Lecture 6 Flashcards
What are the names given to the structures labled 90-94?
(90) : Basihyoid
(91) : Ceratohyoid
(92) : Thyrohyoid
(93) : Epihyoid
(94) : Stylohyoid
Note: in the horse the epihyoid is very small and is usually fused with the stylohyoid
Which of the following hyoid bones is found in the guttural pouch and is responsible for dividing it into a medial and lateral cavity?
Epihyoid
Basihyoid
Stylohyoid
Ceratohyoid
Thyrohyoid
Stylohyoid
Name the structure labeled (90’).
What is the significant difference is there between the horse and the cow for this structure?
It is the lingual process of the basihyoid.
It is very pronounced in the horse but much shorter in the cow.
Name the two muscles highlighted in red and yellow.
Yellow is the cricoarytenoideus dorsalis.
Red is the cricothyroideus.
What is the innervation and action of the cricoarytenoideus dorsalis and the cricothyroideus?
Cricoarytenoideus dorsalis recieves its innervation from the caudal laryngeal nerve and acts to dilate the larynx.
Cricothyroideus muscle recieves its innervation from the cranial laryngeal nerve and acts to tense/relax the vocal cords.
Where would you expect to find the Tympanohyoid?
It articulates with the skull and in the horse is composed of hyaline cartilage.
What are the guttural pouches?
What is there function?
They are diverticula of the auditory tubes.
Function is still not clear but is thought to aid in the cooling of blood going to brain.
Define epistaxis.
What is the clinical significance of epitaxis to horses.
Epistaxis is bleeding from the nose.
Horses will get mycotic infections in the guttural pouch. The bacteria wear away the walls of the internal carotid and cause persistant bleeding.
What is the location of the guttural pouch?
Ventral to the skull and wings of the atlas.
Dorsolateral to the nasopharynx and laryngopharynx.
What is the approximate volume of the guttural pouch and what is it typically filled with?
Volume is between 300-500 ml and is normally filled with air.
What structure is highlighted with the red dotted lines?
The stylohyoid bones
Identify the structure highlighted in blue.
The pharyngeal openings of the auditory tubes.
Identify the structure highlighted in red.
External acoustic meatus
How are the guttural pouches separated from right and left sides.?
Dorsally they are separated by the longus capitus muscle.
Rostral ventral separation is by a thin mucousal membrane.
What is the clinical significance of the rostral ventral mucosal membrane that separates the right and left guttural pouch?
An extremely aggressive infection in one guttural pouch can easily break through this membrane and infect the other pouch.
Identify these structures:
- )
- )
- )
- ) Maxillary artery
- ) External carotid
- ) Internal carotid
Describe the location of the following structures within the guttural pouch.
- ) Internal carotid
- ) External carotid
- ) Maxillary artery
- ) Maxillary vein
- ) Medial compartment of the guttural pouch.
- ) Mostly in the lateral compartement but also the floor of the medial compartment.
- ) Hard to anatomically differentiate it from the external carotid so could be lateral compartment.
- ) Lateral compartment.
List the cranial nerves associated with the guttural pouch.
Glossopharyngeal (IX)
Vagus (X)
Accessory (XI)
Hypoglossal (XII)
Facial (VII)
Also the cranial cervical ganglion and the internal carotid nerve
Which cranial nerves come out of the jugular part of the foramen lacerum?
Glossopharyngeal (IX)
Vagus (X)
Accessory (XI)
Which foramen does the Facial nerve come out of?
Stylomastoid foramen
What type of clinical signs would observe if there was damage to the Glossopharyngeal and Facial nerve due to a guttural pouch disease?
Glossopharyngeal: the gag reflex would not be working
Facial: difficulty with prehension, no menance response, muscles of facial expression would not be functional, upper lip pinch would not illicit a response
What type of clinical signs would you observe if there was damage to the Vagus, Accessory and hypoglossal nerves due to a guttural pouch disease?
Vagus: no gag reflex, no cough reflex and laryngeal hemiplasia
Accessory: possible atrophy to the trapezius muscle
Hypoglossal: deviated tongue, inability to extend or retract the tongue
What are the foramina labeled 1 and 2 and identify the nerves that come out of these foramina.
- ) Hypoglossal foramin
- hypoglossal nerve - ) Stylomastoid foramin
- facial nerve
What is the structure outline in red (1)? What are its components?
What is the name of structure (2)?
What does the blue dotted line outline?
- ) Foramen Lacerum
- components are the jugular, oval and carotid foramina - ) Jugular portion of the foramin lacerum in which the glossopharyngeal, vagus and accessory nerve pass
The blue dotted lines outline the location of the guttural pouch
What nerve exits the foramin lacerum but is not involved in diseases in the guttural pouch?
Why does this occur?
The mandibular branch of the Trigeminal nerve.
It exits too far rostral to be associated with the guttural pouch.
