Human Structure and Function Week 4

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Questions and Answers

Which epithelium type is found in most of the nasal cavity?

Pseudostratified ciliated columnar epithelium (correct)

Stratified squamous epithelium

Simple squamous epithelium

Simple cuboidal epithelium

What is NOT a function of the nasal cavity?

Facilitates gas exchange (correct)

Humidifies and warms the air

Cleans the air

Olfaction (smell)

Which region of the pharynx is located posterior to the nasal cavity?

Oropharynx

Laryngopharynx

Nasopharynx (correct)

Esopharynx

Which of the following structures is involved in directing food away from the respiratory tract?

Epiglottis Signup and view all the answers

What structural change occurs as you move from the trachea to the terminal bronchioles?

Decrease in cartilage Signup and view all the answers

How many lobes does the right lung have?

3 lobes Signup and view all the answers

Which of these best describes the pleura?

A membrane surrounding the lungs Signup and view all the answers

What structure contributes to the gas exchange process in the lungs?

Alveoli Signup and view all the answers

What is the primary function of ventilation in the respiratory system?

Movement of air in and out of the lungs Signup and view all the answers

Which part of the respiratory system is classified as the upper respiratory tract?

Nasal cavity Signup and view all the answers

What is the function of the concha in the nasal cavity?

To increase the surface area for filtering and warming air Signup and view all the answers

Which zone of the respiratory system is responsible for gas exchange?

Respiratory zone Signup and view all the answers

Which function is NOT typically associated with the respiratory system?

Digestion Signup and view all the answers

What structures are involved in the conducting zone of the respiratory system?

Bronchi and bronchioles Signup and view all the answers

How does the respiratory system contribute to the regulation of blood pH?

Through the exchange of respiratory gases Signup and view all the answers

What is the role of the hard palate in the nasal cavity?

It separates the nasal cavity from the oral cavity Signup and view all the answers

What happens to gas movement when the thickness of the respiratory membrane increases?

Gas movement decreases Signup and view all the answers

How is most carbon dioxide transported in the blood?

As bicarbonate ions dissolved in plasma Signup and view all the answers

Which physiological phenomenon is described by the relationship between volume and pressure in the lungs?

Boyle's law Signup and view all the answers

What is the partial pressure of a gas when it is equal on both sides of the respiratory membrane?

There is no net movement of gas Signup and view all the answers

What is the tidal volume in pulmonary volumes?

Amount of air inspired or expired with each breath Signup and view all the answers

During expiration, what is the relationship between intra-alveolar pressure and barometric pressure?

Palv > PB Signup and view all the answers

Which volume measures the air remaining in the lungs after the most forceful expiration?

Residual volume Signup and view all the answers

What process is responsible for moving air into and out of the lungs?

Pulmonary ventilation Signup and view all the answers

What is defined as the total amount of air moved into and out of the respiratory system each minute?

Minute ventilation Signup and view all the answers

What is the purpose of measuring forced vital capacity (FVC)?

To assess the maximal volume of air expired after a deep breath Signup and view all the answers

What force promotes the expansion of the lungs during breathing?

Intrapleural pressure < intra-alveolar pressure Signup and view all the answers

Which parameter quantifies the volume of air expired in the first second of a forced expiration?

Forced expiratory volume in 1 second (FEV1 sec) Signup and view all the answers

What does the forced expiratory volume 1% (FEV1%) represent?

The percentage of forced vital capacity that FEV1 sec represents Signup and view all the answers

How does dynamic lung function differ from static lung function?

Dynamic lung function measures lung volume over time, while static does not. Signup and view all the answers

What is indicated by a minimal movement of the rib cage during breathing?

Quite depth of breathing Signup and view all the answers

Study Notes

Functions of the Respiratory System

Respiration includes ventilation (air movement), external respiration (gas exchange in lungs), transport of respiratory gases, and internal respiration (gas exchange between blood and tissues).
Plays a role in blood pH regulation.
Facilitates voice production.
Responsible for the sense of smell (olfaction).
Provides protection against pathogens and foreign particles.

