Anatomy_ Nerve Tables Flashcards
CN I Olfactory Nerves: Sensory function (VS)
special visceral sensory, sense of smell
CN I Olfactory Nerves: Origin
Olfactory receptor cells (bipolar neurons) in the olfactory epithelium of the nasal cavity
CN II Optic nerves: sensory function (SS)
special somatic sensory, vision
CN II Optic nerves: origin
retina of the eye
CN II Optic nerves: pathway
pass through the optic canal of the sphenoid bone. optic nerves converge to form the optic chiasa, where fibers partially cross over, then contiue as the optic tracts to synapse in the thalamus. thalamic fibers porject to and terminate in the primary visual cortex in the occipital lobe
CN III Oculocomotor nerves: somatic motor function (SM)
innervate four extrinsic eye muscles that direct the eyeball: superior rectus, medial rectus, inferior rectus, inferior oblique muscles
CN III Oculocomotor nerves: visceral motor function (VM) (parasympathetic)
constrictor muscles of the iris constrict the pupil.<br></br>ciliary muscle alters lens shape for near vision.
CN III Oculocomotor nerves: origin
oculomotor nuclei in the ventral midbrain
CN III Oculocomotor nerves: pathway
pass through the superior orbital fissue to enter the orbit. parasympathetic fibers from the brain stem synapse in the ciliary ganglion with post ganglionic neurons that innervate the iris and ciliary muscle.
CN IV Trochlear nerves: somatic motor function (SM)
innervate the superior oblique muscle. this muscle passes through a ligamentous pully at the roof of the orbit, the trochlea, from which its name is derived.<br></br>afferent proprioceptor fibers return from the superior oblique.
CN IV Trochlear nerves: origin
trochlear nuclei in the dorsal midbrain
CN IV Trochlear nerves: pathway
pass ventrally around the midbrain; pass through the superior orbital fissure to enter the orbit
CN V Trigeminal nerves: overview
the large trigemenal nerve forms three divisions (trigeminal=threefold): opthalmic (V1), maxillary (V2), and mandibular (V3) divisions.<br></br>this mixed nerve is the general somatic sensory nerve of the face for touch, temperature, and pain. the mandibular division supplies somatic motor innervation to the chewing muscles.
CN V Trigeminal nerves: sensory function (SS)
V1 General somatic sensation from skin of anterior scalp and forehead, upper eyelid and nose, nasal cavity mucosa, cornea, and lacrimal gland.<br></br>V2 General somatic sensation from skin of cheek, upper lip, and lower eyelid, nasal cavity mucosa, palate, upper teeth.<br></br>V3 General somatic sensation from skin of chin and temporal region of scalp, anterior tongue and lower teeth.
CN V Trigeminal nerves: somatic motor function (SM)
V3 Innervate the muscles of mastication: temporalis, masseter, pterygoids, anterior belly of digastric<br></br>Afferent proprioceptor fibers return from these muscles
CN V Trigeminal nerves: origin
sensory receptors in skin and mucosa of face<br></br>motor fibers from trigeminal motor nucleus in pons
CN V Trigeminal nerves: pathway
Through the skull<br></br>V1 Superior orbital fissure<br></br>V2 Foramen rotundum<br></br>V3 Foramen ovale; mandibular foramen<br></br>Cutaneous Branch<br></br>V1 Supraorbital foramen<br></br>V2 Infraorbital foramen<br></br>V3 Mental foramen<br></br>Cell bodies of sensory neurons of all three divisions located in the large trigeminal ganlion. fibers extend to trigeminal nuclei in the pons
CN VI Abducens nerves: somatic motor function (SM)
innervate the lateral rectus muscle. this muscle abducts the eye.<br></br>afferent proprioceptor fibers return from the lateral rectus.
