Respiratory System

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