Biology Chapter 23: The Respiratory System

Questions and Answers

What structures make up the respiratory system?

Nose, pharynx, larynx, trachea, bronchi, and lungs.

Structurally, how is the respiratory system classified?

1-the upper respiratory system, which includes the nose, nasal cavity, pharynx, and associated structures. 2-the lower respiratory system, which consists of the larynx, trachea, bronchi, and the lungs.

Functionally, how is the respiratory system classified?

1-the conducting zone 2-the respiratory zone.

What is the conducting zone?

Consists of a series of interconnecting cavities and tubes both outside and within the lungs. Signup and view all the answers

What is the respiratory zone?

Consists of tubes and tissues within the lungs where gas exchange occurs. Signup and view all the answers

What structures are associated with the conducting zone and what is their purpose?

Nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles. Their function is to filter, warm, and moisten air and conduct it to the lungs. Signup and view all the answers

What structures are associated with the respiratory zone and what is their purpose?

Includes the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli. These structures are the main site of gas exchange between air and blood. Signup and view all the answers

The frontal bone, nasal bones, and maxillae form the bony framework of the ___________.

external nose Signup and view all the answers

The cartilaginous framework of the external nose consists of the _______, the _, and ______.

septal nasal cartilage, lateral nasal cartilage, and alar cartilage. Signup and view all the answers

What are the two openings on the under surface of the external nose called?

external nares or nostrils Signup and view all the answers

What are the three functions of the internal structures of the external nose?

1-warming, moistening, and filtering incoming air 2-detecting olfactory stimuli 3-modifying speech vibrations. Signup and view all the answers

What is the nasal cavity lined with?

muscle and mucous membrane Signup and view all the answers

What are the two openings that are located in the posterior portion of the nasal cavity in which it communicates with the pharynx?

the internal nares or choanae Signup and view all the answers

What are the two regions called in which the nasal cavity is divided?

1-respiratory region 2-olfactory region Signup and view all the answers

Three shelves formed by projections of the superior, middle, and inferior are called _______.

nasal conchae Signup and view all the answers

What are the three anatomical regions of the pharynx?

1-nasopharynx 2-oropharynx 3-laryngopharynx or hypopharynx Signup and view all the answers

What is the opening in the oropharynx called?

fauces Signup and view all the answers

What is the structure that connects the laryngopharynx with the trachea?

the larynx Signup and view all the answers

How many pieces of cartilage are in the wall of the larynx?

9 Signup and view all the answers

What are the 3 pieces of cartilage of the larynx that occur singly?

thyroid, epiglottis, and cricoid Signup and view all the answers

What are the cartilages in the larynx that are found in pairs?

arytenoid, cuneiform, and corniculate Signup and view all the answers

Of the paired cartilages in the larynx, which is the most important and why?

The arytenoid cartilages, because they influence changes in position and tension of the vocal folds. Signup and view all the answers

What is the larynx cartilage that is also known as the Adam's Apple?

the thyroid cartilage Signup and view all the answers

What is the epiglottis?

the large leaf-shaped piece of elastic cartilage that is covered by epithelium. Signup and view all the answers

What is the glottis?

Consists of a pair of folds of mucous membrane, the vocal folds (true vocal cords) in the larynx, and the rima glottis. Signup and view all the answers

Which of the cartilages of the larynx is attached to the first ring of cartilage of the trachea by the cricotracheal ligament?

cricoid cartilage Signup and view all the answers

What is the landmark site for making an emergency airway/tracheotomy?

cricoid cartilage Signup and view all the answers

What type of joints do the arytenoid cartilages form with the cricoid cartilages?

synovial joints Signup and view all the answers

What are the superior pair of mucous membrane folds of the larynx called?

ventricular folds or false vocal cords Signup and view all the answers

What are the inferior pair of mucous membrane folds of the larynx called?

vocal folds or true vocal cords Signup and view all the answers

What is the space between the ventricular folds called?

rima vestibuli Signup and view all the answers

What are the three layers of the trachea wall?

1-mucosa 2-submucosa 3-hyaline cartilage 4-adventitia (composed of areolar connective tissue) Signup and view all the answers

What is the structure that is also known as the windpipe?

trachea Signup and view all the answers

Where does the trachea divide into right and left primary bronchi?

