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CH 7 A
the axial skeleton
Question | Answer |
---|---|
axial skeleton | forms a longitudinal axis of the body. |
appendicular skeleton | supports the limbs. |
skull | protects the brain and guard the entrances to the digestive and respiratory systems. |
cranium | brain case |
8 cranial bones | occipital, frontal bone, sphenoid, ethmoid, and the paired parietal and temporal bones. |
cranial cavity | fluid filled chamber that cushions and supports the brain. |
Facial bones | protect and support the entrances to the digestive and respiratory tracts. |
nasal septum | subdivides the nasal cavity. |
sinuses | several bones of the skull that contain air-filed chambers |
suture | the connections between the skull bones of adults are immovable joints |
lamboid suture | arches across the posterior surface of the skull and separates the occipital bone frm the two parietal bones. |
Coronal suture | attaches the frontal bone to the parietal bones of either side |
calvaria | formed by occipital, parietal, and frontal bones. |
sagittal suture | extends from the lambdoid suture t the coronal suture, between the parietal bones. Produces midsagital line. |
squamous suture | on each side of the skull forms the boundary between the temporal bone and the parietal bone of that side. |
occipital bone | forms much of the posterior and inferior surfaces of the cranium. |
external occipital proturberance | is a small bump at the midline on the inferior surface. |
external occipital crest | begins at the external occipital proturberance, marks the attachment of a ligament that helps stabilize the vertebrae of the neck. |
occipital condyles | site of articulation between the skull and the first verebra of the neck. |
foramen magnum | connects the cranial cavity, which is enclosed by the vertebral column. This foramen surrounds the connection between the brain and the spinal cord. |
jugular foramen | lies between the occipital bone and the temporal bone. |
internal jugular vein | passes through ths foramen, carrying venous blood from the brain. |
hypoglossal canals | begin at the lateral base of each occipital condyle and end on the inner surface of the occipital bone near the foramen magnum. |
Hypoglossal nerves | cranial nerves that control the tongue muscles, pass through these canals. |
parietal bones | form part of the superior and lateral surfaces of the cranium. |
Frontal bone | forms the anterior portion of the cranium and the roof of the orbits. |
frontal squama | or forehead, forms the anterior, superior portion of the cranium and provides surface area for the attachment of facial muscles. |
superior temporal line | is a continuous with the superior temporal line of the parietal bone. |
supraorbital margin | thickening of the frontal bone that helps protect the eye. |
lacrimal fossa | superior and lateral surface of the orbit is a shallow depression that marks the location of the lacrimal (TEAR) gland, which lubricates the surface of the eye. |
frontal sinuses | extremely variable in size and time of appearance. |
supraorbital foramen | provides passage for blood vessels that supply the eyebrow, eyelids, and frontal sinuses. |
temporal bones | form part of both the lateral walls of the cranium and the zygotic arches. |
squamous part or squama of the temporal bone | convex, irregular surface that borders the squamous suture |
zygomatic process | inferior to the squamous portion, articulates with the temporal process of the zygomatic bone, forming zygomatic arc or cheeckbone. |
zygomatic arch | cheeckbone |
masteoid process | attachment site for muscles that rotate or extend the head. |
Masteoid air cells | small interconnected cavities withn the masteoid process, that are connected to the middle ear cavity. |
styloid processh | near the base of the mastoid process, is attached to ligaments that support the hyoid bone and to the tendons of several muscles associated with the hyoid bone, the tongue, and the pharynx. |
petrous part | located on its internal surface, encloses the structures of the inner ear- sense organs that provide information about hearing and balance. |
auditory ossicles | located on tympanic cavity, middle ear, cavity within petrous part. |
carotid canal | provides passage for the internal carotid artery, a major artery to the brain. |
Foramen lacerum | jagged slit extending between the sphenoid and the petrous portion of the tempora bone and containing hyaline cartilage and small arteries that supply inner surface of the cranium. |
auditory tube | airfilled passageway that connects the pharynx to the tympanic cavity, passes through the posterior portion of the foramen lacerum. |
external acoustic canal or external acoustic meatus | on the lateral surface or ends at the tympanic membrane |
stylomasteoid foramen | lies porsterior to the base of the styloid process. |
facial nerve | passes through this foramen to control the facial muscles. |
internal acoustic canal or internal acoustic meatus | begins on the medial surface of the petrous part of the temporal bone |
sphenoid, or sphenoidal bone | forms part of the floor of the cranium, unites the cranial and facial bones, and acts as a cross brace that strengthens the sides of the skull. |
body | forms the central axis of the sphenoid |
