head and neck final ch 1-12

frontal plane/ coronal section

• plane related to imaginary line dividing body at any level into anterior and posterior parts

• splits body into ventral/ dorsal

horizontal plane/ transverse section

• plane related to imaginary line dividing body at any level into superior and inferior parts

• splits body horizontally

• splits body into “hamburger” style

inferior

• area facing away from head and toward feet

median

• structure at median plane

• exact midline

median plane

• plane related to imaginary line dividing body into right and left halves

sagittal section/ median plane

• section through median plane

• section cuts body vertically into exact left and right halves

• cuts body “hot dog style”

superior

• area facing toward head and away from feet

transverse section

• section through any horizontal plane

• splits the body “hamburger style”

cranium bones

• contains the brain

• PROTECT THE BRAIN

  • 8 total

  • occipital

  • frontal

  • sphenoid

  • ethmoid

  • parietal

  • temporal

facial bones

• support face

• serve as a base for dentition

• PROTECT THE BRAIN

  • vomer

  • lacrimal

  • nasal

  • inferior nasal conchae

  • zygomatic

  • maxilla

  • mandible

occipital bone

• posterior portion of the skull and base of cranium

  • articulation = parietal, temporal, and sphenoid bone

  • contains magnum foramen (passage of spinal cord)

  • condyles are in articulation with the atlas

frontal bone

• anterior part of skull, superior to eyes and located in frontal region

• includes forehead and roof of each orbit

parietal bones

• paired

• articulate with each other at the sagittal suture

• articulate with occipital bone at lambdoidal suture

• also articulates with frontal bone, temporal bones, sphenoid bone

temporal bones

• paired

• form lateral wall of the skull and part of the base of the skull

• articulate with zygomatic bone, parietal bone, occipital bone, sphenoid, mandible

• three parts

  • squamous, tympanic, pterous

sphenoid bone

• appearance of a butterfly

• goes through midsagittal plane and is located between other bones

• forms base of cranium, lateral of skull, floors and walls of orbits

• articulates with frontal bone, parietal bones, ethmoid bone, temporal bones, zygomatic bones, palatine bones, comer, occipital bone, maxilla

• houses pituitary gland

ethmoid bone

• goes through midsagittal plane

• located anterior to sphenoid bone

• contains cribriform plate

• cannot be seen from certain aspect of the skull

vomer

• articulates with sphenoid bone on its superior border

• on its inferior border, the vomer articulates with the median palatine suture

lacrimal bones

• 2

• are the smallest and most fragile of the facial bones

• located posterior to the frontal processes of maxillae

• each bone articulates with the ethmoid bone and frontal bone as well as maxillae

nasal bones

• 2

• fit between the frontal processes of the maxillae and articulate with the maxillae laterally, and the frontal bone superiorly

zygomatic bones

• form cheek of face

• articulates with the frontal bone, temporal bone, and sphenoid bone as well as maxilla

• helps to form lateral wall and floor of orbit

palatine bones

• not tehcnically facial bones

• L shaped, consists of two horizontal and vertical plates

• greater palatine foramen transmits the greater palatine nerve and blood vessels, serving as a landmark for block

maxilla

• 2 fused bones at intermaxillary suture

• infraorbital foramen

• canine fossa (depressions)

• canine eminece (raised protrusion)

• maxillary tuberosity

• posterior superior alveolar foramina

• incisive foramen

• forms the floor of the nasal cavity

• contains maxillary (upper) teeth

mandible

• single facial bone that forms lower jaw

• only freely moveable bone of the skull

• contains the mandibular foramen, mental foramen, and coronoid notch, along with teeth of lower dentition

origin

• end of muscle attached to least movable structure

insertion

• end of the muscle attached to more moveable structure

cervical muscles

• sternocleidomastoid

• trapezius

muscles of facial expression

• responsible for expression, lip movement, smiling, and frowning

• epicranial

  • frontalis

  • occipital belly

• orbicularis oculi

• orbicularis oris

• depressor anguli oris

• mentalis

• platysma

• risorius

• buccinator

• corrugator supercilli

• zygomaticus minor

• zygomaticus major

bells palsy

• causes paralysis or weakness in one side of the face

• paralysis of facial nerve

zygomaticus major facial expression

• smiling (draws corners of the mouth up)

