The Axial Skeleton Flashcards
What is #10?
Coronal suture
Name #1
Parietal bone
Name #2 and the suture line that borders its superior aspect.
Temporal bone; squamous suture
Name #3 and #4
Lambdoid suture; occipital bone
Name #5 and #6 as well as the suture line that borders their posterior aspect (separates the temporal bone from the occipital bone)
External acoustic meatus; mastoid process; occipitomastoid suture
Name #7, #8, and #9
Mandibular ramus; mental foramen; mandible
Name #11, #12, and #13
Frontal bone; sphenoid bone; ethmoid bone
Name #14, #15, and #16
Lacrimal bone; nasal bone; zygomatic bone
Name #17 and #18
Maxilla; zygomatic process
Name C.
Glabella
Name E, F, and G
Sphenoid bone; ethmoid bone, lacrimal bone
Name R, Q, and the site below R and Q that is unlabeled.
Supraorbital margin; supraorbital foramen; superior orbital fissure
Name P, O, and N.
Perpendicular plate; vomer; inferior nasal concha
What are the two aspects of the ethmoid bone?
Middle nasal concha and perpendicular plate
The cranium is divided into what two regions?
The cranial vault (calvaria) and the cranial base (floor)
Prominent bony ridges divide the cranial base into three distinct “steps”, or ________.
Fossae (anterior, middle, and posterior cranial fossae)
How many named openings are included in the cranium? What are a few examples of what they are called?
85 named openings; foramina, canals, fissures
How many bones are in the cranium?
8 bones
Which bone forms the anterior cranium and connects posteriorly with the paired parietal bones via the coronal suture?
Frontal bone
What is the most anterior part of the frontal bone called? What prominent feature does this include?
The vertical squamous part, which includes the forehead
What bone extends posteriorly to form the superior wall of the orbits and most of the anterior cranial fossa?
The frontal bone of the cranium
The forehead portion of the frontal bone ends at the __________ __________.
Supraorbital margins
What is the smooth portion of the frontal bone, located medially to the orbits, called?
Glabella
What lies lateral to the glabella?
The frontal sinuses
The frontal bone meets the nasal bone just inferior to the ______, at the ________ ________.
Glabella; frontonasal suture
What are the curved, rectangular bones that form most of the superior and lateral aspects of the skull and the bulk of the cranial vault?
The parietal bones
The parietal bone meets the frontal bone at what suture?
Coronal
The parietal bones meet each other at what suture? Where is this suture located?
The sagittal suture at the cranial midline
The parietal bones meet the occipital bone at what suture?
Lambdoid
The parietal and temporal bones meet at what lateral sutures?
Squamous
Which bone forms most of the skull’s posterior wall and base?
Occipital bone
The occipital bone articulates anteriorly with what two paired bones?
Parietal and temporal
What bones does the basilar part of the occipital bone join with?
The sphenoid bone
The occipital bones forms the walls of the __________ cranial fossa, which supports the _______ of the brain.
Posterior; cerebellum
What is the foramen magnum?
The hole through which the inferior part of the brain connects with the spinal cord.
What structures flank the foramen magnum and articulate with the first vertebra of the spinal column? What motion does this permit?
Occipital condyles; nodding of the head
What canal is situated medially and superiorly to each occipital condyle? What passes through them?
Hypoglossal canal; a cranial nerve
What protrusion is just superior to the foramen magnum and is the topmost ridge of the occipital bone?
External occipital protuberance
What ridges, other than the external occipital protuberance, mark the occipital bone near the foramen magnum?
Superior and inferior nuchal lines and the external occipital crest
What ligament anchors to the external occipital protuberance? What does it connect?
Ligamentum nuchae; connects the vertebrae of the neck to the skull
What is the function of the nuchal lines?
They anchor neck and back muscles to the occipital bone.
What bones lie inferior to the parietal bones and meet them at the squamous sutures?
Temporal
The temporal bones form the _____________ aspects of the skull and parts of the _______ _____.
Inferolateral; cranial base
What are the three major parts of the temporal bones?
Squamous part, tympanic part, and petrous part
The squamous part of the temporal bones includes what important structures?
The zygomatic process and the mandibular fossa
The mandibular fossa is ________ to the zygomatic process and receives the ________ process of the ________, forming the _______________ joint.
Inferior; condylar; mandible; temporomandibular
The tympanic part of the temporal bones surround the ________ ________ ________.
External acoustic meatus
The petrous part of the temporal bone houses what sensory cavities?
The middle and internal ear cavities
The petrous part of the temporal bone extends from the ________ bone posteriorly to the ________ bone anteriorly.
Occipital; sphenoid
The petrous part of the temporal bone composes the _______ ________ fossa, which supports the _______ lobes of the brain.
Middle cranial; temporal
What foramen lies at the junction of the occipital and petrous temporal bones? What does it transmit?
Jugular foramen; the jugular vein and three cranial nerves
What canal is anterior to the jugular foramen? What is its function?
The carotid canal; transmits the carotid artery, which supplies blood to over 80% of the cerebral hemispheres of the brain
What canal is responsible for the ability to “hear” our pulse in our head?
The carotid canal, close to the internal ear
What jagged opening, seen in dried skulls between the petrous temporal bone and the sphenoid bone, is completely closed by cartilage in living persons?
Foramen lacerum
What is superolateral to the jugular foramen and transmits cranial nerves VII and VIII?
The internal acoustic meatus
What foramen is found between the styloid and mastoid processes of the temporal bone, allowing cranial nerve VII to leave the skull.
Stylomastoid foramen
What process of the temporal bone lies just posterior to the ear and is an anchoring site for neck muscles?
Mastoid process
What numerous openings make the mastoid process susceptible to infection? Why?
The mastoid air cells; their proximity to the inner ear
What is an attachment point for several tongue and neck muscles, as well as for a ligament that secures the hyoid bone?
The styloid process
What is the bat-shaped bone that spans the width of the middle cranial fossa?
Sphenoid
What bone is considered the keystone of the cranium? Why?
The sphenoid; because it articulates with every other bone in the cranium and ties them together
The sphenoid bone consists of a ______ ______ and three pairs of ___________.
Central body; processes
What is the saddle-shaped prominence of the sphenoid central body called?
The sella turcica
The seat of the sella turcica forms the ___________ ______, which houses the ________ _______.
Hypophyseal fossa; pituitary gland
What structures project laterally from the sphenoid body and form parts of the middle cranial fossa? What other structures do they contribute to?
The greater wings of the sphenoid; also form the posterior wall of the orbits and the external wall of the skull, medial to the zygomatic arch
What do the lesser wings of the sphenoid form?
The anterior cranial fossa and part of the medial orbital walls
What processes project inferiorly from the junction of the sphenoid body and greater wings? What do they anchor?
Pterygoid processes; anchor pterygoid muscles, used for chewing
What canals are present anterior to the sella turcica and allow the optic nerves to pass to the eyes?
Optic canals
Lateral to the central body of the sphenoid lie four openings:
Superior orbital fissure, foramen rotundum, foramen ovale, and foramen spinosum
What bone lies between the sphenoid bone and the nasal bones of the face and is the most deeply situated bone of the skull?
The ethmoid bone
What two plates is the superior surface of the ethmoid bone formed by?
Cribriform plates
What do the cribriform plates help to form?
The roof of the nasal cavity and the floor of the anterior cranial fossa
What tiny holes throughout the cribriform plate allow filaments of the olfactory system to pass through? Where do the olfactory filaments originate?
Cribriform foramina; small receptors in the nasal cavity
What is the triangular process that projects superiorly between the cribriform plates called?
Crista galli