Canine Head Flashcards
Cephalic index
Dog cephalic index = 100 x skull width / skull length
Different dog breed with different indexes
Dolichocephalic (grey hound)= below 50
Brachycephalic (frenchie)= over 100
Mesaticephalic= 50-100
What are the palpable structures of the head?
Infraorbital foramen
Mental foramen
Zygomatic arch/ mandible
Sagittal and nuchal crest
What are the superficial muscles of facial expression and what are they innervated by?
Mimetic muscles innervated by the facial nerve
Mimetic muscles
Orbicularis oris
Obicularis oculi
Caninus
Buccinator
Levator Nasolabialis
Levator labii superioris
Facial Nerve paralysis
Inability to close eye (obicularis occuli muscle)
Food in vestibule (buccinator m.)
Dropped ear (rostral and cd. auricular m.)
Which muscles will close the jaw?
Temporalis, masseter, med. and lat. pterygoid m.
Mandibular n.
Which muscle will open the jaw?
Digastricus m.
Cd. part innervated by the facial n.
Rostral part innervated by mandibular n.
Dropped jaw
Mandibular nerve paralysis
Temporalis m. has a dent
Muscles that close the jaw are compromised
Parotid salivary gland and lymph node
Parotid SG and duct opens against the upper 4th premolar
Parotid LN drains the super. structures dorsal to the palate
Mandibular salivary gland and lymph node
SG opens at the sublingual caruncle
LN drains the super. structures and intermandibular space
Sublingual salivary gland
Monostomatic opens at the sublingual caruncle
Polystomatic opens at the sublingual fold
Zygomatic/ buccal salivary gland
SG opens against the upper 2nd molar
Clinical consideration of the ranula and mucocele
Saliva leaks from a damaged salivary gland or duct and collects in the surrounding tissues
Ranula: Pathological dilatation of sublingual gland duct (oral floor)
Mucocele: Collection of mucoid surrounding tissues
Keratoconjuctivitis sica
An eye condition characterized by dryness and tear insufficiency
Treatment: transposition of the parotid duct into the conjunctival sac to compensate for compromised tear production
What are the 2 parts of the oral cavity?
Vestibule and oral cavity proper
Vestibule
Between the lips/ cheeks and teeth/ gum
Oral cavity proper
Between the dental arches
Dorsally: hard and soft palate
Ventrally: tongue and mucosa
Caudally: tongue, soft palate and palatoglossal arch
Permanent dog dental formula
2x ( I 3/3 C1/1 P 4/4 and M2/3) =42
Temporary dog dental formula and the last eruption
2x ( I 3/3 C1/1 P 3/3) = 28
Last eruption 6-8 months
What is the sectorial/ shearing tooth?
Upper P4, lower M1
Cat permanent dental formula
2x ( I 3/3 C1/1 P 3/2 and M1/1) =30
Cat temporary dental formula
2x ( I 3/3 C1/1 P 3/2) =26
Nerve block
Blocking palpebral branch of the auriculopalpebral nerve (facial) for an eye examination at the level of the zygomatic arch
What procedures may require blocking the infraorbital (maxillary) nerve?
Minor procedures in the upper lip, canines and incisors teeth as it emerges from the infraorbital foramen
What procedures may require blocking the mental (mandibular/ inferioralveolar) nerve?
Minor procedures in the lower lip, canines and incisors teeth
What are the structures of the tongue?
Root, body, apex
Mechanical papillae; filiform/ conical
Fungiform, vallate and foliate (taste buds)
Lyssa on the ventral surface
Extrinsic muscles of the tongue?
Geniohyoideus
Styloglossus
Hypoglossus
Genioglossus
Moves the tongue and innervated by the hypoglossal nerve (C12)
Intrinsic muscles of the tongue
Runs longitudinally, transversely and vertically
Stiffen the tongue
Hypoglossal nerve injury
Paralysis of extrinsic and Ipsilateral muscles
Inability to protrude tongue
Tongue deviates towards the injured side
What are the constrictors of the pharynx?
Pterygopharyngeus
Palatopharyngeus
Hyopharyngeus
Thyropharyngeus
Cricopharyngeus
What is the pharynx dilator?
Stylopharyngeus
Larynx
Voice box and prevents food from getting into the trachea
Innervated by the recurrent laryngeal nerve
Laryngeal vestibule
Extends from the entrance to the vocal fold
Glottic Cleft
Rima glottidis
Space between the vocal fold and the arytenoid cartilage
What forms the glottis?
vestibule and glottic cleft
What are the constrictors of the larynx?
Thyroarytenoideus
Cricoarytenoideus lateralis
What are the dilators of the larynx?
Cricoarytenoideus dorsalis
Arytenoideus transversus
What are the intrinsic laryngeal muscles innervated by?
Recurrent laryngeal n. (cd. laryngeal n.)
What is the Cricothryroideus m. innervated by?
Cranial laryngeal n.
Laryngeal Hemiplegia
Paralysis of the cricoarytenoideus dorsalis m.
Leads to laxity in the vocal fold, narrower glottis and obstructed airways
Epiglottic Entrapment
Brachycephalic airways syndrome in obsese large dogs
Redundant mucous membrane tightens during swallowing, keeping the epiglottis permanently covered (entrapped) by the aryepiglottic fold
Treatment for epiglottic entrapment
Through the axial transection of aryepiglottic fold using bistoury
Where do the lymph nodes drain into?
Into the medial retropharyngeal LN that drains into the tracheal duct
