Bio150Lab Review Quiz #4 pt 2

site of articulation of occipital bone and parietal bones

large opening in base of occipital, which allows the spinal cord to join with the brain

rounded projections lateral to the foramen magnum that articulate with the first cervical vertebra (atlas)

opening medial and superior to the occipital condyle through which the hypoglossal nerve (cranial nerve XII) passes

midline prominences posterior to the foramen magnum

bat-shaped bone forming the anterior plateau of the middle cranial fossa across the width of the skull. The sphenoid bone is the keystone of the cranium because it articulates with all other cranial bones

portions of the sphenoid seen exteriorly anterior to the temporal and forming a part of the eye orbits

inferiorly directed trough-shaped projections from the junction of the body and the greater wings

jagged openings in orbits providing passage for cranial nerves III,IV,V and VI to enter the orbit where they serve the eye

a saddle-shaped region in the sphenoid midline. The seat of this saddle, called the hypophyseal fossa, surrounds the pituitary gland (hypophysis)

bat-shaped portions of the sphenoid anterior to the sella turcica

openings in the bases of the lesser wings through which the optic nerves enter the orbits to serve the eyes

opening lateral to the sella turcica providing passage for a branch of the fifth cranial nerve. (this foramen is not visible on an inferior view of the skull.)

opening posterior to the sella turcica that allows passage of a branch of the fifth cranial nerve.

Irregularly shaped bone anterior to the sphenoid. Forms the roof of the nasal cavity, upper nasal septum, and part of the medial orbit walls

vertical projection providing a point of attachment for the dura mater, helping to secure the brain within the skull

bony plates lateral to the crista galli through which olfactory fibers pass to the brain from the nasal mucosa. Together the cribriform plates and the midline crista galli form the horizontal plate of the ethmoid bone

inferior projection of the ethmoid that forms the superior part of the nasal septum

irregularly shaped and thin-walled bony regions flanking the perpendicular plate laterally. Their lateral surfaces (orbital plates) shape part of the medial orbit wall

thin, delicately coiled plates of bone extending medially from the lateral masses of the ethmoid into the nasal cavity. The conchae make air flow through the nasal cavity more efficient and greatly increase the surface area of the mucosa that covers them, thus increasing the mucosa's ability to warm and humidify incoming air

the lower jawbone, which articulates with the temporal bones in the only freely movable joints of the skull

horizontal portion; forms the chin

vertical extension of the body on either side

articulation point of the mandible with the mandibular fossa of the temporal bone

jutting anterior portion of the ramus; site of muscle attachment

posterior point at which ramus meets the body

prominent opening on the body (lateral to the midline) that transmits the mental blood vessels and nerve to the lower jaw

open the lower jaw of the skull to identify this prominent foramen on the medial aspect of the mandibular ramus. This foramen permits passage of the nerve involved with tooth sensation (mandibular branch of cranial nerve V) and is the site where the dentist injects Novocain to prevent pain while working on the lower teeth.

superior margin of mandible; contains sockets in which the teeth lie

anterior median depression indicating point of mandibular fusion

two bones fused in a median suture; form the upper jawbone and part of the orbits. All facial bones, except the mandible, join the maxillae. Thus they are the main, or keystone, bones of the face

inferior margin containing sockets (alveoli) in which teeth lie

form the anterior hard palate; meet medially in the intermaxillary suture

opening under the orbit carrying the infraorbital nerves and blood vessels to the nasal region

large bilateral opening located posterior to the central incisor tooth of the maxilla and piercing the hard palate; transmits the nasopalatine arteries and blood vessels

fingernail-sized bones forming a part of the medial orbit walls between the maxilla and the ethmoid. Each lacrimal bone is pierced by an opening, the lacrimal fossa, which serves as a passageway for tears

paired bones posterior to the palatine processes; form posterior hard palate and part of the orbit; meet medially at the median palatine suture

lateral to the maxilla; forms the portion of the face commonly called the cheekbone, and forms part of the lateral orbit. Its three processes are named for the bones with which they articulate

small rectangular bones forming the bridge of the nose

blade-shaped bone in median plane of nasal cavity that forms the posterior and inferior nasal septum