At the superior border of the fifth thoracic vertebra, the T5. Signup and view all the answers

What shape are the cartilage that provide semirigid support to maintain patency so that the trachea wall does not collapse inward?

they are solid C-shaped rings. Signup and view all the answers

Which of the primary bronchus is wider, shorter, and more vertical?

the right primary bronchus. Signup and view all the answers

What is the internal ridge which is found at the point in which the trachea divides?

the carina Signup and view all the answers

What branches from the primary bronchi?

the secondary/lobar bronchi Signup and view all the answers

How many lobes does the right and left lung have?

right-3 lobes left-2 lobes Signup and view all the answers

What are the smaller bronchi that branch from the secondary bronchi?

tertiary/segmental bronchi Signup and view all the answers

What branches from the tertiary/segmental bronchi?

bronchioles Signup and view all the answers

What structure signifies the end of the conduction zone?

terminal bronchioles Signup and view all the answers

What is the double-layered membrane that surrounds each lung?

the pleural membrane Signup and view all the answers

If someone has pleural effusion, what is wrong with them?

they have excess fluid that has accumulated in the pleural space, due to inflammation. Signup and view all the answers

What is the hilum/hilus?

Found on the mediastinal surface of each lung, through which bronchi, pulmonary blood vessels, lymphatic vessels, and nerves enter and exit. Signup and view all the answers

How much smaller is the left lung, as a result of the cardiac notch?

about 10 percent smaller Signup and view all the answers

What is the segment of lung tissue that each tertiary bronchus supplies called?

bronchopulmonary segment Signup and view all the answers

What is the specific structure that participates in gas exchange?

alveoli Signup and view all the answers

What is the cell type found in alveoli that are the main site of gas exchange?

type I alveolar cells Signup and view all the answers

What alveolar cell type contains microvilli, are fewer in numbers, secretes alveolar fluid, and keeps the surface between the cells and air moist?

type II alveolar cells/septal cells Signup and view all the answers

What are the small compartments found in each bronchopulmonary segment called?

lobules Signup and view all the answers

What does each lobule of the bronchopulmonary segment contain, and what is it wrapped in?

It is wrapped in elastic connective tissue and contains a lymphatic vessel, an arteriole, a venule, and a branch from the terminal bronchiole. Signup and view all the answers

What is the name of the fissure that can be found on both lungs, dividing them into lobes?

Oblique fissure Signup and view all the answers

What is the name of the fissure that can only be found on the right lung?

the horizontal fissure Signup and view all the answers

How many tertiary bronchi are in both lungs?

10 Signup and view all the answers

What are the 4 parts of the respiratory membrane?

1-alveolar wall 2-epithelial basement membrane 3-capillary basement membrane 4-capillary endothelium Signup and view all the answers

What are the two arteries that supply blood to the lungs?

pulmonary and bronchial arteries Signup and view all the answers

What are the only arteries in the body that carries deoxygenated blood?

pulmonary arteries Signup and view all the answers

What is ventilation-perfusion coupling?

A unique feature of pulmonary blood vessels in which constriction is in response to localized hypoxia. Vasoconstriction in response to hypoxia diverts pulmonary blood from poorly ventilated areas of the lungs to well-ventilated regions. Signup and view all the answers

Name some examples of structures and secretions that help maintain patency.

Bony and cartilaginous frameworks of the nose, skeletal muscles of the pharynx, cartilages of the larynx, C-shaped rings of cartilage in the trachea and bronchi, smooth muscles in the bronchioles, and surfactant in alveoli. Signup and view all the answers

Name some factors that compromise patency.

Crushing injuries to the bone and cartilage, deviated nasal septum, nasal polyps, inflammation of mucous membranes, spasms smooth muscle, and a deficiency of surfactant. Signup and view all the answers

What are the three basic steps of respiration?

1-pulmonary ventilation/breathing 2-external/pulmonary respiration 3-internal/tissue respiration Signup and view all the answers

What does pulmonary ventilation/breathing involve?

inhalation (inflow) and exhalation (outflow) of air and involves the exchange of air between the atmosphere and the lungs. Signup and view all the answers

What does external/pulmonary respiration involve?

the exchange of gases between the alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane. In this process, pulmonary capillary gains O2 and loses CO2. Signup and view all the answers

What does internal/tissue respiration involve?

the exchange of gases between blood in systemic capillaries and tissue cells, the blood loses O2 and gains CO2. Signup and view all the answers

In pulmonary respiration, what makes it possible for air to flow between the atmosphere and the alveoli of the lungs?