sella turcica | Turkish saddle, is a bony, saddle-shapped enclosure on the superior surface of the body. |
Hypophyseal fossa | depression within the sella turcica. |
pituitary gland | occupies this fossa |
sphenoidal sinuses | are on either side of the body, inferior to the sella turcica. |
lesser wings | extend horizontally anterior to the sella turcica. |
greater wings | extend laterally from the body and form part of the cranial floor. |
sphenoidal spine | lies at the posterior, lateral corner of each greater wing. |
pterygoid processes | vertical projections that originate on either side of the body. |
optic canals | permit passage of the optic nerves from the eyes to the brain. |
superior orbital fissure, foramen rotundum, foramen ovale, and foramen spinosum. | penetrate each greater wing. These passages carry blood vessels and nerve to the orbit, face, jaws, and membranes of the cranial cavity, respectively. |
ethmoid or ethmoidal bone | forms anteromedial floor of the cranium, the roof of the nasal cavity, and part of the sanal septum and medial orbit wall. |
cribriform plate | forms the anteromedial floor of the cranium and the roof of the nasal cavity. |
crista galli | bony ridge that projects superior to the cribiform plate. |
Falx cerebri | a membrane that stabilizes the position of the brain, attaches to this ridge. |
lateral masses | contain ethmoidal labyrinth |
ethmoidal labyrith | consist of interconnected ethmoidal air cells, |
ethmoidal air cells | open into nasal cavity on each side |
Superior nasal conchae and middle nasal conchae | delicate projections of lateral masses. |
perpendicular plate | forms part of the nasal septum, along with the vomer and a piece of hyaline cartilage. |
olfactory foramina | cribiform plate permit passage of the olfactory nerves, which provide the sense of smell. |
olfactory foramina | cribriform plate, the medial surfaces of the superior portion of the perpendicular plate |
Maxillary bones | Maxillae, support the teeth and form the inferior orbital rim, the lateral margins of the external nares, upper jaw, and most of the hard palate. |
Orbital rim | Protects eye and other structures in the orbit. |
Anterior nasal spine | Found in the anterior portion of the maxillary bone, at its articulation with the maxillary bone of the other side. |
Alveolar process | Borders the mouth supports the upper teeth. |
Palatine processes | Hard palate, bony roofof the mouth |
Maxillary sinuses | Lighten the portion of the maxillary bone superior to the teeth |
Nasolacrimal canal | Formed by the maxillary and lacrimal bones, protects the lacrimal sac and the nasolacrimal duct, which carries tears from the orbit of the nasal cavity. |
infraorbital foramen | marks the path of the major sensory nerve that reaches the brain via the foramen rotundum of the sphenoid. |
inferior orbital fissure | lies between the maxillary bone and the sphenoid, permits passage of cranial nerves and blood vessels. |
palatine bones | form the posterior portion of the hard palate and contribute to the floor of each orbit. |
horizontal plate | forms posterior part of the hard palate. |
perpendicular plate | extends from horizontal plate to the orbital process. |
orbital process | forms part of the floor of the orbit. |
nasal bones | support the superior portion of the bridge of the nose. |
external nares | the entrances to the nasal cavity |
Inferior nasal conchae | createthe nasal turbulence in air passng through the nasal cavity, and increase the epithelial surface area to promote warming and humidification of inhaled air. |
zygomatic bones | contribute to the rim and lateral wall of the orbit and form part of the zygomatic arch. |
temporal process | curves posteriorly to meet the zygomatic process of the temporal bones. |
zygomaticofacial foramen | on the anterior surface of each zygomatic bone carries a sensory nerve that innervates the cheek. |
lacrimal bones | form part of the medial wall of the orbit. |
lacrimal sulfocrus | a groove along the anterior, lateral surface of the lacrimal bone, marks the location of the lacrimal sac. |
mandible | forms the lower jaw |
body of the mandible | is the horizontal portion of the bone. |
alveolar process | supports the lower teeth. |
mental protuberance | is the attachment site for several facial muscles. |
submandibular salivary gland | prominent depression on the medial surface marks the position of.l |
mylohyoid line | marks the insertion of the mylohyiod muscle, which supports the floor of the mouth. |
ramus of the mandible | is the ascending part that begins at the mandibular angle on either side. |
condylar process | articulates with the temporal bone at the temporomandibular joint. |
coronoid process | insertion point for the temporalis muscle, a powerful muscle that closes the jaws. |
mandibular notch | is the depression that separates the condylar and coronoid processes. |
mental foramina | are openings for nerves that carry sensory information from the lips and chin to the brain. |
mandibular foramen | entrance to the mandibular canal, a passageway for blood vssels and nerves that service the lower teeth. |
hyoid bone | supports the larynx and is the attachment site for muscles of the larynx, tongue, and pharynx. |