• elevates corners of mouth

zygomaticus major, levator anguli oris, risorius facial expressions

• all of these contract when smiling

temporalis muscle

• a fan shaped muscle

• main function is to elevate and retract mandible

• originates from the temporal fossa and inserts at the coronoid process of the mandible

• its fibers pass deep to zygomatic arch to attach to mandible

muscles of mastication

• masseter

• temporalis

• medial pterygoid

• lateral pterygoid

• elevate, depress, protrude, retrude, and laterally deviate the mandible

• innervated by the mandibular division of trigeminal nerve

• motor fibers that contract these muscle travel in the trigeminal nerve

• MONSTOR TRUCKS MAKE LOUDNESS

lateral pterygoid muscle

• protrudes and laterally shifts mandible

• a muscle of mastication

• lies superior to the medial pterygoid muscle

• a thick and short triangular shaped muscle located in the infratemporal fossa of the skull

• superior and inferior heads

• causes the power stroke ( moving side to side)

• bilateral contraction:

  • mainly protrusion of mandible with mandible forward

  • slight depression of mandible during opening of jaws

• unilateral contraction

  • lateral deviation of mandible, shift mandible to contralateral side 

trismus

• patient cannot open their mouth due to dysfunction in lateral pterygoid muscle 

• limited opening due to muscle or joint restriction

medial pterygoid muscle

• elevates mandible

• attaches to the mandible and to the medial surface of the lateral pterygoid plate

• bilateral contraction

  • elevation of mandible during closing of jaws

• aids in elevating the mandible while closing the jaw, protruding the mandible, and mastication

masseter muscle

• a muscle of mastication

• attaches to the zygomatic arch

• when contracted it elevates the mandible

• most superficial and is the strongest muscle of mastication, primary chewing muscle

• bilateral contraction:

  • elevation of mandible during closing of jaw

bruxism

• bilateral enlargement of the masseter muscle from trauma (grinding)

• grinding of teeth

• alters facial dimensions

• causes muscular pain in masseter and temporalis

temporomandibular joint

• formed by and articulation between the mandibular condyle and the temporal bones

• the muscles involved are attached to the cranium and the mandible

• allows for the mandible to be elevated and depressed

• contains the mandibular condyle, temporal fossa, and articular disc

• joint disc contains synovial fluid

TMD

• temporomandibular disorder

• joint tenderness, neck/shoulder pain from tension, chronic headaches 

vascular system of the head and neck..

• consists of an arterial blood supply

• a capillary network

• venous drainage

artery

• carry oxygenated blood away from the heart

• strong, muscular blood vessels that carry oxygen-rich blood from the heart to the body

• handle a large amount of force and pressure from your blood flow but dont carry a large volume of blood

bacteremia 

• bacteria traveling within vascular system 

vascular plexus

• large network of blood vessels, usually veins within the system

vein

• deoxygenated blood vessel traveling to the heart carrying blood

• carry oxygen-poor blood 

• hold most of the blood in the body 

venous sinus

• blood-filled space between two layers of tissue

venule

• smaller vein draining capillaries and then joins larger veins

• the veins of the head and neck start out as these and become larger as they near the base of the neck on their way to the heart

major arterial blood supply of the head and neck

• major arteries that supply the head and neck

  • common carotid artery

  • subclavian arteries

• different origins depending on the side of the body

• unique for head and neck arteries because most are symmetrical

common carotid artery

• left side of the body: originate directly from aorta

• right side of body: branch off brachiocephalic artery

• branchless and travels along neck in lateral position to trachea and larynx

• travels in carotid sheath deep to SCM

• internal and external

• key blood supply to head and neck structures

subclavian artery

• left side of body: originate directly from aorta 

• right side of body: branch off brachiocephalic artery

carotid sheath

• contains

  • common carotid artery

  • internal jugular vein

  • vagus nerve X

• surrounds the vascular compartment of neck

• can palpate common carotid against the larynx and obtain pulse

jugular vein

• drains deoxygenated blood from the brain and face

veins in the head and neck start

• as small venules and get larger as they approach the heart

pterygoid plexus

• network of veins that collects blood from deep areas of face and then flows into maxillary vein