CN VI Abducens nerves: origin
abducens nuclei in the inferior pons
CN VI Abducens nerves: pathway
pass through the superior orbital fissure to enter the orbit
CN VII Facial nerves: sensory function (VS, SS)
special visceral sensory from taste buds on anterior two-thirds of tongue<br></br>general somatic sensory from small patch of skin on the ear
CN VII Facial nerves: somatic motor function (SM)
five major branches on face: temporal, zygomatic, buccal, mandibular, and cervical, to innervate the facial muscles. also innervates the posterior belly of digastric.<br></br>afferent proprioceptor fibers return from these muscles
CN VII Facial nerves: visceral motor function (VM) (parasympathetic)
innervate the lacrimal (tear) glands, nasal and palantine glands, and the submandibular and sublingual salivary glands
CN VII Facial nerves: origin
fibers emerge from the pons, just lateral to abducens
CN VII Facial nerves: pathway
fibers enter the temporal bone via the internal acoustic meatus. chorda tympani branches off to innervate the two salivary glands and tongue. branch to facial muscle emerges from the temporal bone through the stylomastoid foramen and courses to lateral aspect of face.<br></br>cell bodies of sensory neurons are in geniculate ganglion.<br></br>cell bodies of postganglionic parasympathetic neurons are in pterygopalantine and submandibular ganglia on the trigeminal nerve.
CN VIII Vestibulocochlear nerves: sensory function (SS)
vestibular branch: special somatic sensory, equilibrium<br></br>cochlear branch: special somatic sensory, hearing<br></br>small motor component adjusts the sensitivity of the sensory receptors
CN VIII Vestibulocochlear nerves: erigin
sensory receptors in the inner ear for hearing (within the cochlea) and for equlibrium (within the semicircular canals and vestibule)
CN VIII Vestibulocochlear nerves: pathway
from the inner ear cavity within the temporal bone, fibers pass through the internal acoustic meatus, merge to form the vestibulocochlear nerve and enter the brain stem at the pons.<br></br>sensory nerve cell bodies for vestibular branch located in vestibular ganglia; for the cochlear branch, in the spiral ganglia within the cochlea
CN IX Glossopharyngeal nerves: sensory function (VS, SS)
special visceral sensory from taste buds on posterior third of tongue.<br></br>general visceral sensory from posterior third of tongue, pharyngeal mucosa, chemoreceptors in the coratid body (which monitor O2 and CO2 in the blood and regulate respiratory rate and depth), and baroreceptors of carotid sinus (regulate blood pressure).<br></br>general somatic sensory from small area of skin on external ear.
CN IX Glossopharyngeal nerves: somatic motor function (SM)
innervate a pharyngeal muscle, stylopharyngeus, which elevates the pharynx during swallowing.<br></br>afferet proprioceptor fibers return from this muscle.
CN IX Glossopharyngeal nerves: visceral motor function (VM) (parasympathetic)
innervate the parotid salivary gland
CN IX Glossopharyngeal nerves: origin
fibers emerge from the medulla oblongata
CN IX Glossopharyngeal nerves: pathway
fibers pass through the jugular foramen and travel to the pharynx.<br></br>cell bodies of sensory neurons are located in the superior and inferior ganglia. cell bodies of postganglionic parasympathic neurons are in otic ganglion on the trigeminal nerve.
CN X Vagus nerves: overview
mixed nerve; major function is parasympathic innervation to the thoracic and abdominal viscera
CN X Vagus nerves: sensory function (VS, SS)
general visceral sensory from the thoracic and abdominal viscera, mucosa of larynx and pharynx, coratid sinus (baroreceptor for blood pressure), and carotid and aortic bodies (chemoreceptors for respiration).<br></br>special visceral sensory from taste buds on the epiglottis.<br></br>general somatic sensory from small area of skin on external ear.
