heart
HIGH PRESSURE
THICK muscular wall
elastic tissue
Arterioles
small arteries
small lumen
(central cavity)
Veins
Carry blood back to the heart
low pressure
thin walls
less elastic tissue
large lumen
(central cavity)
semilunar valves
to prevent blood backflow
Capillaries
Carry blood through organs
Linking arteries & veins
small enough to
fit through cells
1 cell thick
the width of a
red blood cell
BLOOD
Red Blood Cells
erythrocytes
adapted
biconcave, disc-like cells
no nucleus
M/mm3
no nucleus =>
more space for haemoglobin
biconcave=>
more surface area for diffusion
thin shape =>
short diffusion distance
transport of oxygen
via
haemoglobin
haemoglobin + oxygen ->
oxyhaemoglobin
('loaded' w oxygen in lungs)
then 'unloads' in tissues
made in
bone marrow
White Blood Cells
protect against invasion
lymphocytes
(25%)
similar size to RBC
large spherical nucleus
produce
antibodies
to destroy microorganisms
sometimes persist in blood
to give immunity:
memory cells
first exposure ->
'primary
immune response'
if same microorganism appears
antibodies produced
secondary
immune response
much faster
VACCINATIONS
injection of agent
with same antigens
as pathogen
production of
memory cells
several types...
weakened strain of microorganism
eg. polio, TB, measles
dead microorganisms
eg. typhoid, whooping cough
modified toxins of bacteria
eg. tetanus, diptheria
antigens themselves
eg. flu
harmless bacteria
genetically engineered
to carry antigen of
different microorganism
eg. hepatitis B
antibodies - soluble proteins
that pass into plasma
recognise
antigens
chemical markers on
pathogen surfaces
stick to surface antigens
and destroy the pathogens
with different methods...
cause bacteria to stick
together - easier for phagocytes
act as 'label' enabling phagocyte
to recognise the pathogen
cause bacterial cells to burst
neutralise toxins produced
phagocytes
(70%)
MUCH LARGER THAN RBC
Spherical/lobed nucleus
digest & destroy
bacteria & microorganisms
through
phagocytosis
or 'cell eating'
extend their cytoplasm
known as
pseudopodia
enclose microorganism
in a vacuole
secretes enzymes
into vacuole
EATS microorganism
platelets
smallest
soluble plasma protein
fibrinogen
=>
insoluble protein
fibrin
fragments of large cells
made in bone marrow
network across wound
trapping red blood cells
Plasma
liquid, mainly water
carries...
blood cells
dissolved nutrients
hormones
carbon dioxide
urea
heat