Intro to Respiratory system Flashcards
Elements of the upper respiratory system
- external nares
- nasal cavity
- sinuses
- larynx
Elements of lower respiratory system
- Trachea
- Lungs
- Bronchi
- Bronchioles
- Alveoli
External nares
- air enters
- philtrum, groove in lip and middle of the nose separating nostrils
Nasal cavities
facial portion of resp. tract that extends from nostrils to the caudal nares
- separated by cartilaginous septum
- floor formed by hard and soft palate
- entry is called the vestibule; lined with conchae
- each half communicates with pharynx via choanae
- connected to paranasal sinuses and nasopharynx
- on dorsolateral walls of nasopharynx are auditory tubes
- lined with mucosal membrane
Anatomy of the concha and meatus
- Covers and contains scroll like bones-concha
- covered with vascular mucous membranes
- dorsal and ventral conchae occupy rostral areas
- caudally; ethmoid conchae
- separating the cavity into passages; meatus
Function of the conchae and meatus
- mucosa of the conchae is well vascularised; increases air turbulence
- hence warms, humidifies and filters air
- cooling the blood that supplies the brain
- mucous membrane covering ethmoidal conchae is the olfactory epithelium; sensory endings of the olfactory nerve
Nasal meatus
- dorsal meatus leads to the frontal sinus (except in horse; olfactory mucosa instead)
- middle nasal meatus leads to maxillary sinuses and olfactory mucosa
- horse; all paranasal sinuses communicate with middle nasal meatus
- ventral and common meatus leads to principle resp. passage
Paranasal Sinuses
- spaces lined with mucosa, communicate with nasal passages via narrow openings
- function still not fully known
Locations of different sinuses
- ALL species have frontal and maxillary sinuses; frontal at dorsal part of skull, maxillary nasal cavity either side
- large farm animals have sphenoidal and palatine sinuses; sphenoid opens to the nasal cavity, palatine communicates with maxillary sinus
- Lacrimal sinus; swine and ruminants
- Conchal sinus; swine, ruminants and horses. Formed by enclosure of conchae
The two types of paranasal sinuses
- Sinuses that communicate collectively with the middle nasal meatus
- Those that communicate with the ethmoidal nasal meatuses
DOG; paranasal sinuses
- maxillary sinus is termed maxillary recess; large diverticulum of nasal cavity)
- bound by ethmoid, maxillary, palatine and lacrimal bones
- frontal sinus
- sphenoid sinus; within the presphenoid bone
COW; paranasal sinuses
- don’t have fully developed sinuses until age 7
- palatomaxillary sinus within caudal part of hard palate
- frontal sinus has diverticula
Paranasal sinuses function
- affects resonance of the voice
- lightens the weight of the skull
- heat exchange
- sites for mucus secretion
- equalises pressure in nasal cavity
Regions of the pharynx
- Common passageway for air and food
- pharynx; oropharynx, nasopharynx and laryngopharynx
- innervated by vagus nerve
-Musculocartilagenous organ- guards trachea opening - vocal chords
- Glottis; slit opening between vocal chords
- Epiglottis; cranial to glottis, cartilage covered with mucous membrane
- laryngeal cartilage; epiglottis, thyroid, cricoid, arytenoid
- prevent airway collapse
The guttural pouch
- paired diverticula of auditory tubes
- pouches are in direct contact with each other; separated by a thin medial septum
- stylohyoid bone; forms medial and lateral pouches
- communicates with the pharynx via pharyngeal orifice
of the auditory tube covered by thin fibrocartilage
