Chapter 22 - respiratory system Flashcards
What are the 4 things the respiratory system is responsible for and where do they function?
- pulmonary ventilation
- pulmonary gas exchange
- transport respiratory gases
- tissue gas exchange
What is the major organs in the upper respiratory system?
- nose and paranasal sinuses
- pharynx
What is the major organs in the lower respiratory system?
- larynx
- trachea
- bronchi and their smaller branches
- lungs and alveoli
What is the respiratory muscles classified with?
muscular system
Describe the function of the nose.
- produces mucus
- resonance chamber for speech
- receptors for sense of smell
Describe the function of the paranasal sinuses.
- lighten skull
- filters air
Describe the function of he pharynx and the common name.
- passageway for air and food
- connects nasal cavity to larynx and mouth to esophagus
- facilitates exposure of immune system to inhaled antigen
- throat
Describe the function of the larynx.
connects pharynx to trachea (cartilage and dense connective tissue)
- airway passage
- prevents food from entering lower reparatory
- voice production
Describe the function of the trachea.
flexible tube running from larynx and divides 2 main bronchi
- airway passage
- cleans, moistens, warms incoming air
Describe the function of the bronchial tree.
contains right and left bronchi (lack cartilage but has smooth tissue)
- connects air from trachea with alveoli
- cleans, moistens, warms incoming air
Describe the function of the alveoli.
termini of bronchial tree (made of simple squamous epithelium with thin basement membrane)
- main site for gas exchange
- surfactant reduces surface tension (prevents alveolar collapse)
Describe the function of the pleurae.
serous membrane - lines thoracic cavity
- produces lubricating fluid and compartmentalize lungs
What are the two regions of the nose?
- External nose
- Nasal cavity
What are the surface features of the external nose?
- Root: Area between eyebrows.
- Bridge: The upper part of the nose.
- Dorsum nasi: Anterior margin of the nose.
- Apex: Tip of the nose.
- Nostrils (nares): External openings of the nose, bounded laterally by alae.
What is the skeletal framework of the external nose?
- Nasal and frontal bones superiorly: Form the bridge and root.
- Maxillary bones laterally: Form the sides of the nose.
- Plates of hyaline cartilage inferiorly: Includes alar and septal cartilages.
What structures form the nasal septum?
- anteriorly by septal cartilage
- posteriorly by the vomer bone and perpendicular plate of the ethmoid bone
What are the posterior nasal apertures (choanae)?
openings that allow air to pass from the nasal cavity into the nasopharynx
What forms the roof of the nasal cavity?
the ethmoid and sphenoid bones
What forms the floor of the nasal cavity?
Hard palate (bone)
Soft palate (muscle)
What is the nasal vestibule?
part of the nasal cavity located superior to the nostrils and lined with vibrissae (hairs) to filter air particles.
What lines the rest of the nasal cavity?
- olfactory mucosa: lines superior region and contains olfactory epithelium
- respiratory mucosa: line most of the cavity and contains:
- pseudostratified ciliated columnar epithelium with goblet cells
- lamina propria with seromucous nasal glands
What is the function of the respiratory mucosa?
- cilia that sweeps contaminated mucus posteriorly towards the throat
- seromucous nasal glands, which secrete:
- mucous cells
- serous cell (watery with enzymes)
What is the function of the mucosa’s sensory nerve endings?
trigger the sneeze reflex to remove irritants
How is inspired air treated in the nasal cavity?
warmed by plexuses of capillaries and thin-walled veins in the mucosa
What are the nasal conchae and how are they divided?
scroll-like, mucosa-covered projections that protrude medially from the lateral walls of the nasal cavity
1. superior concha
2. middle concha
3. inferior concha
What is the function of the nasal conchae?
- the shape increases the mucosal area exposed to air and enhances turbulent airflow
- helps trap more air particles in mucus, improving air cleaning
What happens during inhalation and exhalation regarding the conchae?
- During inhalation, conchae and nasal mucosa filter, heat, and moisten the air.
- During exhalation, conchae and mucosa reclaim most of the heat and moisture.
What are paranasal sinuses?
- air-filled spaces within the frontal, sphenoid, ethmoid, and maxillary bones that surround and connect with the nasal cavity.
What type of muscle makes up the wall of the pharynx?
skeletal muscle
Into how many regions is the pharynx divided?
- Nasopharynx
- Oropharynx
- Laryngopharynx
Where is the nasopharynx located?
is posterior to, and continuous with the nasal cavity
What type of epithelium lines the nasopharynx?
pseudostratified ciliated columnar epithelium that propels mucus inferiorly
What is the primary function of the nasopharynx?
airway
How does the nasopharynx function during swallowing?
the soft palate and uvula move superiorly to close off the nasopharynx
What structures are located in the posterior wall of the nasopharynx?
contains the pharyngeal tonsils (also known as adenoids).
