Cranial NERVE Flashcards
How many Cranial Nerve Pairs underside of brain
12
How are Cranial Nerves Numbered?
With Roman numerals I to XII
About cranial nerves
Most are mixed both (sensory and motor) nerves
Some are primary sensory associated with special senses
Some are primarily motor innervate muscles or glad
Most are are attached to the brain stem :
First pair- CN I has fibers that start in the nasal cavity ( olfactory nerve)
Second pair- CN II ORIGINATED IN EYES ( Optic nerve)
Oculomotor Nerves
Primary function
Motor (eye movements)
Somatic Motor
* Superior, Inferior and medial rectus muscles
* Inferior Oblique
* Levator palpebrae Superioris
Visceral Motor
* Intrinsic eye muscles (ciliary ganglion)
*Ciliary ganglion nerouns control intrinsic eye muscle ( pupil dilation or contraction)
Deliver autonomic fibers to neurons of ciliary ganglion
Trochlear Nerves
Primary Function:
*Motor ( eye movement)
Destination
*Superior Oblique
Abducens Nerves ( VI)
Primary Function
*Motor (eye movements)
Destination
*Lateral Rectus
Vestibulocochlear Nerve ( VIII)
Also called acoustic or auditory nerve
* Sensory Nerve only
2 branches includes
*Vestibular branch :Sensory from equilibrium receptors of ear
*Cochlear branch: Sensory from hearing receptors
Glossopharyngeal Nerve ( IX)
Mixed Nerve
Sensory from Pharynx, tonsils, part of tongue ( The region posterior to the nasal Cavity, oral cavity and larynx)
Motor impulses to salivary glands and muscles of pharynx for swallowing
Accessory Nerve (XI)
Primarily motor nerve
Formerly called “Spinal Accessory”
Contains cranial and spinal branches:
*Cranial branch : Joins Vagus N; Motor impulses to muscles of soft palate, pharynx and larynx
*Spinal Branch: Motor to muscles of neck and back ; small sensory component ( proprioceptivr fibers)
Hypoglossal Nerve (XII)
Primarily motor nerve
Motor impulses to muscles of the tongue for speaking, chewing, swallowing
- Small sensory component ( Proprioceptive fibers)
3 types of muscle tissue in the muscular system
Skeletal Muscle
Cardiac Muscle
Smooth Muscle
About skeletal Muscle
Attached to bones of skeleton
Voluntary ( consciously controlled)
Multi- Nucleate( multiple nuclei per cell)
Striated (actin - myosin interaction in sarcomere)
About Cardiac Muscle
Makes up most of the wall of heart
Involuntary (non consciously controlled)
Single nucleus (one nucleus per cell
Striated ( Actin-myosin interactions in sarcomere)
Responsible for pumping action of heart
About smooth muscles
Found in walls of internal organs , such as those of digestive tract
Involuntary ( non-consciously controlled)
Single nucleus ( one nucleus per cell)
Non-striated ( no well developed sarcomere)
More about skeletal Muscles
Over 600 skeletal muscles in the body
Under conscious control (Voluntary)
Attached to bones and skin over face
Are organs of the muscular system