Anatomy- Chp 6

axial skeleton

bones along body’s central axis- 80 bones total

functions of axial skeleton

• protect brain, spinal cord, thoracic organs

• support head, neck, trunk

• muscle attachment (posture, breathing)

• houses red bone marrow (blood cell production)

components of axial skeleton

• skull (22 bones)

• associated bones: auditory ossicles (6), hyoid (1)

• vertebral column

• thoracic cage (ribs and sternum)

skull

cranium + facial bones

cranium

8 bones, protects brain

facial bones

14 bones, supports eyes, nose, mouth

sutures

immovable fibrous joints

major sutures: coronal, saggital, lambdoid, squamous, frontonasal

coronal suture

connects frontal and parietal bones

saggital suture

connects (between) parietal bones

lambdoid suture

connects occipital and parietal bones

squamous suture

connects temporal and parietal bones

frontonasal bones

connects frontal and nasal bones

calvaria

cranial vault (frontal + parietal + occipital)

occipital bones

• forms posterior and base of skull

• foramen magnum- spinal cord passes through

• occipital condyles- articulate with C1 (atlas)

• jugular foramen- major vessels/nerves

• hypoglossal canal- tongue motor nerves

frontal bone

forehead, roof of orbits

parietal bones

2; sides and roof of skull

temporal bones

2; ear region, houses auditory ossicles

sphenoid

“keystone” bone, links cranial and facial bones

ethmoid bone

nasal cavity roof, nasal septum, olfaction

cranial bones

• occipital

• frontal

• parietal

• temporal

• sphenoid

• ethmoid

facial bones

• maxilla (2)

• palatine (2)

• nasal (2)

• zygomatic (2)

• lacrimal (2)

• inferior nasal conchae (2)

• vomer (1)

• mandible (1)

alveolar process

tooth sockets

maxillary sinuses

mucus production, lighten skull

maxillae

upper jaw, hard palate, sinuses, upper teeth

palatine bones

posterior hard palate

nasal bones

bridge of nose

zygomatic bones

cheek bones

lacrimal bones

tear drainage

inferior nasal conchae

airflow turbulence

vomer

inferior nasal septum

mandible

lower jaw (only moveable skull bone)

orbits

• 7 bones in each ___

• protect eye + house muscles, nerves, glands

nasal complex

• encloses nasal cavities + paranasal sinuses

• functions

  • lighten skull

  • produce mucus

  • warm and humidify air

  • voice resonance

hyoid bone

• only skull related bone not attached to other bones

• suspended by ligaments

• supports tongue and larynx

• important for swallowing and speech

infant skull

• not fully ossified

• fontanelles = soft spot (anterior, posterior, sphenoidal, mastoid)

  • allow brain growth

  • allow skull compression during birth

  • skull growth mostly complete by age 5

vertebral column

• cervical (7)- neck

• thoracic (12)- rib articulation

• lumbar (5)- weight bearing

• sacrum (5 fused)

• coccyx (3-5 fused)

functions of vertebral column

• protect spinal cord

• support body weight

• allow movement and flexibility

spinal curves

• primary: thoracic, sacral

• secondary: cervical, ;umbar

• maintain balance & center of gravity

body

in vertebrae; weight bearing

vertebral arch

in vertebrae; pedicles (sides), laminae (roof)

vertebral foramen

in vertebrae; spinal cord

spinous process

in vertebrae; muscle attachment

transverse process

in vertebrae; muscle/rib attachment

articular processes

in vertebrae; joints between vertebrae

intervertebral discs

in vertebrae; shock absorption

intervertebral foramina

in vertebrae; spinal nerve exit

vertebral cervical region

small bodies, large foramina, transverse foramina

vertebral thoracic region

rib facets, heart- shaped bodies`

vertebral lumbar region

largest, strongest, least mobile

components of thoracic cage

• sternum

• 12 pairs of ribs

• thoracic vertebrae

rib types

• true (1-7)- attach directly to sternum

• false (8-10)- indirect attachment

• floating (11-12)- no anterior attachment

ribs vocab

• head

• neck

• tubercle

• angle

• costal groove- nerves and blood vessels

sternum

• manubrium- clavicle + rib 1

• body- ribs 2-7

• xiphoid process- diaphragm attachment

skull bones

• cranium- 8

• face- 14

associated skull bones

• auditory ossicles- 6

• hyoid- 1

thoracic cage

• sternum- 1

• ribs- 24

vertebral column

• vertebrae- 24

• sacrum- 1

• coccyx- 1

axial skeleton

• skull and associated bones- 29

• thoracic cage- 25

• vertebral column- 26

total: 80

functions of axial skeleton

• houses CNS → integration centers for reflex arcs, controls skeletal muscles

• houses senses → sight, hearing, taste, smell, balance

• allows for sound production and communication

• feeding

• breathing

• attachment points for appendicular skeleton

thoracic cage

• ribs

• sternum

• thoracic vertebrae

• costal cartilage

facial bones

• maxillae- 2

• palatine- 2

• nasal- 2

• inferior nasal conchae- 2

• zygomatic bones- 2

• lacrimal bones- 2

• vomer- 1

• mandible- 1

cranial bones

• occipital- 1

• parietal- 2

• frontal- 1

• temporal- 2

• sphenoid- 1

• ethmoid- 1

associated bones

• hyoid- 1

• auditory ossicles- 6 (malleus, incus, stapes)

