Anatomy_Key Terms_Ch7 Flashcards
appendicular skeleton
consists of the bones of the upper and lower limbs, including the pectoral (shoulder) and pelvic girdles that attach the limbs to the axial skeleton
axial skeleton
forms the long axis of the body; 80 bones in three regions: the skull, vertebral column, and thoracic cage
skull
formed by cranial and facial bones
cranium
enclose and protect the brain and provide attachment sites for some head and neck muscles
parietal bones
two large bones shaped like curved rectangles that make up the bulk of the calvaria
frontal bone
forms the forehead and the roofs of the orbits
supraorbital margin
aka superior margin of each orbit, is pierced by a hole or by a notch, called the supraorbital foramen or supraorbital notch
supraorbital foramen
aka supraorbital notch, hole or notch in the supraorbital margin or superior margin of each orbit
glabella
smooth part of the frontal bone between the superciliary arches in the midline
frontal sinuses
contained in the regions of the frontal bone lateral to the glabella
anterior cranial fossa
holds the large frontal lobes of the brain
occipital bone
”"”back of the head””, makes up the posterior part of the cranium and cranial base”
external occipital protuberance
knob in the midline at the junction of the base and the posterior wall of the skull
superior nuchal lines
extend laterally from the occipital protuberance
inferior nuchal lines
run laterally from a point halfway along the occipital crest
foramen magnum
”"”large hole””, base of the occipital bone, where the inferior part of the brain connects with the spinal cord”
occipital condyles
flank the foramen magnum, articulate with the first vertebra of the vertebral column in a way that enables the head to nod yes
hypoglossal canal
medial and superior to each occipital condyle, holds cranial nerve XII, the hypoglossal nerve
basilar part of the occipital bone
anterior to the foramen magnum, the jccipital bone joins the sphenoid bone via the _
posterior cranial fossa
holds a part of the brain called the cerebellum
squamous part
plate-shaped part of the temporal bone that abuts the squamous suture
zygomatic process
”"”cheek””, projects anteriorly from the squamous part to meet the zygomatic bone of the face to form the zygomatic arch or cheek bone”
mandibular fossa
inferior surface of the zygomatic process recieves the condylar process of the mandible, forming the freely movable temporomandibular joint
tympanic part
”"”eardrum””, surrounds the external acounstic meatus, or external ear canal”
external acoustic meatus
external ear canal, short tube running medially from the auricle to the eardrum
petrous part
contributes to the cranial base, forms a bony wedge between the occipital bone posteriorly and the sphenoid bone anteriorly
middle cranial fossa
anterior slope of the petrous part that holds the temporal lobes of the brain
jugular foramen
where the petrous part joins the occipital bone; holds the largest vein of the head, the internal jugular vein, and granial nerves IX, X, and XI
carotid canal
“opens on the skull’s inferior aspect, just anterior to the jugular foramen; holds the internal carotid artery, the main artery to the brain”
foramen lacerum
”"”lacerated””, a jagged opening between the medial tip of the petrous part of the temporal bone and the sphenoid bone”
internal acoustic meatus
lies in the cranial cavity on the posterior face of the petrous part and transmit cranial nerves VII and VIII, the facial and vestibulocochlear nerves
styloid process
”"”stake-like””, projects inferiorly from the petrous part of the temporal bone, attachment point for some muscles of the tongue and pharynx and for a ligament that connects the skull to the hyoid bone of the neck”
mastoid process
lateral and posterior to the styloid process, an anchoring site for some neck muscles
stylomastoid foramen
located between the styloid and mastoid processes; a branch of cranial nerve VII, the facial nerve, leaves the skull through this foramen
sphenoid bone
”"”wedge-shaped””, spans the width of the cranial floor, considered the keystone of the cranium because it forms a central wedge that articulaes with every other cranial bone”
sella turcica
saddle-shaped prominence on the superior surface of the sphenoid body; the seat called the hypophyseal fossa holds the pituitary gland or hypophysis
sphenoidal sinuses
within the sphenoid body
greater wings
project laterally from the sphenoid body, forming parts of the middle cranial fossa ond the orbit
lesser wings
form part of the floor of the anterior cranial fossa and a part of the orbit
pterygoid processes
project inferiorly from the greater wings; have both medial and lateral plates; are attachment sites for the pterygoid muscles that help close the jow in chewing
optic canal
lies just anterior to the sella turcica, transmits cranial nerve II, the optic nurve
superior orbital fissure
long slit between the greater and lesser wings, transmits several structures to and from the orbit, such as cranial nerves that control eye movements (III, IV, and VI)
foramen rotundum
lies in the medial part of the greater wing, usually oval
foramen ovale
oval hole posterolateral to the foramen rotundum, holds branch of cranial nerve V
foramen spinosum
posterior and lateral to the foramen ovale, transmits the middle meningeal artery, which supplies blood to the broad inner surfaces of the praetal bones and the squamous part of the temporal bones
ethmoid bone