Thin curved bones protruding medially from the lateral walls of the nasal cavity; serve the same purpose as the turbinate portions of the ethmoid bone (described earlier)

maxillary, sphenoid, ethmoid, and frontal

inflammation of the sinuses, sometimes occurs as a result of an allergy or bacterial invasion of the sinus cavities

not really counted as a skull bone, the hyoid bone is located in the throat above the larynx. It serves as a point of attachment for many tongue and neck muscles. It does not articulate with any other bone and is thus unique. It is horseshoe-shaped U shaped with a body and two pairs of horns, or cornua.

extending from the skull to the pelvis, forms the body's major axial support

rounded central portion of the vertebra, which faces anteriorly in the human vertebralcolumn

composed of pedicles, laminae, and a spinous process, it represents the junction of all posterior extensions from the vertebral body

opening enclosed by the body and vertebral arch; a conduit for the spinal cord

two lateral projections from the vertebral arch

single medial and posterior projection from the vertebral arch

paired projections lateral to the vertebral foramen that enable articulation with adjacent vertebrae. The superior articular processes typically face toward the spinous process (posteriorly), whereas the inferior articular processes face (anteriorly) away from the spinous process

the right and left pedicles have notches on their inferior and superior surfaces that create openings, the intervertebral foramina, for spinal nerves to leave the spinal cord between adjacent vertebrae

lacks a body, and its lateral processes contain large concave depressions on their superior surfaces that receive the occipital condyles of the skull. This joint enables you to nod "yes"

acts as a pivot for the rotation of the atlas (and skull) above. It bears a large vertical process, the dens, or odontoid process, that serves as the pivot pointl The articulation between C1 and C2 allows you to rotate your head from side to side to indicate"no"

the body is somewhat heart shaped, with two small articulating surfaces, on each side (one superior, the other inferior) close to the origin of the vertebral arch.

is a composite bone formed from the fusion of five vertebrae. Superiorly it articulates with L5, and inferiorly in connects with the coccyx.

is a remnant of the spinous processes of the fused vertebrae

winglike, formed by fusion of the transverse processes, articulate laterally with the hip bones

are located at either end of these ridges. These foramina allow blood vessels and nerves to pass

The vertebral canal continues inside the sacrum as the sacral canal and terminates near the coccyx via an enlarged opening called the sacral hiatus. The sacral promontory anterior border of the body of S1 is an important anatomical landmark for obstetricians.

is formed from the fusion of three to five small irregularly shaped vertebrae. It is literally the human tailbone, a vestige of the tail that other vertebrates have. The coccyx is attached to the sacrum by ligaments.

the bony thorax is composed of the sternum, ribs, and thoracic vertebrae. Combined with the costal cartilages, it is referred to as the thoracic cage because of its appearance and b/c it forms a protective cone-shaped enclosure around the organs of the thoracic cavity (heart and lungs, for example)

The sternum (breastbone), a typical flat bone, is a result of the fusion of three bones-the manubrium, body, and xiphoid process. It is attached to the first seven pairs of ribs. The superiormost manubrium looks like the knot of a tie; it articulates with the clavicle (collarbone) laterally. The body (gladiolus) forms the bulk of the sternum. The xiphoid process constructs the inferior end of the sternum and lies at the level of the fifth intercostal space.

(concave upper border of the manubrium) can be palpated easily; generally t is at the level of the third thoracic vertebra

is a result of the manubrium and body meeting at a slight angle to each other, so that a transverse ridge is formed at the level of the second ribs.

the point where the sternal body and xiphoid process fuse, lies at the level of the ninth thoracic vertebra.

• all of the ribs articulate posteriorly with the vertebral column via their heads and tubercles and then curve downward and toward the anterior body surface.
• the fist seven pairs, called the true, or vertebrosternal, ribs, attach directly to the sternum by their "own" costal cartilages.
• The next five pairs are called false ribs; they attach indirectly to the sternum or entirely lace a sternal attachment.
• Of these, rib pairs 8-10, which are also called vertebrochondral ribs, have indirect cartilage attachments tothe sternum via the costal cartilage of rib 7.
• The last two pairs, called floating, or vertebral, ribs, have no sternal attachment.

• indentations between the bones of the fetal skull, called fontanels, are fibrous membranes.
• these areas will become bony (ossify) as the infant ages, completing the process by the age of 20-22 months.
• The fontanels allow the fetal skull to be compressed slightly during birth and also allow for brain growth during late fetal life.
• Notice that some of the cranial bones have conical protrusions.
• These are ossification (growth) centers.
• Notice also that the frontal bone is still bipartite, and the temporal bone is incompletely ossified, little more than a ring of bone.