22.1 Organs and Structures of the Respiratory System

what are the major function of the respiratory system

provide oxygen to body tissues for cellular respiration, remove waste product CO2, nonvital functions, and straining

what is an example of nonvital functions

sensing odors and speech production

what is an example of straining

childbirth or coughing

what are the 2 functional zones of the respiratory system

conducting zone and respiratory zone

what is the conducting zone

organs and structures not directly involved in gas exchange

what is the respiratory zone

where gas exchange occurs

what are the major functions of the conducting zone

provide route for incoming and outgoing air, remove debris and pathogens from the incoming air, and warm and humidify the incoming air

what are examples of conducting zones for sensing odors and metabolize airborne carcinogens

epithelium of nasal passages essential for sensing odors, and the bronchial epithelium that lines the lungs can metabolize airborne carcinogens

what is the major entrance and exit for respiratory system

the nose

what is the two major sections of the nose

external nose and the nasal cavity (internal nose)

what does the external nose consists of

the surface and skeletal structures that result in the outward appearance of the nose and contribute to its numerous functions

what is the root of the nose

the region of the nose located between the eyebrows

what is the bridge of the nose

the part of the nose that connects the root to the rest of the nose

what is the dorsum nasi of the nose

length of nose

what is the apex of the nose

tip of nose

how are nostrils formed

by alae (singular = ala) on either side of the apex

what is the ala of the nose

is a cartilaginous structure that forms the lateral side of each naris (plural = nares), or nostril opening

what is the philtrum of the nose

the concave surface that connects the apex of the nose to the upper lip

what are the nasal bones

is one of a pair of bones that lies under the root and bridge of the nose

where is the nasal bone located

The nasal bone articulates superiorly with the frontal bone and laterally with the maxillary bones

what is septal cartilage

flexible hyaline cartilage

what forms the dorsum nasi

septal cartilage being connected to the nasal bone

what is the alar cartilage

cartilage that supports the apex of the nose and helps shape the nares

the nares are separated into what, how, and open into what

left and right sections, by nasal septum, into the nasal cavity

what is the nasal septum

wall composed of bone and cartilage that separates the left and right nasal cavities

what is the nasal septum formed by

perpendicular plate of the ethmoid bone, vomer bone, and septal cartilage

what are the 3 sublayers of the nasal conchae

superior nasal conchae, middle nasal conchae, inferior nasal conchae

which inferior sublayer of the nasal conchae is separate

inferior conchae

which inferior sublayer of the nasal conchae are portions of the ethmoid bone

superior conchae and middle conchae

what are the purpose of the nasal conchae

serve to increase the surface area of the nasal cavity and to disrupt the flow of air as it enters the nose, causing air to bounce along the epithelium, where it is cleaned and warmed

what is the meatuses and where is it located

spaces located beneath the nasal conchae in the nasal cavity

together, what does the conchae and meatus do

conserve water and prevent dehydration of the nasal epithelium by trapping water during exhalation

what is the floor of the nasal cavity composed of

the palate

what is the hard palate composed of

bone

where is the hard palate located

anterior region of the nasal cavity

where is the soft palate located

posterior portion of the nasal cavity

what is the soft palate composed of

muscle tissue

After passing through the nasal cavities, through which structure does air exit before entering the pharynx?

Air exits the nasal cavities via the internal nares and moves into the pharynx.

what is the nasal conchae

bony projections in the nasal cavity

what are paranasal sinuses and what are their functions

one of air containing spaces within the skull, that serve to warm and humidify incoming air

what are the sinuses within the skull lined with

a mucosa

each paranasal sinus is named after its associated bone, name them

frontal sinus, maxillary sinus, sphenoidal sinus, and ethmoidal sinus

what do sinuses produce and help with

mucus and lighten the weight of the skull

what is the function of the mucous membranes in the nares and anterior portion of the nasal cavities

mucous membranes, along with sebaceous glands and hair follicles, serve to prevent the passage of large debris, such as dirt, through the nasal cavities

where is the olfactory epithelium located in the nasal cavity

deeper in the nasal cavity

what is the function of the olfactory epithelium

detect odors

what are the conchae, meatuses, and paranasal sinuses lined by

respiratory epithelium

what is respiratory epithelium composed of

pseudostratified ciliated columnar epithelium

what do pseudostratified ciliated columnar epithelium contain

goblet cells, one of the specialized, columnar epithelial cells

what do the specialized columnar epithelial cells produce

mucus to trap debris

what does the cilia (hair like structures) of the respiratory epithelium do

help remove the mucus and debris from the nasal cavity with a constant beating motion, sweeping materials towards the throat to be swallowed

how does temperature affect the movement of cilia and what is the result

cold air slows movement of cilia down, resulting in accumulation of mucus that may in turn lead to a runny nose during cold weather