most deeply situated bone of the skull, anterior to the sphenoid bone oand posterior to the nasal bones
cribriform plates
”"”perforated like a sieve””, contribute to the roof of the nasal cavities and the floor of the anterior cranial fossa”
crista galli
a superior projection in the midline between the two cribriform plates, which is attached by a fibrous membrane called the falx cerebri which helps to secure the brain within the cranial cavity
perpendicular plate
projects inferiorly in the median plane, forms the superior part of the nosal septum, the vertical partition that divides the nasal cavity into right and left halves
ethmoidal labyrinth
flanks the perpendicular plate on each side, riddled with ethmoidal air cells (ethmoid sinuses)
superior and middle nasal conchae
extend medially from the ethmoidal labyrinth, protrude into the nasal cavity
orbital plates
lateral surfaces of the labyrinth, contribute to the medial walls of the orbits
mandible
lower jawbone; horizontal body and two upright rami (bruanches)
mandibular angle
where the ramus meets the body posteriorly
coronoid process
”"”crown-shaped””, flat, trianglar projection; insterted by the temporalist muscle which elevates the lower jaw during chewing”
condylar process
posterior process at the superior margin of each ramus; enlarges supriorly to form the head of the mandible
the head of the mandible
articulates with the temporal bone to form the temporomandibular joint
mandibular notch
seperates the coronoid and condylar processes
body of the mandible
anchors the lower teth and forms the chin
alveolar process
superior border of the body of the mandible [or inferior in the maxillae]; tooth sockets (dental alveoli) open onto it
mental protuberance
forms the chin, two halves of the mandible fuse anteriorly at the mandibular symphysis
mandibular foramen
on the medial surface of each ramus; transmits a nerve responsible for tooth sensation (inferior alveolar nerve, a branch of cranial nerve V)
mental foramen
opens onto the anterolateral side of the mandibular body, transmits blood vessels and nerves to the lower lip and the skin of the chin
maxillary bones aka maxillae
”"”jaws””, form the upper jaw and the central part of the facial skeleton; considered the keystone bones of the face because they articulate with all other facial bones except the mandible”
palatine processes
project medially from the alveolar margins to form the anterior region of the hard palate
hard palate
anteriorly where the palate contains the horizontal processes of the palatine bones and the palatine process of the maxillary bone
frontal processes
extend superiorly to reach the frontal bone, forming part of the lateral aspect of the bridge of the nose
maxillary sinuses
the maxillae lie just lateral to the nasal cavity and contain the _
zygomatic processes
where the maxillae articulate with the zygomatic bones
inferior orbital fissure
floor of the orbit, transmits several vessels and nerves including the maxillary nerve (a branch of cranial nerve V) or its contuation the infraorbital nerve
infraorbital foramen
the infraorbital nerve proceeds anteriorly to enter the face through the _
zygomatic bones
aka cheekbones, joins the zygomatic process of the temporal bones posteriorly, the zygomatic process of the frontal bone superiorly, and the zygomatic process of the maxilla anteriorly; form the prominences of the cheeks and define part of the margin of each orbit
nasal bones
poired, retangular bones that join medially to form the bridge of the nose; articulate with the frontal bone superiorly, the maxillae laterally, and the perpendicular plate of the ethmoid bone posteriorly, and inferiorly attach to the cartilages that form most of the skeleton of the external nose
lacrimal bones
lacated in the medial orbital walls; articulate with the frontal bone superiorly, the ethmoid bone posteriorly, and the maxilla anteriorly; contains a deep groove that contributes to a lacrimal fossa which contains a lacrimal sac that gathers tears, allowing fluid to drain from the eye surface into the nasal cavity
palatine bones
posterior to the maxillae; paired L-shaped bones articulate with each other at their inferior horizontal plats, which complete the posterior part of the hard palate; the perpendicular plates form the posterior part of the lateral walls of the nasal cavity and a small part of the orbits
vomer
lies in the nasal cavity, where it forms the inferior part of the nasal septum
inferior nasal conchae
thin, curved bones in the nasal cavity; projecting medially from the lateral walls of the nasal cavity, just inferior to the middle nasal conchae of the ethmoid bone, they are the largest of the three pairs of conchae
nasal cavity
“costructed of bone and cartilage; roof is the ethmoid’s cribriform plates, floor is the palatine processes of the maxillae and the horizontal plates of the palatine bones (hard palate), lateral walls include nasal bones, superior and middle conchae of the ethmoid, inferior nasal conchae, frontal process of the maxilla, and perpendicular plates of the palantine bones”
superior, middle, and inferior meatuses
”"”a passage””, on the lateral walls of the nasal cavity, each of the three conchae forms a roof over a groove-shaped air passageway”
paranasal sinuses
hollow spaces contained internall by the bones surrounding the nosal cavity (the frontal, ethmoid, sphenoid, and both maxillary bones)
orbits
