Respiratory System Processes and Components

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Questions and Answers

What is the primary role of the conducting division in the respiratory system?

Transport of O2 and CO2

Site of gas exchange

Exchange of gases with metabolically active cells

Passageway for air that warms, humidifies, and cleanses (correct)

What is external respiration primarily responsible for?

Exchanging O2 and CO2 between alveoli and blood supply (correct)

Generating speech

Transporting gases throughout the body

Moving air in and out of the lungs

Which function is NOT directly associated with the respiratory system's major processes?

Transporting gases between lungs and blood

Balancing pH levels in blood

Generating speech

Aerating the digestive system (correct)

Under what conditions does the mouth primarily serve as a conduit for air?

During physical exertion Signup and view all the answers

Which component of the respiratory system is specifically responsible for the actual gas exchange?

Respiratory Division Signup and view all the answers

What does a higher solubility coefficient indicate about a gas?

It allows for a greater volume to transfer into a liquid. Signup and view all the answers

Which factor directly affects the rate of gas diffusion in the respiratory system?

Partial pressure of the gas. Signup and view all the answers

What does FEV stand for in terms of ventilatory flow rates?

Forced expiratory volume. Signup and view all the answers

How does the equilibrium value of partial pressure relate to initial values?

It is not the average of the initial partial pressure values. Signup and view all the answers

What does the peak expiratory flow (PEF) measure?

The highest rate of airflow during exhalation. Signup and view all the answers

Which statement is true regarding gas dissolution in liquids?

The amount of gas dissolved equals its partial pressure times the solubility coefficient. Signup and view all the answers

Which of the following influences the resistance of airways?

Ventilatory flow rates. Signup and view all the answers

In gas exchange, what is primarily exchanged during external respiration?

Gases between air in the alveoli and blood in the capillaries. Signup and view all the answers

What is the primary function of alveolar macrophages?

Scavenge microorganisms and particles Signup and view all the answers

How many lobes does the right lung have?

Three lobes Signup and view all the answers

Which layer of the pleural membrane tightly covers each lung?

Visceral pleura Signup and view all the answers

What is contained in the pleural cavity?

Pleural fluid Signup and view all the answers

In the pulmonary blood flow path, what comes after the pulmonary trunk?

Pulmonary arteries Signup and view all the answers

What occurs in Zone 1 of blood flow in the lungs?

Alveolar pressures collapse the capillaries. Signup and view all the answers

What does a pressure differential indicate?

The difference in pressure between any two areas occupied by a gas or fluid. Signup and view all the answers

How does Boyle's Law relate pressure and volume?

Pressure increases when volume decreases at constant temperature. Signup and view all the answers

What is true about Zone 3 of blood flow in the lungs?

Continuous flow from capillary to alveoli ensures good gas exchange. Signup and view all the answers

Which of the following statements about pressure differentials is false?

Pressure differentials are constant regardless of conditions. Signup and view all the answers

What happens to gas pressure when the temperature is increased, assuming other factors remain constant?

Gas pressure increases. Signup and view all the answers

In which zone does the capillary pressure exceed alveolar pressure during systole?

Zone 2 Signup and view all the answers

If a gas occupies a larger volume while the number of particles remains unchanged, what happens to the pressure?

Pressure decreases. Signup and view all the answers

What is the primary function of the nasal sinuses?

To warm and humidify incoming air Signup and view all the answers

Which structure is responsible for dividing the nasal cavity into left and right sides?

Nasal septum Signup and view all the answers

What is the primary role of the ciliated cells within the bronchi?

To trap and move debris Signup and view all the answers

Which part of the pharynx serves as a conduit for both air and food?

Oropharynx Signup and view all the answers

What distinguishes primary bronchi from terminal bronchioles?

Support from cartilage Signup and view all the answers

Which structure is NOT part of the conducting division of the respiratory system?

Alveolar sacs Signup and view all the answers

What is the primary feature of the alveoli that facilitates gas exchange?

Thin walls with large lumen Signup and view all the answers

Which cartilage structure in the larynx prevents it from collapsing?

Thyroid cartilage Signup and view all the answers

What is the role of type II alveolar cells?

Produce surfactant Signup and view all the answers

Which respiratory structure is the shortest and serves both air and food conduction?

Laryngopharynx Signup and view all the answers

What mainly composes the walls of alveolar sacs?

Connective tissue Signup and view all the answers

What triggers coughing in response to solid or liquid substances in the trachea?

Carina Signup and view all the answers

Which structure connects the root of the nose to the rest of the nasal anatomy?

Bridge Signup and view all the answers

Which is a feature found in the inferior portion of the larynx?