what does the moist epithelium of the respiratory epithelium function to do

warm and humidify incoming air

how is the air warmed

caps under the nasal epithelium warm the air by convection

what enzymes and proteins are secreted by serous and mucus producing cells in the nasal epithelium

the cells secrete lysozyme enzyme and proteins called defensins

what is the function of the lysozyme and defensins in the nasal cavity

lysozyme and defensins have antibacterial properties

what provides additional protection in the respiratory epithelium

immune cells that patrol the connective tissue deep to the respiratory epithelium

what do the seromucous glands in the submucosa provide

lubricating mucus

what is the pharynx

a tube formed by skeletal muscle and lined by mucous membrane that is continuous with that of the nasal cavities

what are the 3 major regions of the pharynx

nasopharynx, oropharynx, laryngopharynx

what is the nasopharynx

part of the pharynx flanked by the conchae of the nasal cavity

what does the nasopharynx serve as

serves only as an airway

what structure is located top of the nasopharynx

pharyngeal tonsils

what is a pharyngeal tonsil (adenoid)

is an aggregate of lymphoid reticular tissue similar to a lymph node that lies at the superior portion of the nasopharynx

what does the pharyngeal tonsil (adenoid) contain

a rich supply of lymphocytes

what is the pharyngeal tonsil (adenoid) covered with

ciliated epithelium that traps and destroys invading pathogens that enter during inhalation

what happens to the pharyngeal tonsils (adenoids) as children age

are large but regresses with age and may even disappear

what is the uvula

is a small bulbous, teardrop-shaped structure located at the apex of the soft palate (posterior portion of nasal cavity consists of muscle tissue)

what does the uvula and soft palate do together

move like a pendulum during swallowing, swinging upward to close off the nasopharynx to prevent ingested materials from entering the nasal cavity

what structure opens into the nasopharynx

auditory (eustachian) tubes connect to each middle ear cavity and open into nasopharynx

what often leads to ear infection

colds

what is the oropharynx

part of the pharynx flanked by the nasopharynx, oral cavity, and laryngopharynx

what does the oropharynx serve as

passageway for both air and food

what is the fauces

the opening at the connection between the oral cavity and the oropharynx

as the nasopharynx becomes the oropharynx, what happens to the epithelium

changes from pseudostratified ciliated columnar epithelium to stratified squamous epithelium

what are the two distinct sets of tonsils in the oropharynx

palatine tonsil and lingual tonsil

what is the palatine tonsil and location

one of a pair of structures located laterally in the oropharynx in the area of the fauces

what is the lingual tonsil and location

one of a pair of structures located at the base of the tongue

what are the palatine and lingual tonsils composed of and do (similar to pharyngeal tonsil)

lymphoid tissue, and trap and destroy pathogens entering the body through the oral or nasal cavities

what is the laryngopharynx

part of the pharynx bordered by the oropharynx superiorly and esophagus and trachea inferiorly

what does the laryngopharynx serve as

continues the route for ingested material and air until its inferior end, where the digestive and respiratory systems diverge (separates)

as the oropharynx becomes the laryngopharynx, what happens to the epithelium

nothing, stratified squamous epithelium of oropharynx is continuous with laryngopharynx

what does the laryngopharynx anteriorly open into

the larynx

what does the laryngopharynx posteriorly enter into

the esophagus

what is the larynx composed of

a cartilaginous structure by several pieces of cartilage

where is the larynx located

inferior to the laryngopharynx that connects the pharynx to the trachea

what is the function of the larynx

help regulate volume of air that enters and leaves the lungs

what is the 3 large cartilage of the larynx

thyroid cartilage (anterior), epiglottis (superior), and cricoid cartilage (inferior)

what forms the major structure of the larynx

thyroid cartilage, epiglottis, and cricoid cartilage

what is the thyroid cartilage

largest piece of cartilage that makes up the larynx

what is the laryngeal prominence of thyroid cartilage

region where the two lamine of the thyroid cartilage join, forming a protrusion known as the “Adam’s apple”

what is the cricoid cartilage

thick, forms a ring, with a wide posterior region and a thinner anterior region

what are the three smaller paired cartilages of the larynx

arytenoids, corniculates, and cuneiforms

what is the function of the three smaller paired cartilages (arytenoids, corniculates, and cuniforms)

moving the vocal cords (or folds) to produce speech

what are the three smaller cartilages (arytenoids, corniculates, and cuniforms) attached to

the epiglottis and the vocal cords and muscle

what is the epiglottis attached to

thyroid cartilage

what is the epiglottis

a very flexible piece of elastic cartilage that covers the opening of the trachea

what is the glottis

part of the larynx, that consists of vocal cords (folds) and opening between them, in which air passes when producing speech

what happens to the epiglottis in a “closed” position

position, the unattached end of the epiglottis rests on the glottis

what is the glottis composed of

vestibular folds, the true vocal cords, and the space between these folds