Download Chapter 42

Chapter 42
Circulation and Gas
Exchange
PowerPoint TextEdit Art Slides for
Biology, Seventh Edition
Neil Campbell and Jane Reece
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Objective:
You will be able to explain how various organisms
use circulatory systems to exchange materials.
Do Now:
• Read p. 872 – 873 “Open and closed
circulatory…”
• Differentiate between closed and open
circulatory systems
Blood
• Connects the intercellular fluid to the organs
that exchange nutrients, gasses and wastes
Figure 42.3 Open and closed circulatory systems
Heart
Hemolymph in sinuses
surrounding ograns
Anterior Lateral
vessel vessels
Heart
Interstitial
fluid
Small branch vessels
in each organ
Ostia
Dorsal vessel
(main heart)
Tubular heart
(a) An open circulatory system
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Auxiliary
hearts
Ventral
vessels
(b) A closed circulatory system
Figure 42.4 Vertebrate Circulatory Systems
AMPHIBIANS
REPTILES (EXCEPT BIRDS)
MAMMALS AND BIRDS
Lung and skin capillaries
Lung capillaries
Lung capillaries
FISHES
Gill capillaries
Artery
Pulmocutaneous
circuit
Gill
circulation
Heart:
ventricle (V)
A
Atrium (A)
Systemic
circulation
Vein
Systemic capillaries
Right
systemic
aorta
A
V
Left
Right
Systemic
circuit
Systemic capillaries
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Pulmonary
circuit
A
V
Right
Pulmonary
circuit
Left
Systemic
V aorta
Left
A
Systemic capillaries
A
V
Right
A
V
Left
Systemic
circuit
Systemic capillaries
Figure 42.5 The mammalian cardiovascular
system: an overview
7
Capillaries of
head and
forelimbs
Anterior
vena cava
Pulmonary
artery
Pulmonary
artery
Aorta
9
6
Capillaries
of right lung
Capillaries
of left lung
2
4
3
Pulmonary
vein
Right atrium
3
11
5
1
Left atrium
Pulmonary
vein
10
Left ventricle
Right ventricle
Aorta
Posterior
vena cava
8
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Capillaries of
abdominal organs
and hind limbs
Figure 42.12 Measurement of blood pressure (layer 1)
Artery
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Figure 42.12 Measurement of blood pressure (layer 2)
Pressure
in cuff
above120
Rubber cuff
inflated
with air
Artery
120
Artery
closed
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 42.12 Measurement of blood pressure (layer 3)
Pressure
in cuff
above120
Rubber cuff
inflated
with air
Artery
120
Pressure
in cuff
below 120
120
Sounds
audible in
stethoscope
Artery
closed
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 42.12 Measurement of blood pressure (layer 4)
Blood pressure
Reading: 120/170
Pressure
in cuff
above120
Rubber cuff
inflated
with air
Artery
120
Pressure
in cuff
below 120
Pressure
in cuff
below 70
120
70
Sounds
audible in
stethoscope
Artery
closed
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Sounds
stop
Objective: You will be able to explain how capillaries
exchange materials with the intercellular fluid.
Do Now:
•
Read p. 877 – 888 “Structural differences…”
•
Explain the structural differences between the
three transport vessels
Figure 42.6 The mammalian heart: a closer look
Aorta
Pulmonary artery
Pulmonary
artery
Anterior vena cava
Right atrium
Left
atrium
Pulmonary
veins
Pulmonary
veins
Semilunar
valve
Semilunar
valve
Atrioventricular
valve
Atrioventricular
valve
Posterior
vena cava
Right ventricle
Left ventricle
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 42.7 The cardiac cycle
2 Atrial systole;
ventricular
diastole
Semilunar
valves
closed
0.1 sec
Semilunar
valves
open
0.3 sec
0.4 sec
AV valve
open
1 Atrial and
ventricular
diastole
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
AV valve
closed
3 Ventricular systole;
atrial diastole
Figure 42.8 The control of heart rhythm
1 Pacemaker generates
wave of signals
to contract.
SA node
(pacemaker)
2 Signals are delayed
3 Signals pass
to heart apex.
at AV node.
AV node
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throughout
ventricles.
