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Respiratory System. Respiratory System …What’s the point?. Cells need Oxygen in order to release energy from Nutrient molecules and produce ATP. Main functions…. 1. provides for Gas Exchange between what?. O 2 and CO 2. - PowerPoint PPT Presentation
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Respiratory System
•Cells need Oxygen in order to release energy from Nutrient molecules and produce ATP.
Respiratory System…What’s the point?
Main functions…1. provides for Gas Exchange between what? O2 and CO2
• Cardiovascular system is the taxi
3. Regulation• increase/decrease amount of warm, moist air leaving the body to…• inc/dec amount of CO2 leaving body to control pH of blood
2. Excretion – eliminate CO2 that was produced during cell respiration
4. Miscellaneous• receptors for sense of smell• filter & warm inspired air• produces sound
Respiratory System consists of…• NOSE• PHARYNX (throat)• LARYNX (voice box)• TRACHEA (windpipe)• BRONCHI• LUNGS
Organs of Respiratory System pgs. 444 - 453
Read Take notes on
– Fxn of organs (general)– Pathway of gases– Any specific info dealing w/an organ will be
highlighted in class Purple pages from Ch. 15
– pg. 450 The Effects of Smoking– pg. 452 Asthma: The Manageable Disease– pg. 456 The Return of Tuberculosis– pg. 462-63 Respiration and SCUBA diving
3 main functions1. Warms, moistens, and filters incoming air2. Detects olfactory stimuli3. Modifies speech vibrations
•Conchae & meatuses together increase surface area and trap exhaled water droplets to prevent dehydration
•Membrane in the nasal cavities contains goblet cells which secrete…
mucus
•Blood in the capillaries warms the inhaled air
•Receptors in the Olfactory epithelium line the superior conchae
The NOSE
The material spread by sneezing can travel 2-3 meters
When you sneeze, air rushes through your nose at a rate of 100 miles per hour.
The world record for sneezing is held by Donna Griffiths from Worstershire in the UK, who sneezed for 978 days in a row
FYI:
The PHARYNX (throat)Functions…
•Passageway for air & food•Resonating chamber for speech sounds•Houses tonsils
3 Regions…1. Nasopharynx
2. Oropharynx
3. Laryngopharynx
http://www.gen.umn.edu/faculty_staff/jensen/1135/webanatomy/wa_skeleton/
TRACHEA (windpipe)•Splits into 2 bronchi @ a ridge called the Carina
2
Why 5?
20
Respiratory bronchiolesAlveolar ducts
Branching of the bronchial tree
The LUNGHILUS - the area of each lung where Bronchi, blood vessels, nerves, and lymphatic vessels enter
•3 lobes right (shorter & wider)
•2 lobes left (10% smaller)
Relationship between Lungs and Heart
Respiration - exchange of gases between the external environment / atmosphere & body cells
• Pulmonary ventilation• inspiration• expiration
• External Respiration• Internal Respiration
CO2
O2
PULMONARY VENTILATION
Aka…BREATHING
• Process through which gases are exchanged between the atmosphere & lung alveoli… due to differences in pressure
Mechanics of Breathing: pgs. 453-455
Breathing involves (2) events:1. Inspiration / inhalation / breathing in2. Expiration / exhalation / breathing out
N2 = 78.6%
O2 = 20.9%
CO2 (and all other gases) = 0.5%
“Block” of air at sea level
Partial Pressure of Atmospheric Gases – Dalton’s Law Since our atmosphere is a mixture of gases, we can calculate the
amount of pressure each gas contributes to the total pressure based on their individual percentages… aka partial pressures.
Atmospheric Mixture of Gases:
• N2 = 78.6%• O2 = 20.9%• CO2 (and all other gases) = 0.5%
Pressure @ sea level:• 1 atmosphere• 760 mm Hg ***• 101.3 kPa• 760 Torr
EX. Atmospheric air is made of N2, O2, H2O, CO2, and other gases
Therefore…PN2 + PO2 + PH2O + PCO2 + Pother gases = atmospheric pressure (760 mm Hg)
Each gas moves/diffuses (independently) based on its own partial pressures: Highs chase lows
BOYLE’S LAW - pressure of a gas varies inversely
with volume
When the diaphragm contracts, it actually flattens…
What will this do to the volume in the lungs?
