AP2 Test 4

Nose > Nasal Cavity > Pharynx > Larynx > Trachea > Bronchi > Central Bronchioles > Terminal Bronchioles

To Warm, humidify and purify air

Respiratory Bronchioles > Alveolar Ducts, Surrounded by alveolar sacs, made of alveoli

This is where gas exchange occurs

• Nasopharynx- behind nose
• Oralpharynx- behind mouth
• Laryngopharynx- behind the larynx

• Pharyngeal tonsils
• Eustachian Tube
• Tubal Tonsils
• Start- internal nares, end uvula

• Palatine Tonsils (MALT)
• Starts- Uvula, Ends-Epiglottis

• Behind the Larynx
• Start-Epiglottis, end- Cardiac sphincter

Epiglottis (1), Thyroid Cart. (1), Cricoid Cart. (1), Arytenoid (2), Corniculate (2), Cuneiform ( 2)

Hyaline, except for the epiglottis which is elastic cartilage

• "the Guaridan of the Airways"
• Because it folds over the top of the larynx in order to make sure no food enters the larynx

Laryngeal Prominence on the Thyroid Cartilage

• C-Rings: Hyaline cartilage
• Trachealis Muscle is on the posterior portion

The Trachea divides into the Primary Bronchi at T4

• The Right has 3 secondary Bronchi and is wider,
• The Left has 2 secondary Bronchi and is narrow
• Particles are more likely to enter the Right

Main, Principle

Lobar

Segmented

10

When it's diameter= 1mm

When it contracts the trachea's diameter decreases therefore inreasing air velocity from the lungs

• Central Bronchioles
• Terminal Bronchioles
• Respiratory Bronchioles

Fissures separate the lungs into lobes, The Right side has 3 and the left side has 2

Left

• Type I Pneumocytes ( Simple Squamous)
• Type II Pneumocyte ( Cuboidal

• Secretes Glycoproteins forming Basal Lamina
• Allows for gas exchange

Secretes Surfactan, which reduces the surface tension on the alveoli to keep it expanded

• Type I: 93%
• Type II: 7%

Simple Squamous epithelium that ecretes basal lamina

Each secretes Basal Lamina which fuse together, connecting the two membranes

The Subsegmental Bronchi

• Pulmonary Ventilation
• Internal Respiration
• External Respiration
• Gas Transport

Breathing, movement of air in and out of the lungs

The exchange of gases between the pulmonary capillaries and the alveoli, O2 comes in, CO2 goes out

The exchange of gases between the systemic capillaries and surrounding tissue. O2 goes out, CO2 comes in

The use of blood as a transporting device for gases between the alveoli and tissues

• Pressure in the alveoli of the lungs
• Equals the ATM

• The pressure within the pulmonary cavity
• 4< Intrapulmonary Pressure

Because if the lung would collapse if the pressure was equalized or higher in the intraplura

• Atelectasis- when the pressure in the iraplural and intrapulmonary equalizes
• Pneumothorax- when air penetrates the intraplural cavity

Scalenes, intercostals, sternocleidomastoid

• Boyle's Law: +V, -P
• Diaphragm moves down, which creates more volume, which decreases pressure which allows for P gradient for airflow

Change in Pressure / Resistance

Constricts Bronchi, which increases resistance of airflow, which decreases Gas flow

Dialates Bronchi, which decreases resistance of airflow, which increases gas flow

Ability of the lung to stretch

• Distensibility of the lung tissue
• Alveolar surface tenstion (levels of surfactan)

Fibrosis ( Scar tissue) or lack of surfactan

Age, Emphysema

Less surfactan levels, high water molecule concentration

2x Surface Tension / radius of alveolus

No

At the end of pregnancy, because there is no need for the lungs to be inflated while the baby is still in the womb

• Breaths per min-12
• Tidal Volume (TV)- 500mL
• Expiratory Reserve Volume (ERV)- 1200mL
• Inspiratory Reserve Volume (IRV)- 3100mL

• Total Lung Capacity(TLC)- 6000mL
• Vital Capacity (VC)- 4800mL
• Inspiratory Capacity(IC)- 4800mL
• Functional Residual Capacity (FRC)- 2400mL

• 500mL
• Amount of air inhaled/exhaled with each breath under resting conditions

• 3100mL
• Amount of Air that can be forcefully inhaled beyond the Tidal Volume

• 1200mL
• Amount of air that can be forecully exhaled beyond a normal tidal volume exhalation

• 1200mL
• Amount of air remaining in the lungs after a forced exhalation

• 6000mL
• Sum of all Respiratory Volumes
• TV +IRV+ERV+RV

• 4800mL
• Amount of air that can be expired after a maximum inspiratory effort
• TV + IRV + ERV

• 3600mL
• Maximum amount of air that can be inspired after a normal expiration
• TV + IRV

• 2400mL
• Volume of air remaining in the lungs after a normal tidal volume expiration

• TV x Breaths per min
• (500mL) x 12 = 6000 mL/Breaths per min

• (TV-Anatomical Dead Space) x Breaths per minute
• (500mL - 150mL) x 12 = 4200mL

Volume of air trapped in Conducting Zone

A certain volume of air that has been removed from gas exchange, ex. Lung Collapse

Anatomical Dead Space + Alveolar Dead Space

When a mixture of gases comes into contact with a liquid, each gas will dissolve in proportion with it's partial pressure.