CN X Vagus nerves: somatic motor function (SM)
innervates skeletal muscles of the pharynx and larynx involved in swallowing and vocalization.<br></br>afferent proprioceptor fibers return from the muscles of the larynx and pharynx
CN X Vagus nerves: visceral motor function (VM) (parasympathetic)
innervates the heart, lungs, and abdominal viscera through the transverse colon. Regulates heart rate, breathing, and digestive system activity.
CN X Vagus nerves: origin
fibers emerge from medulla ablongata
CN X Vagus nerves: pathway
fibers exit the skull through the jugular foramen and descend through the neck into the thorax and abdomen
CN XI Accessory nerves: somatic motor function (SM)
innervate the trapezius and sternocleidomastoid muscles that move the head and neck.<br></br>afferent proprioceptor fibers return from these muscles
CN XI Accessory nerves: origin
forms from ventral rootlets arising from C1-C5 of the spinal cord. long considered to have both a cranial and spinal portion, the cranial rootlets have been shown to be part of the vagus nerves
CN XI Accessory nerves: pathway
upon emerging from the spinal corcd, spinal rootlets merge to form the accessory nerves, pass into the skull through the foramen magnum, and then exit the skull through the jugular foramen
CN XII Hypoglossal nerves: somatic motor function (SM)
innervate the intrinsic and extrinsic muscles of the tongue. aid tongue movements during feeding, swallowing, and speech.<br></br>afferent proprioceptor fibers return from these muscles.
CN XII Hypoglossal nerves: origin
from a series of roots from the hypoglossal nuclei in the ventral medulla oblongata
CN XII Hypoglossal nerves: pathway
exit the skull through the hypoglossal canal and travel to the tongue
branches of the cervical plexus, cutaneous branches (superficial): lesser occiptal
ventral rami: C2, C3<br></br>structures innervated: skin on pesterolateral aspect of neck
branches of the cervical plexus, cutaneous branches (superficial):greater auricular
ventral rami: C2, C3<br></br>structures innervated: skin of ear, skin over parotic gland
branches of the cervical plexus, cutaneous branches (superficial):transverse cervical
ventral rami: C2, C3<br></br>structures innervated: skin on anterior and lateral aspect of neck
branches of the cervical plexus, cutaneous branches (superficial): supraclavicular (anterior, middle, and posterior)
ventral rami: C3, C4<br></br>structures innervated: skin of shoulder and clavicular region
branches of the cervical plexus, motor branches (deep): arisa cervicalis (superior and inferior roots)
ventral rami: C1-C3<br></br>structures innervated: infrahyoid muscles of neck (omohyoid, sternohyoid, and sternothyroid)
branches of the cervical plexus, motor branches (deep): segmental and other muscular branches
ventral rami: C1-C5<br></br>structures innervated: deep muscles of neck (geniohyoid and thyrohyoid) and portions of scalenes, levator scapulae, trapezius, and sternocleidomastoid muscles
branches of the cervical plexus, motor branches (deep): phrenic
ventral rami: C3-C5<br></br>structures innervated: diaphragm (sole motor nerve supply)
branches of the bracial plexus to trunk and shoulder muscles: dorsal scapular
corld and spinal roots (ventral rami): branches of C5 rami<br></br>structures innervated: rhomboid muscles and levator scapulae
branches of the bracial plexus to trunk and shoulder muscles: long thoracic
cord ad spinal roots (ventral rami): branches of C5-C7 rami<br></br>structures innervated: serratus anterior muscle
branches of the bracial plexus to trunk and shoulder muscles: subscapular
cord and spinal roots (ventral rami): posterior cord; branches of C5 and C6 rami<br></br>structures innervated: teres major and subscapularis muscles
branches of the bracial plexus to trunk and shoulder muscles: thoracodorsal
cord and spinal roots (ventral rami): posterior cord; branches of C6-C8 rami<br></br>structures innervated: latissimus dorsi
branches of the bracial plexus to trunk and shoulder muscles: suprascapular
cord and spinal roots (ventral rami): upper trunk (C5, C6)<br></br>structures innervated: shoulder joint; supraspinatus and infraspinatus muscles
