Head, Neck, Back Flashcards
skull vs cranium
-
skull: bony skeleton of head
- consists of cranium, facial skeleton, & mandible
- cranium = neurocranium
-
neurocranium: bony case of brain
- calvaria: dome-like roof (‘skullcap’)
- basicranium/cranial base: floor
- where brain sits
- lots of foramina/holes to allow for neurovasculature to travel
- viscerocranium: facial skeleton
frontal bone (1)
- unpaired in adults (only have 1)
- in juvenile period: 2 bones that will completely fuse together
- may have remnant frontal suture (metopic)
- supra-orbital margin: boundary between squamous & orbital parts
parietal bones (2)
- pariet = wall
- paired parietal bones ⇢ one on each side
- flat, nondescript
- protection of frontal bone ⇢ brain & surrounding meninges
temporal bones (2)
- tempor = temple
temporal bones – zygomatic process
- articulates with temporal process of zygomatic bone
- forms zygomatic arch
- palpate ear to ear
- important muscles under region
temporal bones – articular tubercle
- inferior projection of zygomatic process
- anterior to mandibular fossa
- dislocations of TMJ
temporal bones – external acoustic opening ⇢ meatus
- meatus = passageway
- allows sound waves (vibrations) to reach tympanic membrane
- ear sits in that region
- colloquial term for tympanic membrane = eardrum
temporal bones – styloid process
- styl = stake or pole
- inferior projection
- attachment point for muscles and ligaments of tongue and neck
temporal bones – mastoid process
- mastoid = breast-shaped
- contains mastoid air cells – hollow
- superior attachment site for sternocleidomastoid (SCM) muscle
clinical connection: mastoiditis
- inflammation of mastoid air cells
- often caused by middle ear infection spreading into air cells
temporal bones – mandibular fossa
- articulates with condyle of mandible
- temporomandibular joint (TMJ)
temporal bones – petrous part/apex
- petrous = rock
- contains middle & inner ear
- cochlea, semicircular ducts
- ear ossicles ⇢ smallest bone of body within petrous part
ear (auditory) ossicles – within temporal bone
- malleus (2)
- attached to tympanic membrane
- incus (2)
- middle ossicle
- stapes (2)
- towards the inner ear
- sits in oval window ⇢ leads into inner ear
- smallest bone in body
- towards the inner ear
temporal bones – internal acoustic opening ⇢ meatus
- transmits:
- facial nerve (CN VII)
- goes into petrous portion but eventually moves its way out of skull
- vestibulocochlear nerve (CN VII)
- important for hearing
- goes into petrous portion & never comes out
- allows cranial nerves to travel through the bone
- facial nerve (CN VII)
temporal bones – jugular foramen
- between/formed by temporal bone & occipital bone
- the venous sinuses associated w/ brain in that area will drain into and be called internal jugular vein
- transmits:
- internal jugular vein
- located in neck ⇢ drain & make way down – bringing deoxygenated blood back to heart
- glossopharyngeal nerve (CN IX)
- vagus nerve (CN X)
- accessory nerve (CN XI)
- CN IX, X, XI ⇢ cranial nerves that exit the skill via jugular foramen
- internal jugular vein
- irregularly shaped ⇢ bone will form around neurovasculature
occipital bone (1)
occipit = back of head
occipital bone – external occipital protuberance
- prominent projection on posterior surface
- palpable
- attachment site for trapezius muscle
occipital bone – foramen magnum
- medulla oblongata (brainstem) ⇢ spinal cord
- vertebral arteries and accessory nerve (CN XI)
occipital bone – occipital condyles
- articulate with C1
- atlanto-occipital joints formed by condyles
- articulation between skull and vertebral column
sphenoid bone (1)
sphenoid = wedge-shaped
sphenoid bone – optic canal; hypophysial fossa
- lots of foramina ⇢ means by which neurovasculature travels
- optic canal: optic nerve (CN II)
- ophthalmic artery ⇢ supply things associated with the orbit
- hypophysial fossa: pituitary gland
sphenoid bone – superior orbital fissure
- oculomotor nerve (CN III)
- trochlear nerve (CN IV)
- opthalmic division of trigeminal nerve (CN V1)
- abducens nerve (CN VI)
all nerves going to the orbit: innervate extra-ocular eye muscles ⇢ move eye around; provide sensory innervation
ethmoid bone (1)
- ethmoid = sieve-like