Alternating pressure differences created by contraction and relaxation of respiratory muscles. Signup and view all the answers

Air moves into the lungs when the air pressure inside the lungs is _______ than the air pressure in the atmosphere.

less Signup and view all the answers

Air moves out of the lungs when the air pressure inside the lungs is ________ than the air pressure in the atmosphere.

greater Signup and view all the answers

What is the air pressure of the atmosphere at sea level?

760 mmHg Signup and view all the answers

When is the air pressure inside the lungs equal to the air pressure of the atmosphere?

Just before each inhalation (breathing in). Signup and view all the answers

How is a lower pressure (lower than atmospheric pressure) in the alveoli achieved to produce flow of air into the lungs?

Increasing the size of the lungs. Signup and view all the answers

What is Boyle's law?

The inverse relationship between volume and pressure. Signup and view all the answers

What are the main muscles of inhalation?

The diaphragm and external intercostals. Signup and view all the answers

What happens to the diaphragm during normal quiet inhalation?

It contracts causing it to flatten, lowering its dome. This in turn increases the vertical diameter of the thoracic cavity. Signup and view all the answers

What happens when the external intercostals contract during inhalation?

They elevate the ribs and as a result, there is an increase in the anteroposterior and lateral diameters of the chest cavity. Signup and view all the answers

The diaphragm is responsible for % of the air that enters the lungs and the external intercostals are responsible for % during quiet breathing.

75, 25 Signup and view all the answers

During quiet inhalations, what is the pressure between the two pleural layers in the pleural cavity called and what is the pressure?

intrapleural (intrathoracic) pressure, it is always subatmospheric (lower than atmospheric pressure) Signup and view all the answers

As the volume of the lungs increase, what is the pressure in the lungs called?

Alveolar (intrapulmonic) pressure Signup and view all the answers

What are the accessory muscles of inhalation?

sternocleidomastoid muscles, the scalene muscles, and the pectoralis muscles. Signup and view all the answers

Inhalation is said to be a/an ________ process.

active Signup and view all the answers

Exhalation is said to be a/an ________ process.

passive Signup and view all the answers

What muscular contractions are involved in exhalation?

none Signup and view all the answers

When does exhalation start?

When the inspiratory muscles relax. Signup and view all the answers

What is the alveolar pressure in the lungs during exhalation?

762 mmHg Signup and view all the answers

Besides air pressure differences, name three factors that affect the rate of airflow and ease pulmonary ventilation.

Surface tension of the alveolar fluid, compliance of the lungs, and airway resistance. Signup and view all the answers

What is the substance made of phospholipids and lipoproteins that is present in alveolar fluid and reduces surface tension?

surfactant Signup and view all the answers

What is respiratory distress syndrome (RDS)?

A breathing disorder of premature newborns in which the alveoli do not remain open due to lack of surfactant. Signup and view all the answers

What is compliance of the lungs?

This refers to how much effort is required to stretch the lungs and chest wall. Signup and view all the answers

Describe high and low compliance.

high-the lungs and chest wall expand easily low-the lungs and chest wall resist expansion. Signup and view all the answers

Airflow =

the pressure difference between the alveoli and the atmosphere / the resistance Signup and view all the answers

What is eupnea?

the term for the normal pattern of quiet breathing. Signup and view all the answers

What is costal breathing?

A pattern of shallow (chest) breathing that consists of an upward and outward movement of the chest due to contraction of the external intercostals. Signup and view all the answers

What is diaphragmatic breathing?

A pattern of deep (abdominal) breathing that consists of the outward movement of the abdomen due to contraction and descent of the diaphragm. Signup and view all the answers

What is tidal volume (Vt)?

The volume of one breath. Signup and view all the answers

What is the minute volume (MV)?

The total volume of air inhaled and exhaled each minute-respiratory rate x tidal volume. Signup and view all the answers

The air that remains in the conducting airways (about 30 percent) that does not undergo respiratory exchange is called what?

anatomic (respiratory) dead space Signup and view all the answers

What is alveolar ventilation rate?

