Motor cranial nerves
controls extrinsic muscles of the eyes & eyelids
What is the oculomotor nerve (III)?
Responsible for olfaction, axons end in the primary olfactory area of temporal lobe, sensory only
What is the olfactory nerve (I) ?
- Formed from anterior rami of nerves C1-C4, part of C5
- Partial connection with hypoglossal nerve (cranial nerve XII)
What is the cervical plexus?
Nerve that supplies the diaphragm
What is the Phrenic nerve (C3-C5)?
- Protective; flexor muscles contract to avoid pain or injury
- Polysynaptic, ipsilateral
What is a Flexion (withdrawal) reflex?
causes abduction (lateral rotation) of eye
What is the abducens nerve (VI)?
- largest cranial nerve
• - S: touch, pain, temp
• - M: mastication
• - 3 branches (opthalmic,
maxillary, mandibular)
What is the trigeminal nerve (V)?
Formed from anterior rami of C5-C8, T1, most of nerve supply to shoulders & upper limbs
What is the brachial plexus?
Nerve that supplies skin of superior chest & shoulder
What is the supraclavicular nerve (C3-
C4)?
- Controls muscle length; tone
- causes contraction in response to stretching
- monosynaptic, ipsilateral
- e.x, patellar (knee-jerk)
reflex
What is a Simple stretch reflex ?
controls superior oblique muscle of eye and the smallest cranial nerve
What is the trochlear nerve (IV)?
S, multiple visceral sensory inputs
M, innervates smooth & cardiac muscle
M, innervates skeletal muscle (swallowing, vocalization, coughing)
What is the Vagus (X) nerve?
Formed by anterior rami of L1-L4, and supplies anterolateral abdominal wall, external genitals, parts of lower limbs
What is the lumbar plexus?
(L2-L4) controls
- flexor muscle of hip
- extensor muscles of knee
- skin (partial) of thigh, leg & foot
What is the femoral nerve?
– causes relaxation when tension is too high
- Prevents damage to muscles & tendons from excess stretching
- Polysynaptic, ipsilateral
What is a Golgi tendon reflex ?
Directs speech and swallowing
What is the hypoglossal nerve (XII)?
S: taste from anterior 2/3 of tongue
M: facial expression, glandular secretion
What is the Facial (VII) nerve ?
- formed by anterior rami of L4-L5, S1-S4
- supplies buttocks, perineum, lower limbs
What is the sacral plexus?
Nerve that supplies
- adductor muscles of hip
- skin of medial thigh
What is the Obturator nerve (L2-L4)?
- cell body in spinal cord
- stimulate skeletal muscle fibers
(PART OF PNS)
What are lower motor neurons?
controls sternocleidomastoid & trapezius muscles
What is the Accessory (XI) nerve ?
S, balance, vestibular branch
S, hearing, cochlear branch
What is the vestibularcochlear nerve (VII)?
formed by anterior rami of S4-S5 &
coccygeal nerve
What is the Coccygeal plexus?
- largest nerve in the body, often injured
- supplies tibial and common fibular
division
What is the sciatic nerve?
- cell body in primary motor cortex
- ‘decide’ to initiate movement
What are upper motor neurons?