Transcript Document
Circulatory System
in Animals
Regents Biology
2008-2009
Feeding Energy Needs
Why do we need a
circulatory system?
supplies in
fuel (sugars)
digestive system
oxygen
respiratory system
waste out
CO2
respiratory system
need to pick up & deliver
the supplies & wastes
around the body
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circulatory
system
Simple organisms
When your body is only 2-cell layers thick, you can
get supplies in and waste out just through diffusion
all cells within easy reach of fluid
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Biology
Jellyfish
Hydra
Complex organisms
Circulatory system
made up of 3 parts
organ
heart
tissues & cells
blood vessels
arteries
veins
capillaries
blood
red blood cells
plasma
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Circulatory systems
All animals have:
muscular pump = heart
tubes = blood vessels
circulatory fluid = “blood”
open
hemolymph
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closed
blood
Vertebrate Heart
4-Chambered heart
atria (atrium)
thin wall
collection chamber
left
atrium
receive blood
ventricles
thick wall pump
right
pump blood out atrium
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right
ventricle
left
ventricle
Evolution of circulatory system
Not everyone has a 4-chambered heart
fish
2 chamber
V
amphibian
3 chamber
A
A
A
V
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reptiles
3 chamber
A
V
A
V
birds & mammals
4 chamber
A
V
A
V
Lub-dub, lub-dub
4 valves in the heart
flaps of connective tissue
prevent backflow
Heart sounds
closing of valves
“Lub”
SL
AV
AV
force blood against
closed AV valves
“Dub”
force of blood against
semilunar valves
Heart murmur
leaking valve causes hissing sound
blood squirts backward through valve
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Electrical signals
allows atria to empty
completely before
ventricles contract
stimulates ventricles
to contract from
bottom to top, driving
blood into arteries
heart pumping controlled by electrical impulses
Biology
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signal
also transmitted to skin = EKG
Cardiac Cycle
ventricles
fill
How is this
reflected in
blood pressure
measurements?
systolic
________
diastolic
chambers fill
pump
(peak pressure)
_________________
fill
(minimum
pressure)
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Biology
110
________
80
ventricles
pump
Measurement of blood pressure
if systolic > 150
hypertension =
or
(high blood pressure)
if diastolic > 90
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Have a heart?
Ask Questions!!
Regents Biology
2008-2009
Circulatory System
Blood Vessels
Regents Biology
2008-2009
Blood vessels
arteries
veins
artery
venules
arterioles
arterioles
capillaries
venules
veins
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Arteries: Built for their job
Arteries
blood flows away from heart
thicker walls
provide strength for high
pressure pumping of blood
elastic & stretchable
maintains blood
pressure even
when heart relaxes
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Major arteries
aorta carotid = to head
to brain & left arm
to right arm
to body
pulmonary
artery
pulmonary
coronary
artery =
arteries
to lungs
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Coronary artery bypass
bypass surgery
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Veins: Built for their job
Veins
Blood flows
toward heart
blood returns back to heartOpen valve
thinner-walled
blood travels back to heart
at low speed & pressure
why low pressure?
far from heart
blood flows because muscles
contract when we move
Closed valve
squeeze blood through veins
valves in large veins
in larger veins one-way valves
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allow blood to flow only toward heart
Major Veins
superior
vena cava =
from
upper body
pulmonary
vein =
from lung
inferior
Regentsvena
Biology cava = from lower body
pulmonary
vein =
from lung
Structure-function relationship
Capillaries
very thin walls
allows diffusion of
materials across
capillary
O2, CO2, H2O,
waste
body cell
CO2
food, waste
O2
food
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Circulation of Blood
Circulation
to lungs
2 part system
Circulation to lungs
lungs
blood gets O2 from lungs
drops off CO2 to lungs
brings O2-rich blood from
lungs to heart
heart
Circulation to body
pumps O2-rich blood to body
picks up nutrients from
digestive system
collects CO2 & cell wastes
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body
Circulation
to body
Vertebrate circulatory system
2 part system
lungs
artery
to lungs
vein from lungs
to heart
heart
vein from body
to heart
body
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artery
to body
Stops along the way…
Lungs
pick up O2 / clean out CO2
Small Intestines
pick up nutrients from
digested food
Large Intestines
pick up water from
digested food
Liver
clean out worn out
blood cells
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More stops along the way…
Kidneys
filters out wastes
(urea)
extra salts, sugars &
water
Bone
picks up new red
blood cells
Spleen
picks up new white
blood cells
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Circulatory System & Homeostasis
ATP
Homeostasis
keeping the internal environment of the
body balanced
need to balance food & O2 in
need to balance energy (ATP) production
need to balance CO2 & waste out
Exercise
heart beat faster
food
O2
CO2
waste
need more ATP
bring in more O2 & food; remove more CO2 & waste out
Disease
poor lung or heart function = heart beat faster
need to work harder to bring in O2 & food & remove wastes
Regents Biology
Have a heart?
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Regents Biology
2008-2009
Circulatory System
Blood
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2008-2009
Blood & blood cells
Blood is a tissue of fluid & cells
plasma
liquid part of blood
dissolved salts, sugars, proteins, and more
cells
red blood cells (RBC)
transport O2 in hemoglobin
white blood cells (WBC)
defense & immunity
platelets
blood clotting
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Blood Cell production
ribs, vertebrae,
breastbone & pelvis
Stem cells
“parent” cells
in bone
marrow
differentiate
into many
different types
of cells
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white blood cells
white blood
cells
red blood
cells
Red blood cells
Small round cells
produced in bone marrow
5 liters of blood in body
5-6 million RBC in drop of human blood
last 3-4 months (120 days)
filtered out by liver
~3 million RBC destroyed each second
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Hemoglobin
Protein which carries O2
250,000 hemoglobins in 1 red blood cell
O2
O2
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O2
O2
emergency repair of circulatory system
Blood clotting
chemical
emergency
signals
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platelets
seal the hole
protein fibers
build the clot
Cardiovascular disease
Atherosclerosis & Arteriosclerosis
deposits inside arteries (plaques)
develop in inner wall of the arteries,
narrowing their channel
increase blood pressure
increase risk of heart attack, stroke, kidney damage
normal artery
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hardening of arteries
Cardiovascular health
Risk Factors
genetics
diet
high animal fat
exercise & lifestyle
smoking
lack of exercise
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bypass surgery
Heart Disease
Heart disease death rates 1996-2002
Adults ages 35 and older
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Women & Heart Disease
Death rates for heart disease per 100,000 women, 2002
Risk factors
Smoking
Lack of exercise
High fat diet
Overweight
Heart disease is 3rd leading cause of death
among women aged 25–44 years & 2nd
leading cause of death among women aged
45–64 years.
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Have a heart?
Ask Questions!!
Regents Biology
2008-2009