Transcript Circulation Respiration

Circulation and Respiration
Gastrovascular Systems
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Body plan is only two or a few cell layers
thick.
Food enters the same opening as waste
exits.
The fluid in the cavity of cnidarians is
continuous with that around them and
Planarians have a branching cavity that is
adequate for their small thin (flat) bodies.
Larger animals
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Need to have a Circulatory system because diffusion
takes too long.
A system has blood, a heart/pump that generates
blood pressure.
Circulatory systems are powered by cellular energy
Open systems – blood is not separated from body
fluid, it bathes the organs, this “blood” is called
hemolymph. Blood is pumped by the heart in to
spaces called sinuses. It flows back to the heart via
a pressure gradient
Closed systems
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Blood is confined to vessels and
maintained separate from the body fluid.
Cardiovascular systems consist of closed
system with a heart the has one or two
ventricle and one or two atria
Cardiovascular Systems
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Atria – heart chambers that receive blood
Ventricles – heart chambers that pump blood
Artery – vessel that carries blood away from
the heart.
Arterioles – small vessels that carry blood to
the capillaries
Capillaries(bed) thin walled vessel that infiltrate
the body, material exchange occurs here.
Venules – small vessels that carry blood to
veins
Pulmocutaneous circulation
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Amphibians have vessels leading from the
pulmonary arteries to the skin that receive
deoxygenated blood and allow the
capillaries in the skin to remove carbon
dioxide and even absorb some oxygen.
Systemic and Pulmonary Circulation
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Systemic - Supplies nourishment and
removes wastes from the tissue located
throughout the body
Pulmonary – blood vessels in the lungs
flow to and from capillaries where oxygen
is absorbed and carbon dioxide is
removed.
Double Circulation
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(not found in fish)
Blood flowing through the lungs is
pumped separately from the blood flowing
to the body.
Much stronger flow to the brain, muscles,
ect.
ECG or EKG
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Electrocardiogram measures the electrical
currents that are conducted in the body as
the heart goes through the cardiac cycle
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Movement of blood
Adam Movement of blood overview
Movement of oxygen and Carbon Dioxide
capillaries
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Capillary function
Pressure – fluid loss and regain
V. On outline - Blood
Blood cells and cell fragments occupy
about 45% of the blood volume.
 55% is plasma.
 Plasma is 90% water, it contains
electrolytes.
 Plasma proteins help to maintain pH,
osmotic balance, and blood viscosity.
 Some of these proteins are
immunoglobulins that function in defense.
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Cellular Elements
Blood plasma suspends 3 elements:
 1. RBC’s--oxygen transport, most
numerous.(eurythrocytes)
 2. WBC’s--defense of
body.(leukocytes)
 3. Platelets--fragments of cells which
help in the clotting process.
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Eurythrocytes
Shape is related to its function.
 Biconcave increases its surface area.
 Small size and number increases
surface area--related to function.
 Mammalian lack nuclei--allows for
more hemoglobin.
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Leukocytes
These are white blood cells and there
are 5 types:
 1. Monocytes, Neutrophils,
Basophils, Eosinophils, Lymphocytes
 Collectively, these fight infection.
 These spend most of their time in the
interstitial fluid where they fight
invaders.
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Platelets
These plug wounds and prevent
blood loss.
 Wounds release factors that make
platelets sticky and enable them to
adhere to collagen fibers in
connective tissue slowing blood loss.
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Stem cells
 In
the marrow of some bones,
particularly the ribs, vertebrae,
breastbone and pelvis the blood
cells are created from pluripotent
cells that can produce.
Blood clotting
 Platelets
plug wounds and prevent
blood loss.
 Wounds release factors that make
platelets sticky and enable them to
adhere to collagen fibers in
connective tissue slowing blood loss.
Respiratory Systems
Respiratory surfaces allow for the
exchange of gases.
 They are always thin and bathed in
water.
 In most animals, the respiratory
medium is a thin, moist epithelium.
 This separates the respiratory
medium from the blood.
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Gills
Are out-foldings of the body surface
suspended in water.
 They are loaded with capillaries.
 Animals with gills ventilate them
which moves water with a high
concentration of O2 over them.
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Tracheal System
Found in insects.
 It is made up of tubes that branch
through the body which is a variation
on a folded, internal respiratory
surface.
 The trachea branches smaller and
smaller and contacts nearly every
cell.
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Lungs
These are respiratory organs found in
one spot of the body.
 They have a dense net of capillaries
immediately below the epithelium on
the respiratory surface.
 They are connected to a closed
system that transports gases to and
from other regions of the body.
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Ventilating the lungs
Positive pressure breathing-amphibians
 Negative pressure breathing-humans
 Diaphragm – muscle below rib cage
 Tidal volume is the volume of air inhaled
with each breath.
 Max. during forced breathing is 3-4.8L
 Residual volume is the amount remaining
in the lungs after a forced exhale.
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Vital capacity
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maximum volume of air that a person can
exhale after maximum inhalation. It can
also be the maximum volume of air that a
person can inhale after maximum
exhalation.
Control centers in the brain
Human breathing is mostly under
autonomic control.
 2 regions of the brain control this:
 The pons and the medulla.
 The pons controls the medulla which
sets a basic breathing rhythm.
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Sensors in the aorta and carotid
arteries exert secondary control over
breathing.
 These sensors monitor O2, CO2 and
blood pH.
 The pH is largely controlled by CO2
levels.
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Gases
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CO2 levels increase, carbonic
acid levels increase lowering the
blood pH.
 When pH drops, the depth and rate of
breathing increases helping to remove
excess CO2.
 O2 levels only have an effect on
breathing rate at high altitudes.
More Carbon Dioxide
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In addition to transporting O2, hemoglobin
helps transport CO2 and assists in buffering.
Respiring cells produce CO2. Carbonic
anhydrase catalyzes the reaction of CO2 with
H2O to form H2CO3.
H2CO3 dissociates into H+ + HCO3Most of the H+ attaches to hemoglobin and
other proteins minimizing the change in blood
pH.
Diffusion in the Alveoli
Deoxygenated Blood
Air In
& Out
CO2
O2
Alveolus
Oxygenated
Blood
Blood
Capillary
Gas Exchange at the Cells
Body Cells
CO2
O2
Blood
Capillary
Tissue
Fluid