copyright © 2005 pearson education, inc. publishing as benjamin cummings circulatory and...

45
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Circulatory and Respiratory Systems

Upload: karin-hensley

Post on 11-Jan-2016

230 views

Category:

Documents


0 download

TRANSCRIPT

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Circulatory and Respiratory Systems

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

• Most animals have a circulatory system

– That transports O2 and nutrients to cells and takes away CO2 and other wastes

– Must deal with the problem of gravity

How Does Gravity Affect Blood Circulation?

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Circulatory system

• Connects all body tissues

• Arteries, veins and capillaries

Capillary

Nuclei ofsmoothmusclecells

Redbloodcell

LM

70

0

Figure 23.1A

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Capillaries

– Are the sites of exchange between blood and interstitial fluid

Capillary

Interstitialfluid

Tissuecell

Diffusion ofmolecules

Figure 23.1B

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

MECHANISMS OF INTERNAL TRANSPORT

• Several types have evolved

• Cnidarians and flatworms

• Gastrovascular cavity

– Digestion

– Internal transport

Figure 23.2A

Mouth

Circularcanal

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Open circulatory systems

• Arthropods and molluscs

– Open-ended vessels

– Tissue cells directly

Figure 23.2B

PoresTubular heart

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Closed circulatory systems

– Arteries to capillaries

– Veins return blood to the heart

Artery(O2-rich blood)

Arteriole

Capillary beds

Venule

Vein

AtriumVentricle HeartArtery

(O2-poor blood)GillcapillariesFigure 23.2C

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Vertebrate cardiovascular systems

• Fish

– Two-chambered heart

– Single circuit: gill capillaries -> systemic capillaries -> heart

Figure 23.3A Systemic capillaries

Gill capillaries

Heart:

Ventricle (V)

Atrium (A)

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Vertebrate cardiovascular systems

• On land

– Mostly 4 chambered hearts

– Double circulation

– Separate pulmonary and systemic circuits

Pulmonarycircuit

Systemiccircuit

Right Left

AA

V

Lung capillaries

Systemic capillaries

V

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

• Amphibians and reptiles

– Three-chambered hearts

Figure 23.3B

Pulmocutaneouscircuit

Systemiccircuit

Right Left

AA

V

Lung and skin capillaries

Systemic capillaries

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

THE MAMMALIAN CARDIOVACULAR SYSTEM

• Heart

– Two thin-walled atria ->

– Pump blood into the ventricles ->

– Thick-walled ventricles ->

– Pump blood away

– Valves prevent backflow

• AV

• Semilunar

Rightatrium

Leftatrium

Semilunarvalve

Semilunarvalve

Atrioventricular(AV) valve

Atrioventricular(AV) valve

Rightventricle Left

ventricle

Figure 23.4A

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Blood flow

• Human cardiovascular system

Figure 23.4B

1

2 7

8

9

2

3

4

5

6

410

3

9

8

Superiorvena cava

Capillaries ofhead, chest, andarms

Pulmonaryartery

Capillariesof left lung

Pulmonary vein

Aorta

Left atrium

Left ventricleAorta

Capillaries ofabdominal regionand legs

Inferiorvena cava

Right ventricle

Right atrium

Pulmonary vein

Capillariesof right lung

Pulmonaryartery

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Heart function

Contracts and relaxes rhythmically

• Diastole

– Relaxed

– Heart chambers fill

• Systole

– Contractions:

• Atria: blood into the ventricles

• Ventricles: blood into the large arteries (stronger)

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Heart function

Figure 23.6

Heart is relaxed.AV valvesare open.

1 2 Atriacontract.

Systole

Diastole

0.4 sec

0.1sec

0.3 sec 3 Ventriclescontract.Semilunarvalvesare open.

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Heart function

• Cardiac output

– Volume of blood/minute pumped into the systemic circuit

– 5 L per minute

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

The pacemaker

• Pacemaker (SA node) generates electrical signals

– Triggers contraction of the atria

• The AV node

– Relay

– O.1 sec delay to ventricles

– ECG

Figure 23.7

1 2 3 4

Pacemaker(SA node) AV node

Specializedmuscle fibers

Apex

Rightventricle

Rightatrium

ECG

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

The Pacemaker

Heart rate

– Adjustable

• Heart attack?

• Heart murmur?

