ANFS240 lec 19-20 (exam 3)

nasopharynx

caudal to nasal cavity and dorsal to oropharynx(caudal part of oral cavity)

Eustachian (auditory) tubes

tubes that allow the nasopharynx to communicate w/ middle ear; allows air to pass between middle ear to equalize pressure on eardrum

guttural pouch

found only in equine; outpouching of eustachian tube that extends between the base of the skull and the atlas; cools the blood that supplies the brain

Laryngopharynx

where oropharynx and nasopharynx combine; The previously dorsal respiratory tract moves ventrally, and the previously ventral GI tract moves dorsally

larynx

4 cartilaginous structures that prevent entry of food into respiratory tract; plays a large role in vocalization; Suspended from skull via hyoid apparatus

4 peices of laryngeal cartilage

epiglottic cartilage; thyroid cartilage; cricoid cartilage; arytenoid cartilage

Epiglottis

(part of larynx) protects the trachea; Complete structure with mucosa covering it; When an animal swallows, it "flips" backward, covering the tracheal entrance

thyroid cartilage

(part of larynx) Largest; U-shaped; Supportive function; Most rostral part is the Adams Apple

cricoid cartilage

(part of larynx) Ring-shaped; Connects thyroid cartilage to trachea; Made of hyaline cartilage; is susceptible to aging

arytenoid cartilage

(part of larynx) paired; move significantly when breathing; has an aryepiglottic fold

Aryepiglottic fold

fold of tissue between the arytenoid cartilage and the epiglottis, in most species

glottis

Space below the arytenoids and dorsal to the epiglottis; Entry to the trachea

Vocal Cords

soft tissue that extends from the arytenoid cartilage to the thyroid cartilage; Narrowing and widening of the glottis along with vibration of the vocal cords are responsible for

variation in vocalization

trachea

firm tube of cartilaginous rings extending from larynx to lungs; most species its comprised of C shaped rings incomplete dorsally (complete in birds)

inside of trachea

Inner mucosal layer of pseudostratified ciliary epithelium; Produces mucus as barrier; Cilia line inner trachea

Cilia

small hairlike projections on the cells lining the trachea that continuously move foreign material and mucus upward toward the larynx, to be swallowed

bronchi location

trachea bifurcates(around the 4th-6th intercostal space) just cranial to the heart, creating two main bronchi; Larger bronchi are nearly identical to the trachea, with cartilaginous rings and an inner mucosal layer

bronchi

Branch into the different lung lobes, & create more and smaller branches with gradually disappearing cartilage until they ultimately become bronchioles

bronchioles

cartilage of bronchi replaced by glandular cells, muscle and epithelium; less than 1mm diameter; branch several times before terminating as terminal bronchioles; eventually lose mucus producing cells and are replaced w/ cells that create lung surfactant (the material that allows lungs to not stick together when filled with air)

alveoli

blind end of airway where gas exchange occurs; Sac-like structure surrounded by thin epithelium; Closely associated with pulmonary capillaries so O2 and OC2 can be transferred