• near maxillary tuberosity

• helps drain upper and lower jaw

• incorrect PSA block can pierce this or maxillary artery

• help protect maxillary artery from being squeezed when chewing by adjusting blood volume

internal jugular vein

• drains blood from most of head and neck

• exists skull through jugular foramen

• runs alongside common carotid artery and vagus nerve in the carotid sheath

• travels down neck and joins subclavian vein

duct

• passageway to carry secretion from the exocrine gland to set location

exocrine

• gland with associated duct serving as passageway

• all major and minor salivary glands or sweat glands

• only glands that have ducts

endocrine

• ductless gland with secretions being poured directly into vascular system

• what they make is secreted directly into bloodstream 

• adrenal glands

parotid gland

• the largest salivary gland 

• is encapsulated

• innervated by the 9th cranial nerve

• empties around the 2nd maxillary molar which is a site of calculus build-up

another name for parotid duct

• stenson duct

percentage of saliva excreted from parotid duct

• 25%

• serous secretion

mumps is a result of this enlarged saliva gland

parotid

submandibular gland

• is encapsulated 

• innervated by the 7th cranial nerve

• gland drains into the submandibular lymph nodes

• most common site for salivary stones

• seen externally as the sublingual caruncle

another name for submandibular gland

• Wharton’s duct

• “men go to war”

percentage of saliva secreted from submandibular gland

• 65%

• mixed secretions, mostly serous

sublingual gland

• located below the tongue

• is the only gland not encapsulated

• innervated by the 7th and 9th cranial nerve

• seen externally as sublingual caruncle

percentage of saliva excreted by sublingual gland

• 10%

• mixed secretions but mostly mucous

minor salivary glands

• they are most numerous but generally smaller

• located on soft palate, hard palate, and every type of mucosa

• all secrete mucous saliva EXCEPT Von Ebner

thyroid gland

• 2 lobes

• is the largest endocrine gland in the body

• located below the thyroid cartilage where the larynx meets the trachea

• not visible in healthy patients

• deals with metabolism and hormones

  • thyroxine (T4)!!

parathyroid

• 4 small bean shaped glands on the back of the thyroid gland

• cannot be palpated

• produces and secretes the parathyroid hormone which regulates calcium and phosphorus levels

lacrimal glands

• located within the orbit above the lateral end of the eye

• sits in lacrimal fossa

• tears flow down to the medial canthus and drain into the inferior nasal meatus

  • (runny nose when crying)

• innervated by the 7th cranial nerve

• composed of epithelial and lymphatic tissue

cervical lymph nodes

• receive all the lymph from the head and neck 

  • either directly or indirectly via the superficial lymph nodes

• these lie along the internal jugular vein

thymus

• primarily to produce and mature T-cells

• superficial and lateral to the trachea and deep to sternum (cannot palpate)

• attached to lobes of thyroid gland

• innervated by the 10th cranial nerve

• supplied by inferior thyroid and internal thoracic arteries

• shrinks after puperty

T-cells

• a type of white blood cell that helps the body fight infection and disease

afferent nerve

• SENSORY nerve carry info from body periphery TO brain or spinal cord

  • periphery → brain/spinal cord

efferent nerve 

• MOTOR nerve carrying info AWAY from brain or spinal cord to periphery 

  • brain/spinal cord→ periphery

dental plexus

• network of nerves within both maxillary and mandibular arches

the two components of nervous system

• central nervous system

• peripheral nervous system

CN I- Olfactory

• afferent only

• responsible for sense of smell

• passes through cribriform plate of ethmoid bone

  • ( cribs smell)

