Trigeminal + Vago-Accessory Complex (X/XI)

Question 1

What is included in segment 1

Answer 1

No pharyngeal arch therefore no dorsal root nerve
Borrows from dorsal root nerve of segment 2 (= CN V) Opthalmic division of Trigeminal

Question 2

What is included in segment 2

Answer 2

Pharyngeal arch 1 therefore has dorsal root nerve (=CN V)
Mouth divides structures of segment 2
Maxillary division of Trigeminal
Mandibular division of Trigeminal

Question 3

What is included in the Opthalmic division of V

Answer 3

Ectoderm only therefore SA only
SA - skin of forehead and upper eyelid (zygomaticaotemporal n and frontal n), cornea (long ciliary nn.), medial eyelid/canthus (infatrochlear n.), dorsal turbinates (ethmoidal n), base of horn in ox (cornual n)

Question 4

What is contained in the maxillary division of V

Answer 4

Ectoderm only therefore SA only
Skin lower eyelid - zygomatic
Mucosa of nasal cavity - caudal nasal
Mucosa of hard palate - major palatine
Mucosa of soft palate - minor palatine
Cheek and incisor teeth of upper jaw - maxillary alveolar
Upper lips, vibrissae, muzzle - cutaneous branches
Vestibule of nostril - rostral nasal

Question 5

What does the ectoderm portion of the mandibular division of V contain

Answer 5

Lining of cheeks - buccinator
Lower teeth and lower lip - mandibular alveolar and mental
Auricular and temporal regions - auricular and temporal branches
Rostral 2/3 of tongue - lingual

Question 6

What are the muscles of chewing (SVE) in the mandibular region of V

Answer 6

Jaw closers - masseter, pterygoid, temporalis
Jaw opener - rostral belly of digastricus (mylohyoid)
Other muscles - tensor tympani, tensor veli palatini

Question 7

What are the dorsal turbinates from

Answer 7

Ectoderm of segment 1
Ethmoidal n from opthalmic V

Question 8

What is the rest of the nasal cavity from

Answer 8

Ectoderm or segment 2
Caudal nasal n and rostral nasal n from maxillary V

Question 9

Have a look at power point for skin of head

Answer 9

LOOK!

Question 10

What does the mouth separate

Answer 10

Trigeminal into maxillary and mandibular

Question 11

What structures does the maxillary V contain

Answer 11

Palate - palatine n
Upper teeth - max alveolar n

Question 12

What structures does the mandibular V contain

Answer 12

Lower teeth - mand alveolar n
Cheek lining - buccinator n
Tongue - lingual n

Question 13

What 5 nerves are involved in the horn of ruminants

Answer 13

Variation between individuals
5 nerves =
Trigeminal branches - cornual n, Cornual branch of infratrochlear n, frontal n, nerve to frontal sinus (never superficial)
Cutaneous from C1/ C2

Question 14

What gives rise to the muscles of chewing

Answer 14

Arch 1 (segment 2)

Question 15

What are the jaw closers

Answer 15

Masseter
Medial and lateral pterygoid
Temporalis

Question 16

What is the jaw opener

Answer 16

Digastricus
2 bellies - cranial from arch 1 innervated by V, caudal from arch 2 innervated by VII

Question 17

What are all the chewing muscles innervated by

Answer 17

Mandibular V (SVE)

Question 18

What happens if there is damage to Trigeminal

Answer 18

Loss of sensation (SA)
Inability to chew (SVE)
Sometimes in dogs - dropped lower jaw and ridged appearance to crown of head due to wasting of temporalis muscle

Question 19

What are the two components of the Vaal-Accessory complex (X/XI)

Answer 19

Vagus - SA, AA, AE to head. Also major AA (+AE) to thoracic / abdominal viscera
Cranial division of accessory - SVE to head, spinal division of XI is SE to some of neck muscles

Question 20

What does the vagal-accessory complex contain

Answer 20

Pharyngeal arches 4 + 6

Question 21

What does the SA supply in the Vagal-Accessory complex

Answer 21

External ear (auricular nerve)

Question 22

What does the AA supply in the Vagal-Accessory complex

Answer 22

Epithelium of cervical oesophagus, caudal larynx, trachea (rec laryngeal), cranial larynx (cr laryngeal), lungs (pulmonary branches)
Chemo/baro receptors in aorta - aortic n
Taste in pharyngeal mucosa surrounding larynx - cr laryngeal
Epithelium of GI tract

Question 23

What does the AE supply in the Vagal-accessory complex

Answer 23

GI tract to transverse colon

Question 24

What does the SVE supply in the Vagal-Accessory complex

Answer 24

Muscles of pharynx/larynx (pharyngeal/ rec laryngeal
Cricothyroideus (cr laryngeal)