Anatomy Ch 20 PNS
How many cranial nerves are there?
12 pairs
How many pairs of spinal nerves are there?
31
What regions of the body does the cervical plexus innervate?
Anterior neck muscles. Skin of the neck and portions of the head and shoulders. Diaphragm.
The cervical plexus arises from what spinal nerves?
C1-C4
The brachial plexus arises from what spinal nerves?
C5 - T1
Within the spinal cord where is gray matter located and how is it shaped?
Centrally. H-shaped or butterfly-shaped.
List the regions of the spinal cord.
Cervical region, thoracic region, lumbar region, sacral region, coccygeal region
List the regions of the spinal cord and the spinal nerves associated with each region.
Cervical region: C1-C8. Thoracic region: T1-T12. Lumbar region: L1-L5. Sacral region: S1-S5. Coccygeal region: Co
Which of the cranial nerves has the following functions? Sensory function: Taste from the anterior two-thirds of the tongue. Somatic motor function: Innervates the muscles of facial expression and other muscles of the facial region. Parasympathetic motor function: Innervates the lacrimal gland and the submandibular and sublingual salivary glands.
Facial nerve
Where does the spinal cord begin and end in an adult?
From the foramen magnum to the first lumbar vertebra (L1).
What is the name and number of the first cranial nerve?
I Olfactory
What cranial nerve is transmitted by the foramina of the cribriform plate of the ethmoid?
I Olfactory nerve
What is the name and number of the second cranial nerve?
II Optic
What is the name and number of the third cranial nerve?
III Oculomotor
What is the name and number of the fourth cranial nerve?
IV Trochlear
Which of the cranial nerves has the following functions? Somatic motor function: Supplies one extrinsic eye muscle (superior oblique) to move the eyeball inferiorly and laterally.
IV trochlear nerve
What is the name and number of the ninth cranial nerve?
IX Glossopharyngeal
Which of the cranial nerves has the following functions? Sensory function: General sensation and taste from the posterior third of the tongue. Conducts sensory information on blood pressure and blood chemistry from the carotid sinuses. Somatic motor function: Innervates a pharyngeal muscle. Parasympathetic motor function: Innervates the parotid salivary gland.
IX Glossopharyngeal nerve
How does the dura mater within the vertebral canal different from the dura within the cranial cavity?
It consists of one layer rather than two.
The lumbar plexus arises from the anterior rami of what spinal nerves?
L1-L4
The anterior rami of what spinal nerves form the sacral plexus?
L4-S4
What are the three branches of the fifth cranial nerve?
Ophthalmic branch (V1). Maxillary branch (V2). Mandibular branch (V3).
What are the two functions of the spinal cord?
Pathway for sensory and motor impulses. Spinal reflexes.
What opening in the skull transmits the sixth cranial nerve?
Superior orbital fissure
What branch of the trigeminal nerve has the following functions? It conducts sensory impulses from the anterior twothirds of the tongue, skin of the chin, lower jaw, lower teeth, and one third of the sensory fibers of the auricle of the ear. Somatic motor function: Innervates muscles of mastication and other muscles of the lower facial region.
The mandibular branch.
What is the name and number of the fifth cranial nerve?
V Trigeminal
What is the name and number of the sixth cranial nerve?
VI Abducens
What is the name and number of the seventh cranial nerve?
VII Facial
What is the name and number of the eighth cranial nerve?
VIII Vestibulocochlear
Which cranial nerve has the following functions? Sensory function: Conducts impulses of hearing and equilibrium from the inner ear.
VIII Vestibulocochlear nerve
Beginning with a vertebra and going from superficial to deep, list the spaces and structures surrounding the spinal cord.
Vertebra. Epidural space. Dura mater. Subdural space. Arachnoid. Subarachnoid space. Pia mater.
What is the name and number of the tenth cranial nerve?
X Vagus
Which of the cranial nerves has the following functions? Sensory function: Innervates the pharynx, larynx, and thoracic and abdominal viscera, as well as the external auditory canal, eardrum, and pharynx. Somatic motor function: Innervates most pharyngeal and laryngeal muscles. Parasympathetic motor function: Innervates myocardium and the smooth muscle and glands of the thoracic and abdominal viscera.
X Vagus
What is the name and number of the eleventh cranial nerve?
XI Accessory
Which of the cranial nerves has the following functions? Somatic motor function: Cranial root - Travels with CN X fibers to the pharynx. Spinal root — Innervates the trapezius and sternocleidomastoid.
XI Accessory
What is the name and number of the twelveth cranial nerve?