Mucous membrane Signup and view all the answers

Study Notes

Major Processes of the Respiratory System

Ventilation: Moving air in and out of the lungs.
External Respiration: Exchange of oxygen (O2) and carbon dioxide (CO2) between air and blood.
- Air in the alveoli
- Alveoli to the blood supply
Transport: Movement of O2 and CO2 between the lungs and tissues.
Internal Respiration: Exchange of O2 and CO2 between blood and metabolically active cells.
- Blood to cells
Other Functions: Sound production, balance of blood pH, temperature regulation.

Components of the Respiratory System

Conducting Division: Provides a passageway for air to move through the respiratory system.
- Functions:
  - Warms the air.
  - Humidifies the air.
  - Cleanses the air.
Respiratory Division: Provides the site of gas exchange between the lungs and blood.
- Includes:
  - Respiratory bronchioles
  - Alveolar ducts
  - Alveolar sacs

Structures of the Conducting Division: The Mouth

Primary function: Digestion.
Role in Respiration: Acts as an alternate conduit for air entry and exit.
- Especially important during strenuous activities.
Air treatment: Warm, humidify, and cleanse.

Structures of the Conducting Division: External Nose

Anatomy:
- Apex: Tip of the nose.
- Nares (nostrils): Openings to the nose, filter large particles.
- Ala nasi: Cartilaginous flap on the lateral side of each nostril.
- Dorsum nasi: Length of the nose.
- Bridge: Connects the root of the nose to the rest of the nose.
- Root: Region located between the eyebrows.

Structures of the Conducting Division: Internal Structures of the Nose

Anatomy:
- Nasal septum: Divides the nasal cavity into left and right sides.
- Superior, middle, and inferior conchae: Three pairs of C-shaped bones extending from the nasal septum.
- Meatuses: Passageways surrounding the conchae for air to flow.

Structures of the Conducting Division: Nasal Sinuses

Anatomy:
- The nasal cavity is connected to four pairs of sinuses.
- Nasal sinuses are air-filled spaces.
Functions:
- Warm and humidify incoming air.
- Contribute to the resonance of the voice.

Structures of the Conducting Division: The Pharynx

Anatomy:
- Nasopharynx: Conduit for air only.
  - Adenoids are located on the posterior wall.
- Oropharynx: Conduit for both digestion and respiration.
  - Tonsils are found on the border of the oropharynx.
- Laryngopharynx: The shortest portion of the pharynx.
  - Conduit for both air and food.
  - Opens into the larynx and esophagus.

Structures of the Conducting Division: The Larynx

Anatomy:
- Directs air into the trachea and food into the esophagus.
- Contains vocal cords.
- Superior portion is lined with stratified squamous epithelium.
- Inferior portion is lined with a mucous membrane that moves trapped debris into the pharynx.

Structures of the Conducting Division: The Glottis and Laryngeal Cartilage

Anatomy:
- Cartilage in the larynx prevents it from collapsing.
- Large cartilage: Epiglottis, thyroid, cricoid.
- Small cartilage: Arytenoid, corniculate, cuneiform.
- Glottis: Vocal apparatus of the larynx.

Structures of the Conducting Division: The Trachea

Anatomy:
- Extends from the larynx to its division into left and right bronchi.
- Contains hyaline cartilage between fibrous tissue ligaments.
- Carina: Ridge of cartilage that senses solid or liquid substances and triggers coughing to expel them.
- Ciliated cells on the interior of the trachea move mucus and debris toward the pharynx.

Structures of the Conducting Division: Bronchi Through Terminal Bronchioles

Anatomy:
- Primary bronchi  secondary bronchi  tertiary bronchi  primary bronchioles  terminal bronchioles.
Bronchi: Supported by cartilage; interior contain ciliated mucous cells.
Bronchioles: Lack cartilage but have smooth muscle instead; lack mucous cells.

Structures of the Respiratory Division: Respiratory Bronchioles and Alveolar Sacs

Anatomy:
- Respiratory bronchioles: Minimal smooth muscle.
- Alveolar ducts: Short conduits of mainly connective tissue.
- Alveolar sacs: Grape-like clusters of individual alveoli opening from alveolar ducts.
Structure: Very elastic.

Structures of the Respiratory Division: Alveoli

Anatomy:
- The structures across which gas exchange occurs.
- Thin-walled with a large lumen.
- Provide intimate contact between inhaled air and blood in pulmonary capillaries wrapping the alveolar walls.
Surface Area: The collective surface area of all alveoli is 70 m2 (the size of a single tennis court).

Structures of the Respiratory Division: Alveolar Cells

Type I:
- Most common cell type.
- Connected to a thin basement membrane with a pulmonary endothelial cell on the other side (“respiratory membrane”).
Type II:
- Cuboidal cells.
- Produce and secrete surfactant.
  - Surfactant reduces surface tension between water molecules lining alveoli surfaces.
- Babies born before 37 weeks gestation are considered premature because they lack sufficient surfactant.
Type III:
- Inner alveolar macrophages.
- Responsible for scavenging microorganisms and particles.