frontalles

• sphenoidal

• mastoid

• anterior

• posterior

sutures

• saggital

• coronal

• frontal

• lambdoid

• squamous

suture

dense fibrous connective tissue

parietal bones

• right parietal

• saggital suture

• left parietal

• superior temporal line

• inferior temporal line

occipital bone

• external occipital protuberance

• occipital condyle

• foramen magnum

• jugular foramen (with temporal bone)

• hypoglossal canal

temporal bone

• mastoid process

• styloid process

• external acoustic meatus

• carotid canal

• stylomastoid foramen

• internal acoustic meatus

zygomatic arch

• temporal process of zygomatic bone

• zygomatic process of temporal bone

frontal bone

• supra-orbital foramen

• frontal sinuses

sphenoid

• frontonasal suture

• foramen ovale

• foramen lacerum

• hypophyseal fossa within sella tursica

• sphenoid sinuses

lacrimal bone

• lacrimal groove

maxilla

• infra-orbital foramen

• incisive fossa

mandible

• mental foramen

• mental protuberance

• coronoid process

palatine bone

• greater palatine foramen

ethmoid

• crista galli

• cribriform plate

• perpendicular plate

orbit

made of:

• frontal bone

• maxilla bone

• lacrimal bone

• ethmoid bone

• sphenoid bone

• zygomatic bone

sphenoid structures

• foramen rotundum

• anterior clinoid process

• optic groove

• tuberculum sellae

• lesser wing

• greater wing

• foramen ovale

• foramen spinosum

• sphenoidal spine

• optic canal

• sella turcica

• middle clinoid process

• posterior clinoid process

ethmoid structures

• cribriform plate

• crista galli

• superior nasal concha

• middle nasal concha

• perpendicular plate

temporal strcutures

• external acoustic meatus

• mastoid process

• styloid process

• mandibular fossa

• articular tubercle

• zygomatic process

• carotid canal

• jugular fossa

• stylomastoid foramen

• squamous part

• petrous part

• internal acoustic meatus

maxilla structures

• zygomatic process

• body

• frontal process

• lacrimal groove

• orbital surface

• infra-orbital foramen

• maxillary sinus

• anterior nasal spine

• incisive canal

• palatine process

• alveolar process

palatine structures

• orbital process

• perpendicular plate

• conchal crest

• nasal crest

• horizontal plate

• incisive canals

• hard palate

mandible structures

• head

• molars

• mylohyoid line

• coronoid process

• condylar process

• mandibular notch

• ramus

• angle

• body

• mental foramen

• mental protuberance

• alveolar part

• coronoid process

• condylar process

• submandibular fossa

sinuses

• produce mucus

• resonate sound

• lighten skull

• humidifies air

• frontal, sphenoid, maxillary, ethmoid air cells

hyoid structures

• greater horn

• lesser horn

• thyrohyoid ligament

• body

anchor point for:

• tongue

• larynx

7

how many cervical vertebrae

12

how many thoracic vertebrae

5

how many lumbar vertebrae

vertebrae structures

• vertebral arch

• vertebral foramen

• pedicle

• transverse process

• costal process

• bifid tip of spinous process

• spinous process

• lamina

• superior articular process

• superior articular facet

• transverse foramen (only cervical)

• vertebral body

atlas structures

• superior articular facet

• superior articular process

• vertebral foramen

• posterior tubercle

• posterior arch

• facet for dens

• transverse process

• transverse foramen

• costal process

• anterior arch

• anterior tubercle

• inferior articular facet

axis structures

• spinous proces

• lamina

• transverse foramen

• transverse process

• pedicle

• vertebral foramen

• inferior articular process

• inferior articular facet

• superior articular process

• vertebral body

• superior articular facet

• dens

sacrum structures

• articular process

• sacral hiatus

• coccyx

• sacral tuberosity

• lateral sacral crest

• median sacral crest

• sacral cornu

• coccygeal cornu

• sacral promontory

• auricular surface

• sacral curve

• base

• ala

• pelvic surface

• sacral foramina

• transverse lines

• apex

kyphosis

an excessive outward curve of the upper spine, causing a rounded or hunched back

lordosis

an excessive inward curve of the lower spine, causing the lower back to arch more than normal

scoliosis

an abnormal sideways (lateral) curvature of the spine, often shaped like an “S” or “C.”

true ribs

ribs 1-7

false ribs

ribs 8-12

floating ribs

ribs 11-12

sternum structures

• manubrium

• body

• xiphoid process