Transcript Respiratory and Circulatory Systems

Respiratory and Circulatory
Systems
O2
1 Breathing
CO2
Lung
Breathing,
Transport of
gases by
circulatory
system, Capillary
Exchange of
gases with
body cells
Heart
Circulatory
system
Blood
vessels
2 Transport of gases
by the circulatory
system
3 Exchange of
gases with
body cells
Capillary
O2
CO2
Mitochondria
Cell
Animals exchange O2 and CO2
across moist body surfaces
Cross section of the
respiratory surface
(the outer skin)
CO2
O2
Capillaries
Animals exchange O2 and CO2 across
moist body surfaces
• Most animals have specialized body parts that
promote gas exchange:
– gills in most aquatic animals,
– tracheal systems in insects, and
– lungs in terrestrial vertebrates.
• Many animals have adaptations to improve
ventilation, the flow of water or air over the
respiratory surface.
Gills
Body surface
Respiratory
surface
(gills)
CO2
O2
Capillary
GILL STRUCTURE
Water
flow
Blood
vessels
Gill arch
Operculum
(gill cover)
Water flow
Gill filaments
bearing many
platelike lamellae
COUNTERCURRENT EXCHANGE
Direction of blood flow
through capillaries in lamellae
Oxygen-rich
blood going to
body tissues
Diffusion of O2
from water to
Oxygen-rich water
blood
Water flow,
showing
% O2
100
70
40
15
80
60
30
5
Blood flow in capillary,
showing % O2
Oxygen-poor
blood coming from
the heart
Lamella
Oxygen-poor water
Tracheal Systems
Body surface
O2
CO2
Respiratory
surface
(tips of tracheae)
Body cells
(no capillaries)
NOTE: the circulatory system of insects is not involved in
transporting gases
Lungs
Body surface
CO2
CO2
Respiratory
surface
(within lung)
O2
O2
Capillary
EVOLUTION CONNECTION: The evolution
of lungs facilitated the movement of
tetrapods onto land
• Tetrapods seem to have evolved in shallow
water.
– Fossil fish with legs had lungs and gills.
– Legs may have helped them lift up to gulp air.
– The fossil fish Tiktaalik
• lived about 375 million years ago and
• illustrates these air-breathing adaptations.
Eyes on top
of a flat skull
Neck
Shoulder
bones
Fin
Human Respiratory System
Nasal cavity
Left lung
Pharynx
(Esophagus)
Larynx
Trachea
Right lung
Bronchus
Bronchiole
Diaphragm
(Heart)
To the From the
heart
heart
Oxygenrich
blood
Oxygen-poor
blood
Bronchiole
CO
O2 2
Alveoli
Blood capillaries
Breathing is automatically controlled
Brain
1
Nerve signals
trigger contraction
of the rib muscles
and diaphragm.
Cerebrospinal
fluid
2
Medulla
Breathing control
center responds
to the pH of blood
and cerebrospinal fluid.
3
Nerve signals
indicate CO2
and O2 levels.
CO2 and O2
sensors in the aorta
Heart
Diaphragm
Rib muscles
Circulatory systems facilitate exchange
with all body tissues
• Open circulatory systems are found in all
arthropods and most molluscs and consist of
– a tubular heart,
– open-ended vessels, and
– blood that directly bathes the cells and functions
as the interstitial fluid.
© 2015 Pearson Education, Inc.
Circulatory systems facilitate exchange
with all body tissues
• Closed circulatory systems are found in
vertebrates, earthworms, squids, and
octopuses and consist of a circulatory fluid,
blood, that is confined to vessels, keeping
blood distinct from the interstitial fluid.
© 2015 Pearson Education, Inc.
EVOLUTION CONNECTION: Vertebrate
cardiovascular systems reflect
evolution
• Blood passes through the heart of a fish once
in each circuit through the body, an
arrangement called single circulation.
• A single circuit would not supply enough
pressure to move blood through the
capillaries of the lungs and then to the body
capillaries of a terrestrial vertebrate.
© 2015 Pearson Education, Inc.
Fish have 2 chambered hearts
Gill
capillaries
Heart:
Ventricle
Atrium
Body
capillaries
© 2015 Pearson Education, Inc.
EVOLUTION CONNECTION: Vertebrate
cardiovascular systems reflect
evolution
• Land vertebrates have a double circulation in
which blood is pumped a second time after it
loses pressure in the lungs.
– The pulmonary circuit carries blood between the
heart and gas exchange tissues in the lungs.
– The systemic circuit carries blood between the
heart and the rest of the body.
© 2015 Pearson Education, Inc.
Amphibians and Reptiles have 3 chambered hearts
Lung and
skin capillaries
Pulmocutaneous
circuit
Atrium
Atrium
Ventricle
Right
Left
Systemic
circuit
Systemic
capillaries
© 2015 Pearson Education, Inc.
In the threechambered heart of
turtles, snakes, and
lizards,
the ventricle is
partially divided,
and
less mixing of blood
occurs.
Birds and Mammals have 4 chambered hearts
Lung
capillaries
Pulmonary
circuit
Atrium
Atrium
Ventricle
Ventricle
Right
Left
Systemic
circuit
Systemic
capillaries
© 2015 Pearson Education, Inc.
Capillaries of head,
chest, and arms
Superior vena cava
Pulmonary artery
Pulmonary artery
Aorta
Pulmonary circuit
Systemic circuit
Lung
capillaries
Pulmonary
vein
Right
atrium
Inferior
vena cava
Right
ventricle
Left
ventricle
Left
atrium
Pulmonary
vein
Aorta
Capillaries of abdominal
region and legs
© 2015 Pearson Education, Inc.
Blood flow through the heart- animation
Beating Human Heart Video
Capillary
Epithelium
Smooth
muscle
Connective
tissue
Epithelium
Basal lamina
Epithelium
Smooth
muscle
Connective
tissue
Artery
Vein
Arteriole
© 2015 Pearson Education, Inc.
Valve
Venule
Capillary
Interstitial
fluid
Tissue
cell
© 2015 Pearson Education, Inc.
Diffusion of
molecules
Plasma (55%)
Constituent
Major functions
Water
Solvent for
carrying other
substances
Ions (blood electrolytes)
Sodium
Potassium
Calcium
Magnesium
Chloride
Bicarbonate
Plasma proteins
Osmotic balance,
pH buffering, and
maintaining ion
concentration of
interstitial fluid
Cell type
Centrifuged
blood
sample
Clotting
Immunoglobulins
(antibodies)
Defense
Substances transported by blood
Nutrients (e.g., glucose, fatty acids, vitamins)
Waste products of metabolism
Respiratory gases (O2 and CO2)
Hormones
Number
per μL (mm3) of blood
Red blood cells
(erythrocytes)
White blood cells
(leukocytes)
Osmotic balance
and pH buffering
Fibrinogen
© 2015 Pearson Education, Inc.
Cellular elements (45%)
Basophils
Functions
5–6 million
Transport of
O2 and
some CO2
5,000–10,000
Defense
and immunity
Eosinophils
Lymphocytes
Monocytes
Neutrophils
Platelets
250,000–
400,000
Blood clotting
p.
a.
b.
o.
c.
n.
d.
m.
e.
l.
f.
k.
g.
j.
h.
i.
© 2015 Pearson Education, Inc.