AortaSuperiorVena cava

Pulmonaryartery

Leftcoronary artery

Rightcoronary artery

Blockage

Deadmuscletissue

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Atherosclerosis

Connectivetissue

Smoothmuscle

Epithelium

LM

16

0

LM

60

Plaque

Figure 23.8B

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Blood vessels

• Capillaries

– Wall formed by single layer of epithelial cells

• Arteries and veins

– Have smooth muscle and connective tissue

Figure 23.5

Capillary

Epithelium

Basementmembrane

Valve

Epithelium

Smoothmuscle

Connectivetissue

Vein

VenuleArteriole

Artery

Connectivetissue

Smoothmuscle

Epithelium

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Blood pressure

– Is the force blood exerts on vessel walls

– Depends on cardiac output and the resistance of vessels

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Blood pressure

• Highest in the arteries

Figure 23.9A

Pre

ssur

e (m

m H

g)120100806040200

Systolicpressure

Diastolicpressure

Relative sizes andnumbersof bloodvessels

Vel

ocity

(cm

/sec

) 50

40

30

20

10

0

Aor

ta

Art

erie

s

Art

erio

les

Cap

illar

ies

Ven

ules

Ven

ae c

avae

Vai

ns

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Blood pressure

• Muscle contractions and one-way valves

– Keep blood moving

Skeletalmuscle

Direction ofblood flowin vein

Valve(open)

Valve(closed)

Figure 23.9B

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Blood flow• Constriction of arterioles and precapillary

sphincters

– In capillary beds

Figure 23.11

1

2

Sphincters relaxed

Sphincters contractedVenule Arteriole

Venule Arteriole

Precapillary sphincters Thoroughfarechannel

Capillaries

Thoroughfarechannel

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Transfers

Capillaries

TE

M 5

,000

Musclecell

Cleft betweentwo epithelialcells of the capillary wall

Nucleus of epithelial

cell

Capillarywall

Iumen

Interstitialfluid

Figure 23.12A

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Transfers

• Movement of materials in and out of blood

• Diffusion

– Through clefts between epithelial cells

Tissue cells

Osmoticpressure

Arterialend of

capillary

Interstitialfluid

Net fluidMovement out

Net fluidMovement in

Bloodpressure

Bloodpressure

Osmoticpressure

Venousend of

capillary

Figure 23.12B

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

STRUCTURE AND FUNCTION OF BLOOD

Red and white blood cells suspended in plasma

• Plasma is about 90% water

– Inorganic ions, proteins, nutrients, wastes, gases, and hormones

Plasma (55%)

Constituent Major functions

Water Solvent forcarrying othersubstances

Salts (ions)SodiumPotassiumCalciumMagnesiumChlorideBicarbonate

Osmotic balance,pH buffering, andnerve and musclefunction

Plasma proteins

Fibrinogen

Immunoglobulins(antibodies)

Osmotic balance and pH buffering

Immunity

Clotting

Substances transported by blood

Nutrients (e.g., glucose, fatty acids,vitamins) Waste products of metabolismRespiratory gases (O2 and CO2)Hormones

Centrifugedblood

sample

Figure 23.13 (left part)

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

• Red blood cells (erythrocytes)

– O2 bound to hemoglobin

• White blood cells (leukocytes)

– Fight infections and cancer

Centrifugedblood

sample

Cellular elements (45%)

Cell type Numberper L (mm3) of blood

Functions

Erythrocytes(red blood cells)

5–6 million Transport of oxygen (and carbon dioxide)

Leukocytes(white blood cells)

5,000–10,000 Defense andimmunity

Basophil

Eosinophil

Lymphocyte

Monocyte

Blood clotting250,000–400,000

Platelets

Neutrophil

Figure 23.13 (right part)

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Animal Respiration

Breathe?

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Respiratory Surfaces

• Gas exchange

– For all cells in the body.

• Skin

• Gills

• Tracheae (insects)

• Lungs

Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.15a

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.15b

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.15c

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.15d

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Human Respiratory System

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Respiratory System

• Air: mouth and nose -> pharynx -> larynx -> trachea -> bronchus -> bronchioles

• Bronchioles dead-end:

– air sacs: alveoli

• Site of gas exchange

Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.17

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.18

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.21

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Take a Breath

• inhalation (inspiration)

• Exhalation (expiration)

• Automatic

– Control centers in brain

– Respond to CO2 levels in the blood

• Conscious control?

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.19

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.20

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Hemoglobin?

• Oxygen does mix easily with blood.

• Carried in hemoglobin molecules within red blood cells

• Anemia?

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin CummingsFigure 23.23

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings

Question of the Day

Stem cells have been a controversial area of biomedical research. What are they? What diseases and conditions do scientists hope to cure stem cells? Why the controversy?