• Henry's Law
• Solubility coefficient
• Temperature

• Exchanges going on between respiratory gases and pulmonary capillaries
• Humidification of air by conducting zone
• mixing of new and old gases

• Nitrogen dissolves the least in liquid
• Oxygen dissolves much better than Nitrogen

• New gas mixing with old gas
• Humidification of air by conducting zone
• Exchanges going on in external respiration

Gas exchange between the alveoli and the pulmonary capillaries

• Total Surface Area of the lung
• Thickness of the respiratory membrane
• Perfusion rates
• Partial pressure gradient of gases and gas solubilities

• The greater the surface area the greater the rate of external respiration
• The total surface area is around 90m2

• The membrane is usually between .5um-1.0um.
• If the membrane is thicker gas exchange is more difficult

• Po2 in the Venous blood is 40mmHG
• Po2 in the alveoli is 104mmHG
• Pco2 in Venous blood is 45mmHG
• Pco2 in alveoli is 40mmHG
• Gases flow doewn the partial pressure gradient

Since the partial pressure gradient is CO2 is so small, CO2's high solubility allows for it to pass through the respiratory membrane into the alveoli

• The pulmonary capillaries constrict/dialate to redirect bloodflow to areas with high Po2.
• The Bronchioles constrict/dialate to redirect CO2 out of the lungs.

• .25s
• .75s

Between 10%-70% O2 saturation

104mmHG

20mL of O2 per 100mL of Blood

1.5%

98.5%

97.5%

5mL

75%

• -pH, +Pco2, +T, +DPG
• Hemoglobin's affinity for O2 decreases

• +pH, -Pco2, -T, -DPG
• Hemoglobin's affinity for O2 increases

A natural liking for something

• Diphsphoglycerate
• Binds to deoxygenated blood, decreasing hemoglobins affinity for O2

Lack of Oxygen going to the tissues

• Abnormal Hemoglobin
• Abnormal Hemoglobin content
• Decreased Red Blood Cells

• Anemica Hypoxia
• Ischemia
• Histotoxic
• Hypoxemic

• Decreased Blood Flow to the tissues
• eg. Congestive Heart Failure-Inadequate Blood being pumped out of the heart

• Adequate O2 content in the blood, but not enough O2 getting to the tissues
• eg. Metal Poisoning, Cyanide

• Low O2 in the blood
• eg. Pulmonary Disease, problems with gas exchange
• CO poisoning

• Dissolved in the Plasma
• Attached to the globin
• Transported as Bicarbonate in the plasma

7%-10%

20%-30%

60%-70%

CO2 + H2O --> H2CO3 --> H+ + HCO3-

An enzyme in the RBC that acts as a catalyst for CO2 to become HCO3-

H+ and CO2 bind to the hemoglobin causing the release of O2 ino the tissue, which allows for more CO2 to bind to the Hb

he ability for more CO2 to enter the hemoglboin to buffer H+ as more O2 leaves the hemoglobin

HCO3- moves into the plasma, and to counteract the anion shift, CL- is moved in the RBC

When HCO3- moves in the plasma, and to counteract this anion change, Cl- moves into the RBC

• Bohr Effect, so CO2 binds to the Globin
• Then Haldane, CO2 buffers the H+ as O2 leaves the body

in the Brain Stem: Medulla Oblongata and Pons

• Dorsal Respiratory Group (DRG)
• Ventral Respiratory Group (VRG)

• Inspiration
• Pace Setting

• Stimulates Phrenic Nerve, which stimulates the Diaphragm
• Stimulates the Intercostal nerves which stimulate the External Intercostals
• Both of which cause inspiration

Sets Eupnea (normal respiration rate)

• Normal Respiratory Rate of 12 breaths per minute
• 3 sec- Expire, 2 sec-Inspire

• Active during Inspiration
• Inactive during expiration

• Inactive during normal respiration
• Active during Forced Expiration

• Pneumotaxic Center
• Apneustic Center

• In Superior Pons
• Controls Smooth Breathing, inhibits DRG to allow for expiration

• Located in Caudal Pons
• Stimulates DRG to allow for inspiration

• Pulmonary Irritant Reflexes
• Hering-Breuer Reflex
• Higher Brain Centers
• Chemical Composition of Blood

Inhaled Debris/Toxins stimulate receptors in Bronchioles which send nerve impulses along Afferent nerve Fibers which cause Bronchiole constriction to prevent the debris from entering the lung, coughing

• Protects against overexpansion of the lungs
• Visceral Pleura and conducting pathways have stretch receptors, when they are stimulated they inhibit Medulla and cause expiration

• Hypothalamus- Pain/Emotions > excites/inhibits resp. centers
• Cortex-Voluntary Control of Respiration

• Affected by Pco2, Po2, pH in arterial blood
• Central chemoreceptors and Peripheral Chemoreceptors

• In the Medulla
• Respond strongly to CO2 levels and pH
• Respond weakly to O2 levels

• Respond strongly to O2 levels
• Respond weakly to CO2 levels and pH

CO2 levels

7.35-7.45

CO2 in CSF + H2O > HCO3- + H+, there's no buffer in H+ so pH decreases, stimulating Central Chemoreceptors, stimulates respiratory Center, causes hyperventilation, decreases CO2 and increases pH

Increase CO2

Decreased CO2

Increased rate of Breathing

Decreased rate of breathing