Bundle
branches
Heart
apex
ECG
4 Signals spread
Purkinje
fibers
Figure 42.9 The structure of blood vessels
Artery
Vein
Basement
membrane
Endothelium
100 µm
Valve
Endothelium
Smooth
muscle
Endothelium
Capillary
Connective
tissue
Smooth
muscle
Connective
tissue
Artery
Vein
Venule
Arteriole
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Figure 42.13 Blood flow in capillary beds
Precapillary sphincters
Arteriole
(a) Sphincters relaxed
Arteriole
Thoroughfare
channel
Capillaries
Venule
Venule
(b) Sphincters contracted
(c) Capillaries and larger vessels (SEM) 20 m
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Figure 42.14 Fluid exchange between capillaries
and the interstitial fluid
Tissue cell
INTERSTITIAL FLUID
Net fluid
movement out
Capillary
Capillary
Red
blood
cell
Net fluid
movement in
15 m
Direction of
blood flow
Blood pressure
Osmotic pressure
Inward flow
Pressure
At the arterial end of a
capillary, blood pressure is
greater than osmotic pressure,
and fluid flows out of the
capillary into the interstitial fluid.
Outward flow
Arterial end of capillary
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Venule end
At the venule end
of a capillary, blood
pressure is less than
osmotic pressure, and
fluid flows from the
interstitial fluid into
the capillary.
Figure 42.10 Blood flow in veins
Direction of blood flow
in vein (toward heart)
Valve (open)
Skeletal muscle
Valve (closed)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Activity
Many physiological changes occur during exercise.
•
Design a controlled experiment to test the
hypothesis that an exercise session causes
short-term increases in heart rate and
breathing rate in humans.
•
Explain how at least three organ systems are
affected by this increased physical activity and
discuss interactions among these systems.
Objective:You will be able to discuss the structure and
function of blood.
Do Now:
• Read “Plasma” on p. 882 – 883
• Give the functions of plasma
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Objective: You will be able to discuss the structure
and function of blood.
Do Now:
• Read “Plasma” on p. 882 – 883
• Give the functions of plasma
Figure 42.15 The composition of mammalian blood
Plasma 55%
Constituent
Major functions
Water
Solvent for
carrying other
substances
Icons (blood electrolytes
Sodium
Potassium
Calcium
Magnesium
Chloride
Bicarbonate
Plasma proteins
Albumin
Fibringen
Osmotic balance
pH buffering, and
regulation of
membrane
permeability
Cellular elements 45%
Cell type
Erythrocytes
(red blood cells)
Separated
blood
elements
Functions
Number
per L (mm3) of blood
Leukocytes
(white blood cells)
5–6 million
Transport oxygen
and help transport
carbon dioxide
5,000–10,000
Defense and
immunity
Osmotic balance,
pH buffering
Clotting
Immunoglobulins
Defense
(antibodies)
Substances transported by blood
Nutrients (such as glucose, fatty acids, vitamins)
Waste products of metabolism
Respiratory gases (O2 and CO2)
Hormones
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Lymphocyte
Basophil
Eosinophil
Neutrophil
Platelets
Monocyte
250,000
400,000
Blood clotting
Figure 42.16 Differentiation of blood cells
Pluripotent stem cells
(in bone marrow)
Lymphoid
stem cells
Myeloid
stem cells
Basophils
B cells
T cells
Lymphocytes
Eosinophils
Neutrophils
Erythrocytes
Platelets
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Monocytes
Figure 42.17 Blood clotting
2 The platelets form a
1 The clotting process begins
plug that provides
emergency protection
against blood loss.
when the endothelium of a
vessel is damaged, exposing
connective tissue in the
vessel wall to blood. Platelets
adhere to collagen fibers in
the connective tissue and
release a substance that
makes nearby platelets sticky.
3 This seal is reinforced by a clot of fibrin when
vessel damage is severe. Fibrin is formed via a
multistep process: Clotting factors released from
the clumped platelets or damaged cells mix with
clotting factors in the plasma, forming an
activation cascade that converts a plasma protein
called prothrombin to its active form, thrombin.
Thrombin itself is an enzyme that catalyzes the
final step of the clotting process, the conversion of
fibrinogen to fibrin. The threads of fibrin become
interwoven into a patch (see colorized SEM).
Collagen fibers
Platelet releases chemicals
that make nearby platelets sticky
Platelet
plug
Fibrin clot
Clotting factors from:
Platelets
Damaged cells
Plasma (factors include calcium, vitamin K)
Prothrombin
Thrombin
Fibrinogen
Fibrin
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5 µm
Red blood cell
Figure 42.18 Atherosclerosis
Connective
tissue
Smooth muscle
Endothelium
(a) Normal artery
50 µm
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Plaque
(b) Partly clogged artery
250 µm
Figure 42.21 The structure and function of fish gills
Gill arch
Gill
arch
Water
flow
Blood
vessel
Oxygen-poor
blood
Oxygen-rich
blood
Lamella
Operculum
Gill
filaments
Water flow
over lamellae
showing % O2
Blood flow
through capillaries
in lamellae
showing % O2
Countercurrent exchange
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Figure 42.22 Tracheal systems
Body
cell
Air sacs
Tracheae
Air
sac
Tracheole
Trachea
Spiracle
(a) The respiratory system of an insect consists of branched internal
tubes that deliver air directly to body cells. Rings of chitin reinforce
the largest tubes, called tracheae, keeping them from collapsing.
