Head and Neck Objectives

List the two basic subdivisions of the skull

the neurocranium and facial skeleton

List the cavities of the skull

the orbital cavity, cranial cavity, middle ear cavities, and nasal cavity with a left and right side

List the air sinuses of the skull

the frontal, maxillary, ethmoidal sinuses and the sphenoid sinus

Describe the types of articulations found in the skull

majority of the articulations of the skull are composed of non-movable sutures. the temporomandibular joint is a synovial hinge joint 

Name the three prominent sutures of the cranium

the coronal suture runs horizontally between the frontal and parietal bones. the sagittal suture runs vertically down the midline of the skull, between the two parietal bones. the lambdoid suture runs horizontally across the back of the skull, between the parietal and occipital bones.

Describe the temporomandibular joint

the tmj is a synovial hinge joint that can perform protraction and retraction as well as elevation and depression. the articular disc above the mandible allows for a high range of motion

Describe the three cranial fossae and a prominent bony landmark of each

the anterior cranial fossa has the cribriform plate, the middle cranial fossa has the sella turcica, the posterior cranial fossa houses the foramen magnum

Define the pterion, bregma and lambda

The pterion is indicated by an "H-shaped" formation of sutures that unite to frontal, parietal, temporal, and sphenoid bones. it is the weakest part of the skull where the middle meningeal a. runs. if ruptured it will cause an epidural hematoma. the bregma is the coronal and sagittal suture. the lambda is the lambdoid and sagittal suture

Describe the four major subdivisions of the brain.

Brainstem, diencephalon, cerebellum, cerebrum

Describe the primary functions of each of the subdivisions of the brainstem

The medulla controls vital reflexes and non-vital reflexes like coughing and vomiting, the pons controls vital reflexes and is the relay center between the cerebellum and brain, the midbrain is responsible for visual and auditory reflexes

Describe the primary function of the cerebellum

The primary function of the cerebellum is to send motor output after functions as a comparator to regulate the rate, range, and force of movements. Losing this ability results in ataxia. The cerebellum compares what it wants to do with what is happening.

List four characteristics of the cerebrum (Consider functional and anatomic properties)

the cerebrum has four major lobes, is somatotopically arranged, has grooves and ridges to increase surface area and is the largest section 

Describe the four lobes of the cerebrum, their position to each other and their function

Anterior is the frontal lobe responsible for planning and higher motor functions (location of primary motor cortex), the parietal lobe is the location of the primary somatosensory cortex, the occipital lobes is the primary visual cortex and the temporal lobes process audition, learning and memory 

Describe the gray matter of the cerebrum, its location/function

in the gyri of the cerebral cortex and functions in determining approprietness (basal nuclei)

Describe the white matter of the cerebrum, its different fiber tracts and their destinations

the white matter has three major tracts. the association tract connects the lobes within hemispheres, the commissural tracts cross midline, the projection fibers connect the spinal cord to cerebellum

Define "functional localization"

Functional localization is the idea that certain functions are localized in certain areas of the brain

Be able to name and draw the branches off the aortic arch that give rise to the head's blood supply

The branches that come off the aortic arch are the brachiocephalic trunk, left common carotid, and left subclavian arteries. Off the brachiocephalic trunk branches the R common carotid and right subclavian artery. Off the subclavian arteries branch the vertebral arteries. From common carotid arteries the branches are internal and external carotid arteries.

Be able to name and identify the primary branches of the external carotid artery

superior thyroid artery (supplies the thyroid, neck, and larynx), lingual artery, facial artery, occipital artery (supplying the scalp), maxillary artery (terminally supplying the gums and mastication muscles and branching into middle meningeal through foramen spinosum), superficial temporal artery

Describe the functions of the cranial meninges

the cranial meninges compartmentalize to create venous sinuses, support the brain, and limit movement

Name and describe the individual layers of the meninges surrounding the brain

from deep to superficial are the pia, arachnoid, inner meningeal layer of dura adherent to the arachnoid mater and outer periosteal layer of dura adhered to the skull

Name the different dural infoldings and their associated venous sinuses.

the falx cerebri divides the left and right cerebral hemispheres and houses the superior and inferior sagittal sinuses. the tentorium cerebelli divides the cerebrum and cerebellum and contains transverse sinuses. the falx cerebelli divides the left and right cerebellar hemispheres containing the occipital sinus

Describe the flow of venous blood from the brain

Superior Sagittal Sinus drains into the confluence then transverse Sinuses drain into Sigmoid Sinuses into Internal Jugular Vein. Cavernous Sinuses drain into Superior Petrosal Sinuses into Transverse Sinuses then Sigmoid Sinuses and into Internal jugular vein. Cavernous Sinuses drain into Inferior Petrosal Sinuses then internal Jugular Vein

What is unusual about the veins of the face and dural sinuses - are there any connections between the two?

