Ch. 7 - The Axial Skeleton Flashcards
What are the 5 basic types of bones?
long, short, flat, irregular, sesamoid
What are sutures?
jointed areas where flat bones come together
What are the 2 major types of bone surface markings?
- depressions and openings: passageway for soft tissues (BV, nerves) and form joints
- processes: outgrowths that are attachments for CT (tendons, ligaments), form joints
What is a fissure?
narrow slit bt bones for passage of BV or nerves
What is a foramen?
hole for passage of BV, nerves, ligaments
What is a fossa?
shallow depression
What is a sulcus?
furrow on bone for passage of BV, nerve, tendon
What is a meatus?
tube-like opening
What is a condyle? What is an epicondyle?
rounded projection with a smooth articular surface; roughened projection on a condyle (for attachment)
What is a facet?
smooth, flat, slightly concave articular surface
What is the head? (bone surface marking)
head - rounded a. process supported on a neck
What is the difference between a crest and a line?
prominent ridge/elongated process; line is long and narrower ridge (less prominent)
What is a spinous process?
sharp, slender, projection
What is a trochanter and where is it found?
large projection found only on femur
What is a tubercle?
variably sized rounded projection
What is a tuberosity?
variably sized projection with rough, bumpy surface
What does the axial skeleton comprise of?
skull bones, auditory ossicles, hyoid bone, ribs, sternum, vertebrae, sacrum
What does the appendicular skeleton comprise of?
bones of upper & lower limbs, bones forming pectoral and pelvic girdles
What are the 8 cranial bones?
frontal parietal (2) temporal (2) occipital sphenoid ethmoid
What does the frontal bone form?
frontal squama (forehead), roof of orbits, anterior cranial floor, supraorbital margin (browline), frontal sinus
How does a black eye occur?
can result from accumulation of fluid and blood in upper eyelid following a sharp blow to browline
What do the parietal bones form?
sides and roof of cranial cavity
What do the temporal bones form?
inferior and lateral walls of cranium, part of cranial floor, temporal squama (temples), zygomatic process, external auditory meatus, mastoid process, styloid process, mandibular fossa, articular tubercle
What are the mastoid and styloid processes?
M - attachment point for neck muscles
S - attachment point for muscles and ligaments of the tongue
What are specific markings on the occipital bone?
foramen magnum (where medulla oblongata connects with spinal cord)
occipital condyles (articulates with atlas)
external occipital protuberance
superior and inferior nuchal lines
What does the sphenoid bone form?
parts of floor and walls of orbits; holds all cranial bones together
What does the sphenoid bone comprise of?
greater wings, lesser wings, body
What is lateral to the body of the sphenoid bone?
pterygoid processes; form posterior part of nasal cavity, provide attachment points for some muscles that move mandible
What is the optic foramina?
in sphenoid bone, located inferior to lesser wings and lateral to body; where optic nerve passes
Where is the pituitary gland located?
hypophyseal fossa, in sella turcica of sphenoid bone
What does the ethmoid bone support and form?
major support and component of nasal cavity; forms part of anterior cranial floor and medial wall of orbits
What are 4 special surface markings on the ethmoid bone?
cribriform plate, crista galli, perpendicular plate, nasal conchae
What is the function of the nasal conchae?
increase vascular and mucous membrane SA; warms and moistens air; causes air to swirl
What are the 3 ossicles?
incus, malleus, stapes
Which facial bones are paired?
nasal, lacrimal, palatine, interior nasal concha, maxillae, zygomatic
What are the smallest facial bones? What does it contain?
lacrimal; each contain a lacrimal fossa that houses a lacrimal sac
lacrimal sac gathers tears from eyeball and passes them into nasal cavity
What is distinct about the interior nasal concha? How does it differ from the other 2 conchae?
it is a separate bone; superior and middle conchae are part of ethmoid bone
What do the maxillary bones form? What do they contain?
upper jawbone; each bone contains large maxillary sinus
Which bones articulate with every facial bone except the mandible?
maxillary bones
What do the zygomatic bones form?
cheekbones
What forms the zygomatic arch?
temporal process of zygomatic bones articulating with the zygomatic process of the temporal bone
What do alveolar processes hold?
upper and lower teeth
What is distinct about the mandible? (lower jawbone)
largest & strongest facial bone; only moveable skull bone
What does the nasal septum comprise of? What does it do?
perpendicular plate of ethmoid bone, septal cartilage, vomer; divides nasal cavity into L and R
Which bones compose the orbits?
frontal, sphenoid, ethmoid, zygomatic, maxilla, palatine, lacrimal
What are sutures?
immobile joint that holds skull bones together
What are the 4 main sutures and what do they respectively unite?