branches of the bracial plexus to trunk and shoulder muscles: pectoral (lateral and medial)
cord and spinal roots (ventral rami): branches of lateral and medial cords (C5-T1)<br></br>structures innervated: pectoralis major and minor muscles
branches of the lumbar plexus: iliohypogastric
ventral rami: L1<br></br>structures innervated: skin on side of bottock and skin on pubis; proprioceptor and motor to the most inferior parts of the internal oblique and transversus abdominis muscles
branches of the lumbar plexus: ilioinguinal
ventral rami: L1<br></br>structures innervated: skin of external genitalia and proximal medial aspect of the thigh
branches of the lumbar plexus: genitofemoral
ventral rami: L1, L2<br></br>structures innervated: motor to internal oblique and transversus abdominis muscles. skin of scrotum in males, of labia majora in females, and of anterior thigh inferior to middle portion of inguinal region; cremaster muscle in males
branches of the lumbar plexus: lateral femoral cutaneous
ventral rami: L2-L3<br></br>structures innervated: skin of lateral thigh; some sensory branches to peritoneum
additional branches of the sacral plexus: superior gluteal
ventral rami: L4, L5, S1<br></br>structures innervated: motor branches to gluteus medius and minimus and tensor fasciae latae
additional branches of the sacral plexus: inferior gluteal
ventral rami: L5-S2<br></br>structures innervated: motor branches to gluteus maximus
additional branches of the sacral plexus: posterior femoral cutaneous
ventral rami: S1-S3<br></br>structures innervated: skin of most inferior part of buttock, posterior thigh, and popliteal region; length variable; may also innervate part of skin of calf and heel
additional branches of the sacral plexus: pudendal
ventral rami: S2-S4<br></br>structures innervated: supplies most of skin and muscles of perineum (region encompassing external genitalia and anus and including clitoris, labia, and vaginal mucose in female, and scrotum and penis in males); external anal sphincter
special visceral sensory, sense of smell
CN I Olfactory Nerves: Sensory function (VS)
Olfactory receptor cells (bipolar neurons) in the olfactory epithelium of the nasal cavity
CN I Olfactory Nerves: Origin
special somatic sensory, vision
CN II Optic nerves: sensory function (SS)
retina of the eye
CN II Optic nerves: origin
pass through the optic canal of the sphenoid bone. optic nerves converge to form the optic chiasa, where fibers partially cross over, then contiue as the optic tracts to synapse in the thalamus. thalamic fibers porject to and terminate in the primary visual cortex in the occipital lobe
CN II Optic nerves: pathway
innervate four extrinsic eye muscles that direct the eyeball: superior rectus, medial rectus, inferior rectus, inferior oblique muscles
CN III Oculocomotor nerves: somatic motor function (SM)
constrictor muscles of the iris constrict the pupil.<br></br>ciliary muscle alters lens shape for near vision.
CN III Oculocomotor nerves: visceral motor function (VM) (parasympathetic)
oculomotor nuclei in the ventral midbrain
CN III Oculocomotor nerves: origin
pass through the superior orbital fissue to enter the orbit. parasympathetic fibers from the brain stem synapse in the ciliary ganglion with post ganglionic neurons that innervate the iris and ciliary muscle.
CN III Oculocomotor nerves: pathway
innervate the superior oblique muscle. this muscle passes through a ligamentous pully at the roof of the orbit, the trochlea, from which its name is derived.<br></br>afferent proprioceptor fibers return from the superior oblique.
CN IV Trochlear nerves: somatic motor function (SM)
trochlear nuclei in the dorsal midbrain
CN IV Trochlear nerves: origin
pass ventrally around the midbrain; pass through the superior orbital fissure to enter the orbit
CN IV Trochlear nerves: pathway
the large trigemenal nerve forms three divisions (trigeminal=threefold): opthalmic (V1), maxillary (V2), and mandibular (V3) divisions.<br></br>this mixed nerve is the general somatic sensory nerve of the face for touch, temperature, and pain. the mandibular division supplies somatic motor innervation to the chewing muscles.