So pressure will…
Therefore…
moves
Inspiration – Inhalation – breathing in
Pressure (# of collisions) = Force / Unit AreaP = K V
Variables that may affect pressure – relationship1. Temp (direct)2. Volume (indirect)3. # of molecules (direct)
• Must look at each variable alone to see its affect on pressure. Therefore other variables must be kept constant
• pg. 454 fig 15-10More pressureLess volumeMore collisions
Less pressureMore volumeLess collisions
•assume same temp and same molecule #
Sequence of Events for Inspiration: Active Process
1. Diaphragm relaxed (at rest) • then contraction of diaphragm (it lowers)
& external intercostal muscles2. Volume of thoracic cavity increases
• Due to Boyle’s Law3. Pressure of thoracic cavity drops4. Air rushes from the external environment / atmosphere into
the alveoli of the lungs • (all because of only a 1-3 mmHg pressure gradient that’s
created) in order to reach equilibrium.
HIGHS CHASE LOWSatmosphere alveoli
Important Terms for Muscle Movement
Origin• point of attachment to the more stationary bone
Insertion• point of attachment to the more movable bone
Nerve innervation• what nerve “talks” to the muscles to cause contraction or relaxation
Action• coordinated response of a group of muscles to bring body into movement
TREND:• When a muscle contracts, it shortens. This shortening causes the muscle’s insertion to move toward the origin… movement
DataChart: Muscles Involved w/Breathing
Diaphragm Origin
Insertion
Nerve Innervations
Action
The Respiratory Muscles
The Respiratory Muscles
The higher the partial pressure of a gas over a liquid and the higher the solubility coefficient, the more the gas will stay in the solution
REAL WORLD example…
Opening a soft drink causes a hissing sound and bubbles of CO2 to rise to the surface
The drink was bottled/canned under high pressure, keeping the CO2 dissolved…once the cap is removed the pressure decreases and the gas begins to bubble out of solution
HENRY’S LAWStates that…the quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility coefficient
In other words…
What is this???
Hyperbaric chamber
It provides O2 at an increased pressure so that more O2 will dissolve into the blood
Why does Oxygen and Carbon dioxide move in their respective directions… based on Dalton’s Law of Partial Pressure keeping in mind cell respiration and photosynthesis?
CO2
O2
H -> L H -> L H -> L
L <- H L <- H L <- H
PO2 of alveolar air is 105 mmHg
PO2 of deoxygenated blood in pulmonary capillaries is
40 mmHg
WHAT DOES THIS MEAN? Hint…think about how gases move
Oxygen will move out of the alveoli and into the blood
CO2 will move out of the blood and into the alveoli
( PCO2 of deoxygenated blood is 45 mm Hg and the PCO2 of alveolar air is 40 mm Hg)
What happens here?
External Respiration – exchange of gases between the alveoli of lungs and bloodstream
*Partial pressure establishes a pressure gradient which leads to the mvmt of particles based on their own pp’s*
TRANSPORT OF O2Hemoglobin + O2 = Oxyhemoglobin
Iron containing pigment; when it combines with O2 it turns bright red
Each hemoglobin molecule can combine with 4 O2 molecules
The affinity of O2 to hemoglobin is how tight it holds the O2
O2 leaves blood and diffuses into the cellCO2 leaves cells and diffuses into the blood
Internal Respiration – exchange of gases between the bloodstream and body cells (vessel air switched w/tissues)
1. What are the organs involved?
2. What 2 processes are shown & which one can we already assume took place during respiration?
3. Using Boyle’s & Dalton’s gas Laws, explain the direction of mvmt for CO2 & O2
4. What role does cell respiration play?
INTERNALRESPIRATION
Tissue cells:Low PO2
High PCO2
Book pg. 459
Heart is a “double pump”• Right – Pulmonary circ.• Left – Systemic circ.
CO2 O2 O2 CO2
Which diagram represents the cells making up tissues & organs w/in body systems? Explain.
Which diagram represents the cells w/in alveoli of the lungs? Explain.
