AP Biology

BR: Explain the connection between the cardiovascular system and… Respiratory System Digestive System Excretory System

Objectives Students will explain the internal transport

system in animals

HW

AP Biology

December 13, 2011 BR:

Why would the heart rate increase during physical activity?

Objectives Students will explain the internal

transport system in animals

HW Chp 36 notes

AP Biology 2008-2009

Circulatory Systems

AP Biology

AP Biology

Exchange of materials Animal cells exchange material across

their cell membrane fuels for energy nutrients oxygen waste (urea, CO2)

If you are a 1-cell organism that’s easy! diffusion

If you are many-celled that’s harder

AP Biology

Overcoming limitations of diffusion

O2

CHO

CHO

aa

aa

CH

CO2

NH3aa

O2

CH

aa

CO2

CO2

CO2

CO2

CO2

CO2 CO2

CO2

CO2

CO2

NH3

NH3 NH3

NH3

NH3

NH3

NH3NH3

O2

aa

CH

aa

CHO

O2

Diffusion is not adequate for moving material across more than 1-cell barrier

AP Biology

In circulation… What needs to be transported

nutrients & fuels from digestive system

respiratory gases O2 & CO2 from & to gas exchange systems: lungs, gills

intracellular waste waste products from cells

water, salts, nitrogenous wastes (urea) protective agents

immune defenses white blood cells & antibodies

blood clotting agents regulatory molecules

hormones

AP Biology

Circulatory systems All animals have:

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

open closed

hemolymph blood

AP Biology

Open circulatory system Taxonomy

invertebrates insects,

arthropods, mollusks

Structure no separation

between blood &

interstitial fluid hemolymph

AP Biology

Closed circulatory system Taxonomy

invertebrates earthworms, squid,

octopuses vertebrates

Structure blood confined to

vessels & separate from interstitial fluid 1 or more hearts large vessels to smaller

vessels material diffuses

between blood vessels & interstitial fluid

closed system = higher pressures

AP Biology

Learning Check List several advantages and

disadvantages of open and closed circulatory systems

AP Biology

Vertebrate circulatory system Adaptations in closed system

number of heart chambers differs

4 chamber heart is double pump = separates oxygen-rich & oxygen-poor blood; maintains high pressure

What’s the adaptive value of a 4 chamber heart?

2 3 4

low pressureto body

low O2

to body

high pressure & high O2

to body

AP Biology

Evolution of vertebrate circulatory system

fish amphibian reptiles birds & mammals

A A

VV V VV

A AAAA

V

2 chamber 3 chamber 3 chamber 4 chamber

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Evolution of 4-chambered heart

convergentevolution

Selective forces increase body size

protection from predation bigger body = bigger stomach for

herbivores endothermy

can colonize more habitats flight

decrease predation & increase prey capture

Effect of higher metabolic rate greater need for energy, fuels, O2,

waste removal endothermic animals need 10x energy need to deliver 10x fuel & O2 to cells

AP Biology

Vertebrate cardiovascular system Chambered heart

atrium = receive blood ventricle = pump blood out

Blood vessels arteries = carry blood away from heart

arterioles veins = return blood to heart

venules capillaries = thin wall, exchange / diffusion

capillary beds = networks of capillaries

AP Biology

Mammalian heart

Coronary arteries

to neck & head& arms

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Coronary arteries

bypass surgery

AP 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 contract “lub”

Semilunar valves between ventricle & arteries prevent backflow from arteries into

ventricles while they are relaxing “dub”

AP Biology

AV

SL

AV

Lub-dub, lub-dub Heart sounds

closing of valves “Lub”

recoil of blood against closed AV valves

“Dub” recoil of blood against

semilunar valves

Heart murmur defect in valves causes hissing sound when

stream of blood squirts backward through valve

AP Biology

Learning Check Explain how defective valves in the

heart can lead to altered cardiovascular function

AP Biology

Cardiac cycle

systolic________diastolic

pump (peak pressure)_________________fill (minimum pressure)

