Ch. 20 Cranium Part 2
The jugular foramen is an important large opening in the skull for two reasons: 1. ____________ 2. ____________
1. it allows blood to drain from the brain via the internal jugular vein 2. it lets three cranial nerves pass through it
The sella turcica lies in the MIDSAGITTAL plane of the cranium at a point _____ inch (1.9cm) ANTERIOR and ____ inch (1.9cm) SUPERIOR to the level of the _____ ______ _______ (EAM)
3/4 3/4 External Acoustic Meatus
The cells of each side are arbitrarily divided into three groups: _________ , ___________ , and _________ ethmoidal air cells
Anterior Middle Posterior
The _____ surface of the body of the sphenoid bone forms the posterior bony wall of the NASAL CAVITY
Anterior Posterior
Each process of the lesser wings arises from two roots; _____ root and ______ root
Anterior (superior) Posterior (inferior)
The ______ root is thin and flat, and the ______ root, referred to as the _______ strut, is thick and rounded
Anterior (superior) Posterior (inferior) Sphenoid
In an adult, the ________ part of the occipital bone fuses with the body of the sphenoid bone, resulting in the formation of a continuous bone
Basilar
The _______ portion of the occipital bone curves ANTERIORLY and SUPERIORLY to its juntion with the body of the sphenoid
Basliar
The ____ of the sphenoid bone contains the sphenoidal sinuses, which are incompletely separated by a median septum
Body
On the either side of the sella turcica is a groove, the ______ sulcus, in which the internal carotid artery and the cavernous sinus lie
Carotid
The MEDIAL ends of the lesser wings POSTERIOR borders form the ANTERIOR ______ processes
Clinoid
The _____ supports the pons
Clivus
The sloping surface of the junction between the dorsum sellae of the sphenoid bone and the basilar portion of the occupiutal bone is called the ____________
Clivus
At the POSTERIOR end of the condyles are the ___________ canals, through which the emissary veins pass
Condylar
The greater wings form part of the middle _______ fossa, the POSTEROLATERAL walls of the Orbits, the lower margin of the SUPERIOR Orbit Sulci , and the greater part of the POSTERIOR margin of the INFERIOR orbital sulci
Cranial
The ____ plate is forated by foramina for the transmission of Olfactory nerves
Cribriform
The horizontal portion of the ethmoid bone, called the _____ plate, is received into the ethmoidal notch of the frontal bone
Cribriform
The cribriform plate also has a thick, concial process, the ______ _______ , which projects SUPERIORLY from its anterior midline and serves as the anterior attachment for the FALX CERBRI
Crista Gilla
Situated between the orbits, the ____ bone forms part of the anterior cranial fossa, the nasal cavity, and orbital walls, and the bony nasal septum
Ethmoid
The _____ bone articulates with the frontal and sphenoid bones of the cranium
Ethmoid
The _____ bone is a small, cube-shaped bone that consists of a horizontal plate; vertical plate; and two light spongy lateral masses called ___
Ethmoid Labyrinths
The occiptal bone also has a large aperture, the _________ magnum, through which the INFERIOR portion of the __________ oblongata passes as it exits the cranial cavity and joins the spinal cord
Foramen Medulla
The ______ ______ , _______ , and _______ are paired and are situated in the greater wings
Foramina Rotundum Ovale Spinosum
Each parietal bone articulates with ____ , ______ , _____ , and opposite ______ bones of the cranium
Frontal Temporal Occipital Parietal
The _____ wings arise from the sides of the body of the sphenoid bone and curve Laterally, Anteriorly, Posteriorly, and Superiorly
Greater
The INFERIOR extremetity of the MEDIAL lamina possesses an elongated, hooked shaped process, the pterygoid ________, which makes it longer and narrower than the LATERAL lamina
Hamulus
The __________ canals are found at the ANTERIOR ends of the condyles and transmit the hypoglossal nerves
Hypoglossal
The ANTERIOR portion of the occipital bone contains a deep notch that forms a part of the __________ foramen
Jugular
The ____ contain the ethmoidal sinuses, or air cells
Labyrinths
The walls of the ____ form part of the MEDIAL walls of the ORBITS and part of the LATERAL walls of the NASAL CAVITY
Labyrinths
The _____ wings are triangular in shape and nearly HORIZONTAL in position
Lesser
The _____ wings form the POSTEROMEDIAL portion of the roofs of the orbits, the POSTERIOR portion of the ANTERIOR fossa, the upper margin of the SUPERIOR ______ fissures, and the optic canal
Lesser Orbital
The _____ wings arise, one on each side, from the ANTEROSUPERIOR portion of the body of the _______ bone and project LATERALLY, ending in sharp points
Lesser Sphenoid
Each pterygoid process consists of two plates of bone, the _______ and _______ pterygoid laminae, which are fused together at their superoanterior parts
