A&P - Chapter 7: Axial Skeleton Study Flashcards

Division of the 80 bones of the axial skeleton

8 cranial

14 facial

6 auditory

Hyoid bone

Sternum

24 ribs

24 vertebrae

Sacrum

Coccyx

Functions of the axial skeleton

- supports and protects organs in body cavities

- provides points of attachment for muscles (adjust position of head, neck, and truck, perform breathing movements, stabilize part of appendicular skeleton)

Facial bones

9 superficial - muscle attachment

5 deeper - separate oral and nasal cavities, increase surface area of nasal cavities, help form the nasal septum

Lamboid suture

Separates occiptal from parietal bones + suture bones

Coronal suture

attaches frontal bone to parietal bones

Sagittal suture

between parietal bones

Squamous sutures

between parietal and temporal bones on each side of skull

Sinuses

Air-filled chambers in the skull. Functions to decrease the weight of the skull, lined with mucous membrane that produce mucous that moisten and cleans the air, and serve as resonating chambers in speech

Occiptal bones

Forms much of posterior and inferior surfaces of cranium

External occipital crest

Attaches the ligamentum nuchae

Occipital condyles

articulate with first cervical vertebra

Foramen magnum

Connects cranial cavity with vertebral canal

Jugular foramen

internal jugular vein

Hypoglossal canals

hypoglossal nerve (XII)

Parietal bones (functions)

form part of the superior and lateral surfaces of the cranium

Frontal bone (functions)

Forms the anterior cranium and upper eye sockets

Contains frontal sinuses + frontal sinuses

supra-orbital margin

protects the eye

Lacrimal fossa

Depression for the lacrimal gland

Supra-orbital foramen

Blood vessels of eyebrows, eyelids, and frontal sinuses

Supra-orbital notch

an incomplete supra-orbital foramen

Temporal bones (functions)

1. Lateral wall of cranium and zygomatic arches

2. Articulates with mandible

3. Surround and protect internal ear

4. Attach muscles of jaw and head

Squamous part

borders the squamous suture

Mastoid process

For muscle attachment and contains mastoid cells that connect to middle ear cavity

Petrous part

Encloses sutures of internal ear

Auditory ossicles

Three tiny bones in tympanic cavity and transfer sound vibrations from tympanic membrane to internal ear

corotid canal

internal carotid artery

foramen lacerum contains

hyaline cartilage, small arteries, and auditory tube

external acoustic meatus of temporal bone

leads and ends at the tympanic membrane

stylomastoid foramen of temporal bone

facial nerve

internal acoustic meatus of temporal bone contains

blood vessels, nerves of the internal ear, and facial nerves

sphenoid bones functions

forms part of the floor of the cranium

unites the cranial and facial bones

strengthens the sides of the skull

body of the sphenoid

forms central axis of the sphenoid

sella turcica of sphenoid bone

saddle-shaped enclosure on the superior surface of the body of the sphenoid that houses the pituitary gland

hypophyseal fossa of sphenoid bone

depression within the sella turcica that holds the pituitary gland

sphenoidal sinuses of the sphenoid

either sides inferior to the sella turcica

lesser wings of the sphenoid

inferior to the sella turcica

greater wings of the sphenoid

form part of the cranial flor + sphenoidal spine lies at corner of each wing

pterygoid process of the sphenoid

forms the pterygoid plates to attach muscles of the lower jaw and soft palate

optic canals of the sphenoid

optic nerves

prechiasmatic sulcus

optic groove

superior orbital fissure of sphenoid bone

blood vessels and nerves of the orbit

foramen rotundum and foramen ovale

blood vessels and nerves of the face and jaw

foramen spinosum

blood vessels and nerves of membranes

ethmoid bones functions

forms the anteromedial floor of the skull, roof of the nasal cavity, and part of the nasal septum

cribriform pate of the ethmoid

Forms roof of the nasal cavity and contains crista Galli to attach falx cerebri

ethmoidal labyrinths

air-filled cavities that consist of ethmoidal cells, located in the superior nasal conchae and middle nasal conchae

