The cranium

lab 5

How many portions can the skeleton be organized and what are they?

Two major portions the axil skeleton and appendicular Skeleton

The axial skeleton

It consists of the bony and Cartilaginous parts that support the and protect the head, neck, and trunk

* Skull: cranium and facial bones
* Hyoid Bone: Supports the tongue and aids in swallowing
* Vertebral Column
* Thoracic cage : Ribs and sternum

\

The Appendicular Skelton

This consists of the bones of the upper and Lower libs and the bones that anchor the limbs to the axil skeleton

* Pectoral gridle: Clavicle and scapula
* Upper limbs: Humerus , ulna, radius, carpals, metacarpals, and phalanges
* Pelvic girdle: 2 hip bones
* Lower limbs: femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges

Major Bones of the skeleton

Axial Skeleton

Appendicular skeleton

Condyle

Rounded process that usually articulates with another bone

Ex: Occipital condyle of the occipital bone

Crest

Narrow, Ridgelike projection

Ex: LiliacE Crest of the lilum

Epicondyle

Projection situated above a condyle

Ex: Medial Epicondyle of the humerus

Facet

Small, Nearly flat surface

Ex: Costal facet of the thoracic vertebra

Fontanel

Soft spot in the skull where membrane cover the space between bones

Ex: Anterior Fontanel between the frontal and partial bones

Foramen

Opening through a bone that usually is a passageway for blood vessels, nerves, or ligaments

Ex: Foramen magnum of the occipital bone

\

Fossa

Relatively deep pit or depression

Ex: Olecranon fossa of the humerus

Fovea

Tiny pit or depression

Ex: Fovea capitis of the femur

Head

Enlargement of the end of a bone

Ex: Head of the humerus M

Meatus

Tublike passageway within a bone

Ex: External Acoustic meatus of the temporal bone

Process

Prominent Projection on a bone

Ex:Mastoid process of the temporal boneS

Sinus

Cavity within a bone

Ex: Frontal sinus of the frontal bone

Spine

Thorline porjection

Ex: Spine of the scapula

Sulcus

Furrow or groove

Ex: Intertubercular sulcus of the humerus

Trochanter

Relatively large process

Ex: Greater trochanter of the fumer

\

Tubercle

Small, knoblike process

Ex: Greater tubercle of the humerus

Tuberosity

Knoblike process usually larger than a tubercle

Ex: Radial Tuberosity of the radius

The skull

* It is made up 22 bones: 8 Cranial bones and 14 facial bones; there are also 3 bones in each middle ear


* Expect for Lower jaw, skull bones are connected by immovable joints called sutures

Bones of the cranium

This encloses and protects the brain, provides attachment for muscles, and contains air-filled paranasal sinuses that reduce its weight and increase vocal resonance

Frontal bone (Bones of the cranium)

Forms anterior part of the skull, above eyes; features include the supraorbital foramen and the frontal sinuses

Parietal Bones (Bones of the cranium)

Form the rood and sides of the skull, just behind the frontal bone; they join along the midline at the sagittal suture and meet the frontal bone along the coronal suture

Anterior View of the skull

The paranasal sinuses

Coronal Suture Frontal bone

Coronal Suture Parietal bones

Lambdoid suture Occipital bone

Lambdoid Suture Parietal Bones

Labled

Ligamentum

Sagittal suture partial bones

Squamous suture parietal bone

Squamous Suture temporal bone

Frontal Bone

Partial bones

Optical bone

Lambdoid suture

Sagital suture

Coronal suture

Where does the occipital bone form?

it forms the back of the skull and the base of the cranium; features include foramen magnum, and occipital condyles; joins parietal bones at lambdoid suture

Where does the temporal bone form?

form parts of the sides and base of the cranium; features include the external acoustic meatus, mandibular fossae, mastoid process, styloid process, and zygomatic process; connects to parietal bones at squamous suture

Where does the sphenoid bone form?

It forms the base of the cranium sides of the skull and protions of the orbits; features include the sella turcica and sphenoidal sinuses

Where is the ethmoid bone located?

Located in front of the sphenoid bone; features include the cribriform plates, croata galia a perpendicular plate superior and middle nasal conchae and ethomoidal sinus

The facial structure

* It contains 13 immovable bones and a movable lower jawbone


* These bones form the basic shape of the face and provide attachments for muscles that move the jaw and control facial expressions

Maxillae bone of facial structure

Form the upper jaw, hard palete floor of the eye orbits sides of the nasal cavity house the upper teeth and contain large maxillary sinuses features include the maxillary sinus palatine and alveolar processes and alveolar arch

Palatine bones

Are L shaped bones located behind the maxillae that from the floor & lateral walls of the nasal cavity and the portion of the hard palate

Zygomatic bones

Form the cheekbones and lateral walls of the orbits; features include the temporal process, which joins the zygomatic process to form zygomatic arch

Lacrimal bones

Form part of the medial walls of the orbits

Nasal bones

Form the bridge of the nose

Vomer bone

Makes up a portion of the nasal septum to

Inferior nasal conchae

Are fragile scroll shaped bones that support mucous membranes in the nasal cavity

Mandible

Or lower jawbone supports the lower teeth and includes the body mandibular condyle coronoid process and alveolar arch

Frontal bone

Supraorbital notch

Lateral view of skull

Parietal bone

Squamous suture

Mastoid process

Squamous portion of temporal bone

External auditory meatus

Zygomatic process of temporal bone

Temporal process of zygomatic bone

Zygomatic bone

Greater wing of sphenoid bone

Temporal bone lateral view

Temporal bone medial view

Inferior view of skull

Occipital bone inferior view

Hypoglossal canal

Foramen magnum

Jugular foramen

Internal acoustic meatus

Floor of the Cranial Cavity, Viewed from Above

Sphenoid bone Posterior view

Sphenoid bone Superior view

Sphenoid foramina Foramen rotundum

Sphenoid foramina Foramen ovale

Sphenoid foramina Foramen spinosum

Superior orbital fissure Sphenoid foramina

Optic canal

Sagittal Section of the Skull

Ethmoid bone

Body of sphenoid

Sella turcica

Optic canal

Cribriform plate

Crista gali

Maxillae

Maxillary teeth

Infraorbital foramina

Maxillae lateral view and medial view

Palatine bones

Zygomatic bones

Zygomatic bones

Lacrimal bones