CN V Trigeminal nerves: overview
V1 General somatic sensation from skin of anterior scalp and forehead, upper eyelid and nose, nasal cavity mucosa, cornea, and lacrimal gland.<br></br>V2 General somatic sensation from skin of cheek, upper lip, and lower eyelid, nasal cavity mucosa, palate, upper teeth.<br></br>V3 General somatic sensation from skin of chin and temporal region of scalp, anterior tongue and lower teeth.
CN V Trigeminal nerves: sensory function (SS)
V3 Innervate the muscles of mastication: temporalis, masseter, pterygoids, anterior belly of digastric<br></br>Afferent proprioceptor fibers return from these muscles
CN V Trigeminal nerves: somatic motor function (SM)
sensory receptors in skin and mucosa of face<br></br>motor fibers from trigeminal motor nucleus in pons
CN V Trigeminal nerves: origin
Through the skull<br></br>V1 Superior orbital fissure<br></br>V2 Foramen rotundum<br></br>V3 Foramen ovale; mandibular foramen<br></br>Cutaneous Branch<br></br>V1 Supraorbital foramen<br></br>V2 Infraorbital foramen<br></br>V3 Mental foramen<br></br>Cell bodies of sensory neurons of all three divisions located in the large trigeminal ganlion. fibers extend to trigeminal nuclei in the pons
CN V Trigeminal nerves: pathway
innervate the lateral rectus muscle. this muscle abducts the eye.<br></br>afferent proprioceptor fibers return from the lateral rectus.
CN VI Abducens nerves: somatic motor function (SM)
abducens nuclei in the inferior pons
CN VI Abducens nerves: origin
pass through the superior orbital fissure to enter the orbit
CN VI Abducens nerves: pathway
special visceral sensory from taste buds on anterior two-thirds of tongue<br></br>general somatic sensory from small patch of skin on the ear
CN VII Facial nerves: sensory function (VS, SS)
five major branches on face: temporal, zygomatic, buccal, mandibular, and cervical, to innervate the facial muscles. also innervates the posterior belly of digastric.<br></br>afferent proprioceptor fibers return from these muscles
CN VII Facial nerves: somatic motor function (SM)
innervate the lacrimal (tear) glands, nasal and palantine glands, and the submandibular and sublingual salivary glands
CN VII Facial nerves: visceral motor function (VM) (parasympathetic)
fibers emerge from the pons, just lateral to abducens
CN VII Facial nerves: origin
fibers enter the temporal bone via the internal acoustic meatus. chorda tympani branches off to innervate the two salivary glands and tongue. branch to facial muscle emerges from the temporal bone through the stylomastoid foramen and courses to lateral aspect of face.<br></br>cell bodies of sensory neurons are in geniculate ganglion.<br></br>cell bodies of postganglionic parasympathetic neurons are in pterygopalantine and submandibular ganglia on the trigeminal nerve.
CN VII Facial nerves: pathway
vestibular branch: special somatic sensory, equilibrium<br></br>cochlear branch: special somatic sensory, hearing<br></br>small motor component adjusts the sensitivity of the sensory receptors
CN VIII Vestibulocochlear nerves: sensory function (SS)
sensory receptors in the inner ear for hearing (within the cochlea) and for equlibrium (within the semicircular canals and vestibule)
CN VIII Vestibulocochlear nerves: erigin
from the inner ear cavity within the temporal bone, fibers pass through the internal acoustic meatus, merge to form the vestibulocochlear nerve and enter the brain stem at the pons.<br></br>sensory nerve cell bodies for vestibular branch located in vestibular ganglia; for the cochlear branch, in the spiral ganglia within the cochlea
CN VIII Vestibulocochlear nerves: pathway
special visceral sensory from taste buds on posterior third of tongue.<br></br>general visceral sensory from posterior third of tongue, pharyngeal mucosa, chemoreceptors in the coratid body (which monitor O2 and CO2 in the blood and regulate respiratory rate and depth), and baroreceptors of carotid sinus (regulate blood pressure).<br></br>general somatic sensory from small area of skin on external ear.
