A/P of Head and Neck Midterm

anterior (ventral) root

motor/efferent fibers from cell bodies in the anterior horn

posterior (dorsal) root

sensory (afferent) fibers that convey neural impulses to the posterior horn

spinal nerve and rami

the anterior and posterior roots unite at the intervertebral foramen to form a spinal nerve

spinal nerves divide into

• posterior (dorsal) primary rami

• anterior (ventral) primary rami

where do the anterior and posterior roots unite?

intervertebral foramen

spinal nerves are… (sensory, motor, or mixed/both?)

mixed!

dorsal nerves go to…

the back

central nerves go to the…

cervical plexus

function of the posterior (dorsal) primary rami

innervate the deep muscles of the back and the skin of the posterior head, neck, and trunk

what makes up the anterior (ventral) primary rami

• cervical plexus C1-C4

• brachial plexus C5-T1

• thoracic spinal nerves T1-T12

• lumbar plexus T12-L4

• sacral plexus L4-S4

how many pairs of spinal nerves?

31

what is the cervical plexus formed by?

the ventral (anterior) rami of spinal nerves C1-C4

muscular branches of the cervical plexus

• longus capitis

• longus colli

• scalenes

• geniohyoid

• thyrohyoid

• ansa cervicalis

  • omohyoid, sternothyroid, sternohyoid

• phrenic nerve (C3, 4, 5)

function of muscular branches of cervical plexus

control neck muscles

phrenic nerve function

primary nerve for controlling diaphragm

C5 is part of…

• the brachial plexus

• branches from cervical plexus

• and its mixed!

the phrenic nerve travels to the…

• pericardium and the diaphragm via the anterior of the anterior scalene muscle

the phrenic nerves make their way…

across the anterior scalene, deep to the transverse cervical artery and suprascapular artery, travel down into the chest cavity to innervate the diaphragm

of a nerve is damaged above the diaphragm but below C5 will you still be able to breath?

yes! the phrenic nerve is C3-C5 and it innervates the diaphragm meaning breathing will be unaffected

ansa cervicalis superior root

C1 and C2

ansa cervicalis inferior root

C2 and C3

the shape of the ansa cervicalis is a…

loop!

cutaneous branches location

emerge around the middle of the posterior border of the SCM

Erb’s point

nerve point of the cutaneous branches of the cervical plexus

cutaneous branches of the cervical plexus

• lesser occipital nerve

• greater auricular nerve

• transverse cervical nerve

• supraclavicular nerves

lesser occipital nerve vertebrae

C2

great auricular nerve vertebrae

C2 and C3

transverse cervical nerve vertebrae

C2 and C3

Supraclavicular nerve vertebrae

C3 and C4

greater auricular goes to…

the ear

lesser occipital goes to…

occipital bone from posterior rami and ventral rami cervical plexus

transverse cervical goes to…

crosses the sternocleidomastoid

supraclavicular nerve is…

on top of the clavicle

brachial plexus is…

formed by the ventral (anterior) rami of the spinal nerve

erb’s point

space where nerves fan out on the neck, near SCM

brachial plexus

• C5-T1

• formed by central (anterior) rami of spinal nerves

function of brachial plexus

supplies upper extremities and shoulders with sensation/motor function

roots (rami) of the brachial plexus

• anterior rami of C5 to T1 spinal nerves

• pass through the anterior and middle scalene muscles

CN V sensory function

• transmits sensations of pain, touch, temperature, pressure, and proprioception from the face to the brain stem

  • this is general sensory/somatic sensory

CN V branches

• ophthalmic

• maxillary

• mandibular

tongue sensation for CN V

provides anterior 2/3 of tongue sensations

motor function of CN V

• muscles of mastication

• tensor tympani

• tensor veli palatini

• mylohyoid and anterior belly of the digastric

ophthalmic CN-V1

• nerves come in via superior orbital fissure

• goes to the eye

maxillary CN-V2

goes to maxilla and includes upper teeth

mandibular CN-V3

goes to mandible, but only motor fibers and it is used for mastication muscles

sensory nerves of CN V

• ophthalmic

• maxillary

motor nerves of CN V

mandibular

mandibular CN V3 nerve branches off into…

• inferior alveolar nerve

• mylohyoid nerve

• mental nerve

• AND LINGUAL

inferior alveolar nerve runs through….

mandibular canal

mental nerve exits through…

mental foramen

lingual nerve

• branch of mandibular

• somatic sensory of anterior 2/3 of the tongue— pain, temperature, etc

infraorbital nerve exits through the…

infraorbital notch

supraorbital nerve exits through the…

supraorbital notch

supraorbital nerves can help identify….

if someone is actually unconscious. you can press the area (like the sternum) to wake them up

pathway of CN VII

• brainstem (pons)

