Transcript Chapter 50 - Cloudfront.net

Respiratory System
Composition of Air
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All Oxygen comes from PHOTOSYNTHESIS
78% N2, 21% O2, .93% Noble gases, .03% CO2
Less Oxygen at Higher Altitudes
Air Pressure measures 760 mm of Hg at Sea Level
Structure of Respiratory System
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Pair of lungs in Thoracic cavity
Both Bronchi connected to a single Trachea
Trachea passes upward
Pass Larynx to rear of mouth
Air enters nostrils, Hair filters out particles
Each Bronchus divides into many Bronchioles
Which leads to Alveoli
Mechanics of Breathing
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Intrapleural fluid supports & applies even
pressure to all lungs
System analogous to 1 balloon inside another
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Space between balloons filled with fluid
Inner balloon(lung) opens to atmosphere
Pressure on inner balloon= air pushing out +
H2O pushing in
Mechanics of Breathing (Continued)
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Walls of chest cavity expand with Inhalation
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Chest cavity (outer Balloon) is enlarged
Expansion of the fluid space Decreases fluid
pressure
Pressure Less than the internal pressure in the
Lungs
Air moves in from atmosphere to Equalize
pressure
The Structure of Lungs
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Alveoli
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Exchange zones in the Lungs
Increases the surface area
Short path length increases diffusion
How The Lungs Work
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Function as one-cycle pump
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Chest walls expand during Inspiration
Enlarges the chest
Rib cage moves upward & outward
Diaphragm moves downward
See Figure 50-15
Gas Transport & Exchange
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Association of Respiratory & Circulatory Systems
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HEMOGLOBIN: O2 carrier protein in Blood
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Transport of O2 very slow if by Diffusion
Transported by CIRCULATORY SYSTEM via
CARRIER PROTEINS
Bright RED when bound with O2,
O2 bounded to IRON portion of Protein
HEMOCYANIN: O2 carrier protein in invertebrates
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Bright BLUE when bound with O2
O2 bounded to COPPER portion of Protein
OXYGEN Transport
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Only 5% transported in blood plasma
95% bound to HEMOGLOBIN in RBCs
Partial Pressure of OXYGEN= PO2
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If higher in lungs MORE O2 will dissolve in blood
and combine with Hemoglobin
Lower at tissues so Hemoglobin gives up O2 to
tissues
Presence of CO2 at tissues
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Causes Hemoglobin to change its shape thus
UNLOADING O2
The Exchange Process
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Oxygen-rich air interfaces with Oxygen-poor blood
at Alveoli
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Oxygen in plasma diffuses into red blood cells
CO2 Transport
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As RBCs Unload O2, Blood absorbs CO2 from
tissues
RBCs carry CO2 back to Lungs as Bicarbonate ions
Looking Ahead to CIRCULATION
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At Lungs RBCs Acquire O2 & Release CO2
At Tissues RBCs Acquire CO2 & Release O2
Circulatory System
Function Of Circulatory System
1.
Nutrient & Waste Transport
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Nutrients enter blood through small intestines
Carried to Liver for storage or Metabolism
Dissolved Glucose & Metabolites carried to
ALL body cells
Waste carried to Kidney for removal
Function Of Circulatory System
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Oxygen & Carbon Dioxide Transport
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3.
Temperature Maintenance
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O2 diffuses into blood through the lungs
O2 accumulates in Hemoglobin of erythrocytes
O2 released at metabolizing cells
CO2 is released by cells in blood
Waste CO2 carried back to Lungs & released
Heat distributed by circulating blood
Hormone Circulation
Pathway of Blood
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Superior & Inferior Vena 
Cava
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Right Atrium
Tricuspid Valve
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Right Ventricle
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Right Semi lunar valve
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Rt & Lt Pulmonary
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Arteries
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Lungs
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Rt. & Lt. Pulmonary veins
Left Atrium
Bicuspid valve (Mitral
Valve)
Left Ventricle
Left semi lunar valve
Aorta
Arteries
Arterioles
Capillaries, Venules, Veins
The Cardiovascular System
1.
3 Elements of Closed Circulatory System
1. Heart: muscular pump
2. Blood Vessels
Arteries: direct flow AWAY from the heart
2. Arterioles: Smaller vessels leading AWAY
3. Capillaries: Exchange of gases in tissues
4. Venules: small vessels that collect blood from
capillaries
5. Veins: Large vessels that carry blood to heart
3. Blood: circulating fluid
1.
Arteries: Highways from the heart
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Walls are composed of 4 layers
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Innermost endothelial cells
Thick layer of elastic fibers
Layer of smooth muscle
Encased in connective tissue
Elastic sheath allows artery to expand &
increase its volume
Muscle layer prevents over expansion
Connective tissue protects vessels
Arterioles: Little arteries
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Hormones, Metabolites can relax muscle layer
thus increases the blood flow
Nerve stimulation contracts muscle, decreases
blood flow
Capillaries: where exchange takes place
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Single cell layer thick
They directly connect arterioles with venules
Found in the tissues
Veins & Venules
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Returns blood to the Heart
One-way valves direct flow toward the heart
Blood flow assisted by movement of muscles
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Lymphatic System: recovers lost fluid
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Collects fluid & returns it to the blood
Lymphatic vessels contain vein-like one-way valves
Fluid movement assisted by muscle
Blood
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Blood plasma: the Blood’s fluid
Water
Metabolites & wastes
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Salts & Ions
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Metabolites, vitamins, hormones, & wastes
Primary Na, Cl, & Bicarbonates
Proteins
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Antibodies & Globulin proteins of immune system
Fibrinogen…Blood clotting
Serum Albumin…maintains osmotic counterforce
Blood Cells
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Erythrocytes: Red Blood Cells
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Leukocytes: White Blood Cells
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45% of Blood Volume
Cells produced in Bone Marrow
120 days
Less than 1% of total Blood cells
Function to defend body against pathogens
2 years life span
Platelets: Thrombocytes… Helps blood to Clot
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(10 days)
Blood Groups
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O= 45% US Caucasians
A= 40% US Caucasians
B= 11% US Caucasians
AB= 4% US Caucasians
O
A
B
AB
Rh System
1. Rh+= 87%
Rh-= 13%
2.
During Pregnancy
Mother: Rh- Baby: Rh+
1st Pregnancy: Rh+ may leak into mother’s
circulation system, causing mother to produce
anti-Rh antibodies.
2nd Pregnancy: Mother’s anti-Rh antibodies may
cross placenta & destroy Fetus’s RBC’s