Human Anatomy Exam 2

chapter 6

The axial system contains of how many bones forms what part of the body what does it support and protect

80 bones, forms the long axis of the body, supports the head neck and trunk, and protects the brain, spinal cord and thoracic organs

What are the 3 major regions in the axial system

1. the skull

2. vertebral column

3. bony thorax

What is the skull formed by?

cranial (cranium) and facial bones 

What is the most complex bony structure of the skeleton 

The skull

What are most flat bones connected by?

sutures

What is the Cranial Vault (calvarium)

Skull cap or roof of skull

There are 85 named openings commonly called what?

Foramina (singular foramen) canals or fissures sometimes lacerum

How many bones comprise the skull?

22 bones 8 cranial bones form the cranium 14 create the facial bones comprise the rest

What forms the forehead and the roofs of the orbits

Frontal bone

Glabella is what?

smooth part in the midline of frontal bone between the superciliary arches, which support the eyebrows

Supraorbital margins mark what?

superior limits of the orbits, the bony recesses that

support and protect the eyeballs

Supruorbital foramen do what?

opening above each orbit, which transmit the supraorbital artery and nerve

Lacrimal fossa marks what?

marks the location of the lacrimal (tear) gland that lubricates the

surface of the eye

Parietal bones located where? And what are they

Parietal bones are pair of curved rectangular bones

1. Located posterolateral to the frontal bone, forming the sides of the cranium

2. Superior and inferior temporal lines: low ridges on the external surface of each bone, marking the attachment of the temporalis muscle (closes the mouth)

3. Parietal eminence: the smooth parietal surface superior to the temporal lines

4. Four of the major sutures are associated with the parietal bones, at which they articulate with other cranial bones

How many cranial bones?

8

OCCIPITAL BONE is where?

most posterior of the cranial bone

What forms the floor and back wall of the skull?

Occipital bone

what is FORAMEN MAGNUM

hole in the base of occipital bone through which spinal cord

passes and is connected to the brain

OCCIPITAL CONDYLES

facets on the base of the skull, which articulate with the

superior facets of the C, (ATLAS) vertebra (plural = vertebrae)

Hypoglossal canals

passageway for hypoglossal cranial nerve XII; begin at the

lateral base of each occipital condyle

Basioccipital

a band of bone anterior to the foramen magnum, which is the point of

articulation between the occipital bone and the sphenoid

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)

Superior and inferior nuchal lines

horizontal ridges that intersect the external occipital crest; these lines mark the attachment of muscles and ligaments that stabilize the articulation between the first vertebra, C, and the occipital condyles

TEMPORAL BONES is where?

inferior to parietal bones on lateral skull

How many majors are there in the temporal bones? and what are there

4 squamous, tympanic, mastoid, and petrous

SQUAMOUS region

the lateral surface bordering the squamous sulure SQUAMA: the convex external surface of the region

CEREBRAL SURFACE

the concave internal surface, whose curvature parallels

the surface of the brain

ZYGOMATIC PROCESS

the inferior margin of the region, which curves

laterally and anteriorly to meet the temporal process of the zygomatic bone;

together, they form the zygomatic arch (or cheekbone), which defines the

projection of the cheek

The squamous region abuts what bone?

The parietal bone on each side

TYMPANIC region

surrounds the external acoustic meats (or external

auditory canal), immediately posterior and lateral to the mandibular fossa

styloid process marks what?

attachment site for ligaments that support the hyoid

bone and for muscles of the tongue, pharynx, and larynx which is part of the “petrous region”

MASTOID region

"breast-shaped' area posterior to the ear “incorporated with the petrous region”

PETROUS region

the most massive portion of the temporal bone

contributes to the cranial base and forms the lateral region of the skull base

The petrous region contains the JUGULAR FORAMEN, which is the?

passageway through which the internal

jugular vein (largest vein of the head) and cranial nerves IX, X, and XI pass

The petrous region contains the CAROTID CANAL, which does what?

opens in this region on the skull's inferior aspect, just

anterior to the jugular foramen; passageway for internal carotid artery

The petrous region contains the FORAMEN LACERUM, which does?

jagged opening between the medial tip of the petrous

portion of the temporal bone and the sphenoid bone; almost completely closed by

cartilage in a living person, but conspicuous in a dried skull

The petrous region contains the INTERNAL ACOUSTIC MEATUS, which does?

lies in the cranial cavity on the posterior

face of the petrous region; transmits cranial nerves VII and VITI

SPHENOID

"bat-shaped" bone

1.Forms the anterior plateau of the middle cranial fossa

2. Spans the width of the cranial floor

SPHENOID BODY PROCESSES How many?

3

SPHENOID BODY PROCESSES GREATER WINGS what does it do?

visible exteriorly anterior to temporal; form a portion of the

orbits of the eyes

SPHENOID BODY PROCESSES LESSER WINGS what does it do?

bat-shaped portions located anterior to the sella turcica

SPHENOID BODY PROCESSES PTERYGOID PROCESSES what does it do? 

vertical projections that begin at the boundary

between the greater and lesser wings

1.Contain attachment sites for pterygoid muscles that move the lower jaw and

soft palate

SELLA TURCICA where is it located?

on the superior surface of the body

What does sella turcica contain?