The volume of air per minute that actually reaches the respiratory zone. Signup and view all the answers

What is the average inspiratory reserve volume (additional inhaled air) in males and females?

3100 mL in males 1900 mL in females Signup and view all the answers

What is the average expiratory reserve volume (additional exhaled air) in males and females?

1200 mL in males 700 mL in females Signup and view all the answers

What is forced expiratory volume in one second (FEV 1.0)?

the volume of air that can be exhaled from the lungs in one second with maximal effort following a maximal inhalation. Signup and view all the answers

Study Notes

Respiratory System Overview

Comprised of structures: nose, pharynx, larynx, trachea, bronchi, and lungs.
Divided structurally into upper (nose, nasal cavity, pharynx) and lower (larynx, trachea, bronchi, lungs) respiratory systems.
Functionally classified into conducting zone (air passage) and respiratory zone (gas exchange).

Conducting Zone

Includes: nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles.
Main function: filter, warm, and moisten air before reaching lungs.

Respiratory Zone

Composed of: respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
Primary site for gas exchange between air and blood.

External Nose

Bony framework formed by frontal bone, nasal bones, and maxillae.
Cartilaginous structure includes septal nasal cartilage, lateral nasal cartilage, and alar cartilage.
Features external nares (nostrils) for airflow.

Internal Nose and Nasal Cavity

Lined with muscle and mucous membrane for air conditioning.
Divided into respiratory and olfactory regions.
Contains nasal conchae which enhance airflow and filtration.

Pharynx

Consists of three regions: nasopharynx, oropharynx, laryngopharynx.
Fauces is the opening in the oropharynx leading to the larynx.

Larynx Structure

Connects laryngopharynx to trachea; composed of 9 cartilages.
Contains: thyroid, cricoid, epiglottis (Adam's Apple).
Arytenoid cartilages control vocal fold tension and position.

Trachea

Known as the windpipe; divides into left and right primary bronchi at T5 vertebra.
Supported by C-shaped cartilage rings to maintain patency against collapse.
Lined with mucous membrane and cilia to trap debris.

Bronchi and Lungs

Right lung has 3 lobes; left lung has 2 lobes due to cardiac notch.
Tertiary bronchi branch into bronchioles, terminating at terminal bronchioles, marking the end of the conducting zone.

Alveoli and Gas Exchange

Alveoli are primary sites of gas exchange, composed mainly of type I alveolar cells.
Type II alveolar cells secrete surfactant, which reduces surface tension.
Each bronchioles' lobule contains lymphatic vessels, arterioles, and venules.

Pulmonary Blood Supply

Supplied by pulmonary and bronchial arteries; unique in carrying deoxygenated blood (pulmonary arteries).
Ventilation-perfusion coupling improves blood flow matching to airflow.

Respiration Mechanics

Consists of three phases: pulmonary ventilation, external respiration, and internal respiration.
Inhalation increases lung volume, creating lower pressure inside the lungs, allowing air to flow in.
Diaphragm contributes 75% of inhalation effort, external intercostals 25%.
Exhalation is primarily a passive process through relaxation of muscles.

Breathing Patterns

Eupnea refers to normal quiet breathing patterns.
Costal breathing involves shallow chest movements; diaphragmatic breathing involves deep abdominal movements.

Lung Volumes and Capacities

Tidal volume (Vt) is the volume of one breath; minute volume (MV) is the total air exchanged per minute.
Anatomic dead space consists of air remaining in conducting airways that does not participate in gas exchange.
Averaged specific lung volumes for males and females include inspiratory reserve (3100 mL males, 1900 mL females) and expiratory reserve (1200 mL males, 700 mL females).

Key Concepts

Boyle's law describes the inverse relationship between volume and pressure during respiration.
Compliance of lungs describes mechanical stretchability; high compliance indicates ease of expansion, while low compliance resists it.
Respiratory distress syndrome (RDS) can occur in premature newborns lacking adequate surfactant.

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Test your knowledge on the respiratory system with these flashcards. Covering structures and classifications, this quiz helps reinforce your understanding of the anatomy and function of the respiratory system.