Structures of the Respiratory Division: The Lungs

Anatomy:
- Occupy most of the thoracic cavity; encased by the pleural membrane.
- Right lung: Has 3 lobes.
- Left lung: Has 2 lobes.
- Lobes are further divided into bronchopulmonary segments.
- Bronchopulmonary segments are divided into pulmonary lobules.

Structures of the Respiratory Division: Lung Pleura

Anatomy:
- Each lung is surrounded by a pleural membrane with two layers:
  - Visceral pleura: Tightly covers each lung.
  - Parietal pleura: Lines the inner wall of the thoracic cavity.
- Pleural cavity: Small space between the layers containing pleural fluid (secreted by mesothelial cells).

Pulmonary blood flow in the Lungs

Flow: Deoxygenated blood → pulmonary trunk → pulmonary arteries → lobar arteries → capillary beds surrounding alveoli → oxygenated blood → venules → small veins → pulmonary veins.

Zones of Blood Flow in the Lungs

Zones: Based on pressure differences caused by gravity.
- Zone 1:
 - Capillary pressure < alveolar pressure.
 - Blood flow is reduced due to pressure differences.
 - Close to atmospheric pressure, collapse, and may help to prevent flow through the capillaries.
- Zone 2:
 - Capillary pressure (systole) > alveolar pressure.
 - Capillary pressure (diastole) < alveolar pressure.
 - Flow intermittent due to pressure differences between systole and diastole.
 - May collapse.
- Zone 3:
 - Capillary pressure > alveolar pressure.
 - Continuous blood flow.
Requirement for Adequate Gas Exchange: Ventilation must match perfusion (blood flow) between the alveoli and capillaries.

Pressure Differentials and Gradients

Pressure differential: The difference in pressure between two spaces occupied by a gas, independent of whether the gas can move between those spaces.

Determinants of Gas Pressure

Amount of gas particles: Higher concentration of gas particles in a volume, higher pressure.
Temperature: Higher temperature, higher pressure.
Volume of space: Higher volume, lower pressure.
- Boyle's Law: Pressure and volume are inversely related for a fixed amount of gas at a constant temperature.
  - P1V1 = P2V2
- Examples: Laughing/crying: Emotional states can influence ventilatory patterns.

Ventilatory Volumes and Capacities

Tidal Volume (TV): Volume of air inhaled or exhaled during normal breathing.
Inspiratory Reserve Volume (IRV): Additional volume of air that can be inhaled after normal inspiration.
Expiratory Reserve Volume (ERV): Additional volume of air that can be exhaled after normal expiration.
Residual Volume (RV): Volume of air remaining in the lungs after maximum expiration.
Inspiratory Capacity (IC): Maximum volume of air that can be inhaled after normal expiration (TV + IRV).
Vital Capacity (VC): Maximum volume of air that can be exhaled after maximum inspiration (TV + IRV + ERV).
Total Lung Capacity (TLC): Total volume of air that the lungs can hold (VC + RV).
Functional Residual Capacity (FRC): Volume of air remaining in the lungs after normal expiration (ERV + RV).

Ventilatory Flow Rates

Flow rates: Provide information about the resistance of airways.
- Peak Expiratory Flow Rate (PEF): Maximum rate of air exhaled forcefully.
- Forced Expiratory Volume (FEV): Volume of air expelled during a forced exhalation.
- Forced Vital Capacity (FVC): Maximum volume of air that can be exhaled forcefully after maximum inspiration.

Gas Exchange

Diffusion: The movement of molecules from an area of higher concentration to an area of lower concentration.
Partial Pressure: The pressure exerted by a specific gas in a mixture of gases.
- Partial Pressure = Total Pressure x Fraction of Gas
Solubility Coefficient: The measure of how easily a gas dissolves in a liquid.

Gas Diffusion Between Air and Blood

External respiration: Takes place between air in the alveoli and blood in the capillaries.
- The rate of gas diffusion depends on the solubility coefficient.
- Higher solubility coefficients are associated with faster rates of diffusion.
Equilibrium: Occurs when the partial pressure of a gas in the air and in the blood are equal.

Key Points About Gas Diffusion and Partial Pressures

Equilibrium values: Not the average of the initial partial pressure values.
Larger partial pressure changes: Result from greater percentage changes in gas volumes.
Higher solubility coefficients: Associated with greater gas transfer into or out of a liquid.
“Amount” of gas in a liquid: Expressed as the equivalent volume transferred from the gas mixture, not an additional volume added to the liquid.

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Description

This quiz covers the major processes of the respiratory system, including ventilation and gas exchange as well as the components involved in these processes. Test your knowledge on how air moves through the respiratory tract and the functions of various structures. Perfect for students studying human physiology!