Contains the hypophyseal fossa, which holds the pituitary gland (hypophysis)

ANTERIOR CLINOID PROCESSES

located on either side of the sella turcica are these posterior projections of the lesser wings of the sphenoid

TUBERCULUM SELLAE

forms the anterior border of the sella turcica

DORSUM SELLAE

forms the posterior border

POSTERIOR CLINOID PROCESSES

PROCESSES: extend laterally on either side of the

dorsum sellae

OPTIC GROOVE

transverse groove that crosses to the front of the saddle, above

the seat

OPTIC CANAL

openings at either end of the optic groove

How many important openings of the sphenoid and what are they?

5, Optic foramen, superior orbital fissure, foramen rotundum, foramen ovale, and foramen spinosum

OPTIC FORAMEN

 anterior to sella turcica 

CN Il passes through from the orbit into the cranial cavity

SUPERIOR ORBITAL FISSURE

long slit between the greater and lesser wings

Transmits CN III, IV and VI (control eye movement)

FORAMEN ROTUNDUM

lateral to sella turcica

Passage for a branch of CN V

FORAMEN OVALE

posterior to sella turcica

Passage for a branch of CN V

FORAMEN SPINOSUM

inferior aspect

Transmits the middle meningeal artery, which supplies the broad inner

surfaces of the parietal and temporal bones

what is ETHMOID BONE

irregularly shaped bone

Forms part of the orbital wall, the anteromedial floor of the cranium, the roof of the

nasal cavity, and part of the nasal septum

3 major parts to the ethmoid bone are what?

CRIBRIFORM PLATES, ETHMOIDAL LABYRINTH, and PERPENDICULAR PLATE

CRIBRIFORM PLATES

contributes to roof of nasal cavities and floor of

anterior cranial fossa

ETHMOIDAL LABYRINTH

an interconnected network of ethmoidal air cells

PERPENDICULAR PLATE

forms superior part of NASAL SEPTUM

CORONAL SUTURE

where the parietal bones articulate with the frontal bone

SOUAMOUS SUTURE

where the parietal bones articulate with the temporal bones

inferiorly

SAGITTAL SUTURE

where right and left parietal bones meet

LAMBDOID SUTURE

where the parietal bones articulate with occipital bone

How many facial bones?

14

MANDIBULAR BODY

horizontal portion that supports the teeth

RAMI of the MANDIBLE

ascending portions from each side of the body

MANDIBULAR ANGLES

where each ramus meets the body

ALVEOLAR MARGIN or PART

thickened area that contains the alveoli

and the roots of the teeth

CONDYLAR PROCESSES

posterior processes that enlarge superiorly to form the mandibular condyles, which articulate with mandibular fossae of the temporal bones to form the temporomandibular joint

CORONOID PROCESSES

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

MANDIBULAR NOTCH

the 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

MYLOHYOID LINE OF MANDIBLE

lies on the medial aspect of the body, marking the origin of the mylohyoid muscle

SUBMANDIBULAR FOSSA

a depression inferior to the mylohyoid line, in which the submandibular branch of CN V (for tooth sensation)

MAXILLARY BONES or MAXILLAE

The largest facial bones that form the upper jaw and central par of facial skeleton

All facial bones except what? articulate with the maxillae

the mandible

PALATINE PROCESSES

form anterior part of the hard palate (bony roof of the mouth)

FRONTAL PROCESSES

lateral aspect of the bridge of the nose; articulates with the

frontal bone and the nasal bones

ZYGOMATIC PROCESSES

articulate with zygomatic bones

INFERIOR ORBITAL FISSURE

elongated opening within each orbit, formed by

the maxillae and the sphenoid

INFRAORBITAL FORAMEN

opening under each orbit, in the orbital rim; passageway for infraorbital nerves and vessels that serve the nasal region

ALVEOLAR MARGINS or PROCESSES

the oral margins of the maxillae, which contain the upper teeth

TEMPORAL PROCESS

articulates with zygomatic process of the temporal bone lo

form the zygomatic arch

ZYGOMATICOFACIAL FORAMEN

located on the anterior surface of each zygomatic bone; transmits a sensory nerve innervating the check

Small, rectangular bones forming the bridge of the nose

Nasal bone 

Articulates with the frontal bone at the frontonasal suture

nasal bone

Delicate, finger-nail shaped bones

lacrimal bones

LACRIMAL GROOVE (or LACRIMAL SULCUS)

SULCUS): a shallow depression that leads to a narrow passageway, called the nasolacrimal canal

NASOLACRIMAL CANAL

formed by the lacrimal bone and the maxilla

PALATINE BONES

Small, L-shaped bones

HORIZONTAL PLATES

posterior part of hard palate; articulate with the maxillae

PERPENDICULAR PLATES

(vertical portion of the "L" shape of the bone)

posterior part of the lateral walls of the nasal cavity and small part of the orbits

ETHMOIDAL CREST

ridge on the medial surface, marking the articulation

with the middle nasal concha of the ethmoid

NASAL CREST

a ridge that forms where the right and left palatine bones interconnect, marking the articulation with the vomer

VOMER

Slender, plow-shaped bone in the medial plane of the nasal cavity

INFERIOR NASAL CONCHAE

Thin, curved (scroll-like) bones protruding medially from the lateral walls of the nasal

cavity

ORBITS (or ORBITAL COMPLEXES) of the eyes do what?

1. Enclose and protect the eyes

2. Comprised of parts of 7 bones of the skull

Air- filled chambers that act as extensions of and open into the nasal cavities

PARANASAL SINUSES