Medial Lateral
The _____ bone is situated at the posteroinferior part of the cranium
Occipital
The ________ condyles project ANTERIORLY, one from each side of the squam, for articulation with atlas of the cervical spine
Occipital
Part of each lateral portion of the ________ condyles curves MEDIALLY to fuse with the basilar portion and complete the ________ magnum, and part of it projects LATERALLY to form the _______ process
Occipital Foramen Jugular
The ____________ joints are on the INFERIOR surface of the curved parts, extending from the level of ________ magnum ANTERIORLY to the level of its ANTERIOR margin, reciprocally shaped condyles articulate with the SUPERIOR facet of the atlas; the only bony articulations between the skull and neck
Occipitoatlantal Foramen
The circular opening between the two roots is the _____ canal
Optic
The ______ groove extends across the ANTERIOR portion of the tuberculum sellae; groove ends on each side at the optic canal
Optic Tuberculum
The optic canal is the opening into the apex of the _____ for the transmission of the OPTIC NERVE and OPHTHALMIC ARTERY; or known as the ______ foramen
Orbit Optic
The pterygoid processes articulate with the _______ bones ANTERIORLY and with the wings of the vomer , where they enter into the formation of the nasal cavity
Palatine
Each parietal bone presents a prominent bulge, called the _______ eminence, near the central portion of its external surface
Parietal
The ____ bones form a large portion of the sides of the cranium
Parietal
The two ___ bones are square and have a CONVEX external surface and a CONCAVE internal surface
Parietal
The _____ bones also form the POSTERIOR portion of the cranial roof by their articulation with each other at the ______ suture in the MSP
Parietal Sagittal
The width of the head should be measured at the _____ ______ because it is the widest point of the head
Parietal Eminence
The occipital bone articulates with the two ___________, the two ____________ bones and the ____________ of the cranium, and the first __________ vertebra
Parietals Temporal Sphenoid Cervial
The vertical portion of the ethmoid bone is called the _____ plate
Perpendicular
The ____ plate is thin, flat bone that projects INFERIORLY from the INFERIOR surface of the _____ plate and, with the nasal spine, forms the SUPERIOR portion of the bony septum of the nose
Perpendicular Cribriform
The occipital bone forms the ________ half of the base of the cranium and the greater part of the posterior _________ fossa
Posterior Crainial
On the external surface of the squama, midway between its summit and the foramen magnum, is a prominent porcess termed the EXTERNAL occipital ________, or ________, which corresponds in position with the INTERNAL occipital ___________
Protuberance Inion Protuberance
The ____ processes project INFERIORLY and curve LATERALLY on the sphenoid bone
Pterygoid
The _____ processes arise from the lateral portions of the INFERIOR surface of the body of the sphenoid bone and the MEDIAL portions of the INFERIOR surfaces of the _____ wings
Pterygoid Greater
The superior surface of the sphenoid bone presents a deep depression called the _____ ______ and contains a gland called the _____ gland
Sella Turcica Pituitary
The _____ bone articulates with each of the other seven bones of the cranium
Sphenoid
The _____ bone is an irregularly wedge-shaped bone that resembles a bat with its wing extended
Sphenoid
The ____ bone consists of a body; two _____ wings and two _____ wings, which project LATERALLY from the sides of the body; and two _______ processes, which project INFERIORLY from each side of the INFERIOR surface of the body
Sphenoid Lesser Greater Pterygoid
The _____ bone is situated in the base of the cranium ANTERIOR to the ____ bones and BASILAR part of the _____ bone
Sphenoid Temporal Occipital
Saucer-shaped, convexed EXTERNALLY
Squama
The _____ curves POSTERIORLY and SUPERIORLY from the foramen magnum and is curved from side to side
Squama
______ articulates with the parietal bones at the lambdoidal sutures and with the mastoid portions of the temporal bones at the occipitomastoid sutures
Squama
The occipital bone has four parts: _______, two occipital _______, and _______ portion
Squama Condyles Basilar
Projecting INFERIORLY from each MEDIAL wall of the labyrinths are two thin, scrolling shaped processes called the _____ and _____ nasal conchae
Superior Middle
The sella turcica is bonded ANTERIORLY by the ______ sellae and POSTERIORLY by the _______ sellae, which bears the posterior _______ processes
Tuberculum Dorsum Clinoid
Extend ANTERIORLY, one on each side of the foramen magnum
Two occipital condyles
The slanted area of the sphenoid bone POSTERIOR and INFERIOR to the dorsum sellae is continuous with the basilar portion of the occuputal bone and is called the ______
clivus