CN IX Glossopharyngeal nerves: sensory function (VS, SS)
innervate a pharyngeal muscle, stylopharyngeus, which elevates the pharynx during swallowing.<br></br>afferet proprioceptor fibers return from this muscle.
CN IX Glossopharyngeal nerves: somatic motor function (SM)
innervate the parotid salivary gland
CN IX Glossopharyngeal nerves: visceral motor function (VM) (parasympathetic)
fibers emerge from the medulla oblongata
CN IX Glossopharyngeal nerves: origin
fibers pass through the jugular foramen and travel to the pharynx.<br></br>cell bodies of sensory neurons are located in the superior and inferior ganglia. cell bodies of postganglionic parasympathic neurons are in otic ganglion on the trigeminal nerve.
CN IX Glossopharyngeal nerves: pathway
mixed nerve; major function is parasympathic innervation to the thoracic and abdominal viscera
CN X Vagus nerves: overview
general visceral sensory from the thoracic and abdominal viscera, mucosa of larynx and pharynx, coratid sinus (baroreceptor for blood pressure), and carotid and aortic bodies (chemoreceptors for respiration).<br></br>special visceral sensory from taste buds on the epiglottis.<br></br>general somatic sensory from small area of skin on external ear.
CN X Vagus nerves: sensory function (VS, SS)
innervates skeletal muscles of the pharynx and larynx involved in swallowing and vocalization.<br></br>afferent proprioceptor fibers return from the muscles of the larynx and pharynx
CN X Vagus nerves: somatic motor function (SM)
innervates the heart, lungs, and abdominal viscera through the transverse colon. Regulates heart rate, breathing, and digestive system activity.
CN X Vagus nerves: visceral motor function (VM) (parasympathetic)
fibers emerge from medulla ablongata
CN X Vagus nerves: origin
fibers exit the skull through the jugular foramen and descend through the neck into the thorax and abdomen
CN X Vagus nerves: pathway
innervate the trapezius and sternocleidomastoid muscles that move the head and neck.<br></br>afferent proprioceptor fibers return from these muscles
CN XI Accessory nerves: somatic motor function (SM)
forms from ventral rootlets arising from C1-C5 of the spinal cord. long considered to have both a cranial and spinal portion, the cranial rootlets have been shown to be part of the vagus nerves
CN XI Accessory nerves: origin
upon emerging from the spinal corcd, spinal rootlets merge to form the accessory nerves, pass into the skull through the foramen magnum, and then exit the skull through the jugular foramen
CN XI Accessory nerves: pathway
innervate the intrinsic and extrinsic muscles of the tongue. aid tongue movements during feeding, swallowing, and speech.<br></br>afferent proprioceptor fibers return from these muscles.