The veins in the face are able to allow blood to flow in both directions. The veins in the face form anastomoses with venous sinuses.

Describe the two possible routes of arterial blood in the brain

Arterial blood can reach the brain through the internal carotid artery or vertebral arteries

Describe the production of CSF, include a description of the choroid plexus

csf is constantly being produced and reabsorbed which is called circulation turnover. csf is produced by modified fenestrated capillaries known as the choroid plexus which are located in every ventricle

Be able to describe the circulation of CSF, beginning with its production at the choroid plexuses and ending with its reabsorption into the blood

arterial blood to the choroid plexus to the subarachnoid space to the arachnoid villi to the dural venous sinuses to the internal jugular vein 

Describe the ventricular system of the brain, their arrangement and position and their connections with the subarachnoid space

the two lateral ventricles are located in each cerebral hemisphere and connect the diencephalon. They connect with the third ventricle in the diencephalon via the interventricular foramina. Between the pons and cerebellum is the fourth ventricle connecting to the third ventricle via the aquaduct of the midbrain. The fourth ventricle opens to the subarachnoid space via one median and two lateral apertures.

Describe hydrocephalus, its causes; include possible sites of blockage and

accumulation of CSF

hydrocephalus is when excess csf accumulates in the brains ventricles causing increased intracranial pressure

Be able to describe the differences between cranial nerves and spinal nerves

cranial nerves have special sense, the LMN cell bodies are in the brainstem, have somatic control of facial expression and mastication and only parasympathetic autonomic function

Be able to identify the muscles of facial expression and describe their action

CN seven innervates the occipitofrontalis (surprise), zygomaticus (smiler), orbicularis oris (kisser). orbicularis oculi, and buccinator (trumpeter) muscle

What is unusual about the superficial fascia of the face, of the scalp?

the face only has superficial fascia

Be able to name and describe the layers of the scalp

Scalp stands for skin-connective tissue- aponeurosis- loose connective tissue- periosteum

Describe the special sense function of the facial nerve

the special sense of cranial nerve seven includes sensory responsibility to the anterior two thirds of the tongue

Be able to identify the muscles of mastication and describe their action

The temporalis muscle elevates and retracts the jaw, the masseter and medial pterygoid muscles protract and depress the jaw, and the lateral pterygoid protracts and depresses the jaw

Describe the branches of the trigeminal nerve including any named nerves discussed in lecture and/or lab

The branches are ophthalmic, maxillary and mandibular divisions. the ophthalmic division is responsible for sensory innervation to the forehead and frontal sinuses. the maxillary division is responsible for sensory innervation to the lateral nose. the mandibular division is responsible for sensory innervation to the anterior 2/3 of the tongue

Define the triangles of the neck

the anterior triangle of the neck has borders of the sternocleidomastoid posteriorly, body of the mandible superiorly, and midline of the neck anteriorly. the posterior triangle of the neck has borders of the sternocleidomastoid anteriorly, the trapezius posteriorly, and the clavicle bone inferiorly.

What structures are involved in "thoracic outlet syndrome”?

thoracic outlet syndrome describes when your anterior and middle scalene muscles constrict the brachial plexus leading to arm discomfort

What is a "neurovascular bundle" and what are the contents of this "bundle" in the neck?

The carotid sheath is a neurovascular bundle containing the common carotid artery, internal jugular vein and vagus nerve.

What are the primary target organs of the hyoid muscles?

The hyoid muscles target the tongue, pharynx, larynx, thyroid structures, and other viscera that contribute to functions of speaking and swallowing.

What daily activities are affected by the hyoid muscles?

Daily activities affected by the hyoid muscles include speaking, swallowing, and breathing

List the actions of the suprahyoid muscles.

Suprahyoid muscles include the mylohyoid which elevates the floor of the mouth, the geniohyoid which depresses the mandible, the anterior and posterior bellies of the digastric muscle which depresses the mandible and the stylohyoid which elevates and retracts the hyoid.