- cribriform foramina ⇢ axons pass through on way to brain (small holes)
- cribri = sieve
- olfactory nerve (CN I)
nasal septum
- ethmoid + vomer + cartilage
nasal conchae/turbinates
- thin bones lined w mucous membrane
- highly vascularized
- concha = shell
- increase vascular & mucous membrane surface area in nasal cavity
- allow for things to not go into/past nasal cavity (eg pathogens)
- warms, moistens, and humidifiers inhaled air
-
superior & middle nasal conchae
- parts of ethmoid bone
-
inferior nasal conchae (2)
- separate paired bones
nasal bones (2)
bridge of nose
maxillae (2) = maxillary bones
- maxilla = jawbone
- upper jaw
- maxillary teeth – upper teeth
hard palate
- maxillae ⇢ play biggest role
- palatine processes
- horizontal plates of palatine bones (2)
clinical connection: cleft palate
faire of palatine process to unite during embryonic development ⇢ hard + soft
zygomatic bones (2)
zygo = yokelike
⇢ cheekbones
lacrimal bones (2)
lacrim = teardrops
paranasal sinuses
- para = beside
- muscous membrane-lined cavities
- hollow areas ⇢ lightening skull
- drain into lateral nasal wall
- located in 4 bones:
- maxillae
- frontal
- sphenoid
- ethmoid
clinical connection: sinusitis / sinus infection
inflammation of mucous membrane of 1+ paranasal sinus
cranial fossae
- cranial bones form around developing brain
- create a mold that approximates brain shape
- ‘stepping down stairs’ – deeper as you go posterior
- anterior, middle, & posterior cranial fossae
mandible (1)
- mand = to chew
- only movable skull bone
- lower jaw
mandible – mandibular condyle; coronoid process
- mandibular condyle
- articulates with mandibular fossa of temporal bone
- TMJ
- more posteriorly located
- articulates with mandibular fossa of temporal bone
- coronoid process
- anterior to condyle (more toward teeth)
- inferior attachment (insertion): temporalis muscle ⇢ chewing
mandibular foramen
transmits infeior alveolar neurovasculature
⇢ IAN block: knock out sensation from one half of mandibular teeth
types of teeth
- incisor
- thin, cutting edges
- canine
- one on each quadrant
- single, prominent cones
- premolar/bicuspid
- 2 cusps
- molar
- most posterior teeth
- 3+ cusps
adult dentition
- 32 permanent teeth
- 2:1:2:3
- types of teeth per quadrant
- 2 incisors, 1 canine, 2 premolars, 3 molars
sutures
immovable (in adults; children ⇢ growth) fibrous joints
coronal/frontal suture
“crown location”
unites frontal bone & both parietal bones
saggital suture
saggit = arrow
unites parietal bones in midline
squamous sutures
squam = flat, like flat ovedrlapping scales of a snake
unite parietal & temporal bones
pterion – craniometric point
- articulation point of Frontal, Parietal, Temporal & Sphenoid bones
- branches of middle meningeal artery travel deep to this spot
- epidural hematoma ⇢ b/w blood & dura mater
lambdoid(al) suture
unites both parietal bones & occipital bone
fontanels
- soft spots
- fontanels = little fountains
- dense CT regions between incompletely formed cranial bones
- juvenile skulls (~1-6)
- Eventually replaced by bone via intramembranous ossification
temporomandibular joint (TMJ)
- synovial joint
- bony parts:
- mandibular condyle of mandible
- mandibular fossa of temporal
TMJ articular discs; actions
-
articular disc – complete fibrocartilaginous disc
- divides joint cavity into 2 cavities (superior & inferior) ⇢ allowing actions to occur separately
-
actions:
-
elevation (closing mouth)/depression (opening mouth)
- inferior compartment
- hinge joint
- more dominant movement
-
protraction (jutting out mandible)/retraction (bringing it back)
- superior compartment
- gliding joint
-
elevation (closing mouth)/depression (opening mouth)
clinical connection: facial paralysis (Bell palsy)
facial nerve compromised (pinched, severed) ⇢ unilateral paralysis of facial muscle
muscles of facial expression – orbicularis oculi muscle
sphincteric muscle (surrounding an opening)
action: closes eyelids
muscles of facial expression – buccinator muscle
- buccae = cheek
- majority of muscular portion of cheek
- deeper plane - deep to subcutaneous tissue
-
actions
- presses cheek against molar teeth
- with tongue, keeps food out of oral vestibule
- resists distension (when blowing)
