Anatomy & Physiology Lab 1: The Axial Skeleton
1.The Skull
2.The Vertebral Column
3.The Thoracic Cage
Three parts of the Axial skeleton
-encloses and protects the fragile brain tissue
Cranial Bones
-supports the eyes and position them anteriorly
-provides attachment sites for facial muscles
Facial Bones
Sutures
All but one of the bones of the skull are joined by interlocking joints called ____________.
freely movable joint
The mandible, or lower jawbone is attached to the rest of the skull by a _______________.
-the superior, lateral, and posterior walls of the skull
Cranial Vault/Calvaria
-forms the skull bottom
Cranial Base
1.Anterior cranial fossae
2.Middle cranial fossae
3.Posterior cranial fossae
What are the three distinct depressions of the cranial base?
-anterior portion of cranium
-forms the forehead
Frontal Bone
-opening above each orbit allowing blood vessels and nerves to pass
Supraorbital foramen (notch)
-smooth area between the eyes
Glabella
-posterolateral to the frontal bone, forming sides of the cranium
Parietal Bone (2)
-midline articulation point of the two parietal bones
Sagittal Suture
-point of articulation of parietals with frontal bone
Coronal Suture
-inferior to parietal bone on lateral skull
Temporal Bone
1. Squamous part
-border the parietals
2.Tympanic part
-surrounds the external ear opening
3.Petrous
-forms the lateral portion of the skull base and contains the mastoid process
What are the three major parts of the temporal bone?
-point of articulation of the temporal bone with the parietal bone
Squamous Suture
- bridgelike projection joining the zygomatic bone (cheekbone) anteriorly
Zygomatic Process
-rounded depression on the inferior surface of the zygomatic process
-forms the socket for the condylar process of the mandible
-where the mandible joins the lower cranium
Mandibular Fossa
-canal leading to eardrum and middle ear
External Acoustic Meatus
-needlelike projection inferior to external acoustic meatus
-attachment point for muscles and ligaments of the neck
Styloid Process
-opening medial to the styloid process through which the internal jugular vein and cranial nerves IX, X, and XI pass
Jugular Foramen
-opening medial to the styloid through which the internal carotid artery passes into the cranial cavity
Carotid Canal
-opening on posterior aspect (or petrous part) of temporal bone allowing passage of cranial nerves
Internal Acoustic Meatus
-jagged opening between the petrous temporal bone and the sphenoid providing passage for a number of small nerves and for the internal carotid artery to enter the middle cranial fossa
Foramen Lacerum
-tiny opening between the mastoid and styloid processes through which cranial nerve VII leaves the cranium
Stylomastoid Foramen
-Rough projection inferior and posterior to external acoustic meatus
-attachment site for muscles
Mastoid Process
-most posterior bone of the cranium
Occipital Bone
-site of articulation of occipital bone and parietal bones
Lambdoid Suture
-large opening in base of occipital, which allows the spinal cord to join with the brain
Foramen Magnum
-rounded projections lateral to the foramen magnum that articulate with the first cervical vertebra (atlas)
Occipital Condyles
-opening medial and superior to the occipital condyle through which the hypoglossal nerve pass
Hypoglossal Canal
-midline prominences posterior to the foramen magnum
External Occipital Crest and Protuberance
Bat-shaped bone forming the anterior plateau of the middle cranial fossa across the width of the skull.
-articulates with all the other cranial bones
Sphenoid Bone
-portions of the sphenoid seen exteriorly anterior to the temporal and forming a part of the eye orbits
Greater Wings
-inferiorly directed trough-shaped projections from the junction of the body and the greater wings
Pterygoid Processes
-jagged openings in orbits provding passages for cranial nerves III, IV, V, and VI to enter the orbit where they serve the eye
Superior Orbital Fissures
- saddle shaped region in the sphenoid midline
Sella Turcica
-bat shaped portions of the sphenoid bone anterior to the sella turcica
Lesser Wings
- openings in the bases of the lesser wings through which the optic nerve (cranial nerve II) enter the orbits to serve the eyes
Optic Canals
- opening lateral to the sella turcica providing passage for a branch of the fifth cranial nerve
Foramen Rotundum
opening posterior to the sella turcica that allows passage of the fifth cranial nerve.
Foramen Ovale
opening lateral to the foramen ovale which the meningeal artery passes
Foramen Spinosum
irregularly shaped bone anterior to the sphenoid
Ethmoid Bone
vertical projection providing a point of attachment for the dura meter, helping to secure the brain within the skull
Crista Galli
bony plates lateral to the crista galli through which olfactory fibers pass to the brain
Cribriform Plates
inferior projection of the ethmoid bone that forms the superior part of the nasal septum
Perpendicular Plate
irregularly shaped and thin-walled bony regions flanking the perpendicular plate laterally
Lateral Masses
the lower jawbone, which articulates with the temporals in the only freely movable joints of the skull
Mandible
horizontal portion; forms the chin
Mandibular body
vertical extension of the body on either side
Mandibular Ramus
articulation point of the mandible with the mandibular fossa of the temporal bone
Condylar Process
jutting anterior portion off the ramus
-site of muscle attachment
Coronoid Process
posterior point at which ramus meets the body
Mandibular Angle
-prominent opening on the body that transmits the mental blood vessels and nerve to the lower jaw
Mental Foramen
-permis passage of the nerve involved with tooth sensation
Mandibular Foramen
superior margin of the mandible, contains sockets in which the teeth lie
Alveolar Process
-two bones fused in a median suture
-forms the upper jawbone and parts of the orbits
Maxillae
-from the anterior hard palate; meets medially in the intermaxillary suture
Palatine Processes
-opening under the prbit carrying the infraorbital nerves and blood vessels to the nasal region
Infraorbital Foramen
-fingernail sized bones forming part of the medial orbit walls between the maxilla and the ethmoid bone
Lacrimal Bone
-paired bones posterior to the palatine processes
Palatine Bone