Enlarged portions of tracheae form air sacs near organs that require
a large supply of oxygen. Air enters the tracheae through openings
called spiracles on the insect’s body surface and passes into smaller
tubes called tracheoles. The tracheoles are closed and contain fluid
(blue-gray). When the animal is active and is using more O2, most of
the fluid is withdrawn into the body. This increases the surface area
of air in contact with cells.
(b) This micrograph shows cross
sections of tracheoles in a tiny
piece of insect flight muscle (TEM).
Each of the numerous mitochondria
in the muscle cells lies within about
5 µm of a tracheole.
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Air
Tracheoles
Body wall
Myofibrils
Mitochondria
2.5 µm
Figure 42.23 The mammalian respiratory system
Branch
from the
pulmonary
vein
(oxygen-rich
blood)
Branch
from the
pulmonary
artery
(oxygen-poor
blood)
Terminal
bronchiole
Nasal
cavity
Pharynx
Left
lung
Alveoli
50 µm
Larynx
Esophagus
Trachea
50 µm
Right lung
Bronchus
Bronchiole
Diaphragm
Heart
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SEM
Colorized SEM
Figure 42.24 Negative pressure breathing
Rib cage
expands as
rib muscles
contract
Air inhaled
Rib cage gets
smaller as
rib muscles
relax
Air exhaled
Lung
Diaphragm
INHALATION
Diaphragm contracts
(moves down)
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EXHALATION
Diaphragm relaxes
(moves up)
Figure 42.26 Automatic control of breathing
Cerebrospinal
fluid
4 The medulla’s control center also
helps regulate blood CO2 level. Sensors
in the medulla detect changes in
the pH (reflecting CO2 concentration)
of the blood and cerebrospinal fluid
bathing the surface of the brain.
The control center in the
medulla sets the basic
rhythm, and a control center
in the pons moderates it,
smoothing out the
transitions between
inhalations and exhalations.
1
Pons
Nerve impulses trigger
muscle contraction. Nerves
from a breathing control center
in the medulla oblongata of the
brain send impulses to the
diaphragm and rib muscles,
stimulating them to contract
and causing inhalation.
2
Nerve impulses relay changes in
CO2 and O2 concentrations. Other
sensors in the walls of the aorta
and carotid arteries in the neck
detect changes in blood pH and
send nerve impulses to the medulla.
In response, the medulla’s breathing
control center alters the rate and
depth of breathing, increasing both
to dispose of excess CO2 or decreasing
both if CO2 levels are depressed.
5
Breathing
control
centers
Medulla
oblongata
Carotid
arteries
In a person at rest, these
nerve impulses result in
about 10 to 14 inhalations
per minute. Between
inhalations, the muscles
relax and the person exhales.
Aorta
3
The sensors in the aorta and
carotid arteries also detect changes
in O2 levels in the blood and signal
the medulla to increase the breathing
rate when levels become very low.
6
Diaphragm
Rib muscles
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Figure 42.27 Loading and unloading of respiratory gases
Inhaled air
Exhaled air
160 0.2
O2 CO2
120 27
Alveolar spaces
O2 CO2
104
Alveolar
epithelial
cells
40
O2 CO2
Blood
entering
alveolar
capillaries
40
O2
CO2
2
1
O2
Alveolar
capillaries
of lung
45
O2 CO2
104
Pulmonary
veins
Systemic
arteries
Systemic
veins
CO2
40
45
40
O2 CO2
Pulmonary
arteries
Blood
leaving
tissue
capillaries
Blood
leaving
alveolar
capillaries
Heart
Tissue
capillaries
O2
3
4
O2
CO2
Blood
entering
tissue
capillaries
100
40
O2 CO2
O2 CO2
Tissue
cells
<40 >45
O2 CO2
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Figure 42.28 Hemoglobin loading and unloading O2
Heme group
Iron atom
O2 loaded
in lungs
O2 unloaded
In tissues
Polypeptide chain
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O2
O2
Unnumbered figure page 897
100
Fetus
O2 saturation of
hemoglobin (%)
80
Mother
60
40
20
0
0
20
40
60
PO2 (mm Hg)
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80
100