All Bones/Markings to Know!

squamous suture

The squamous suture connects the temporal bone and the parietal bone on each side of the skull.

lamboid suture

located at the back of the skull that connects the parietal bones to the occipital bone

Sagittal suture

connects the two parietal bones

coronal suture

connects the frontal bone and parietal bones.

cranial fossa/cranial cavity

look at the diagram, could help u understand more LOL

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The cranial cavity is the interior space of the skull that holds and protects the brain. Its floor, known as the base of the skull, is divided into three distinct, stepped depressions called cranial fossae: the anterior, middle, and posterior cranial fossae

Frontal bone

forms the forehead, superior part of the orbit, and the floor of the anterior cranial fossa

has...

- Glabella

- Supraorbital margin

- Supraorbital foramen (notch)

- Anterior cranial fossa

- Orbital surface (frontal bone)

Glabella

smooth area between the eyes

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basically the lil part above ur nose bridge where u see wrinkles when you furrow ur eyebrows

Supraorbital margin

thick margin of the eye socket that lies beneath the eyebrows

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is the brow bone

Supraorbital foramen (notch)

opening above each orbit allowing blood vessels and nerves to pass

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Basically little dots/ openings between eye socket and brow bone

Anterior cranial fossa

sitting directly above the eye sockets and nasal cavity to support the front part of the brain.

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Basically if you cut the cap off our skulls, the front part thats in the pic is "Anterior cranial fossa"

most of it is frontal bone but technically theres some sphenoid there too and the ethmoid bone too

Orbital surface (frontal bone)

internal surface on upper part of eye orbit

Parietal bones

form the superior and lateral aspects of the skull (***has two sides, left and right connected by sagittal sutures)

Temporal Bones

The temporal bones are two major, symmetrically paired bones located on the lower sides and base of the skull that protect the temporal lobes of the brain and house the structures of the ear.

In here is...

- Squamous portion

- Petrous portion

- Zygomatic process (temporal bone)

- Styloid process (temporal bone)

- Mastoid process

- External auditory meatus

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THINK: temporal= temples!

Squamous portion

located inferior to the squamous suture; smooth part of temporal bones (connects to parietal bone with

squamous suture)

Petrous portion

forms a bony wedge between the sphenoid and occipital bones and contributes to the cranial base

*part of temporal bones

*if u see it from the cranial fossa perspective, youll see how in the pic its those lil knobs

Zygomatic process (temporal bone)

originates from the squamous portion of the temporal bone and reaches forward to meet the zygomatic bone

Styloid process (temporal bone)

needlelike projection that serves as an attachment point for ligaments and muscles of the neck

Mastoid process

located posterior to the external auditory meatus; serves as an attachment point for neck muscles

*part of temporal bone

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basically feel the bony part behind ur jaw on the skull part... thats the mastoid process

External auditory meatus

canal leading to the middle ear and eardrum

Occipital bone

is most of the base of the skull

has...

- Nuchal lines

- Foramen magnum

- Occipital condyles

- Posterior cranial fossa

Nuchal lines

site where muscles of the posterior neck and back attach to the skull

Foramen magnum

large opening in the base of the bone, which allows the spinal cord to join with the brain stem

Occipital condyles

rounded projections lateral to the foramen magnum that articulate with the first cervical vertebra (atlas)

Posterior cranial fossa

major posterior internal groove that supports the cerebellum of the brain

Sphenoid bone

bat-shaped bone that is described as the keystone bone of the cranium because it articulates with all other cranial bones

has...

