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