Lec 16: Cranial and Spinal Nerves Flashcards
Cranial and Spinal Nerves
Cranial Nerves
Olfactory Nerves (location)
From nasal mucosa to olfactory bulbs
Cranial Nerves
Olfactory nerves (function)
Afferent sensory fibers for smell
Cranial Nerves
Optic Nerves (location)
Fibers from retina form optic nerve which passes through optic foramen of orbit
Cranial Nerves
Optic Nerves (function)
Afferent sensory fibers for vision
Cranial Nerves
Oculomotor Nerves (location)
Fibers from ventral midbrain (near pons) through bony orbit eye
Cranial Nerves
Oculomotor Nerves (function)
Adjust and coordinate eye position during movemen
4/6 extrinsic muscles of eyeball
Cranial Nerves
Trochlear Nerves (pulley) (location)
Motor fibers from dorsal midbrain to superior oblique eye muscle
Cranial Nerves
Trochlear Nerves (pulley) (function)
Innervates trochlea to lift the eyes so you can look down
Trigeminal Nerves Divisions
Opthalmic division
Maxillary division
Mandibular division
Ophthalmic Division (location)
Runs forward in the lateral wall of the cavernous sinus below the oculomotor and trochlear nerves
Ophthalmic Division (function)
Purely sensory (afferent) nerve
Maxillary division (location)
Passes through the foramen rotundum and into the infraorbital canal, where, at the pterygopalatine fossa
Maxillary division (function)
Supplies sensory innervation to the middle third of the face
Mandibular Division (location)
Enters the infratemporal fossa and passes through the foramen ovale in the sphenoid bone
Mandibular Division (function)
Transmits the sensory information from the lower third of the face
Cranial Nerves
Abducens Nerves (location)
Not N.
In the pons at the floor of the fourth ventricle
Cranial Nerves
Abducens Nerves (function)
Controls extrinsic eye muscle that abducts eyeball
Cranial Nerves
Vestibulocochlear Nerves (location)
Not N.
Emerges from the brain at the cerebellopontine angle and exits the cranium via the internal acoustic meatus of the temporal bone
Cranial Nerves
Vestibulocochlear Nerves (function)
Sensory nerve for hearing and balance
Cochlear (hearing) and Vestibular (balance) branches
Cranial Nerves
Facial Nerves (location)
From pons to lateral face
Cranial Nerves
Facial Nerves (function)
Controls muscles that help you make expressions like raising an eyebrow, smiling or frowning
Cranial Nerves
Vagus Nerves (location)
From your brain to your large intestine
Cranial Nerves
Vagus Nerves (function)
Responsible for the regulation of internal organ functions, such as digestion, heart rate, and respiratory rate
Cranial Nerves
Accessory Nerves (location)
From the medulla of the brainstem
Cranial nerves
Accessory Nerves (function)
Head rotation; Head tilting; Neck flexion
Cranial Nerves
Hypoglossal Nerves (location)
From the hypoglossal nuclei pair in the lower medulla
Cranial nerves
Hypoglossale Nerves (function)
Enables tongue movement
Cranial Nerves
Oh, Oh, Oh, To Touch And Feel Very Good Velvet, Such A Heaven
Olfactory nerve (CN I)
Optic nerve (CN II)
Occulomotor nerve (CN III)
Trochlear nerve (CN IV)
Trigeminal nerve (CN V)
Abducens nerve (CN VI)
Facial nerve (CN VII)
Vestibulocochlear nerve (CN VIII)
Glossopharyngeal nerve (CN IX)
Vagus nerve (CN X)
Accessory nerve (CN XI)
Hypoglossal nerve (CN XII)
Cranial Nerves
Some say money matters, but my brother says big brains matter most
Sensory, motor or both
Sensory (CN I)
Sensory (CN II)
Motor (CN III)
Motor (CN IV)
Both (CN V)
Motor (CN VI)
Both (CN VII)
Sensory (CN VIII)
Both (CN IX)
Both (CN X)
Motor (CN XI)
Motor (CN XII)
Spinal Nerves
Cervical Plexus and Neck (location)
C1-C4; - innervates neck structures
Spinal nerves
Cervical Plexus and Neck (function)
Provide skeletal muscle control of the neck and upper torso as well as providing cutaneous sensation to parts of the occiput, neck, and shoulder
Spinal Nerves
Brachial Plexus and Upper Limb (location)
C5-C8; Most T
Spinal Nerves
Brachial Plexus and Upper Limb (function)
Major network of nerves transmitting signals responsible for motor and sensory innervation of the upper extremities, including the shoulder, arm, and hand
Axillary nerve
To/from shoulder
Musculocutaneous nerve
To/from biceps brachii and brachialis to flex arm
Median nerve
Flexor muscles in anterior forearm and palm
(Pronate forearm, flex wrist/fingers, oppose thumb)
(Pronate forearm, flex wrist/fingers, oppose thumb)
Ulnar nerve
Medial to elbow (“funny bone”) & follows ulna along medial forearm
(Wrist & finger flexion and adduction & abduction of medial fingers)
Radial nerve
C5-C8
To humerus and dorsal part of hand
elbow ext., supination forearm, extension wris &fingers, abduction thumb
Spinal Nerves- The Back
Dorsal Rami
Follow the segmented plan to innervate dorsal muscles and skin; no recombining into plexus
Spinal Nerves - Anterolateral Thorax
Ventral Rami
T1-T12
Simple & segmented as for the dorsal rami– no recombining into plexuses
Spinal Nerves - Lumbar Plexus
Lumbar Plexus
L1-L4
Branches travel to abdominal wall muscles and anterior and medial thigh
Limbar Plexus
Femoral Nerve
Anterior thigh muscles -> Thigh flexors and knee extensors
Lumbar Plexus
Obturator Nerve
Medial thigh -> Adductor muscles
Spinal Nerves - Sacral Plexus
Sacral Plexus
L4-S4
Immediately caudal to lumbar plexus- branches to buttocks, lower limbs, pelvis
Sacral Plexus
1) Sciatic Nerve
1-3 connected
Posterior thigh
Sacral Plexus
2) Tibial Nerve
1-3 are connected
Behind knee joint to posterior calf and sole of foot
Sacral Plexus
3) Common Fibular Nerve
To knee joint, calf (anterolateral) & dorsum of foot
Sacral Plexus
4) Superior & Inferior Gluteal Nerves
To buttocks
5) Pudendal nerve
Muscles & skin of perineum (e.g. erection, voluntary urination)
Dermatome
Area of skin innervated by cutaneous branches of a single spinal nerve
Endoneurium
Loose CT that encloses nerve fibre + associated myelin or neurilemma sheath
Perinerium
Coarser CT wrapping around a group of fibres (fascicles)
Epinerium
Tough fibres sheath around all the fascicles to make nerve