cone-shaped bony cavities that hold the eyes, the muscles that move the eyes, some fat, and the tear-producing glands; the walls of each orbit are formed by parts of seven bones: the frontal, sphenoid, zygomatic, maxillary, platane, lacrimal, and ethmoid bones; the superior and inferior orbital fissures, optic canal, and lacrimal fossa are also in the orbit
hyoid bone
just inferior to the mandible in te anterior neck; the only bone in the skeleton that does not articulate directely with any other bone; contains a body and two pairs of horns (cornu)
vertebral column
spinal column or spine, consists of 26 bones
cervical vertebrae
7 vertebrae of the neck (including the atlas and axis)
sacrum
articulates with the hip bones of the pelvis
servical and lumbar curvatures
concave posteriorly, secondary curvatures that develop when the baby starts to lift its head at 3 months (cervical) and when the baby begins to walk at about 1 year (lumbar)
thoracic and sacral curvatures
convex posteriorly, primary curvatures (well developed at birth)
anterior and posterior longitudinal ligaments
major supporting ligaments running vertially along the anterior and posterior surfaces of the bodies of the vertebrae from the neck to the sacrum
ligamentum flavum
connects the lamina of adjacent vertebrae; contains elastic connective tissue and is especially strong
intervertebral disc
cushionlike pad composed of an inner sphere, the nucleu pulposus, and an outer collar of about 12 concentric rings, the anulus fibrosus
nucleus pulposus
gelatinous, acts like a rubber ball, enabling the spine to absorb compressive stress
anulus fibrosus
the outer rings consist of ligament and the inner ones of fibrocartilage; function is to contain the nucleus pulposes, and function like a woven strap, binding the successive vertebrae together, resisting tension on the spine, and absorbing compressive forces; collagen fibers in adjacent rings in the anulus cross like an X, allowing the spine to withstand twisting
vertebral arch
forms the posterior portion of the vertebra; composed of two pedicles and two laminae
pedicles
”"”little feet””, short, bony walls that project posteriorly from the vertebral body and form the sides of the arch”
laminae
”"”sheets””, flat, bony plates that complete the vertebral arch posteriorly, extending from the transverse processes to the spinous process”
vertebral foramen
large hole encircled by the body and vertebral arch, successive vertebral foramina of the articulated vertebrae form the long vertebral canal, through which the spinal cord and spinal nerve roots pass
spinous process
median, posterior projection arising athe junction of the two laminae; attachment site for muschles and ligaments that move and stabilize the vertebral column
transverse process
projects laterally from each pedicle-lamina junction; attachment sites for the muscle and ligaments
superior and inferior articular processes
protrude superiorly and inferiorly from the pedicle-lamina junctions and form movable joints between successive vertebrae
facets
”"”little faces””, smooth joint surfaces of inferior and superior articular processes”
intervertebral foramina
notches on the superior and inferior borders of the pedicles form lateral openings between adjacent vertebrae; spinal nerves from the spinal cord pass through these foramina
atlas
lacks a body and a spinous process; ring of bone consisting of anterior and posterior arches, plus a lateral mass on each side with articular facets on both its superior and inferior surfaces; the superior facets receive the occipital condyles of the skull and thus they carry the skull, and participate in plexion and extension of the head on the neck to nod yes
axis
knob-like dens (tooth) projecting superiorly from its body
dens
”"”tooth””, cradled in the anterior arch of the atlas the dens acts as a pivot for the rotation of the atlas and skull, as in to say no”
transverse foramen
hole in the transverse process through which the vertebral blood vessels pass
vertebra prominens
C7, large spinous process is used as a landmark for counting the vertebrae in living people
superior and inferior costal facet
lies at the superior and inferior edge of the side of the thoracic vertebral body, to articulate with the head of the ribs
transverse costal facets
transverse processes have facets that articulate with the tubercles of the rids (except T11 and T12)
thoracic vertebrae
next 12 vertebrae, all articulate with ribs
lumbar vertebrae
mid-lower 5 vertebrae, small of the back, receives the most stress
sacral promontory
“human body’s center of gravity lies about 1 cm posterior to the anterosuperior margin of the first sacral vertebra which bulges anteriorly into the pelvic cavity”
transverse ridges
cross the anterior surface of the sacrum, marking the lines of fusion of the sacral vertebrae
anterior sacral foramina
transmit the ventral divisions (ventral rami) of the sacral spinal nerves
median sacral crest
represents the fused spinous processes of the sacral vertebrae
posterior sacral foramina
lateral to the median sacral crest; transmit the dorsal rami of the sacral spinal nerves
lateral sacral crest
lateral to the posterior sacral foramina; representing the tips of the transverse processes of the sacral vertebrae
sacral canal
vertebral canal continues within the sacrum
sicral hiatus
”"”gap””, at the inferior end of the sacral canal, the laminae of the fifth (and sometimes the fourth) sacral vertebrae fail to fuse medially, leaving an enlarged external opening”