Name the following structures:
- )
- )
- )
- )
- )
- ) Medial compartment of the guttural pouch
- ) Lateral compartment of the guttural pouch
- ) Stylohyoid bone
- ) External jugular
- ) Internal jugular
What are the dorsal, ventral and rostral boundaries of the Viborg’s Triangle?
Dorsal: Sternomandibularis)
Ventral: Linguofacial vein
Rostral: Caudal border of the ramus of the mandible
Identify the major blood vessels labeled:
- )
- )
- )
- )
- )
- ) Common Carotid artery
- ) Internal Carotid artery (first branch off of the CC)
- ) External Carotid artery
- ) Occipital artery
- ) Linguofacial artery
Identify the following arteries labeled:
- )
- )
- )
- )
- ) Facial artery
- ) Lingual artery
- ) Inferior labial artery
- ) Superior labial artery
Identify the following arteries labeled:
- )
- )
- )
- ) Dorsal nasal artery
- ) Lateral nasal artery
- ) Angularis Oculi
Identify the following arteries labeled:
- )
- )
- )
- )
- )
- )
- ) Caudal auricular artery
- ) superficial temporal artery
- ) Transverse facial artery
- ) Inferior alveolar artery
- ) Infraorbital artery
- ) Major palatine artery
What branch marks the demarcation between the Maxillary artery and the external carotid.
Superficial temporal
What are the two terminal branches of the Maxillary artery?
- ) Infraorbital artery
- ) Major palatine artery
Where is the location on the skull where the facial artery transitions from medial-lateral?
Vascular notch
What is the clinical significance of the major palatine artery in the horse?
Found just to the lingual surface of the maxillary cheek teeth in the hard palate.
Use caution during horse dental to avoid accidentally hitting this artery.
Identify the following arteries labeled: (Cow)
- )
- )
- )
- )
- )
- ) Common carotid artery
- ) External carotid artery
- ) Occipital artery
- ) Linguofacial trunk
- ) Facial artery
In the cow which artery is present in uterine life but has the extra cranial portion degenerating during the post natal life?
Internal carotid
Identify the following arteries labeled:
- )
- )
- )
- )
- )
- ) Inferior labial artery
- ) Lingual artery
- ) Superior labial artery
- ) Lateral nasal artery
- ) Angularis oculli
True/False: In the cow the dorsal nasal artery is a branch from the facial artery.
False
The dorsal nasal artery in the cow arises from a different artery but not the facial artery.
(Don’t need to know which branch)
In the cow what are the two terminal branches of the superficial temporal artery?
- ) Cornual artery
- ) Transverse facial
Identify the following arteries labeled:
- )
- )
- )
- )
- )
- ) Caudal auricular artery
- ) Maxillary artery
- ) Superficial temporal artery
- ) Transverse facial artery
- ) Cornual artery (rostral and ventral)
What are the terminal branches of the Ox maxillary artery?
- ) Infraorbital artery
- ) Major palatine
Identify the following arteries labeled (sheep):
- )
- )
- )
- )
- ) Common carotid artery
- ) Occipital artery
- ) External carotid artery
- ) Lingual artery
True/False: Sheep have an internal carotid artery.
False: it degenerates in the sheep post natally as seen in the cow
True/False: The sheep does not have a facial artery (branch from the external carotid).
If True what artery will increase in size to make up for the absence of this artery?
True: The sheep and other small ruminants do not have a facial artery
Transverse facial will be larger to compensate.
Identify the following arteries in the Sheep labeled:
- )
- )
- )
- )
- ) Transverse facial artery
- ) Superficial temporal artery
- ) Maxillary artery
- ) Caudal auricular
Identify the structures in this angiogram and which compartment of the guttural pouch they reside in.
- ) Common carotid
- ) Internal carotid (medial compartment)
- ) External carotid (Lateral compartment and the floor of the medial)
- ) Linguofacial trunk
- ) Guttural pouch
Collectively what is the name of these structures?
What are its components labeled:
- )
- )
- )
Venous sinuses
- ) Transverse facial venous sinus
- ) Deep facial venous sinus
- ) Buccal venous sinus
How does the blood leave the venous sinuses in the horse?
During mastication the masseter muscle contracts and pushes the sinuses against the maxilla “pumping” blood out of the sinuses.
How would you go about taking a blood sample from the venous sinuses in the horse?
Start at the medial and lateral canthus drawing two lines ventral until they meet. You should be just touching the facial crest and just ventral to that will be the transverse facial venous sinus.
What is the name of this structure in the cow and what is its function?
Deep facial venous plexus
Functions the same way as the venous sinuses in the horse but not as well developed
Identify the blood vessels in the cow that are labeled:
- )
- )
- )
- ) Dorsal nasal vein
- ) Angularis oculi vein
- ) Frontal vein
What is the structure highlighted in the pig?
Opthalamic (orbital) venous sinus