List the actions of the infrahyoid muscles.

the sternohyoid depresses the hyoid, the omohyoid depresses and retracts the hyoid, the thyrohyoid depresses the hyoid but elevates the larynx and the sternothyroid which depresses thyroid cartilage

Define the "pharynx”

a musculomembranous space that is posterior and inferior to the nasal and oral cavities, providing a common origin for food and air.

Define the boundaries and contents of the three subdivisions of the pharynx

The nasopharynx runs from the base of the skull to the to the soft palate containing the nasal conchae, opening of the auditory tube, and pharyngeal tonsils. The oropharynx runs from the soft palate to the epiglottis containing the palatoglossal and palatopharyngeal arches. The laryngopharynx is the space from the epiglottis to the inferior portion of the larynx containing the vocal and vestibular folds.

What muscles form the pharynx? What is their action, attachments and nerve supply.

The pharynx is formed by pharyngeal constrictor muscles and innervated by the pharyngeal plexus of cranial nerves nine and ten. The superior constrictor originates at the pterygomandibular raphe. The middle constrictor originates at the hyoid bone. The inferior constrictor originates at the thyroid cartilage. 

What is the general motor and sensory supply to the pharynx?

motor innervation is provided by vagus cn ten and sensory inervation is provided by glossopharyngeal cn nine.

What are the "tonsils" and where are they located?

Tonsils are lymph structures. The palatine tonsils are in the back of the oral cavity and the pharyngeal tonsils are in the back of the nasal cavity.

What are the "arches" of the oropharynx and what actually forms them?

The arches include the palatoglossal arch and palatopharyngeal arch and are formed by muscles.

What is a pattern generator?

A pattern generator is when you initiate a movement and a reflex follows like in sneezing, swallowing, and blinking

What are the general "problems" associated with swallowing and how are they solved?

Swallowing problems include our common opening for air and food and therefore we need to close the nasopharynx. We need to move the trachea anterior and superior. 

What muscles are involved in solving the problems in swallowing?

The suprahyoid muscles pull the trachea forward. The palatopharyngeus elevates the soft palate. The levator palati and tensor palati elevate the soft palate

How is the auditory tube opened?

The tensor palati lifts the upper part of the opening

List the stages of swallowing.

First, Tongue forces food back into oropharynx (voluntary). Then, Food moves from oropharynx to laryngopharynx - breathing and chewing stop, sup & middle constrictors move food inferiorly, pharyngeal muscles contract so food cannot enter nasopharynx, pharynx is stabilized by stylopharyngeus muscle, hyoid and larynx elevated and brought forward so epiglottis is forced down over top of larynx by suprahyoids (involuntary). Last, Food moved from laryngopharynx to esophagus by inferior constrictors (involuntary)

List the functions of the larynx.

Functions of the larynx are to increase intrathoracic and intraabdominal pressure, phonation, and is a protective sphincter

Describe the larynx in terms of the cartilages that compose it.

The larynx is composed of epiglottic cartilage superior to thyroid cartilage, cricoid cartilage, and arytenoid cartilages

List and describe the articulations of the larynx.

the cricoarytenoid articulation functions to change the size of the rima glottidis. the cricothyroid articulation changes tension on the vocal folds.

Describe the muscles that work on the articulations in the larynx.

Muscles that adduct the vocal folds are the arytenoid, lateral cricoarytenoid, and vocalis muscles. The posterior cricoarytenoid muscle abducts the vocal folds. The cricothyroid muscles can tense the vocal cords to control pitch

What is the rima glottidis?

the space between the vocal folds that allows air to pass through

Describe the nerve supply to larynx.

Innervation to the larynx is provided by branches of the vagus nerve. The superior laryngeal nerve branches into the internal laryngeal nerve responsible for all sensory innervation above the vocal folds. The other external laryngeal nerve branch is responsible for motor innervation of the cricothyroid muscle. The recurrent laryngeal nerve is responsible for sensory innervation below the vocal folds and motor innervation to all structures of the larynx except the cricothyroid. 

Describe the folds of the larynx

the vestibular folds are inferior to the vestibule and protect the airway. the vocal folds sit more inferior and create sound by vibrating

List and define the processes involved in speech.

In order for speech to occur the larynx must create phonation, the pharynx creates resonance, muscles aid in air movement, and the tongue and muscles of expression help with articulation