perpendicular plate of the ethmoid bone

forms part of the nasal septum

olfactory foramina of ethmoid bone

located in the cribriform plate (tiny holes) for the olfactory nerves

maxilla functions

- support upper teeth

- form inferior orbital rims

- form lateral margins of sternal nares

- form upper jaw and most of hard palate

- contain maxillary sinuses

orbital rim of the maxillae

protects eye and other structures of the orbit

Anterior nasal spine of maxilla

attaches to the anterior nasal septum

alveolar process of the maxilla

support upper teeth

palatine process of maxilla

forms most of the hard palate

maxillary sinuses

lighten the bone

nasolacrimal canal

protect the lacrimal sac and the nasolacrimal duct

infra-orbital foramen (maxilla)

sensory nerve to the brain (via foramen rotundum)

inferior orbital fissure (maxilla)

cranial nerves and blood vessels

palatine bones functions

- forms the posterior portions of hard palate

- contribute to the floors of the orbits

horizontal plate (palatine bones)

forms posterior part of the hard palate

perpendicular plate (palatine bones)

extends from horizontal plate to orbital process of orbit floor

foramina of the palatine bones

small blood vessels and nerves supplying the roof of the mouth

nasal bones general function

support a bridge of the nose and connect to cartilages of distal parts of the most that extend to external nares

vomer functions

forms inferior portion of the nasal septum

inferior nasal conchae functions

slow inhaled air

create air turbulence in the nasal cavity

increase epithelial surface are to warm and humidify the air

zygomatic bones functions

contribute to rims and lateral walls of orbits and forms parts of zygomatic arches

temporal process of the zygomatic bone

meets the zygomatic process of the temporal bone

zygomaticofacial foramen

sensory nerve of the cheeks

lacrimal bones

- smallest facial bones

- form parts of medial walls of orbit

lacrimal sulcus of lacrimal bones

location of the lacrimal sac and leads to the nasolacrimal canal

mandible functions

forms the lower jaw

body of the mandible

horizontal portion of the lower jaw

alveolar part

supports the lower teeth

mental protuberance of the mandible

attaches facial muscles

depression on the medial surface of the mandible

submandibular salivary gland

mylohyoid line of mandible

insertion of mylohyoid muscle

ramus of the mandible

vertical portion of the lower jaw that ascends from the angle of the mandible

condylar process of madible

articulates with the temporal bone at temporomandibular joint

coronoid process of the mandible

insertion point for temporalis muscle (closes te jaw)

mandibular notch

separates condylar and coronoid processes

mental foramen of mandible

sensory nerves of lips and chin

mandibular foramen

entrance to mandibular canal and passageway for blood vessels and nerves of lower teeth

hyoid bone functions

supports the larynx and attaches muscles of larynx, pharynx, and tongue

body of the hyoid bone

attaches muscles of larynx, pharynx, and tongue

greater horns of hyoid bone

supports the larynx and attaches muscles of the tongue

lesser horns of hyoid bone

attache stylohyoid ligaments and supports hyoid and larynx

bones of the orbital complex (7)

frontal bone

maxilla

lacrimal bone

ethmoidal labyrinth

sphenoid

palatine bone

zygomatic bone

nasal complex

frontal, sphenoid, and ethmoid (superior walls)

maxilla, lacrimal, ethmoid, inferior nasal conchae (lateral walls)

maxilla and nasal bones (bridge of nose)

paranasal sinuses

air filled chambers connected to the nasal cavities

functions of the paranasal sinuses

lighter skull bones and release mucus into nasal cavity (mucous epithelium)

characteristics of an infant skull

- grows rapidly

- is large compared to the body

- has many ossification centers

- fusion of bones are not completed

divisions of the bones of the skull at birth

2 frontal bones

4 occipital bones

several sphenoid and temporal bones

fontanelles

- large areas of fibrous connective tissue

- covers unfused bones baby

- allow the skull to flex during birth

sphenoidal fontanelle

junction of squamous and coronal sutures

mastoid fontanelle

junction of squamous and lambdoid sutures

anterior fontanelle

at intersection of frontal, sagittal, and coronal sutures

posterior fontanelle

junction of lambdoid and sagittal sutures

vertebral column functions

protects the spinal cord and supports the head/body

divisions of bones of the spine

24 vertebrae

sacrum

coccyx

primary curves (accommodation curves)

thoracic and sacral curves that appear during fetal development and accommodate internal organs

secondary curves (compensation curves)

cervical and lumbar curves that appear after birth, shift body weight to permit upright posture