CN II - Optic

• afferent only

• responsible for vision

• enters optic canal of sphenoid bone

• both R and L nerves join at the optic chiasma where the fibers cross to contralateral sides before entering the brain

CN III - oculomotor

• efferent only

• controls most eye muscles and pupil constriction

• passes through superior orbital fissure of sphenoid bone

CN IV - Trochlear

• efferent only

• controls superior oblique muscles of the eye

• exits skull through superior orbital fissure of sphenoid bone

CN V - Trigeminal

• both sensory and motor roots

• afferent- teeth, tongue, oral cavity, lacrimal gland, nasal cavities, and skin of face

• sensory to teeth, gingiva, oral mucosa

• motor to muscles of mastication

• efferent - muscle of mastication

• three divisions

  • opthalmic (V1)

  • maxillary (V2)

  • mandibular (V3)

opthalmic division of trigeminal nerve

• sensory

• enters at superior orbital fissure

maxillary branch of trigeminal nerve

• sensory

• enters at foramen rotundum

mandibular branch of trigeminal nerve

• motor AND sensory

• enters at foramen ovale

CN VI - Abducens

• efferent only

• supplies muscles for eye movement and innervates lateral rectus muscle of eye

• exits through superior orbital fissure of sphenoid bone

• 1st nerve affected by serious sinus infections

CN VII - Facial

• both afferent and efferent

• efferent - facial expression muscles

• afferent - taste anterior 2/3 of the tongue

• passes through stylomastoid foramen

• gives motor innervation to stylomastoid muscles

chorda tympani

• branch of facial nerve

CN VIII -Vestibulocochlear

• afferent only

• helps with hearing and balance

• passes through internal acoustic meatus 

• damage causes vertigo, hearing loss, tinnitus

CN IX- Glossopharyngeal

• both motor and sensory

• efferent - stylopharyngeus muscle, parotid gland

• afferent - taste and sensation to posterior 1/3 of tongue

  • includes gag reflex

• passes through jugular foramen

CN X- Vagus

• both motor and sensory 

• efferent - soft palate, pharynx, larynx, thoracic organs

• afferent - taste sensation for epiglottis

• passes through jugular foramen

• helps with speech and swallowing

CN XI - Accessory

• motor only

• provides innervation for trapezius and sternocleidomastoid muscles, muscle of soft palate, and muscles of pharynx

• passes through jugular foramen

• damage may cause shoulder droop and difficulty turning head

CN XII- Hypoglossal

• motor only

• controls tongue movements

• aids in speech

• passes through hypoglossal canal of occipital bone

branches we block for trigeminal nerve

• V2 Maxillary

• V3 Mandibular 

maxillary arch local anethetic blocks

• PSA

• MSA

• ASA

• NP

• GP

Mandibular arch local anethetic blocks

• IA

• Long buccal nerve block

• mental/ incisive nerve block 

posterior superior alveolar nerve block (PSA)

• insertion: mucobuccal fold above the DB root of the 2nd molar

  • target is maxillary tuberosity

• can cause hematoma if injected into pterygoid plexus

• teeth anesthetized: maxillary molars except the MB root of the 1st molar

• soft tissue anethetized: buccal gingiva of the maxillary molars

middle superior alveolar nerve block (MSA)

• insertion: mucobuccal fold above 2nd premolar 

• teeth anesthetized: maxillary premolars and MB root of the 1sst molar

• soft tissue anethetized: buccal gingiva of maxillary premolars

anterior superior alveolar nerve block (ASA)

• insertion: height of the mucobuccal fold near mesial aspect of maxillary canine

• teeth anesthetized: maxillary incisors/cuspids and MSA teeth

• soft tissue anesthetized: maxillary incisors and cuspid gingiva

Nasopalatine nerve block (NP)

• insertion: palatal mucosa just lateral to the incisive papilla

• soft tissue anethetized: lingual gingiva of the maxillary incisor/cuspids