Transcript Circulation and Respiration

Animal Circulation and
Gas Exchange
Cardiovascular
System
• Heart
– atria &
ventricles
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Arteries
Arterioles
Capillaries
Venules
Veins
Evolution of the Vertebrate Heart
• Two chambers (one atria and one ventricle)
– along with a sinus venosus and a conus
venosus)
• Two chambers plus septa
– lungfish
Evolution of the Vertebrate Heart
• Three chambers (two atria and one ventricle)
– amphibians, reptiles
Evolution of the Vertebrate
Heart
• Four chambers (two
atria and two
ventricles)
– Crocodilians,
mammals, birds
Path of Blood Through
The Heart
• Anterior and Posterior
Vena Cava
• Right Atria
• Atrioventricular (AV)
Valve (tricuspid)
• Right Ventricle
• Semilunar Valve
• Pulmonary Arteries
• Lungs
• Pulmonary Veins
• Left Atria
• Atrioventricular (AV)
Valve (bicuspid)
• Left Ventricle
• Semilunar Valve
• Aorta
• Body
Cardiac Cycle
Diastole
Contract
Neither
Atrial
Systole
Atria
Valves
AV open
Semilunar
closed
0.4 sec
AV open
Semilunar
closed
0.1 sec
Time
Function Fill Heart Overfill
Ventricle
Ventricular
r Systole
Ventricle
AV closed
Semilunar
open
0.3 sec
Pump
Blood
Cardiac Output
• Volume of blood per minute from the left
ventricle
• Depends on two factors
– Heart rate (pulse)
– Stroke volume
• Average Human
– 75 ml/beat
– 70 beats/min
– 5.25 L/min (your blood volume)
Control of Heart Rhythm
• Sinoatrial node (pacemaker)
• Atrioventricular node
Mammalian Blood Composition
• Plasma (55%)
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Water
Ions
Plasma Proteins
Nutrients
Wastes
Gases
Hormones
• Cellular Elements
(45%)
– Erythrocytes
– Leukocytes
– Platelets
Blood Clotting
• Injury triggers platelets to area
• Changes prothrombin to thrombin which than
converts fibrinogen to fibrin
Blood Pressure
• Systolic Pressure
• Diastolic Pressure
Cardiovascular Disease
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Hypertension
Heart Attack
Stroke
Atherosclerosis
Arteriosclerosis
LDL’s
HDL’s
Cardiovascular “Surgeries”
• Angiogram
• Angioplasty
• Stents
Cardiovascular “Surgeries”
• Bypass Surgery
Cardiovascular Disease
Cardiovascular Disease
Cardiovascular Disease
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Hypertension
Heart Attack
Stroke
Atherosclerosis
Arteriosclerosis
LDL’s
HDL’s
Gas
Exchange
Conditions for Respiratory
Surfaces
• Large surface area
• Thin
• Moist
Aquatic vs. Terrestrial
• Less than 1% oxygen
• Oxygen amounts
decrease as the
temperature
increases
• Aquatic animals use
large amounts of
energy to obtain
oxygen (20%)
• About 21% oxygen
• Developed
invaginations to
increase surface area
and decrease
evaporation
• Terrestrial animals
may use only 1% 2% of its energy to
obtain oxygen
Respiratory Surfaces
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Cutaneous Respiration
Gills
Tracheal Systems
Lungs
Cutaneous Respiration
• Direct diffusion of gases between the
organism and the environment
• Found in Porifera, Cnidarians,
Platyhelminthes, nematodes, and some
annelids
• Supplements other organisms
Gills
• Found in echinoderms, mollusks,
annelids,
arthropods, some
vertebrates
• Countercurrent
Gas Exchange
Countercurrent Gas Exchange
• Maintains gradient over the whole length of
the capillaries
• Extracts 80% of the oxygen from the water
Tracheal Systems
• Found in arthropods
• Tracheae
– open tubes
• Spiracles
– openings
• Tracheoles
– contact with cells
• Muscle
– increase amount of
Carbon Dioxide removed
Tracheal Systems
Diffusion Lungs
• Found in invertebrates
• Gas moved primarily by diffusion
– may be increased by body movement
• Modifications
– snails - cavity with gill modified into lung
– scorpions and spiders - invaginations of the
abdomen
Ventilation
Lungs
• Found in
amphibians,
reptiles,
mammals and
birds
• Pharynx
• Larynx
• Trachea
• Bronchi
• Bronchioles
• Alveoli
Alveoli
Ventilating The Lungs
• Positive Pressure
Breathing
• Negative Pressure
Breathing
– pushes air down
trachea
– seen in frogs and
other amphibians
– suction created by
diaphragm
– seen in mammals
Negative Pressure Breathing
Avian Respiration
• Airs sacs allow for one-way ventilation
• Parabronchi rather than alveoli
Breathing
Control
• Occurs in
Medulla
oblongota and
Pons
• Monitors Carbon
Dioxide (converts
to carbonic acid)
– lowers pH and
causes increase
in depth and rate
of breathing
Carbon Dioxide Transport
• Carbon dioxide transported from tissue by
erythrocyte
– 7% transported as Carbon Dioxide in blood
– 23% of Carbon Dioxide and most of the
Hydrogen ions are attached to hemoglobin
– 70% transported as Bicarbonate in plasma
Deep-diving Mammals
• Stores large amounts of
oxygen in blood and muscles
(twice as much as us)
– twice the volume of blood
– huge spleen
– myoglobin
Deep-diving Mammals
• Conservation techniques
– exhale before diving (prevent
bends / pressure)
– decrease heartrate and oxygen
consumption
– reduce blood supply to muscles
(anaerobic)
Smoking
• In the United States, an estimated 26.2
million men (23.5 percent) and 20.9 million
women (18.1 percent) are smokers. These
people are at higher risk of heart attack
and stroke.
• Every eight seconds, someone dies from
tobacco use.
• Cigarettes cause more than one in five
American deaths.