Nerve Supply to Head Lecture 8 Flashcards
(56 cards)
What does Efferent mean?
Efferent refers to nerve transmission AWAY from the CNS, and is responsible for MOTOR activity
What does Afferent mean?
Afferent refers to nerve transmission TOWARD the CNS, and is purely SENSORY
What does Somatic mean?
Somatic refers to STRIATED muscle. Meaning voluntary control over the muscle.
What does Visceral mean?
Visceral refers to SMOOTH muscle and SECRETORY activity, or involuntary control over the muscle/viscera/glandular secretions.
What muscle activity in the head are Somatic Efferent nerves in control of?
All STRIATED muscle activity in the head. Eye movement, tongue movement, hyoid/laryngeal movement, mastication, facial expression, movement of palate/pharynx, and larynx/esophagus
What muscle activity are Visceral Efferent nerves in control of?
SMOOTH muscle and GLANDS. Glands in the eye, parotid glands, and secretory activity in the thoracic cavity and abdominal cavity
What muscle activity in the head are Somatic Afferent nerves in control of?
(SENSORY INPUT STRIATED MUSCLE) Vision, hearing, touch/pain/thermal from face and ear, and proprioception and nociception
What muscle activity in the head are Visceral Afferent nerves in control of?
(SENSORY INPUT SMOOTH MUSCLE) Smell, taste, internal sensory info from tongue, pharynx, carotid sinus, viscera etc.
What are the functional components of CN III (Oculomotor)? What muscle does this nerve carry fibers to?
CN III only has an efferent root, both somatic and visceral divisions.
Carries EFFERENT fibers to all eye muscles EXCEPT dorsal oblique, lateral rectus, and retractor bulbs muscles
Where does CN III enter the orbit?
Orbital Fissure
Where do the PREganglionic parasympathetic fibers of CN III go?
PREganglionic Parasympathetic fibers go to the ciliary ganglion
Where do the POST ganglionic parasympathetic fibers of CN III go?
Pupillary constrictor muscle and the ciliary body
Which cranial nerves have parasympathetic fibers?
CN III, VII, IX, and X
Clinical signs of nerve damage to CN III
Pupillary dialation, lateral ventral strabismus (deviation of the globe), ptosis (drippy eye)
What is another name for the sympathetic division of the autonomic system?
Thoraco Lumbar Divsion
Where does sympathetic innervation originate from?
The spinal cord. It goes to the cranial cervical ganglion (preganglionics)
What are the 3 divisions of CN V (Trgeminal)
Mandibular, Maxillary, Opthalmic
The mandibular division has what kind of nerves?
Somatic afferent and efferent fibers that go to skeletal muscle.
What do the afferent nerves of the Mandibular divsion innervate?
roatral 2/3 of the tongue (sensory but not taste), general sensation to skin of lower face, lower teeth, and oral/nasal cavities
What do the efferent nerves of the Mandibular division innervate?
Motor muscles that CLOSE the jaw
List the nerves we need to know from the Mandibular division
Lingual branch of CN V, mental nerve, auriculotemporal, and buccal nerve
What are the clinical signs of nerve damage to the Mandibular division?
Jaw drop, analgesia (lack of sensation) of lower jaw, lower dentition of oral mucosa and tongue.
Massater and temporalis muscle atrophy
Prominant zygomatic arch
The maxillary division has what kind of nerves?
Somatic afferent only (sensory)
What does the maxillary division innervate?
Upper teeth, muzzle (nostrils and upper lip), innervates the horn of non equines via the zygomaticotemporal branch