muscles of facial expression – orbicularis oris muscle
- sphincteric muscle
- actions: closes oral fissure; protudes/purses lips
muscles that move eyeball (extrinsic eye muscles/extra-occular eye muscle)
attached to sclera (whites of eye)
innervation: most by oculomotor nerve (CN III)
extrinsic eye muscle actions
- elevation (looking up) / depression (looking down)
- abduction (looking towards side) / adduction (looking towards nose)
muscles of mastication
- thickest muscles of the head
- move the mandible (TMJ)
- innervation: mandibular nerve/V3
- actions:
- elevation (closing the mouth)
- depression
- protraction/retraction
temporalis muscle
- bony attachments:
- superior & inferior temporal lines
- coronoid process of mandible ⇢ distal attachment – movable bone
- palpable
masseter muscle
- mirrors medial pterygoid muscle on superficial side of ramus of mandible
- palpable
medial pterygoid muscle
mirrors masseter muscle on deep side of ramus of mandible
lateral pterygoid muscle
- has 2 heads (superior & inferior)
- superior ⇢ direct attachment to articular capsule & a bit on articular disc of TMJ
- actions:
- stabilization of TMJ
- depression of mandible**
- inferior head ⇢ only muscle that will depress mandible
muscles of soft palate
- 5 muscles
- actions:
- elevation/depression
- making palate taut
- innervation: vagus nerse (CN X)
- parasympathetic innervation
- except 1
muscles of tongue
- tongue is a mass of muscles
- covered by mucosa
- extrinsic muscles (4)
- alter position of tongue – stick out, move
- originate outside tongue & attach to it distally
- intrinsic muscles (4)
- alter shape of tongue – smaller/precise movements
- attachments entirely within tongue
- innervation: hypoglossal nerve (CN XII)
- except 1
hyoid bone (1)
- does not articulate with any other bone
- suspended in anterior neck by ligaments & muscles
- between mandible and larynx
- supports tongue
- moving hyoid out of way ⇢ allow things to move through GI system
vertebrae
- vertebral column = vertebrae + CT
- functions:
- protects spinal cord ⇢ bony encasement
- allows movement (some more movable; some not movable)
- flexion/extention/lateral flexion
- rotation
- point of attachment for bones & muscles
- ex: ribs on thoracic vertebrae
types of vertebrae
-
cervical (7): C1-C7
- cervic = neck
-
thoracic (12): T1-T12
- thorax = chest
- attachment to ribs
- thorax = chest
-
lumbar (5): L1-L5
- lumb = loin
- largest vertebrae
- sacrum (5 fused vertebrae)
- sacrum = sacred bone
- attachment to hip bones
- no movement
- sacrum = sacred bone
- coccyx (4 fused vertebrae)
- coccyx = cuckoo
- no movement
structures common to most vertebrae: vertebral body; pedicles
-
vertebral body
- main weight-bearing component
- anteriorly-placed
- spongy bone – compact bone externally
-
pedicles
- pedicle = little feet
- project posteriorly from body to unite with laminae
structures common to most vertebrae: laminae, transverse processes, spinous process
-
laminae
- flat portion of bone
- = thin layer
-
transverse processes
- extend posterolaterally
- points of attachment for muscle and bone
- muscle ⇢ all vertebral column
- bone ⇢ some vertebral column - thoracic
-
spinous process
- extends posteriorly (palpable)
- can be bifid (split into 2) – in cervival region
structures common to most vertebrae: notches, intervertebral foramen
-
notches (superior & inferior)
- indentations on pedicles
- form foramen when articulate together
-
intervertebral foramen
- opening between adjacent vertebrae
- superior + inferior notch
- passage of spinal nerves/branches
- spinal nerves exit to innervate rest of body
- opening between adjacent vertebrae
cervical vertebrae (C1-C7)
- considerable range of movement
- smalest movable vertebrae
- unique characteristics:
-
transverse foramina
- allows for vertebral artery & vein to traverse this region
- vertebral artery: branch of subclavian artery: ascend neck ⇢ get into skull ⇢ one of dominant arterial supplies of the brain
- bifid spinous processes
- C2-C6
-
transverse foramina
cervical vertebra: C1 – Atlas
- ring of bone
- lacks vertebral body & spinous process
- superior articular facets
- articulate with occipital condyles
- atlanto-occipital joint - yes (nodding)
- articulate with occipital condyles
