2006-2007 Regents Biology

Circulatory SystemBlood

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

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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

white bloodcells

red bloodcells

white blood cells

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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

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Hemoglobin Protein which carries O2

O2O2

O2

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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

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Blood clottingfibrin protein fibersbuild clot

emergency repair of circulatory system

plateletsseal the hole

chemicalemergencysignals

2006-2007 Regents Biology

Circulatory Systemin Animals

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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

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Circulatory system Made up of 3 parts

organ heart

tissues & cells blood

red blood cells blood vessels

(vascular system)arteriesveinscapillaries

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Circulatory systems All animals have:

muscular pump = heart tubes = blood vessels circulatory fluid = “blood”

open closed

hemolymph blood

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Vertebrate Heart 4-Chambered heart

atria (atrium) thin wall collection chamber receive blood

ventricles thick wall pump pump blood out

rightatrium

leftatrium

rightventricle

leftventricle

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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

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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

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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”

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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

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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

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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 signal also transmitted to skin = EKG

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pump (peak pressure)_________________fill (minimum pressure)

Cardiac CycleHow is this reflected in blood pressure measurements?

chambers fill

ventriclesfill

ventriclespump

systolic________diastolic

110________80

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Measurement of blood pressure

hypertension =(high blood pressure)

if systolic > 150or

if diastolic > 90

2006-2007 Regents Biology

Any Questions??

2006-2007 Regents Biology

Circulatory SystemBlood Vessels

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Blood vesselsarteries

arterioles

capillaries

venules

veins

artery

arteriolesvenules

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

pulmonaryartery

pulmonaryartery =to lungs

aorta carotid = to headto brain & left arm to right arm

coronary arteries

to body

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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

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Major Veins

pulmonaryvein =

from lung

superiorvena cava = from upper body

pulmonaryvein = from lung

inferiorvena cava = from lower body

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Structure-function relationship Capillaries

very thin walls allows exchange of

materials across capillary

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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

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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?

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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

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Vertebrate circulatory system

heart

lungs

body

2 part system

arteryto body

arteryto lungs

vein from lungsto heart

vein from bodyto heart

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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)

excess salts, sugars & water

Bone picks up new red

blood cells Spleen

picks up new white blood cells

2006-2007 Regents Biology

Any Questions??

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

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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

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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

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Heart DiseaseHeart disease death rates 1996-2002Adults ages 35 and older

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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

2006-2007 Regents Biology

Any Questions??

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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

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Lymph System

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Thermoregulation

Vasoconstriction Vasodilation

Vasodilation & vasoconstriction adjusts blood flow evaporative cooling

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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

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Coronary arteries

bypass surgery

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Simpler organismsWhen 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

HydraJellyfish