Transcript Ch 42 Respiration Circulation

BIOLOGY
CONCEPTS & CONNECTIONS
Fourth Edition
Neil A. Campbell • Jane B. Reece • Lawrence G. Mitchell • Martha R. Taylor
Chapter 42
Circulation and Gas Exchange
Modules 22.1 – 22.4
From PowerPoint® Lectures for Biology: Concepts & Connections
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Respiration
• Respiration controls the inhalation of oxygen
and the exhalation of carbon dioxide
• There are 3 phases of gas exchange:
– 1. Breathing: oxygen enters the lungs and carbon
dioxide is breathed out
– 2. Oxygen is transported throughout the body by
the heart and the blood (and CO2 is removed)
– 3. Cells take up oxygen from the blood and send
back CO2
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Gills
• Gills are out-foldings of the
body surface that are
suspended in the water.
• They are easy to keep moist,
but the warmer the water the
less oxygen is dissolved in it.
• Blood flows in the opposite
direction of water over the
gills, this is called
countercurrent exchange,
and increases diffusion of
oxygen.
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Tracheal Systems
• In insects, there are tiny air tubes that branch
throughout the body.
• This increases surface area for gas exchange.
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Lungs
• In humans and other mammals, air enters
through the nose
– It passes through the pharynx and larynx (voice
box) into the trachea (windpipe)
– The trachea forks to form two bronchi, one goes
to each lung
– Each bronchus branches into numerous
bronchioles (smaller tubes) inside the lungs
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• The human respiratory system
Nasal
cavity
Pharynx
(Esophagus)
Left lung
Larynx
Trachea
Right
lung
Bronchus
Bronchiole
Diaphragm
(Heart)
Figure 22.6A
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• The bronchioles end in clusters
of tiny sacs called alveoli
– Alveoli form the respiratory
surface of the lungs
– Oxygen diffuses
through the thin
walls of the
alveoli into
the blood
Figure 22.6C
Oxygen-rich
blood
Oxygen-poor
blood
Bronchiole
Alveoli
Blood capillaries
Figure 22.6B
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The diaphragm
• The diaphragm, a sheet of skeletal muscle that
forms the bottom of the rib cage, controls the
volume of our lungs
• We ventilate our lungs through negative
pressure breathing, we suck air into our lungs
(it’s pulled not pushed)
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Chapter 23: Circulation
• The function of the circulatory system is to
transport oxygen throughout our body
– It transports O2 and nutrients to cells
– It takes away CO2 and other wastes
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Open vs. Closed
• Humans have a closed circulatory system, all of
our blood is in vessels
• Insects have an open circulatory system, blood
bathes all organs directly
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Heart Evolution
• Fish have 2 chambered hearts
• Amphibians and reptiles have 3 chambered
hearts
• Birds and mammals have 4 chambered hearts
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The Heart
• The mammalian heart has two thin-walled
atria that take in blood from the body
• It also has thick-walled ventricles that pump
blood to the body and lungs
• In pictures, blue blood has NO oxygen, red
blood has oxygen
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Pulmonary
artery
Aorta
Superior
vena cava
Pulmonary
artery
LEFT
ATRIUM
RIGHT
ATRIUM
Pulmonary
veins
Pulmonary
veins
Semilunar
valve
Semilunar
valve
Atrioventricular
valve
Atrioventricular
valve
Inferior
vena cava
RIGHT
VENTRICLE
LEFT
VENTRICLE
Figure 23.4A
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Arteries, Veins, Capillaries
• Arteries carry oxygenated
blood away from the heart
and to the body
• Veins carry deoxygenated
blood from the body back
to the heart and lungs to
get oxygen
• Capillaries are 1 cell thick
to make diffusion easier
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Blood
• Blood is made of:
– Plasma
– Red Blood Cells (Erythrocytes)
– Platelets
– White Blood Cells (Leukocytes)
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Plasma
• Plasma is
mostly water
and contains
nutrients and
minerals
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Red Blood Cells
• Red blood cells contain
hemoglobin
– Hemoglobin enables the
transport of O2
– They are produced in the
bone marrow
Figure 23.14
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White Blood Cells
• White blood cells (leukocytes) fight infections
and cancer
Basophil
Eosinophil
Monocyte
Neutrophil
Lymphocyte
Figure 23.15
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Platelets
• When a blood vessel
is damaged or cut,
platelets respond
– They help trigger the
formation of a clot
that plugs the leak
Figure 23.16B
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