XII Hypoglossal
Which of the cranial nerves has the following functions? Somatic motor function: Innervates intrinsic and extrinsic tongue muscles.
XII Hypoglossal nerve
Other than the regions innverated by the femoral and obturator nerves, what other regions of the body do small branches of the lumbar plexus innervate?
abdominal wall, the scrotum and the labia, interior portions of the abdominal muscles
Which of the cranial nerves has the following functions? Somatic motor function: Innervates one extrinsic eye muscle (lateral rectus) for abduction of the eyeball.
abducens
What are the two main divisions of the sacral plexus?
anterior & posterior
The numerous small attachments of a spinal nerve to the spinal cord converge to form what structures?
anterior & posterior roots
Spinal nerves are formed by the convergence of what structures within what structure?
anterior and posterior roots within the intervertebral foramen
The cell bodies of motor neurons within the spinal cord are found in what structures?
anterior horn
Within the spinal cord what are the anterior masses of gray matter that contain the cell bodies of somatic motor neurons?
anterior horns
What is the motor innervation of the musculocutaneous nerve?
anterior muscles of the brachium
What is the motor innervation of the femoral nerve?
anterior thigh muscles
List the five nerves that innervate the upper extremity.
axillary nerve, median nerve, musculocutaneous nerve, radial nerve, ulnar nerve
What are the spinal nerves that extend from the end of the spinal cord to the end of the vertebral canal? A pair of them exits the canal at each of the lower levels.
cauda equina
What fills the central canal of the spinal cord?
cerebrospinal fluid
What division of what nerve innervates the short head of the biceps femoris?
common fibular division of the sciatic nerve
What nerve is formed from the posterior division of the sciatic nerve?
common fibular nerve
What branches of a spinal nerve are associated with the autonomic nervous system?
communicating rami (rami communicantes)
What are the nerves that extend from the brain?
cranial nerves
What nerve innervates the skin between the first and second toes of the dorsum of the foot?
deep fibular
What nerve innervates the anterior leg muscles and the muscles of the dorsum of the foot?
deep fibular nerve
What are the two main divisions of the common fibular nerve?
deep fibular nerve & superficial fibular nerve
Where is the cervical plexus located?
deep on the lateral side of the neck
What is the motor innervation of the axillary nerve?
deltoid & teres minor
What is a specific segment of skin supplied by a single spinal nerve?
dermatomes
Where does the white matter of the spinal cord lie in relation to the gray matter?
external
What is the main nerve of the posterior division of the lumbar plexus?
femoral nerve
What nerve provides cutaneous innervation of the anterior and inferomedial thigh and the medial aspect of the leg?
femoral nerve
What opening in the skull transmits the mandibular branch of the fifth cranial nerve?
foramen ovale
What openings in the skull transmit the maxillary branch of the fifth cranial nerve?
foramen rotundum
What openings in the skull transmit the first cranial nerve?
foramina of the cribriform plate of the ethmoid
Nerves emerging from the sacral plexus innervate what portions of the body?
gluteal region, pelvis, perineum, posterior thigh, almost all of the leg and foot
What horizontal bar of gray matter surrounds the central canal within the spinal cord?
gray commissure
What portion of the spinal cord is composed of dendrites and cell bodies of neurons and glial cells and unmyelinated axons?
gray matter
What opening in the skull transmits the twelfth cranial nerve?
hypoglossal canal
In general, what do intercostals nerves innervate?
intercostal muscles & skin of the anterior and lateral thoracic wall
The anterior rami of T1-T11 travel in intercostals spaces. What are these nerves called?
intercostal nerves
What opening in the skull transmits the eighth cranial nerve?
internal acoustic meatus
What openings in the skull transmit the seventh cranial nerve?
internal acoustic meatus and stylomastoid foramen
What opening in the skull transmits the eleventh cranial nerve?
jugular foramen
What opening in the skull transmits the ninth cranial nerve?
jugular foramen
What opening in the skull transmits the tenth cranial nerve?
jugular foramen
Within the spinal cord from T1-L2 what structures contain the cell bodies of autonomic motor neurons?
lateral horns
Where is the brachial plexus located?
lateral neck & axilla
What is the cutaneous innervation of the musculocutaneous nerve?
lateral surface of the forearm
What is the motor innervation of the obturator nerve?
medial thigh muscles
What nerve innervates the anterior forearm muscles, the thenar muscles, and the two lateral lumbricals?
median
Carpal tunnel syndrome results in nocturnal hand paresthesia (a sensation of pricking, tingling, or creeping on the skin that has no objective cause) and pain, and sometimes sensory loss and wasting in the hand. The lateral palmar side of the hand, the two lateral lumbricals and the thenar group are affected. What nerve is involved?