cervical vertebra: C2 – Axis
- dens/odontoid process
- dens = tooth
- projecting from vertebral body up towards C1
- articulates with C1 (atlanto-axial joint)
- arrangement allows rotational movement - shaking head no
- pivot joint
- arrangement allows rotational movement - shaking head no
cervical vertebra: C7 – vertebra prominens
- most proinent spinous process (non-bifid)
- seen/felt at base of the neck
- clinically important: count vertebrae
- seen/felt at base of the neck
thoracic vertebrae – T1-T12
- get progressively larger
- costal facets/demifacets
- attachment of ribs – unique to thoracic vertebrae
- body of vertebrae
- transverse processes
- longer transverse processes
- less mobility than cervical & lumbar vertebrae ⇢ bc ribs attached
lumbar vertebrae: L1-L5
- identifiable by:
- large size ⇢ bearing lots of weight
- lack of transverse foramina & costal facets
- prominent superior articular processes
curvatures of vertebral column
- adults have 4 curvatures:
-
thoracis & sacral kyphoses
- concave anteriorly
-
cervical & lumbar lordoses
- concave posteriorly
-
thoracis & sacral kyphoses
- functions of curvatures:
- flexibility
- shock-absorbing resilience
primary vs secondary curvatures
- primary curvatures
- develop during fetal period in relationship to fetal (flexed) position
- thoracic and sacral )
- secondary curvature
- result from extension from fetal position
- cervical and lumbar (
- developmental landmarks helping to develop these curvatures ⇢ babies hold head up on their own; beginning to walk
clinical connections: abnormal curvatures
- excessive thoracic kyphosis
- Dowager’s hump
- often caused by effects of osteoporosis ⇢ microfractures associated with vertebral bodies
- excessive lumbar lordosis
- hollow back/sway back
- characterized by anterior tilting of pelvis
- often associated with weakened trunk musculature or sudden weight gain (ex: pregnancy)
clinical connections: scoliosis
- scoliosis: abnormal lateral curvature
- rotation of vertebrae
- structural vs idiopathic causes
- structural ⇢ issues w muscles/ligaments in vertebral column
- idiopathic ⇢ don’t know reason
intervertebral discs (ex joints of vertebral bodies)
- symphyses – cartilaginous joints
- located between each vertebral body, except:
- between C1 & C2 ⇢ rotational joint
- non-movable vertebrae (sacral & coccygeal)
- there is one between L5 & S1 – most inferior one
- vary in thickness in different regions
- increases inferiorly
components of intervertebral discs
- anulus fibrosus – protective
- outer component
- fibrocartilage
- thinner posteriorly
- nucleus pulposus
- pulpa = fleshy
- inner component
- semifluid ⇢ fluidity varies w health and age
clinical connection: herniation of nucleus pulposus (‘slipped disc’)
- herniation = something’s moving out of the place that it should be through another structure
- herniation through anulus fibrosus
- typically occurs posteriorlaterally ⇢
- anulus fibrosus thinner posteriorly
- L4-L5 or L5-S1 levels most common
- generally around intervertebral foramen region ⇢ pinching of spinal nerve – sensory & motor implications
sternocleidomastiod muscle attachments
superior attachments:
- mastiod process of temporal bone
- occipital bone
inferior attachments:
- manubrium of sternum
- clavicle
crosses cervical vertebral joints
sternocleidomastoid muscle actions – cervical vertebral joints
- bilateral contractions:
- flexion of cervical vertebrae (aka neck flexion)
- unilateral contraction:
- lateral flexion of neck
- rotation of head (in opposite direction)
sternocleidomastoid muscle innervation
efferent (motor): accessory nerve (CN XI)
afferent (sensory): C2 & C3
supra- and infra-hyiod muscle
superior & inferior to hyoid bone
- supra-hyoid muscle (4)
- support and elevate hyoid
- floor of mouth
- infra-hyoid muscle (4)
- supports and depresses hyoid & larynx
- during swallowing and speaking
- supports and depresses hyoid & larynx
erector spinae muscles
- action:
- extension of vertebrae
- lateral flexion (side to side) of vertebrae
- commonly strained
- improperly lifting something
- 3 parts: (lateral ⇢ medial)
- iliocostalis muscle (lateral)
- longissimus muscle (middle)
-
spinalis muscle (medial)
- “i love spaghetti”