Divisions of the Respiratory System

Structural Classification:
- Upper respiratory tract: nose, nasal cavity, pharynx.
- Lower respiratory tract: larynx, bronchi, bronchioles, alveoli.
Functional Classification:
- Conducting zone: passage for air movement.
- Respiratory zone: site of gas exchange within the lungs.

Anatomy of the Nose

External Nose and Nasal Cavity:
- Nasal cavity extends from nostrils (nares) to choanae.
- Vestibule: entryway lined by stratified squamous epithelium with glands and hair follicles.
- Hard palate forms the floor of the nasal cavity.
- Nasal septum divides cavity into left and right portions.
Nasal Conchae:
- Bony "ridges" (superior, middle, inferior) create superior, middle, and inferior meatus.
- Lined by pseudostratified ciliated columnar epithelium for function.
Functions of Nasal Cavity:
- Air passage and cleaning via mucous and cilia.
- Humidifies and warms air with moisture and blood.
- Supports olfaction and contributes to voice resonance.

Pharynx Structure

Regions of the Pharynx:
- Nasopharynx: posterior to nasal cavity, has Eustachian tube openings, and pharyngeal tonsils.
- Oropharynx: posterior to oral cavity, contains palatine and lingual tonsils.
- Laryngopharynx: posterior to the epiglottis.

Larynx

Known as the voice box, composed of 9 cartilages (6 paired and 3 unpaired).
Functions: facilitates air passage, directs food away from respiratory tract, enables sound production, traps debris to protect lungs.

Trachea and Bronchial Tree

Descends from larynx, supported by 15-20 C-shaped cartilage rings.
Tracheal lumen lined with pseudostratified ciliated columnar epithelium with goblet cells.
As bronchi divide, smooth muscle increases while cartilage decreases. Epithelium changes from pseudostratified to simple ciliated types.

Alveoli and Lungs

Cone-shaped lungs: left lung has 2 lobes (with cardiac notch), right lung has 3 lobes.
Lobes separated by fissures; hilum serves as entry for blood vessels, lymphatics, and bronchi.

Gas Exchange Mechanism

Involves respiratory membrane between alveoli and capillaries.
Factors affecting gas exchange: membrane thickness, surface area, diffusion coefficient, and partial pressure differences.

Gas Transport

Oxygen Transport: Mostly via red blood cells (98.5% bound to hemoglobin); additional 1.5% dissolved in plasma.
Carbon Dioxide Transport: 70% as bicarbonate (HCO3-), 23% bound to hemoglobin, 7% dissolved in plasma.

Ventilation Mechanics

Pulmonary Ventilation: Air movement driven by diaphragm, rib cage, sternum, and intercostal muscles.
Inspiration increases lung volume; expiration decreases it.
Boyle's Law states that volume is inversely proportional to pressure.

Alveolar Pressure Dynamics

Barometric pressure (PB) typically equals 760 mm Hg.
Intra-alveolar pressure (Palv) varies during breathing:
- During inspiration, PB > Palv (air flows into lungs).
- During expiration, Palv > PB (air flows out).

Respiratory Volumes and Capacities

Pulmonary Volumes:
- Tidal volume: air volume with each breath.
- Inspiratory and expiratory reserve volumes for additional air capacity.
- Residual volume is air remaining post-forced expiration.
Pulmonary Capacities:
- Sum of two or more volumes: inspiratory capacity, functional residual capacity, vital capacity, total lung capacity.

Measurements of Lung Function

Utilized to diagnose lung diseases; includes static and dynamic measurements.
Dynamic Lung Function Parameters:
- Forced vital capacity (FVC): maximal air expelled after deep inhalation.
- Forced expiratory volume in 1 second (FEV1 sec): air expelled in first second.
- FEV1%: FEV1 expressed as a percentage of FVC.

Additional Breathing Definitions

Respiratory Rate (RR): Number of breaths per minute.
Minute Ventilation: Total air moved per minute (TV x RR).
Anatomic Dead Space: Volume of air not participating in gas exchange.
Alveolar Ventilation: Effective air volume available for gas exchange per minute.

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Description

This quiz covers the anatomy of the respiratory system and its functions, focusing on respiration and ventilation. It's designed for students studying Human Structure and Function at Curtin University. Test your knowledge on the essential aspects of human anatomy related to the respiratory system.