- Body

- Sella turcica

- Lesser wing

- Greater wing

- Middle cranial fossa

- Orbital surface

- Medial and lateral pterygoid plates

- Hamulus

Sphenoid bone body

the central, roughly cuboidal portion of the butterfly-shaped Sphenoid Bone located at the base of the skull

Sella turcica

"Turkish saddle" located on the superior surface of the body, the seat of the saddle, called the hypophyseal fossa, holds the pituitary gland

Lesser wings

form part of the floor of the anterior cranial fossa and part of the orbit

Greater wings

project laterally from the sphenoid body, forming parts of the middle cranial fossa and the orbits

Middle cranial fossa

formed by part of the sphenoid bone and the temporal bone

Orbital surface (sphenoid bone)

posterior surface of the orbit

Lateral pterygoid plates

project inferiorly from the greater wings; attachment site for chewing muscles, lateral

Medial pterygoid plates

project inferiorly from the greater wings; attachment site for chewing muscles, medial

Hamulus

a hook-like end that serves as a site for muscle attachment located on medial pterygoid processes

(name is also in the hand but for skull is "Pterygoid hamulus")

Ethmoid bone

contributes to the anterior cranial fossa, forms part of the nasal septum and the nasal cavity, contributes to the medial wall of the orbit

has...

- Crista gali

- Cribriform plate

- Orbital plate

- Perpendicular plate

Crista galli

"rooster's comb"; a superior projection that articulates into the frontal bone and attaches to the dura mater, helping to secure the brain within the skull

Cribriform plates

located lateral to the crista galli; form a portion of the roof of the nasal cavity and the floor of the anterior cranial fossa

Orbital plates (ethmoid bone)

lateral surfaces of ethmoid bone that contribute to the medial surfaces of the orbits

Perpendicular plate (ethmoid bone)

inferior projection that forms the superior portion of the nasal septum

Nasal bones

small rectangular bones forming the bridge of the nose

Lacrimal bones

each forms part of the medial orbit in between the maxilla and the ethmoid bone

Maxillae

keystone facial bones because they articulate with all other facial bones

has...

- Frontal process

- Lacrimal notch

- Zygomatic process

- Alveolar process

- Palatine process

- Sinus

Frontal process (maxillae)

forms part of the lateral aspects of the bridge of the nose, articulates with frontal bone

Zygomatic process (maxillae)

articulation process for zygomatic bone

Alveolar process (maxillae)

inferior margin of maxillae; contains sockets in which the teeth lie

Palatine process

forms the anterior hard palate; meet anteriorly in the intermaxillary suture

Lacrimal notch (maxilla)

articulation with lacrimal bones

Sinus (maxilla)

large opening in medial portion of maxillae, partially covered by palatine bones

Zygomatic bone

commonly called the cheekbones, each forms part of the lateral orbit

has...

- Frontal process

- Temporal process

- Orbital surface

Frontal process (zygomatic bone)

articulates zygomatic bone with frontal bone

Temporal process (zygomatic bone)

short extension from the zygomatic bone that forms the anterior portion of the zygomatic arch and articulates with the temporal bone

Orbital surface (zygomatic bone)

lateral surface of eye orbits

Palatine bones

forms the posterior hard palate, a small part of the nasal cavity, and part of the orbit

has...

- Horizontal plate

Horizontal plate (palatine bone)

forms the posterior hard palate

Vomer

thin, blade-shaped bone that forms the inferior nasal septum

has...

-Ala

Ala (vomer)

two wing-like bone extensions on the top border of the vomer bone

Mandible

the lower jaw bone, which articulates with the temporal bone to form the only freely movable joints in the skull (temporomandibular joints)

has...

- Body

- Angle

- Ramus

- Coronoid process

- Condylar process

- Mandibular condyle

- Alveolar process

- Mental and mandibular foramen

Mandibular body

horizontal portion that forms the chin

Mandibular angles

posterior points where the ramus meets the body

Mandibular ramus

vertical extensions of the mandibular body

Coronoid process (mandible)

"crown-shaped" portion of the ramus for muscle attachment

Condylar processes (mandible)

articulate with the mandibular fossa of the temporal bones

mandibular condyle

Articulation point of the mandible with the mandibular fossa of the temporal bone

Alveolar process (mandible)

superior margin of the mandible; contains sockets in which the teeth lie

Mental foramina

paired openings on the mandibular body; transmit blood vessels and nerves to the lower lip and skin of the chin

Mandibular foramina

located on the medial surface of each ramus; passageway for the nerve involved in tooth sensation

