Upper Respiratory Passageways: Anatomical features of the nose, nasal cavity and nasopharynx

The respiratory system consists of

Ancillary organs

The lungs

The diaphragm

Muscles of the thoracic body wall

Ancillary organs

Passageways leading to and from the lungs

The diaphragm

Main muscle of respiration

Forms partition between the thorax and abdominal cavities

The lungs

Passageways within each organ leading to the exchange tissue

General functions of the respiratory system

Gaseous exchange

Vocalization

Olfaction

Temperature regulation

Acid-base balance

Gaseous exchange

Volume regulation and air conditioning system via ancillary organs

Blood gas barrier=alveoli

Lateral bony boundaries of nasal cavity

Incisive, Maxilla, Zygomatic, and Lacrimal bones

Ventral bony boundary of nasal cavity

Incisive, maxilla, and palatine bones

Dorsal bony boundaries of nasal cavity

Incisive, maxilla, nasal, and frontal bones

Skull type of a greyhound

Dolichocephalic

Skull type of Labrador

Mesocephalic (or Mesaticephalic)

Skull type of Bulldog

Brachycephalic

Nostrils are divided by

Philtrum

Nostril appearance looks

Comma shaped

Skin of the nose

a glandular, hairless, pigmented and grooved

Nose is moistened by secretions produced by

Lacrimal glands

Lateral nasal glands

Blood supply to the nose/nasal plate is via

Sphenopalatine artery

Levator nasolabialis

“Snarl muscle”

Dilates the nostril and elevates the upper lip

Levator labii maxillaris

Elevates the upper lip and exposes the teeth

More medially located

Caninus

Elevates the upper lip and exposes the teeth

More laterally located

Motor supply of levator nasolabialis, levator labii maxillaris, and caninus

Facial nerve (VII)

Sensory innervation of nose

Infra-orbital nerve (Br. of Trigeminal (V))

Nostrils lead to the

Nasal vestibule

Nasal vestibule extends

beyond the bony skull

The nasal septum is ____ rostrally but becomes more ____ at its more caudal attachment

Cartilage

Bony

Nasal septum attached to what caudally?

The ethmoid bone

Nasal septum is supported ventrally by

The Vomer

Features of the nasal vestibule

Alar fold

Nasolacrimal duct

Lateral nasal glands

Alar fold

Largest mucosal fold found within the nasal vestibule

The nasolacrimal duct and lateral nasal gland ducts terminate

In the nasal vestibule

Dorsal and Ventral conchae are

Fragile scrolled bony networks covered in a very vascular mucosaF

Function of dorsal and ventral conchae

“Air conditioning”

Direct, slow, clean, warm, and moisten air

Ethmoidal conchae contain

Olfactory epithelium

Function smell

Air passageways in the nasal cavity are called

Dorsal, middle, ventral, and ethmoidal meatuses

Where do dorsal, middle, and ventral meatuses meet

Common nasal meatus

Paranasal sinus features

Air filled space(s) between the plates of bone which form the boundaries of each nasal cavity

Highly variable between species and age groups

Communicate directly with the nasal cavity

Lined with respiratory epithelium

Functions of the nasal cavity

Lighten head

Protect cranium

Increase are for muscular attachment without increase in weight of skull

Resonance function

What species have a maxillary recess?

Carnivores only

Clinical relevance of the presence of several compartments of the frontal sinus

Infection/aspergillosis is possible in these locations

What other structure is located within the maxillary recess

Lateral nasal glands

Vomeronasal organ features

Associated with ventral nasal meatus on both sides of s=nasal sptum

Tube filled with special olfactory mucosa

Vomeronasal organ function

Detection of pheromones

Incisive ducts features

Incisive papilla links oral cavity to vomeronasal organI

Incisive ducts function

Appraisal of small amounts of fluid from oral cavity

The boundaries of the nasopharynx are

Position of internal nares

Base of cranium

Palatopharyngeal arch

Soft palate

Features of the nasopharynx

Openings of the auditory tubes

Pharyngeal tonsil

Auditory tube features

Lead to tympanic bulla or middle ear

Lined by respiratory epithelium (possible site of infection)A

Auditory tube function

Equalization of pressure

Pharyngeal tonsil features

Part of the retro-pharyngeal lymph center

Lymphatic tissue - immuno-surveillances

Features of the common pharynx

Dual role - breathing and swallowing

Pharyngeal muscles form the wall - constrict, dilate, and shorten

Esophagus lies _________ to larynx and the trachea

caudal and dorsal

The larynx is supported by

Hyoid apparatus

How is the larynx moved during swallowing

“swings” rostrally