• internal auditory meatus

• facial nerve canal

• stylomastoid foramen

• posterior edge of parotid gland

• facial expession muscles

motor functions of the facial nerve

• facial expression muscles

• stapedius muscle

visceral motor/parasympathetic meaning

involuntary fibers

visceral motor function of CN VII

• lacrimal gland — crying

• submandibular and sublingual glands — salivation

submandibular gland

below the mandible

sublingual gland

below the tongue

visceral sensation of CN VII

• anterior 2/3 of tongue taste

• sensation of parts of auricle and retroauricular region

CN VII exits through the…

• internal acoustic meatus

• stylomastoid foramen

chorda tympani

facial and lingua nerves join here

CN IX emerges from…

medulla oblongata

CN IX exits from…

cranial cavity through the jugular foramen

CN IX lies…

between internal carotid artery and internal jugular vein, curves and passes deep to the styloid process

functions of CN IX

• parotid gland

• stylopharyngeal muscle

• carotid sinus and carotid body

• lingual branch

• sensation oropharynx

• tympanic branches to middle ear, tympanic membrane, and E.T.

lingual branch of glossopharyngeal nerve CN IX function

posterior 1/3 tongue taste AND general sensation

CN X location

originates from medulla oblongata and exits the skull through the jugular foramen

• passes through carotid sheath

• moves down to thoracic cavity

CN X left superior laryngeal nerve location

left superior laryngeal nerve moves down into left concurrent laryngeal nerve, it U-turns around the aortic arch and moves back up

CN X right superior laryngeal nerve location

moves down past the right subclavia artery and makes a U-turn, then it becomes the right recurrent laryngeal nerve and goes back up

recurrent laryngeal nerves

branch from the vagus CN X nerve

• hooks underneath aortic arch and subclavian artery then goes toward larynx

recurrent laryngeal nerve function

innervates the majority of the intrinsic muscles of the larynx

motor innervation for the CN X

• muscles of the:

  • pharynx

  • soft palate

  • intrinsic muscles of larynx

• EXCEPT:

  • stylopharyngeus

  • tensor veli palatini

CN X sensory innervation function

• laryngopharynx and superior part of the larynx

• auricle, external acoustic meatus, dura mater of the posterior cranial fossa

• aortic body, esophagus, lung, bronchi, heart, intestines

• taste from epiglottis

CN X parasympathetic innervation

smooth muscle and glands of the pharynx, larynx, thoracic and abdominal organs

CN XI location

exit cranial cavity via the jugular foramen, passes deep to SCM, enters lateral cervical region at posterior border of SCM, disappears deep to the anterior border of the trapezius

CN XI innervates…

SCM and trapezius muscle

CN XII location

from medulla oblongata. exits cranium via hypoglossal canal, travels to lower border of posterior belly of digastric muscle, then goes deep to mylohyoid and lies on lateral surface of hyoglossus

CN XII innervation

innervates all the muscles of the tongue, except palatoglossus muscle which is supplied by the vagus nerve

sympathetic trunk

lies lateral to the vertebral bodies for the entire length of the vertebral column

• preganglionic sympathetic fibers

superior cervical ganglion

postganglionic fibers contribute to the innervation of the iris, salivary glands, sweat glands, and blood vessels in the head and neck

3 pairs of sympathetic ganglion

• superior cervical region

• middle cervical region

• stellate ganglion

sympathetic ganglion at C2-3

superior cervical ganglion

sympathetic ganglion at C6

middle cervical ganglion

sympathetic ganglion at C7

stellate ganglion

visceral relates to…

organs— produced sympathetic and parasympathetic

arteries of the arch of the aorta

• left subclavian

• left common carotid

• brachiocephalic trunk

brachiocephalic trunk two parts

• right common carotid artery

• right sublclavian artery

subclavian artery

• vertebral artery

• internal thoracic

• thyrocervical trunk

• costocervical trunk

• dorsal scapular artery

thyrocervical trunk supplies….

the thyroid!

thyrocervical trunk parts

• ascending cervical artery

• inferior thyroid artery

• suprascapular arterty

• transverse cervical artery

common carotid artery parts

• external carotid

• internal carotid

• carotid sinus

Internal carotid artery enters the cranium through the…

carotid canal

branches of external carotid artery

• superior thyroid artery — superior laryngeal artery

• ascending pharyngeal artery

• lingual artery

• facial artery

• occipital artery

• posterior auricular artery

• maxillary artery

• superficial temporal artery

superior thyroid artery supplies…

the thyroid

lingual artery supplies the…

tongue

facial artery supplies the…

face

occipital artery supplies the…

eye area

posterior auricular artery supplies the…

ear area