stylohyoid ligaments | connect the lesser horns to the styloid processes of the temporal bones. |
body of the hyoid | attachment site for muscles of the larynx, tongue, pharynx. |
greater horns | greater cornua, help support the larynx and are attached to muscles that move the tongue. |
lesser horns | lesser cornua, are attached to the stylohyoid ligaments; from these ligaments; |
TMJ syndrome or myofacial pain syndrome | the mandible is pulled slightly out of alignment, generally by spasms in one of the jaw muscles. |
orbits | bony recesses that contain eyes |
orbital complex | seven bones of each orbit. |
nasal complex | includes the bones that enclose the nasal cavities and the paranasal sinuses |
paranasal sinuses | air filled chambers connected to the nasal cavities. |
fontanels | the largest fibrous areas between the cranial bones |
vertebral column | consist of 26 bones |
vertebra | 24 |
sacrum | a bone |
coccyx | tailbone |
cervical vertebrae | constitute the neck and extend inferiorly to the trunk |
thoracic vertebrae | 12, form superior portion of the back |
lumbar vertebrae | 5, form inferior portion of the back. |
primary curves | thoracic and sacral curves that form a C shape |
accomodation curves | appear in late fetal development they accomodate on the thoracic and abdominopelvic area. |
secondary curves | do not appear until several months after birth. |
compensation curves | secondary curves, help shift the weight to permit an upright posture. |
vertebral body | centrum, is the part of the vertebra that transfers weight along the axis of the vertebral column. |
intervertebral disks | pads of fibrocartilage. |
vertebral arch | forms the posterior margin of each vertebral foramen |
pedicles | walls of the vertebral arch |
laminae | flat layers |
vertebral canal | encloses the spinal cord |
spinous process | projects posteiorly from the point where the vertebral laminae fuse to complete the vertebral arch. |
transverse processes | project laterally or dorsolaterally on both sides from the point where the laminae join the pedicles. |
articular processes | arise at the junction between the pedicles and the laminae. |
superior and inferior articular process | lie on each side of the vertebra |
articular facet | smooth concave surface each articular process has. |
intervertebral foramina | gaps that permit the passage of nerves running to or from the enclosed spinal cord. |
costal processes | originate near the ventrolateral portion of the vertebral body. |
bifid | notched spinous process. |
transverse foramina | surrounded by costal and transverse processes encircle prominent. These passageways to protect the vertebral arteries and vertabral veins. |
whiplash | used to describe such an injury, because the movement of the head resembles the cracking of a whip. |
Atlas | cervical vertebra C1, holds up the head, articulating with the occipital condyles of the skull. |
anterior and posterior arches | bound the large round vertebral foramen |
axis | fuse with atlas C2 |
dens | fusion process |
vertebra prominens | seventh cervical vertebra |
ligamentum nuchae | stout elsatic ligament, begins at the vertebra prominens and extends to an isertion along the occipital crest of the skull. |
costal facets | on the vertebral bodies articulate with the heads of the ribs. |
transverse costal facets | for rib articulation |
sacral canal | passageway that begins between these articular processes and extends the length of the sacrum. |
median sacral crest | ridge formed by the fused spinous processes of the sacral vertebrae |
sacral cornua | Laminae of the fifth sacral vertebra fail to contact one another at the midline |
sacral hiatus | the opening at the inferior end of the sacral canal. |
sacral foramina | four pairs crest that open on either side of the median sacral crest. |
lateral sacral crest | on each side is a ridge that represents the fused transverse processes of sacral vertebrae. |
auricular surface | thickened, flattened area lateral and anterior to the superior portion of the lateral sacral crest. |
sacral tuberosity | roughened area between the lateral sacral crest and the auricular surface. |
apex | inferior portion of the sacrum |
base | the superior portion. |
sacral promontory | promineny buldge at the anterior tip of the base; important landmark for females during pelvic examinations and during labor and delivery. |
ala or wing | extends on either side |
coccygeal cornua | first coccygeal vertebrae. |
thoracic cage | skeleton of the chest. |
true ribs | vertebrosternal ribs |
costal cartilages | catilaginous extensions. |
false ribs | ribs 8 - 17 |
head | capitulum vertebral end. |
tubercle | tuberculum a small elevation that projects dorsally. |
tubercular body | shaft |
sternum | breastbone |
manubrium | articulated with thw clavicles (collarbone) and the cartilages of the first pair of ribs. |
jugular notch | located between the clavicular articulations, is a shallow indentation on the superior aurface of the manubrium. |
body attached to the tongue shaped sternum | attaches to the inferior surface of the manubrium and extends inferiorly along the midline. |
xiphoid process | the smallest part of the sternum, is attached to the inferior surface of the body. The muscular diaphragm and rectus abdominis muscles attach to the xiphoid process. |