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Regents Biology
Blood & blood cells Blood is a tissue of fluid & cells
plasma (55% of volume) fluid dissolved salts, sugars, proteins, and more
cells (45% of volume) 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
in bone marrow
differentiate into many different types of cells
white bloodcells
red bloodcells
white blood cells
Regents Biology
Red blood cells Small round cells
produced in bone marrow lose nuclei & mitochondria
more space for hemoglobin iron-containing protein that transports O2
last 3-4 months (120 days) filtered out by liver ~3 million RBC destroyed each second
Regents Biology
Red blood cell production 5-6 million RBC in tiny drop of human
blood 5 liters of blood in body = 25 trillion RBC
produce ~3 million RBC every second in bone marrow to replace cells lost
each RBC 250,000 molecules hemoglobin
each Hb molecule carries 4 O2
each RBC carries 1 million O2
Regents Biology
Blood clottingfibrin protein fibersbuild clot
emergency repair of circulatory system
plateletsseal the hole
chemicalemergencysignals
Regents Biology
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 circulatory system
Feeding the Need for Energy
Regents Biology
Circulatory system Made up of 3 parts
organ heart
tissues & cells blood
red blood cells blood vessels
(vascular system)arteriesveinscapillaries
Regents Biology
Circulatory systems All animals have:
muscular pump = heart tubes = blood vessels circulatory fluid = “blood”
open closed
hemolymph blood
Regents Biology
Vertebrate Heart 4-Chambered heart
atria (atrium) thin wall collection chamber receive blood
ventricles thick wall pump pump blood out
rightatrium
leftatrium
rightventricle
leftventricle
Regents Biology
Evolution of circulatory system
fish amphibian reptiles birds & mammals
A A
VV V VV
A AAAA
V
2 chamber 3 chamber 3 chamber 4 chamber
Birds ANDmammals!
Wassssup?!
Not everyone has a 4-chambered heart
Regents Biology
Evolution of circulatory systems
convergentevolution
What advantage was a 4-chambered heart increase body size fuel warm-blooded enable flight
Higher energy needs greater need for energy,
fuel, O2, waste removal warm-blooded animals &
flying need 10x energy need to deliver 10x fuel & O2
Regents Biology
AV
SL
AV
Heart valves 4 valves in the heart
flaps of connective tissue prevent backflow
Atrioventricular (AV) valve between atrium & ventricle keeps blood from flowing back
into atria when ventricles pump “lub”
Semilunar valves between ventricle & arteries prevent backflow from arteries into
ventricles “dub”
Regents Biology
AV
SL
AV
Lub-dub, lub-dub Heart sounds
closing of valves “Lub”
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
Cardiac cycle 1 complete sequence of pumping
heart contracts & pumpsheart relaxes & chambers fill contraction phase
systole ventricles pumps blood out
relaxation phase diastole atria refill with blood
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 signal also transmitted to skin = EKG
Regents Biology
pump (peak pressure)_________________fill (minimum pressure)
Cardiac CycleHow is this reflected in blood pressure measurements?
chambers fill
ventriclesfill
ventriclespump
systolic________diastolic
110________80
Regents Biology
Measurement of blood pressure
hypertension =(high blood pressure)
if systolic > 150or
if diastolic > 90
Regents Biology
Blood vesselsarteries
arterioles
capillaries
venules
veins
artery
arteriolesvenules
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 maintains blood
pressure even when heart relaxes
Regents Biology
Major arteries
pulmonaryartery
pulmonaryartery =to lungs
aorta carotid = to headto brain & left arm to right arm
coronary arteries
to body
Regents Biology
Veins: Built for their job Veins
blood returns back to heart 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 squeeze blood through veins
valves in large veins in larger veins one-way valves
allow blood to flow only toward heart
Open valve
Blood flowstoward heart
Closed valve
Regents Biology
Major Veins
pulmonaryvein =
from lung
superiorvena cava = from upper body
pulmonaryvein = from lung
inferiorvena cava = from lower body
Regents Biology
Structure-function relationship Capillaries
very thin walls allows exchange of
materials across capillary
Regents Biology
Controlling blood flow to tissues Capillary function
exchange between blood & tissues O2, CO2, H2O, food, waste
blood flow in capillaries controlled by pre-capillary sphincter valves
pre-capillary sphincters open pre-capillary sphincters closed
Regents Biology
Capillary Beds Blood flow
at any given time, only 5-10% of body’s capillaries have blood flowing through them supply varies as blood is needed after a meal, blood supply to
digestive tract increases during strenuous exercise, blood
is diverted from digestive tract to skeletal muscles
capillaries in brain, heart, kidneys & liver usually filled to capacity
Why?
Regents Biology
Circulation of Blood 2 part system
Circulation to lungs blood gets O2 from lungs brings O2-rich blood back
to heart Circulation to body
pumps O2-rich blood to body
picks up nutrients from digestive system
brings CO2 & cell wastes from body to heart
heart
lungs
body
Circulationto lungs
Circulationto body
Regents Biology
Vertebrate circulatory system
heart
lungs
body
2 part system
arteryto body
arteryto lungs
vein from lungsto heart
vein from bodyto heart
Regents Biology
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 wastes (urea)
excess salts, sugars & water
Bone picks up new red
blood cells Spleen
picks up new white blood cells
Regents Biology
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 hardening of arteries
Regents Biology
Cardiovascular health Genetic effects Diet
diet rich in animal fat increases risk of CV disease
Exercise & lifestyle smoking & lack of
exercise increases risk of CV disease
bypass surgery
Regents Biology
Cardiovascular health (U.S. 2001)
Heart Disease 696,947
Cancer 557,271
Stroke 162,672
Chronic lower respiratory diseases 124,816
Accidents (unintentional injuries) 106,742
Diabetes 73,249
Influenza/Pneumonia 65,681
Alzheimer's disease 58,866
Nephritis, nephrotic syndrome & nephrosis
40,974
Septicemia 33,865
Regents Biology
Women & Heart Disease
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.
Risk factorsSmokingLack of exerciseHigh fat dietOverweight
Death rates for heart disease per 100,000 women, 2002
Regents Biology
Lymphatic system Parallel circulatory system
transports WBC defending against infection
collects interstitial fluid & returns to blood maintains volume & protein
concentration of blood drains into circulatory system
near junction of vena cava & right atrium
transports fats from digestive system to circulatory system
Regents Biology
Thermoregulation
Vasoconstriction Vasodilation
Vasodilation & vasoconstriction adjusts blood flow evaporative cooling
Regents Biology
Counter Current Exchange
Cold blood
Warm blood
Capillarybed
Veins
Veins
5˚Ctemperature
of environment
36˚C core body
temperature
Artery
blood from arteries warms blood in veins