BIO 169 Chapter 23: The Respiratory System

Functions

-movement of air/ gas exchange

-protection / filter, warm, humidify

-sound production

-olfaction

Respiratory Tract (rt), Conducting Portion

-brings air to gas exchange surface

-rt- alveoli and terminal bronchioles

Respiratory Tract (rt), Respiratory Portion

-gas exchange region

-alveoli and terminal bronchioles

Respiratory Mucosa

-epithelial layer + lamina propria

Respiratory Mucosa, Goblet Cells

-produce mucous/catch debris

Respiratory Mucosa, Pseudostratified Ciliated Epithelia

-sweep mucous

(Upper Respiratory System) Nose, External Nares

-opening brings air into vestibule

(Upper Respiratory System) Nose, Nasal Vestibule

-hairs trap debris

(Upper Respiratory System) Nasal Cavity

-chamber bound by inter/exter nares

(Upper Respiratory System) Nasal Cavity, Nasal Septum

-separates cavity

(Upper Respiratory System) Nasal Cavity, Nasal Conchae

-warms/humidifies air

-site of olfaction

(Upper Respiratory System) Nasal Cavity, Internal Nares

-opening to throat (nasopharynx)

(Upper Respiratory System) Pharynx

-tube from nasal cavity to larynx and esophagus

(Lower Respiratory System) Larynx

-cartilaginous voicebox

(Lower Respiratory System) Cartilages, Thyroid Cartilage

-largest structural support

(Lower Respiratory System) Cartilages, Cricoid Cartilage

-smaller structural support

(Lower Respiratory System) Cartilages, Corniculate and Arytenoid Cartilages

-very small

-open and close glottis

(Lower Respiratory System) Glottis

-space between vocal folds

(Lower Respiratory System) Glottis, Vocal Folds (Cords)

-elastic tissue vibrates and produces sound

-pitch depends on length/tension

(Lower Respiratory System) Epiglottis

-cartilaginous fold over glottis

-prevents entry of food/liquid

(Lower Respiratory System) Trachea

-tube connects larynx and lungs

-has C-shaped trachea cartilages

-trachealis muscle controls diameter

(Lower Respiratory System) Primary (1°) Bronchi

-L and R branches of trachea

-extrapulmonary outside of lung

-intrapulmonary inside of lung

(Lower Respiratory System) Lungs

-organs of respiration

-right side has 3 lobes, left side has 2 lobes

(Lower Respiratory System) Secondary (2°) Bronchi

-form as primary divide

-lower cartilage than primary, higher smooth muscle

(Lower Respiratory System) Tertiary (3°) Bronchi

-form as secondary divide

-less cartilage than secondary, higher smooth muscle

(Lower Respiratory System) Bronchioles

-form as tertiary divide

-much higher smooth muscle, control diameter

(Lower Respiratory System) Bronchioles, Terminal Bronchioles

-form as bronchioles divide

-deliver air to pulmonary lobule

(Lower Respiratory System) Pulmonary Lobule

-has arteries, veins, connective tissue

(Lower Respiratory System) Respiratory Bronchioles

-form as terminal bronchioles branch

 -deliver air to alveoli via duct

(Lower Respiratory System) Alveolar Sacs

-chamber at end of duct with alveoli

(Lower Respiratory System) Alveoli

-highly vascularized blind pockets

(Lower Respiratory System) Type I Pneumocyte

-simple squamous cells

(Lower Respiratory System) Type II Pneumocyte

-produce surfactant

(Lower Respiratory System) Surfactant

-lower surface tension, prevents collapse

(Lower Respiratory System) Macrophages

-protection against pathogens

(Lower Respiratory System) Alveolar Membrane

-site of gas exchange

-thin membrane = rapid diffusion

(Pleural Cavity) Parietal Pleura (pp)

-outer lining of pleural cavity

-covers thoracic cavity

(Pleural Cavity) Visceral Pleura (vp)

