A&P Chapter 7: Axial Skeleton
The thoracic cage includes ____ pairs of ribs and the sternum
12
The smooth ridge located immediately anterior of the mandibular fossa
articular tubercle
A zig-zag shaped tunnel that provides passage through the base of the skull for one of the major arteries that supplies the brain
carotid canal
The ____ _____ of the sutures allows for continued growth of the skull bones as the brain enlarges during childhood growth
connective tissue
Another name for brain case
cranial vault
Allows for passage of the spinal cord as it exists the skull
foramen magnum
The point of emergence for a sensory nerve that supplies the anterior face below the orbit
infraorbital foramen
This opening is located inside the cranial cavity, on the medial side of the petrous ridge. It connects to the middle and inner ear cavities of the temporal bone.
internal acoustic meatus
Supports the skull and prevents it from falling forward
nuchal ligament
-Consists of a softer, more gel like material -Serves to resist compression and thus is important for weight bearing
nucleus pulposus
Each _____ bone is also bounded anteriorly by the frontal bone, inferiorly by the temporal bone, and posteriorly by the occipital bone
parietal
Contains the cerebellum of the brain
posterior cranial fossa
The ribs are located _______ to the 12 thoracic vertebrae
posteriorly
The thoracic curve and sacrococcygeal curve are _____ curves
primary
A small, capital H shaped suture line that unites the frontal bone, parietal bone, squamous portion of the temporal bone, and greater wing of the sphenoid bone; weakest part of the skull
pterion
Has facets and costal facets
thoracic
The walls of each orbit include contributions from ___ skull bones
7
A single, midline bone that form the roof and lateral walls of the upper nasal cavity, the upper portion of the nasal septum, and contributes to the medial wall of the orbit
ethmoid bone
This is the large opening on the lateral side of the skull that is associated with the ear
external acoustic meatus
Largest region of each of the palatine bones
horizontal plate
Provide passage for an important nerve to the tongue
hypoglossal canal
This opening is located on the medial side of the ramus of the mandible. The opening leads into a tunnel that runs down the length of the mandibular body. The sensory nerve and blood vessels that supply the lower teeth enter the mandibular foramen and then follow this tunnel.
mandibular foramen
A triangular-shaped bone that is thick and wide across its superior base where it is weight bearing and then tapers down to an inferior, non-weight bearing apex
sacrum
The frontal bone forms the ______ _____ of the orbit
supraorbital margin
Ribs 1-7
true ribs
The skull is formed by _____ bones
22
The vertebral column consists of _____ bones
24
Intervertebral dics account for _____ percent of your body height between the top of the pelvis and the base of the skull
25
How many bones make up the ear ossicles?
3
Ribs __-__ attach to the sternal body
3-7
How many bones make up the hyoid bone?
7
The brain case consists of ____ bones
8
The axial skeleton of the adult consists of ____ bones
80
The______ vertebra does not have a body or spinous process
C1
The outside margin of the mandible, where the body and ramus come together is called the _____ __ ____ _____
angle of the mandible
Serves to resist excess backward bending of the vertebral column
anterior longitudinal ligament
Bending forward causes compression on the _____ portion of the disc but expansion of the ______ disc
anterior, posterior
The tough, fibrous outer layer of the disc
anulus fibrosus
The transverse process of the _______ are longer and extend more laterally than do the transverse processes of any other cervical vertebrae
atlas
Forms the vertical, central axis of the body and includes all bones of the head, neck, chest, and back
axial skeleton
The _____ is easily distinguished by the dens, a bony projection that extends upward from the vertebral body
axis
A complex area that varies in depth and has numerous openings for the passage of cranial nerves, blood vessels, and the spinal cord
base of the skull
The ______ is the anterior portion of each vertebra and is the part that supports the body weight
body
-Have a small body (carry the least amount of weight) -Usually have a bifid (Y-shaped) spinous process -Transverse processes are sharply curved (U-shaped) to allow for passage of the cervical spinal nerves -The superior and inferior articular processes are flattened and largely face upward or downward, respectively
cervical vertebrae
Not weight bearing in standing position, but may receive some body weight when sitting
coccyx
Joins the frontal bone to the right and left parietal bone
coronal suture
The interior space that is almost completely occupied by the brain is called the ____ ____
cranial cavity
The shape of each conforms to the shape of the brain regions that it contains
cranial fossae
Small, nerve branches from the olfactory areas of the nasal cavity pass through these openings to enter the brain
cribriform plate
Functions as an anterior attachment point for one of the covering layers of the brain
crista galli
Serves as an attachment site for a ligament of the posterior neck
external occipital protuberance
Ribs 8-12
false ribs
Ribs 11 and 12
floating ribs
This irregular opening is located in the base of the skull, immediately inferior to the exit of the carotid canal. This opening is an artifact of the dry skull, because in life it is completely filled with cartilage. The word "lacerum" tells us that this opening has ragged edges and thus nothing passes through it.