How are the lateral walls of the nasopharynx connected to the middle ear?
are connected to the middle ear by the pharyngotympanic (auditory) tubes
What is the function of the pharyngotympanic tubes and what protects the entrance?
drain the middle ear and allow pressure to equalize with atmospheric pressure
- tubal tonsils
What is a swollen adenoid?
- infection can block air passage in nasopharynx (breath through mouth)
- can disrupt speech and sleep
Where is the oropharynx located and its function?
- posterior to, and continuous with, the oral cavity
- passageway for food and air from the level of the soft palate to the epiglottis
What is the archway between the oropharynx and the oral cavity called?
isthmus of fauces
What type of epithelium lines the oropharynx?
protective stratified squamous epithelium.
Where are the palatine tonsils located?
in the lateral walls of the oropharynx, posterior to the oral cavity
What is the location of the lingual tonsil?
the posterior surface of the tongue
Where is the laryngopharynx located and its function?
- posterior to the larynx
- passageway for both food and air
What type of epithelium lines the laryngopharynx?
stratified squamous epithelium
How far does the laryngopharynx extend?
to the bottom of the larynx, where it is continuous with the esophagus
How is the respiratory system divided?
Respiratory zone: gas exchange; consists of respiratory bronchioles, alveolar ducts, and alveoli
Constructing zone: all other airways (from nose to respiratory bronchiole)
- transport air to and from sites of gas exchange
- cleanse, warm and humify incoming air
What is the larynx connected to superiorly and inferiorly?
laryngopharynx and trachea
What is the framework of the larynx composed of?
nine cartilages connected by membranes and ligaments
Where is the larynx located and what are the 3 main functions?
- attaches to the hyoid bone
1. provides an open airway
2. routes air and food into proper channels
3. voice production (houses vocal cords)
What are the eight hyaline cartilages of the larynx?
- Thyroid cartilage (shield-shaped).
- Cricoid cartilage (ring-shaped).
- Three pairs of small cartilages: arytenoid, cuneiform, and corniculate cartilages.
What is the thyroid cartilage, and what is its prominent feature?
is shield-shaped, and its anterior, midline ridge is called the laryngeal prominence (commonly known as the Adam’s apple).
What is the function of the epiglottis?
(elastic cartilage) covers the laryngeal inlet during swallowing as the larynx is pulled superiorly
What is the epiglottis covered in?
taste bud–containing mucosa
What is the structure of vocal ligaments and why do they appear white?
- elastic fibers
- lack blood vessels
What are vocal folds (true vocal cords) and what do they do?
- are mucosal folds that contain the vocal ligaments and vibrate
- produce sound as air passes through them during expiration.
What is the opening between the vocal folds called?
glottis
What are vestibular folds (false vocal cords), and do they produce sound?
- are found superior to the vocal folds
- do not produce sound but help close the glottis during swallowing.
What type of epithelium lines the superior part of the larynx (above the vocal folds)?
epithelium superior to the vocal folds is protective stratified squamous epithelium.
What type of epithelium lines the inferior part of the larynx (below the vocal folds)?
epithelium inferior to the vocal folds is pseudostratified ciliated columnar epithelium
What is the function of the cilia in the laryngeal epithelium?
The cilia in the pseudostratified ciliated columnar epithelium sweep mucus superiorly toward the pharynx
How is speech produced in terms of airflow and the glottis?
by the intermittent release of expired air during the opening and closing of the glottis
What determines the pitch of the voice?
by the length and tension of the vocal folds. Tenser folds vibrate faster to produce a higher pitch.
How is sound shaped into language?
by the muscles of the pharynx, tongue, soft palate, and lips.
How can vocal folds function as a sphincter?
can act as a sphincter by closing the glottis to prevent air passage.
How many generations of branching do the airways undergo, and what do they form?
- 23 gens
- bronchial tree
Conducting zone - What is the first division of the trachea?
The trachea divides into the right and left main (primary) bronchi, one for each lung.
What is the relationship between the conducting zone and respiratory zone structures?
At the tips of the bronchial tree, conducting zone structures give rise to respiratory zone structures.
Conducting zone - What happens after the primary bronchi divide?
Each primary bronchus branches into lobar (secondary) bronchi, one for each lobe of the lung.
- Right lung: 3 lobar bronchi
- Left lung: 2 lobar bronchi
Conducting zone - Where do the primary bronchi enter the lungs, and how do they differ between the right and left lungs?