-inner lining of pleural cavity

-covers lung

(Pleural Cavity) Pleural Cavity

-space between Parietal Pleura (pp) and Visceral Pleura (vp)

-has pleural fluid (reduces friction)

(Airflow into Lungs) Pressure and Volume

-atmosphere pressure+ 760 mmHg (sea level)

-gas has lower density than liquid cause molecules farther apart

(Airflow into Lungs) Pressure and Volume: Boyle’s Law

-pressure and volume are inversely proportional (P=1/V)

-lower volume, higher molecular collisions, higher pressure

(Airflow into Lungs) Pressure Changes and Airflow

-air moves from high pressure to low

(Airflow into Lungs) Pressure Changes and Airflow: Inhalation

-active process

(Airflow into Lungs) Pressure Changes and Airflow: Inhalation, Diaphragm

-contracts, moves down, tc volume increases

-intrapulmonary pressure decreases (759 mm Hg) and air moves in

(Airflow into Lungs) Pressure Changes and Airflow: Inhalation, External Intercostals

-contract, rib cage moves up, tc volume increases

-intrapulmonary pressure decreases (759 mm Hg) and air moves in

(Airflow into Lungs) Pressure Changes and Airflow: Exhalation

-passive process

(Airflow into Lungs) Pressure Changes and Airflow: Exhalation, Elastic Rebound

-lungs contain lots of elastic tissue

-muscles relax, lungs rebound

-air moves out

(Airflow into Lungs) Pressure Changes and Airflow: Exhalation, Intrapleural Pressure

-negative pressure between pleurae

-elastic fibers pull, fluid bond resists

-trauma can introduce air into tc (pneumothorax), increased pressure may cause lung collapse

-atelectasis, term for collapsed lung

(Airflow into Lungs) Pressure Changes and Airflow: Compliance

-how easily lungs expand

-lower cm = higher force needed to fill lungs

-higher cm = lower force needed to fill lungs

(Gas Exchange) Gas Laws: Dalton’s Law

-each gas contributes to total pressure in proportion to abundance

-air is 78.6% N2, 20.9% O2, ect

(Gas Exchange) Gas Laws: Partial Pressure

-pressure contributed by single gas in a gas mixture (P_n2, P_O2, P_co2)

-P_N2 + P_o2 + P_co2 + P_h2O= 760 mmHg

-P_o2 = (.209) 760 mmHg = 159 mmHg

(Gas Exchange) Gas Laws: Henry’s Law

-at given temperature, amount of gas in solution is proportional to partial pressure of gas

-higher P_gas, more gas goes into solution

-lower P_gas, less gas goes into solution

(Gas Exchange) Gas Exchange

-efficient because small diffusion distance, large surface area and partial pressures favor diffusion

(Gas Exchange) Gas Exchange: PPs in Pulmonary Circuit

-O₂ (air) -> blood, CO₂ (blood) -> air

(Gas Exchange) Gas Exchange: PPs in Systemic Circuit

-O₂ (blood) -> IF, CO₂ (IF) -> blood

(Gas Exchange) Gas Pickup and Delivery: Oxygen Transport

(Gas Exchange) Gas Pickup and Delivery: Factors Affecting Hb Saturation

(Gas Exchange) Gas Pickup and Delivery: CO₂ Transport

(Respiratory Volumes) Tidal Volume (V_T)

(Respiratory Volumes) Respiratory Rate (f)

(Respiratory Volumes) Respiratory Minute Volume (V_E)

(Respiratory Volumes) Expiratory Reserve Volume (ERV

(Respiratory Volumes) Residual Volume (RV)

(Respiratory Volumes) Inspiratory Reserve Volume (IRV)

(Respiratory Volumes) Inspiratory Capacity (IC)

(Respiratory Volumes) Functional Residual Capacity (FRC)  

(Respiratory Volumes) Vital Capacity (VC)

(Respiratory Volumes) Total Lung Capacity (TLC)