Respiratory System

• Respiratory system


  The connected structures from the nostrils and oral cavity to and including the lungs. Its major function is transport and exchange of gaseous oxygen and carbon dioxide into and out of the blood.
• Respiratory system

  • It is a portal of entry into the body and must be guarded
  • The upper respiratory tract, nasal cavity, and nasopharynx optimally warm or cool the gases brought into the body
  • Hairs associated with the nares filter out large particles
  • Smaller particles get stuck in the lining mucosa
  • Many ciliated lining cells drive the mucous coat back to the oral cavity for elimination
• Phonation


  Production of sound caused by movement of air across the vocal folds, causing them to vibrate
• Olfaction


  The sense of smell, perceived in the brain (cerebral cortex), involves receptors (olfactory nerve, CN I) located in the nasal cavity
• Heat regulation


  The dog helps control body temperature via evaporation through panting
• External nose


  The rostral structure protruding slightly from the face
• Philtrum


  The groove in the lip and middle of the nose separating the nostrils
• Nostrils (cranial nares)


  The external openings into the nasal cavity, thus, the respiratory system
• Bony nasal aperture


  The rostral ends of the nasal bones and the incisive bones, referred to as the immovable nose
• Movable portion of the nose

  The nasal cartilages, their ligaments and skin coverings
• Nasal cartilages


  The structures giving the nose its characteristic appearance
• Species differences in philtrum

  • Deep in carnivores and small ruminants
  • Shallow or absent in pig, ox and horse
• Nasal cavity


  The facial portion of the respiratory tract extending from the nostrils to the caudal nares, divided into halves by the median nasal septum
• Vestibule


  The rostral part of the nasal cavity just inside the nostril
• Nasal conchae


  Thin scrolls of bone covered by mucous membrane that fill the middle part of the nasal cavity
• Nasal meatuses


  Passages between the nasal conchae
• Ethmoturbinates


  The numerous bony scrolls filling the caudal part of the nasal cavity
• Median nasal septum


  The perpendicular partition separating the nasal cavity into left and right halves
• Ventral nasal concha


  The extensively folded structure filling the middle lumen of the nasal cavity
• Ethmoidal conchae


  The delicate, mucosa-covered, bony scrolls known as ethmoturbinates filling the caudal part of the nasal cavity
• Dorsal nasal concha


  The upper concha extending from the ethmoid bone's cribriform plate to the rostral nasal cavity
• Dorsal nasal meatus


  The narrow passageway between the dorsal nasal concha and the nasal bones leading into the caudal nasal cavity
• Middle nasal meatus


  The passageway between the dorsal nasal concha and the ventral nasal concha leading into the caudal nasal cavity
• Common nasal meatus


  The narrow vertical space between the median nasal septum and the conchae, from the roof to the floor of the nasal cavity
• Ventral nasal meatus


  The largest meatus located between the ventral nasal concha and the hard palate, leading directly into the nasopharynx
• Nasopharyngeal meatus


  The short passageway connecting the ventral nasal meatus with the caudal nares (choanae)
• Caudal nares or choanae


  The two openings of the nasopharyngeal meatus into the nasopharynx, separated by the vomer bone
• Nasal diverticulum ("false nostril") in horses: the dorsal passage through the nostrils into a blind cutaneous pouch
• Rostral bone (os rostrale) in pigs: the bone in the nose to help it "root"
• Larynx


  The musculocartilaginous tube connecting the laryngopharynx with the trachea and containing the vocal cords
• Laryngeal cartilages


  The group of cartilages forming the structure of the larynx, including the epiglottic, thyroid, cricoid, and paired arytenoid cartilages
• Epiglottis or epiglottic cartilage


  The rostral most cartilage giving structure to the epiglottis which closes the laryngeal opening during deglutition (swallowing), protecting the lungs from foreign material
• Epiglottic


  The rostral most cartilage giving structure to the epiglottis which closes the laryngeal opening during deglutition (swallowing), protecting the lungs from foreign bodies
• Cricoid


  The signet ring-shaped cartilage
• Hyoid apparatus


  Part of the laryngeal cartilages
• Arytenoid


  The paired, irregular, pyramid shaped cartilages articulating medially with the rostrodorsal border of the cricoid cartilage
• Corniculate process


  The rostral horn-like process that forms the dorsal part of the laryngeal opening
• Muscular process


  The lateral process of the arytenoid cartilage, providing a point of insertion of the intrinsic muscles of the larynx, especially the dorsal cricoarytenoideus muscle
• Thyroid


  The largest cartilage, single and open dorsally
• The laryngeal prominence is the ventral projection of the thyroid cartilage, known as the palpable "Adam's apple" in man