1 complete sequence of pumping heart contracts & pumps heart relaxes & chambers fill contraction phase

systole ventricles pumps blood out

relaxation phase diastole atria refill with blood

110

____

70

AP Biology

Measurement of blood pressure

High Blood Pressure (hypertension) if top number (systolic pumping) > 150 if bottom number (diastolic filling) > 90

AP Biology

Mammaliancirculation

What do blue vs. red areas represent?What do blue vs. red areas represent?

pulmonary

systemic

systemic

AP Biology

Blood vesselsarteries

arterioles

capillaries

venules

veins

artery

arteriolesvenules

veins

AP Biology

Arteries: Built for high pressure pump Arteries

thicker walls provide strength for high

pressure pumping of blood narrower diameter elasticity

elastic recoil helps maintain blood pressure even when heart relaxes

AP Biology

Veins: Built for low pressure flow Veins

thinner-walled wider diameter

blood travels back to heart at low velocity & pressure

lower pressure distant from heart blood must flow by skeletal muscle

contractions when we move squeeze blood through veins

valves in larger veins one-way valves

allow blood to flow only toward heart

Open valve

Blood flowstoward heart

Closed valve

AP Biology

Capillaries: Built for exchange Capillaries

very thin walls lack 2 outer wall layers only endothelium

enhances exchange across capillary

diffusion exchange between

blood & cells

AP Biology

Controlling blood flow to tissues Blood flow in capillaries controlled by

pre-capillary sphincters 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

sphincters open sphincters closed

Why?

AP Biology

Exchange across capillary walls

Arteriole

Bloodflow

Venule

Lymphaticcapillary

Interstitialfluid

Fluid & solutes flows out of capillaries to tissues due to blood pressure “bulk flow”

Interstitial fluid flows back into capillaries due to osmosis plasma proteins osmotic pressure in capillary

BP > OP BP < OP

15% fluid returns via lymph

85% fluid returns to capillaries

What aboutedema?

Capillary

AP Biology

Learning Check Describe how the structure of arteries,

veins, and capillaries are all well suited for their respective functions

AP Biology

Lymphatic system Parallel circulatory system

transports white blood cells defending against infection

collects interstitial fluid & returns to blood maintains volume & protein

concentration of blood Filters interstitial fluid through

lymph nodes drains into circulatory system

near junction of vena cava & right atrium

AP Biology

Lymph systemProduction & transport of WBCs

Traps foreign invaders

lymph node

lymph vessels(intertwined amongst blood vessels)

AP Biology

Learning Check Explain the connection between the

circulatory and lymphatic systems

AP Biology

December 12, 2011 BR: Explain the variables we are testing in

this lab Ind variable (changing) Dep variable (measuring) Control

Objectives Students will collect data to explain cardiac

physiology

HW Lab Analysis

AP Biology

Lab 10: Circulatory Physiology

Description:study factors that affect heart rate and blood pressure

- body position- level of activity

AP Biology

Lab 10: Circulatory Physiology Part A: Resting BP

Practice measuring blood pressure and obtain average resting BP

Decide who will be the ONE test subject for the remainder of the lab

Part B: Fitness Test Test 1- change in BP reclining to standing Test 2- resting standing pulse Test 3- resting reclining pulse Test 4- change in pulse rate reclining to

standing Test 5- recovery rate

AP Biology

Measuring Pulse What is a pulse and

where do you measure pulse?

Pulse Pressure wave of

blood entering circulation when the ventricles contract

Monitored at “pressure points” in arteries where pulse is easily palpated

Pulse averages 70–76 beats per minute at rest

AP Biology

Measuring Arterial Blood Pressure

Figure 11.20a

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Measuring Arterial Blood Pressure

Figure 11.20c

AP Biology

March 25, 2011 BR:

Describe how the structure of the heart allows it to function well as a pump

Objectives Students will explain the internal transport

system in animals Student will conduct a lab to determine function

of the cardiovascular system

HW Quiz Monday- Review notes/ SG chps 40, 41,42,

44, 48, 49 Chp 43 due monday