Exam 2 Anatomy 261 IUPUI

The axial skeleton contains

skull, vertebral column, bony thorax

Mostly flat bones are connected by

sutures

The cranium is divided into 2 major areas:

cranial vault and cranial base (or floor)

cranial vault

roof of the skull

cranial base or floor

skulls inferior aspect

22 bones of the skull

8 cranial and 14 facial

Glabella

Smooth area between the eyes

supraorbital foramen (notch)

opening above each orbit allowing blood vessels and nerves to pass

foramen magnum

A large opening at the base of the skull through which the brain connects to the spinal cord.

occipital condyles

facets on the base of the skull, which articulate with the superior facets of the C1 atlas. allows you to nod your head yes.

hypoglossal canal

passageway for hypoglossal nerve (XII)

external occipital crest and protuberance

midline prominences posterior to foramen magnum; the crest extends posteriorly from the foramen magnum, ending in the protuberance (a small midline bump)

squamous region of temporal bone

lateral surface bordering the squamous suture

squama

The convex external surface of the squamous region.

cerebral surface

the concave internal surface, whose curvature parallels the surface of the brain

zygomatic process of temporal bone

inferior to the squamous portion, articulates with temporal process of zygomatic bone, forms zygomatic arch (cheekbone)

tympanic region of temporal bone

surrounds the external acoustic meatus

styloid process

needlelike projection inferior to external acoustic meatus; attachment point for muscles and ligaments of the neck

mastoid region

posterior to ear, contains mastoid process

mastoid process of temporal bone

a rough projection, anchors some neck muscles that rotate and extend the head

petrous region of temporal bone

largest portion of the temporal bone, contributes to the cranial base and forms the lateral region of the skull base

jugular foramen

passage for internal jugular vein, cranial nerves IX (glossopharyngeal), X (vagus), XI (accessory)

internal acoustic meatus

lies in the cranial cavity on the posterior face of the petrous region; transmits cranial nerves VII and VIII

greater wing of sphenoid

bone immediately anterior to the temporal bone - appears to be 2 bones, one on each side of skull, is actually single bone extending across skull. forms a portion of the orbits of the eyes.

lesser wing of sphenoid bone

bat shaped anterior to sella turcica

sella turcica

pituitary gland sits here

posterior clinoid process

Extends laterally on either side of the dorsum sellae.

optic canal

openings at either end of the optic groove

superior orbital fissure

long slit between greater and lesser wings. transmits CN III,IV, and VI

foramen rotundum

lateral to the Sella turcica. passage for branch of CN V

foramen ovale

posterior to Sella turcica. passage for branch of CN V

foramen spinosum

inferior aspect. transmits the middle meningeal artery.

cribiform plate of ethmoid bone

roof of nasal cavity

olefactory foramina

transmits olfactory fibers of CN I. sense of smell

crista galli

tip of iceberg. superior projection in the middle of the cribriform plate of the ethmoid bone. helps secure the brain within the cranial cavity.

Ethmodial Labyrinths

interconnected network of ethmoidal air cells

inferior nasal conchae

bone on its own. protrude medially from the lateral walls of the nasal cavity

superior and middle nasal conchae

Thin scrolls of bony structures that contribute to the conchae of the nasal cavity on either side of the perpendicular plate.

perpendicular plate

forms superior part of nasal septum

coronal suture

the suture between the parietal and frontal bones of the skull

squamous suture

Between parietal and temporal bones

saggital suture

suture between parietal bones

lambdoid suture

between parietal bones and occipital bone

frontonasal suture

boundary between the superior aspects of the two nasal bones and the frontal bone

occipitomastoid suture

connects occipital and temporal bones

mandibular body

Horizontal portion that supports the teeth

rami of mandible

ascending portions from each side of the body

condylar processes

posterior processes that enlarge superiorly to form the mandibular condyles

coronoid processes

jutting anterior portion of each ramus; site of temporalis muscle attachment

mandibular notch

depression that lies between the condylar and coronoid processes

mental foramina

prominent openings lateral to the midline, penetrating the body on each side; passageway for mental blood vessels and nerve that serve the lower jaw

all facial bones, except for the _____ articulate with the maxillae

mandible

frontal process

forms part of the lateral aspect of the bridge of the nose. articulates with the frontal bone and the nasal bones

inferior orbital fissure

elongated opening within each orbit, formed by the maxillae and the sphenoid

superior orbital fissure

Elongated opening in the upper lateral part of the orbit between the greater and lesser wings of the sphenoid.