Hyoid bone

U-shaped bone located in the throat above the larynx; supports the tongue

Vertebral body

rounded central weight-bearing portion of the vertebra, which faces anteriorly in the human vertebral column

Intervertebral disc

mass of fibrocartilage between adjacent vertebrae

Vertebral arch

composed of two pedicles and two laminae

Vertebral pedicle

project posteriorly from the body of the vertebra and provide side protection from the spinal cord and nerves

Vertebral lamina

flattened posterior portion of the vertebral arch

Vertebral foramen

opening enclosed by the body and vertebral arch; a passageway for the spinal cord

Intervertebral foramen

lateral opening formed from superior and inferior notches on the pedicles that allow for spinal nerves to leave the spinal cord

Transverse processes

two lateral projections from the vertebral arch

Spinous process

single medial and posterior projection formed at the junction of the two laminae

Superior articular process

Inferior articular process

Superior and inferior articular facets

smooth, cartilage-coated surfaces on the bony projections (processes) of adjacent vertebrae that lock together to form facet joints

Think of your spine like a stack of Lego bricks.

Articular facet just means a smooth, flat "kissing" spot where one bone touches another bone.

Superior means top (facing up).

Inferior means bottom (facing down).

How They Fit Together

The inferior articular facet of a vertebra on top points downward.

The superior articular facet of the vertebra right below it points upward.

They click or stack together like puzzle pieces or small hinges.

Cervical Region has...

Transverse foramen

Dens

Bifed

Transverse foramen

only found in the cervical vertebrae and allow passage of the vertebral artery, vein, and nerve

Dens

process only in C2 (axis) that allows rotation of C1 (atlas)

cervical region

Bifid

forked process found on C5 that locks into spinous process of C6

cervical region

Transverse facet

facets found on transverse processes of thoracic vertebrae for articulation with tubercle of ribs

Costal facets

facets lateral and posterior to the body of the vertebrae for articulation with head of ribs

Sacral foramina (superior and inferior)

openings found on either side of the sacral crest that allow for passage of blood vessels and nerves

Sacral crest

formed by fused spinous processes and run down center of posterior sacrum

Sacral canal

continuation of the vertebral canal in the sacrum, ending at sacral hiatus

Sacral promontory

anterior border of S1 in the sacrum

cervical region

the first 7 vertebrae, comprising the neck

has axis and atlas

c1-c7

thoracic region

The thoracic region of the human spine contains 12 vertebrae, labeled T1 through T12.

lumbar region

L1-L5

sacral region

The sacral region consists of five individual vertebrae (S1 through S5) that fuse together into a single, wedge-shaped bone called the sacrum during late adolescence and early adulthood (typically by age 30).

Situated at the base of the spine, slotted between the two hip bones (ilia) in the posterior pelvis.

Coccyx

four vertebrae fused together to form the tailbone

atlas

C1

axis

c2

cervical vertebrae

thoracic vertebrae

Heart-Shaped Body: The main weight-bearing body is roughly heart-shaped, larger than cervical vertebrae but smaller than lumbar vertebrae.

Costal Facets / Demifacets: Smooth articular surfaces on the sides of the vertebral body where the heads of the ribs attach.

Transverse Costal Facets: Found on the transverse processes of vertebrae T1 through T10 to articulate with rib tubercles.

Long Spinous Processes: The spinous processes are long, slender, and point sharply downward/inferiorly.

No Transverse Foramina: Unlike cervical vertebrae, thoracic vertebrae do not have holes in their transverse processes

lumbar vertebrae

Location: Directly below the rib cage (thoracic spine) and above the triangular sacrum at the base of the spine.

Curve: Features a natural inward curvature known as a lordotic curve (shaped like a backward "C").

Structure: Consists of a large, kidney-shaped vertebral body, a protective bony arch (laminae and pedicles), a triangular spinal foramen, and sturdy spinous and transverse processes.

Vertebrosternal ribs

ribs 1-7, connect directly to sternum by their own costal cartilages