1 2
Regulation of pH
pH • power (potential) of H+ ions• pH is controlled by buffer systems, respiratory system, urinary system• pH of body fluids, especially blood, is despite changes that occur w/diet, exercise, stress, etc…
Buffer systems• homeostatic mechanisms w/in the body that keep acid and base concentrations stable
Alterations in pH
Can become life threatening if measures are not taken to remove excess hydrogen ions; can cause irreversible damage to enzymes, functional and structural proteins
Less frequent, but dangerous
pH - power (potential) of H+ ions
• Even minor changes in pH can be a big deal… denaturation of proteins• ex. A pH of 6.35 is 10X more acidic than 7.35 and 5.35 is 100X more acidic than 7.35… logrithmic scale
Acids• a molecule that releases one or more H+ when it ionizes in
H2O• acids + water = dissociation – breaking apart of compounds
1. HCl + H2O H+ + Cl-
2. H2SO4 + H2O H+ + SO4 2-
3. HNO3 + H2O H+ + NO3 -
Bases• a molecule that reduces the concentration of H+ in solution• bases + water = hydroxide
1. NaOH + H2O Na+ + OH-
2. Al(OH)3 + H2O Al3+ + OH-
3. Ca(OH)2 + H2O Ca2+ + OH-
ex. Ca OH OH
2 ways that O2 is transported w/in the blood
1. Oxyhemoglobin • O2 attached to the iron portion of the Hb on an RBC• 98%• “bus”
2. O2 dissolved in the plasma• 2%• “pedestrian”
How well do gases dissolve in warm H2O?
O2 O2
O2 O2O2
O2
O2
Hemoglobin and 02 Transport 280 million
hemoglobin/ RBC. Each hemoglobin
has 4 polypeptide chains and 4 hemes.
Each heme has 1 atom iron that can combine with 1 molecule 02.
3 ways that CO2 travels in the blood
1. CO2 dissolved in plasma • “pedestrian”• 10%
2. CO2 attached to Hb in the RBC’s• “bus”• Carboxyhemoglobin• 25%
3. Bicarbonate ions HCO3-
• “disguised”• A pocket of magma lies beneath the lake and leaks carbon dioxide (CO2) into the water,
changing it into carbonic acid. Nyos is one of only three known exploding lakes to be saturated with carbon dioxide in this way.
• August 21, 1986, possibly triggered by a landslide, Lake Nyos suddenly emitted a large cloud of CO2, which suffocated 1,700 people and 3,500 livestock in nearby towns and
villages
CO2 + H2O H2CO3 HCO3- + H+
Regulation of pH of body fluids/blood
Carbonicanhydrase
Weak acid Dissociation
MetabolicWaste: cell respiration
Drink/eat
Forward rxn occurs in capillaries close to tissue cells going through cell respiration
Reverse rxn occurs in capillaries near alveoli of lungs
Free H immediately affects pH
Ventilation Patterns
Eupnea - Normal, quiet breathing Dyspnea - Difficult breathing Apnea - absence of breathing Tachypnea - Rapid breathing rate Bradypnea - Slow breathing Hyperpnea - Deep breathing Hypopnea - Shallow breathing Hyperventilation - Rapid, deep
breathing Cheyne-Stokes breathing - periods of
apnea interspersed with hyperpnea
CO2 CO2 CO2
CO2 CO2 CO2
CO2 CO2 CO2
In the body:CO2
H2CO3-
H+
pH
Respiratory Alkalosis Hyperventilation. Excessive loss of CO2.
pH increases. Plasma HCO3
- decreases.
PCO2 decreases.
CO2
CO2
In the body:CO2
H2CO3-
H+
pH
Respiratory Acidosis Hypoventilation. Accumulation of CO2 in the tissues.
pH decreases. Plasma HCO3
- increases.
Pc02 increases.
