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