CN XII Hypoglossal nerves: somatic motor function (SM)
from a series of roots from the hypoglossal nuclei in the ventral medulla oblongata
CN XII Hypoglossal nerves: origin
exit the skull through the hypoglossal canal and travel to the tongue
CN XII Hypoglossal nerves: pathway
ventral rami: C2, C3<br></br>structures innervated: skin on pesterolateral aspect of neck
branches of the cervical plexus, cutaneous branches (superficial): lesser occiptal
ventral rami: C2, C3<br></br>structures innervated: skin of ear, skin over parotic gland
branches of the cervical plexus, cutaneous branches (superficial):greater auricular
ventral rami: C2, C3<br></br>structures innervated: skin on anterior and lateral aspect of neck
branches of the cervical plexus, cutaneous branches (superficial):transverse cervical
ventral rami: C3, C4<br></br>structures innervated: skin of shoulder and clavicular region
branches of the cervical plexus, cutaneous branches (superficial): supraclavicular (anterior, middle, and posterior)
ventral rami: C1-C3<br></br>structures innervated: infrahyoid muscles of neck (omohyoid, sternohyoid, and sternothyroid)
branches of the cervical plexus, motor branches (deep): arisa cervicalis (superior and inferior roots)
ventral rami: C1-C5<br></br>structures innervated: deep muscles of neck (geniohyoid and thyrohyoid) and portions of scalenes, levator scapulae, trapezius, and sternocleidomastoid muscles
branches of the cervical plexus, motor branches (deep): segmental and other muscular branches
ventral rami: C3-C5<br></br>structures innervated: diaphragm (sole motor nerve supply)
branches of the cervical plexus, motor branches (deep): phrenic
corld and spinal roots (ventral rami): branches of C5 rami<br></br>structures innervated: rhomboid muscles and levator scapulae
branches of the bracial plexus to trunk and shoulder muscles: dorsal scapular
cord ad spinal roots (ventral rami): branches of C5-C7 rami<br></br>structures innervated: serratus anterior muscle
branches of the bracial plexus to trunk and shoulder muscles: long thoracic
cord and spinal roots (ventral rami): posterior cord; branches of C5 and C6 rami<br></br>structures innervated: teres major and subscapularis muscles
branches of the bracial plexus to trunk and shoulder muscles: subscapular
cord and spinal roots (ventral rami): posterior cord; branches of C6-C8 rami<br></br>structures innervated: latissimus dorsi
branches of the bracial plexus to trunk and shoulder muscles: thoracodorsal
cord and spinal roots (ventral rami): upper trunk (C5, C6)<br></br>structures innervated: shoulder joint; supraspinatus and infraspinatus muscles
branches of the bracial plexus to trunk and shoulder muscles: suprascapular
cord and spinal roots (ventral rami): branches of lateral and medial cords (C5-T1)<br></br>structures innervated: pectoralis major and minor muscles
branches of the bracial plexus to trunk and shoulder muscles: pectoral (lateral and medial)
ventral rami: L1<br></br>structures innervated: skin on side of bottock and skin on pubis; proprioceptor and motor to the most inferior parts of the internal oblique and transversus abdominis muscles
branches of the lumbar plexus: iliohypogastric
ventral rami: L1<br></br>structures innervated: skin of external genitalia and proximal medial aspect of the thigh
branches of the lumbar plexus: ilioinguinal
ventral rami: L1, L2<br></br>structures innervated: motor to internal oblique and transversus abdominis muscles. skin of scrotum in males, of labia majora in females, and of anterior thigh inferior to middle portion of inguinal region; cremaster muscle in males
branches of the lumbar plexus: genitofemoral
ventral rami: L2-L3<br></br>structures innervated: skin of lateral thigh; some sensory branches to peritoneum
branches of the lumbar plexus: lateral femoral cutaneous
ventral rami: L4, L5, S1<br></br>structures innervated: motor branches to gluteus medius and minimus and tensor fasciae latae
additional branches of the sacral plexus: superior gluteal
ventral rami: L5-S2<br></br>structures innervated: motor branches to gluteus maximus
additional branches of the sacral plexus: inferior gluteal
ventral rami: S1-S3<br></br>structures innervated: skin of most inferior part of buttock, posterior thigh, and popliteal region; length variable; may also innervate part of skin of calf and heel
additional branches of the sacral plexus: posterior femoral cutaneous
ventral rami: S2-S4<br></br>structures innervated: supplies most of skin and muscles of perineum (region encompassing external genitalia and anus and including clitoris, labia, and vaginal mucose in female, and scrotum and penis in males); external anal sphincter
additional branches of the sacral plexus: pudendal