foramen lacerum
This large, oval-shaped opening in the floor of the middle cranial fossa provides passage for a major sensory nerve to the lateral head, cheek, chin, and lower teeth
foramen ovale
This rounded opening is located in the floor of the middle cranial fossa, just inferior to the superior orbital fissure. It is the exit point for a major sensor nerve that supplies the cheek, nose and upper teeth
foramen rotundum
This small opening, located posterior-lateral to the foramen ovale, is the entry point for an important artery that supplies the covering layers surrounding the brain. The branching pattern of the artery forms readily visible grooves on the internal surface of the skull and these grooves can be traced back to their origin at the foramen spinosum.
foramen spinosum
Slight depression in the frontal bone
glabella
-An independent bone that does not contact any other bone and is thus not apart of the skull -Movements coordinate with the movements of the tongue, larynx, and pharynx during swallowing and speaking
hyoid bone
A fibrocartilaginous pad that fills the gap between adjacent vertebral bodies
intervertebral disc
The bodies of adjacent vertebrae are strongly anchored to each other by an _____ ____
intervertebral disc
Several cranial nerves from the brain exit the skull via this opening
jugular furamen
Joins the occipital bone to the right and left parietal and temporal bones
lambdoid suture
Fused transverse processes of the sacral vertebrae
lateral sacral crest
The strong connective tissue bands that hold the bones at a moveable joint together and serve to prevent excessive movements from the joint that would result in injury
ligament
These serve to resist excess forward or backward bending movements of the vertebral column
ligaments
-Short transverse processes -Short- blunt spinous process -Large articular processes
lumbar
Carry the greatest amount of body weight and are thus characterized by the large size and thickness of the body
lumbar
Which is the only moveable bone of the skull?
mandible
This is the deep, oval-shaped depression located on the external base of the skull, just in front of the acoustic meatus. The mandible joins with the skull at this site as part of the temporomandibular joint, which allows for movements of the mandible during opening and closing of the mouth.
mandibular fossa
Serves as a muscle attachment site for the skull
mastoid process
Remnats of the fused spinous processes
median sacral crest
The opening located on each side of the anterior-lateral mandible, which is the exit site for a sensory nerve that supplies the chin
mental foramen
The forward projection from the inferior margin of the anterior mandible that forms the chin
mental protuberance
Has a butterfly shape
middle cranial fossa
Each side of the ______ cavity is triangular in shape, with a broad inferior space that narrows superiorly
nasal
Serve to swirl the incoming air, which helps to warm and moisturize it before the air moves into the delicate air sacs of the lungs. Also allows mucus to trap incoming dust, pollen, bacteria, and viruses.
nasal conchae
The lacrimal fluid ( tears) serves to maintain the moist surface of the eye and drains at the medial corner of the eye into the _________ canal
nasolacrimal canal
Condyles that form joints with the first cervical vertebra and thus supporting the skull on top of the vertebral column
occipital condyle
One of a pair of irregularly shaped bones that contribute small areas to the lateral walls of the nasal cavity and the medial wall of each orbit
palatine bone
-Hollow, air-filled spaces located within certain bones of the skull -Reduce bone mass and thus lighten the skull, and they also add resonance to the voice
paranasal sinuses
Located inside the _____ _____ are small cavities that house the structures of the middle and inner ears
petrous ridge
Unites the right and left parietal bones
sagittal suture
Widespread pain that radiates from the lower back down the thigh and into the leg
sciatica
The cervical curve and the lumbar curve are _____ curves
secondary
Serves as a "keystone" bone because it joints with almost every other bone of the skull
sphenoid bone
Unites the squamous portion of the temporal bone with the parietal bone
squamous suture
This structure serves as an attachment site for several small muscles and for a ligament that supports the hyoid bone of the neck
styloid process
Located between the mastoid and styloid process. The point of exit for the cranial nerve that supplies the facial muscles
stylomastoid foramen
These junctions form slightly moveable joints between the adjacent vertebrae
superior and inferior articular processes
Represents the most superior point at which muscles of the neck attach to the skull
superior nochal line
This large, irregular opening into the posterior orbit is located on the anterior wall of the middle cranial fossae, lateral to the optic canal, and under the projecting margin of the lesser wing of the sphenoid bone. Nerves to eyeball and associated muscles, and sensory nerves to the forehead pass through this opening.
superior orbital fissure
Provides passage of a sensory nerve to the skin of the forehead
supraorbital foramen
Supports the vertebral column during forward bending motions
supraspinous ligament
An immobile joint between adjacent bones of the skull
suture
Both the _______ ____ and _____ _____ contain muscles that act on the mandible during chewing
temporal fossa, infratemporal fossa
Attaches muscle to bone
tendon
Each _____ is anchored into a deep socket called an alveolus
tooth
The ligament flavum has large numbers of elastic fibers, which have a ________ color, allowing it to stretch and then pull back
yellowish
One of the major muscles that pulls the mandible upward during biting and chewing arises from the _____ _____
zygomatic arch