Conversion of CO2 into HCO3-
Helps Regulate pH of body fluids/bloodCO2 + H2O H2CO3 HCO3
- + H+
___ ______ _____ ____
1) Situation: Heavy exercise: ________________________
2) Assume no compensation yet in the body:• ____ CO2
• ____ H2CO3
• ____ HCO3-
• ____ H+ • ____ pH
3) Show pH change on scale 0_______________7_______________14
4) Goal: Respiratory system_______ inc/dec rate & depth of breathing
5) Show pH direction change to maintain homeostasis
Conversion of CO2 into HCO3-
Helps Regulate pH of body fluids/bloodCO2 + H2O H2CO3 HCO3
- + H+
___ ______ _____ ____
1) Situation: : _______________________________________
2) Assume no compensation yet in the body:• ____ CO2
• ____ H2CO3
• ____ HCO3-
• ____ H+ • ____ pH
3) Show pH change on scale 0_______________7_______________14
4) Goal: Respiratory system_______ inc/dec rate & depth of breathing
5) Show pH direction change to maintain homeostasis
Regulation of Breathing Neurons in the medulla
oblongata forms the rhythmicity center:– Controls automatic
breathing. Brain stem respiratory
centers:– Medulla.– Pons.
Create a feedback loop on the Rate & Depth of Breathing – pH Pgs. 460 - end
Receptors
C.C.
Effectors
Normal
The LARYNX (voice box)•Lies anterior to C4-C6
•Made up of 9 pieces of cartilage
•Air passing through allows for voice production
•Thyroid cartilage (Adam’s apple)
•Arytenoid cartilageInfluence the positions & tensions of the vocal cords
•Throughout the epithelium goblet cells are found along with cilia which continue to trap any dust/debris that may have been missed
•Epiglottis – epithelium covered, elastic cartilage…covers the glottis during swallowing
The LARYNX (voice box) continued…
•Cricoid cartilage – landmark for tracheostomies
The LARYNX & SPEECH•Air moving across the Vocal folds (vocal cords) produces sound
But how do we make this sound into something we understand?
Pharynx allows for what sounds?
Face, tongue and
lips…
Other structures act as resonating chambers to provide for recognizable speech…
Like the pharynx, mouth, and nasal cavity
The ability to enunciate words comes from the movement of muscles found in the…
LARYNX & Speech continued…
Pitch of voice is controlled by the tension on the vocal cords
Tension = Pitch
Tension = Pitch
Males’ vocal cords are longer and thicker, thus…
They vibrate more slowly and give off a lower pitch than those of women
Other examples…
ALVEOLI
~300 million alveoli found in the lungs
tiny air sacs very thin epithelial tissue (only 0.5um thick) WHY?
WHY?
secretes alveolar fluid for moisture• contains surfactant – lowers surface tension of the fluid which reduces the tendency of alveoli collapsing
contains macrophages (dust cells) – remove fine dust particles & other debris in the alveolar space
DIFFUSION is the reason for the thinness of the epithelial tissue
it is the physical process of gases crossing the membrane
air
PULMONARY VENTILATION (cont.)
when air pressure in the lungs is < air pressure in the atmosphere
( & vice versa )
Give me an example of an inverse relationship…
BOYLE’S LAW – pressure of a gas varies inversely with volume
EXHALING is a passive process due to a lack of muscle contractions
TIDAL VOLUME – the volume of one breath, averaging ~500 ml
External Respiration – the exchange of O2 and CO2 between air in the alveoli and blood in the pulmonary capillaries
•is governed by 2 laws… Dalton’s law and Henry’s law
Dalton’s Law: each gas in a mixture of gases exerts its own pressure as no other gases were present
• each gas in a mixture has a specific pressure which is called its partial pressure (Px)
EX. Atmospheric air is made of N2, O2, H2O, CO2, and other gases
Therefore…PN2 + PO2 + PH2O + PCO2 + Pother gases = atmospheric pressure (760 mm Hg)
As we know… gases move from areas of higher pressure to areas of lower pressure
This occurs between the atmosphere & lungs, between the lungs & blood, and between blood & body cells
The rate of Gas Exchange depends on the following:
1. Partial pressures of gases…EX… high altitude sickness - occurs due to low O2 content in the blood
2. Surface area for gas exchange…EX… emphysema – alveolar walls disintegrate
3. Diffusion distance – thinness of the alveolar epithelium
3 main factors that affect affinity (attraction)
1. Acidity (pH)… as pH goes down so does the affinity
2. PCO2 … as PCO2 rises affinity goes down
3. Temperature… as temp goes up affinity goes down
High affinity less O2 is released
As affinity decreases more O2 is released
Carbon dioxide• the majority is found in the blood as bicarbonate ions• blood detects this and transports it to the lungs to be exhaled
Control of Respiration
• controls rate of breathing