median nerve
What nerve has the following cutaneous innervation: palmar side of the lateral 3 1/2 fingers and the lateral one-half of the ring finger and the dorsal tips of the same fingers?
median nerve
What is the motor innervation of the superficial fibular nerve?
muscles of the lateral compartment
Nerves of the sacral plexus arising from the posterior division tend to innervate what muscles?
muscles that extends (or dorsiflex) part of the lower limb
Nerves of the sacral plexus arising from the anterior division tend to innervate what muscles?
muscles that flex (or plantar flex) parts of the lower limb
What is a network of interweaving anterior rami of spinal nerves?
nerve plexuses
Within the regions of the spinal cord's gray matter what are the various functional groups of neuron cell bodies?
nuclei
What is the main nerve of the anterior division of the lumbar plexus?
obturator nerve
Which cranial nerve has the following functions? Somatic motor function: Supplies four extrinsic eye muscles (superior rectus, inferior rectus, medial rectus, inferior oblique), which move the eyeball, and the levator palpebrae superioris, which elevates the upper eyelid. Parasympathetic motor: Innervates sphincter pupillae (pupil constrictor) muscle in eye to make pupil constrict; contracts ciliary muscles to make lens of eye more puffy (thicker, as needed for vision)
oculomotor
What opening in the skull transmits the second cranial nerve?
optic foramen
What is the general shape of the spinal cord in cross-section?
oval (AP compression)
What regions of the body does the brachial plexus innervate?
pectoral girdle and upper extremity
What branch of the cervical plexus innervates the diaphragm?
phrenic nerve
What is the cutaneous innervation of the tibial nerve?
plantar surface of the foot
The white matter of the spinal cord is partitioned into three regions. What each called?
posterior funiculus, lateral funiculus, anterior funiculus
Within the spinal cord what are the posterior masses of gray matter that contain the axons of sensory neurons and the cell bodies of interneurons?
posterior horns
What depressions lie on the anterior and posterior surface of the spinal cord?
posterior median sulcus, anterior median sulcus.
What are the two main branches of a spinal nerve?
posterior ramus & anterior ramus
The cell bodies of sensory neurons associated with the spinal cord are found in what structures?
posterior root ganglion
What nerve has the following motor and cutaneous innervation? Motor - Posterior arm muscles & the posterior forearm muscles. Cutaneous innervation - Posterior arm and forearm surface and the dorsolateral side of the hand.
radial nerve
What nerve innervates the posterior arm muscles and the posterior forearm muscles?
radial nerve
What nerve provides cutaneous innervation of the posterior arm and forearm surface and the dorsolateral side of the hand?
radial nerve
Anteriorly and posteriorly what are the small attachments of a spinal nerve to the spinal cord?
rootlets
What is the largest and longest nerve in the body?
sciatic nerve
What is the function of the first cranial nerve?
sensory function: olfaction
What is the function of the second cranial nerve?
sensory function: vision
What term is used to refer to T12 because it lies below the ribssubcostal nerve rather than between them?
subcostal nerve
What nerve innervates the skin of the anteroinferior part of the leg and most of the dorsum of the foot?
superficial fibular
What opening in the skull transmits the fourth cranial nerve?
superior orbital fissure
What opening in the skull transmits the third cranial nerve?
superior orbital fissure
What openings in the skull transmit the ophthalmic branch of the fifth cranial nerve?
superior orbital fissure
What is the cutaneous innervation of the axillary nerve?
superolateral portion of the arm
What is the cutaneous innervation of the obturator nerve?
superomedial skin of the thigh
What branch of the trigeminal nerve has the following functions: It conducts sensory impulses from nasal mucosa, palate, gums, and cheek?
the maxillary branch.
What branch of the trigeminal nerve has the following functions: It conducts sensory impulses from the cornea, nose, forehead and anterior scalp?
the ophthalmic branch.
What division of what nerve innervates the hamstrings?
tibial division of the sciatic nerve
What nerve is formed from the anterior divisions of the sciatic nerve?
tibial nerve
Within the leg, what nerve innervates the plantar flexors of the foot and the flexors of the toes?
tibial nerve
What nerve innervates of some of the anterior forearm muscles and intrinsic muscles of the hand (hypothenar muscles, palmar and dorsal interossei, and the medial two lumbricals).
ulnar nerve
What nerve provides cutaneous innervation of the dorsal and palmar aspects of the medial 1 1/2 fingers (the medial aspect of digit 4 and all of digit 5)?
ulnar nerve
What portion of the spinal cord is composed of myelinated axons?
white matter
