Transcript LE - 5 - Circulatory System

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
Regents Biology
 circulatory
system
Circulatory System
 Organ

heart
 Tissues & cells

blood vessels
 arteries
 veins
 capillaries

blood
 red blood cells
 plasma (liquid)
Regents Biology
Vertebrate Heart
 4-Chambered heart

atria (atrium)
 thin wall
 collection chamber
left
atrium
 receive blood

ventricles
 thick wall pump
 pump blood out
Regents Biology
right
atrium
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
Regents Biology
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 tissue
prevent backflow of blood
 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
Regents Biology

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
 Regents
signal
also transmitted to skin = EKG
atria empty
into ventricles
Cardiac Cycle
How is this
reflected in
blood pressure
measurements?
chambers begin
to fill
pump (peak pressure)
__________________
fill (minimum pressure)
110
______
80
Regents Biology
ventricles
pump
Measurement of blood pressure
hypertension =
(high
blood pressure)
Regents Biology
if top number > 150
or
if bottom number > 90
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
Regents Biology
Arteries: Built for their job
 Arteries
blood flows away from heart
 thicker walls

 provide strength
for high pressure
pumping of blood

elastic & stretchable
Regents Biology
Major arteries
aorta carotid = to head
to brain & left arm
to right arm
to body
pulmonary
artery
pulmonary
artery =
to lungs
coronary arteries
Regents Biology
Coronary artery bypass
bypass surgery
Regents Biology
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
Regents Biology
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

waste
body cell
CO2
 O2, CO2, H2O,
food, waste
O2
food
Regents Biology
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
Regents Biology
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
Regents Biology
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
Regents Biology
More stops along the way…
 Kidneys
filters out cell wastes
(urea)
 extra salts, sugars
& water

 Bone

pick up new red
blood cells
 Spleen

pick up new white
blood cells
Regents Biology
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?
Ask Questions!!
Regents Biology
2008-2009
Circulatory System
Blood
Regents Biology
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
Regents Biology
Blood Cell production
ribs, vertebrae,
breastbone & pelvis
 Stem cells
“parent” cells
white blood cells
in bone
marrow
 develop into all
the different
types of blood
red blood
cells

 red blood cells
 white blood cells
Regents Biology
cells
white 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
Regents Biology
Hemoglobin
 Protein which carries O2

250,000 hemoglobin proteins in one red
blood cell
O2
O2
Regents Biology
O2
O2
emergency repair of circulatory system
Blood clotting
chemical
emergency
signals
Regents Biology
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
Regents Biology
hardening of arteries
Cardiovascular health
 Risk Factors
genetics
 diet

 high animal fat

exercise & lifestyle
 smoking
 lack of exercise
Regents Biology
bypass surgery
Heart Disease
Heart disease death rates 1996-2002
Adults ages 35 and older
Regents Biology
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.
Regents Biology
Have a heart?
Ask Questions!!
Regents Biology
2008-2009