infraorbital foramen

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

zygomatic bones

form the cheekbones and part of the lateral rims of the orbits

horizontal plate of palatine bone

forms posterior part of hard palate. articulate with the maxillae

sinuses are only present in the

skull

only bone that does not articulate with another bone

hyoid

hyoid

its body and horns are attachment points for tongue and neck muscles that raise and lower the larynx for swallowing.

Greater horn

larger process on the hyoid

lesser horn

connected to the stylohyoid ligaments. act like a swing from the limb of a tree.

vertebral column functions

-Protect the spinal cord

-Support the head

-Serve as a point of attachment for the ribs, pelvic girdle, and muscles

consists of 26 irregular bones.

7 cervical

12 thoracic

5 lumbar

1 sacral

1 coccyx

vertebral column

convex curve

a curve that extends outward or in relation to the body, posteriorly.

example-a ball

concave curve

The back inward curve of a lens, and sometimes the front curve in extremely high minus lenses

intervertebral discs

fibrocartilage pads that separate and cushion the vertebrae. prevent bone to bone contact. adds height to an individual. absorb shock

vertebral arch

formed by 2 pedicles and 2 laminae

pedicles

"little feet" the sides of the arch, which are short bony walls that project posteriorly from the vertebral body

laminae

roof of the vertebral arch

vertebral foramen

canal through which spinal cord passes

spinous process

median posterior projection from the vertebral arch

transverse process

project laterally from each pedicle-lamina junction

superior articular process

form movable joints with inferior articular processes of vertebrae located immediately superior to it. typically face inward to spinous process

inferior articular process

form movable joints with superior articular processes of vertebrae located immediately inferior to it. typically face away from spinous process.

intervertebral foramen

Opening formed by the inferior and superior notches on the pedicles of adjacent vertebrae. Allows passage of spinal nerves and vessels.

Cervical Vertebrae (C1-C7)

small and wide. short bifid processes projects directly posteriorly. increases in size. transverse processes with transverse foramina- vertebral artery and vein

Atlas (C1)

contains no body and no spinous process. ring of bone consisting of anterior and posterior arches.

articular facet

do not extend beyond arches.

occipital condyles

allows flexion and extension of the head and neck. allows you to nod yes.

Axis (C2)

contains a body and a spinous process. dens project superiorly from its body, fuses with the atlas during development. acts as a pivot for the rotation. allows head to shake no.

no intervertebral disc between

C1 and C2

thoracic vertebrae

larger and heart shaped. bears 2 costal demi facets. long sharp spinous process projects inferiorly.

lumbar vertebrae

massive kidney shaped. makes up the back, largest

sacrum

small of back, formed by 5 fused vertebrae.

Coccyx

tailbone, 4 fused vertebrae

bony thorax (thoracic cage)

composed of the thoracic vertebrae dorsally, the ribs laterally, and the sternum and costal cartilages anteriorly. protects heart, lungs, and other thoracic organs

xiphoid process

inferior end of sternum

Ribs

12 pairs that help to protect your vital organs. Attached to vertebrae. true, false, and floating.

true ribs

first 7 pairs of ribs; attach directly to sternum

false ribs

last 5 pairs of ribs; attach indirectly to sternum

floating ribs

last two pairs of ribs; do not attach to sternum

head (wedge shaped)

articulates with vertebral bodies at 2 facets

neck

short, constricted region just lateral to the head

Tubercle

knob like projection just lateral to the neck on the posterior side.

Pectoral Girdle contains

scapula and clavicle bones

Clavicle

ice cream cone shaped. the collar bone, a slender bone that connects the manubrium of the sternum to the scapula

sternal end of clavicle

articulates with the manubrium of the sternum

acromial end of clavicle

flattened, lateral end. articulates with scapula