- hilum
- the right bronchus is wider, shorter, and more vertical than the left.
What happens after the lobar bronchi divide?
Secondary (lobar) bronchi branch into segmental (tertiary) bronchi, and these divide repeatedly into smaller branches.
What are the smallest branches of the bronchial tree?
bronchioles
What are terminal bronchioles?
the smallest bronchioles
How do the walls of the main bronchi compare to those of the bronchioles?
- similar to trachea, but airways progress to bronchioles
- structural changes occur: replacement of cartilage rings with irregular cartilage plates and a decrease in cartilage presence in bronchioles
What structural changes occur in the epithelium as airways move from bronchi to bronchioles?
The epithelium thins as it transitions from pseudostratified columnar to simple columnar, and finally to simple cuboidal in bronchioles.
How do the cilia and goblet cells change as you move from bronchi to bronchioles?
The number of cilia and goblet cells decreases as the airways progress from bronchi to bronchioles.
What structures follow the respiratory bronchioles in the respiratory zone?
lead into alveolar ducts, which then connect to alveolar sacs
How does the amount of smooth muscle change in the conducting zone?
increases, allowing bronchioles to control their diameter and provide resistance to airflow as needed.
Where do the respiratory zone structures begin?
begins at the terminal bronchioles and into respiratory bronchioles.
What is contained within the alveolar sacs?
contain clusters of alveoli, which are the sites of gas exchange.
What is the function of the respiratory membrane and main components?
- extremely thin and acts as a blood-air barrier, allowing gas exchange by simple diffusion
- alveolar and capillary walls with a shared basement membrane
What type of epithelium makes up the alveolar wall?
simple squamous epithelium, primarily composed of Type I alveolar cells.
What is the role of Type II alveolar cells?
are scattered cuboidal cells that secrete surfactant and antimicrobial proteins along the inner surface of the alveoli.
What happens to the alveolar macrophages after they consume debris?
carried by cilia to the throat and then swallowed
What surrounds the alveoli and how does it aid in lung function?
- fine elastic fibers and a dense network of pulmonary capillaries
- help with gas exchange and provide structural support.
What is the function of alveolar pores?
- connect adjacent alveoli to equalize air pressure
- provides alternate routes in case of airway blockages.
What is the role of the pulmonary circulation?
carries systemic venous blood from the heart to the lungs for oxygenation
- is a low-pressure, high-volume system
What is the costal surface of the lung?
refers to the anterior, lateral, and posterior surfaces of the lung, which lie deep to the ribs
How is the right lung structured?
is divided into superior, middle, and inferior lobes
- the superior and middle lobes are separated by the horizontal fissure
- the middle and inferior lobes are separated by the oblique fissure.
What is the hilum of the lung?
is located on the mediastinal surface of the lung and serves as the entry/exit point for blood vessels, nerves, bronchi, and lymphatic vessels.
How is the left lung structured?
is divided into superior and inferior lobes by the oblique fissure.
- smaller than the right (bc heart)
What are the two circulations that perfuse the lungs?
are perfused by two circulations: pulmonary circulation and bronchial circulation.
- differ in size, origin, and function.
What is the function of the pulmonary capillary endothelium?
- has enzymes that assist in gas exchange for blood
What is the bronchial circulation?
provides oxygenated blood to the lung tissue
- blood from aorta and enters through hilum and supplies all lung tissue except the alveoli
How is bronchial circulation different from pulmonary circulation?
are part of the systemic circulation, so they are high-pressure and low-volume
How are the lungs innervated?
by parasympathetic, sympathetic, and visceral sensory fibers.
- enter through the pulmonary plexus at the lung root and follow the bronchial tree and blood vessels.
What is the effect of parasympathetic innervation on the lungs?
cause bronchoconstriction, narrowing the airways.
What is the effect of sympathetic innervation on the lungs?
cause bronchodilation, relaxing the airways and increasing airflow
What is the term for fluid in the pleural cavity and other fluids may accumulate in it?
- Blood from damaged blood vessels.
- Capillary filtrate when left-sided heart failure occurs.
- pleural effusion
What is each lung lobe divided into and how many segments are in each lung?
- bronchopulmonary segments
- right: 10 segments
- left: 8-10 segments
What structures serve each bronchopulmonary segment and how are they separated?
- has its own artery, veins, and bronchus
- by connective tissue septa
Can diseased bronchopulmonary segments be removed?
Yes
What are lobules in the lung and what serves each lung?
- smallest subdivision of the lungs visible to naked eye and are hexagonal
- conducting bronchioles and their respiratory branches
What separates the lobules?
- connective tissue
Why is elasticity important in lung tissue?
- reduces the work of breathing