- coronal - frontal and both parietal
- squamous - parietal and temporal
- sagittal - 2 parietal bones
- lambdoid - parietal and occipital
Which bones contain sinuses? What are these sinuses lined by?
frontal, sphenoid, ethmoid, maxillae’ mucous membranes
What are the functions of paranasal sinuses?
- decrease skull weight
- resonating chambers for speech
- increase SA of nasal mucosa
What are fontanels?
areas where unossified mesenchyme develop into dense irregular CT; fill gaps bt cranial bones
What do the soft spots in fontanels allow?
allow fetal skull to change shape as it passes through birth canal; rapid growth of brain during infancy
How and when do fontanels close?
intramembranous ossification by 2 yo
What are the 4 major fontanels?
anterior, posterior, anterolateral, posterolateral
What are the 5 regions of the vertebrae?
Cervical, thoracic, lumbar, sacrum, coccyx
Which regions of the vertebral column are convex and concave?
Convex - cervical, lumbar
Concave - thoracic, sacral
What are intervertebral discs made of?
fibrocartilagenous ring filled with soft elastic material
- sup and inf surfaces are hyaline cartilage
What are symptoms of a herniated disc?
- shooting, tingling nerve pain
- loss of sensation
- affected moving/strength
Describe the vertebral body and arch
together form the vertebral foramen
body: located anteriorly; below and above interV discs
arch: located posteriorly; consists of pedicles and laminae
What does the spinal canal contain?
spinal cord, adipose tissue, areolar CT, BV
What are the 7 vertebral processes and what do they form?
spinous, transverse (2), superior articular process (2), inferior articular process (2)
- form joints or sites for musc. attachment
What are intervertebral joints?
2 sup art processes articulate with 2 inf art processes of the superior vertebra; articulate at facets of processes
What are some characteristics of cervical vertebrae?
- smaller body
- 3 foramina (1 vert, 2 transverse); largest vertebral foramina
- split spinous process
- thick interV discs
What are some characteristics of thoracic vertebrae?
- larger body; large trans/spin processes
- 1 vert foramen
- coastal facets on body to attach to ribs (vertebrocostal joints)
- thin interV discs
What are some characteristics of lumbar vertebrae?
- strongest and largest vertebrae
- 1 vert foramen
- short thick processes; heavy spinous processes; large trans processes
- thickest interV discs
What is the sacrum and some of its features?
- fusion of 5 vertebrae
- foundation for pelvic girdle
- continuation of spinal canal
Which vertebral curves are formed during fetal development?
thoracic and sacral
When are the secondary vertebral curves formed?
cervical - 4 months when infant raises head
lumbar - 1 year when infants begins to sit up and walk
What bones compose the thoracic cage?
sternum, ribs, costal cartilages
What does the sternum consist of?
manubrium, body, xiphoid process
What attaches the manubrium and the body?
sternal angle
What are clavicular notches?
located lateral to suprasternal notch (depression on sup surface of manubrium)
- sternum articulates with clavicles to form sternoclavicular joints
Which parts of the sternum articulate with the ribs?
manubrium and body
What does each rib articulate with?
posteriorly with its thoracic vertebrae; head of rib to body of V; tubercle of rib to transverse process
C/C true and false ribs
T (vertebrosternal ribs) - directly connect to sternum via coastal cartilage (ribs 1-7)
F (vertebrochondral ribs) - costal C attach to sternum indirectly via cartilage of 7th rib (ribs 8-10)
What are floating ribs?
anterior ends do not attach to sternum
What are costal cartilage made of?
hyaline C to allow flexibility when breathing
What are some features of the ribs?
- body has costal groove containing nerves and BV
- intercostal spaces contain intercostal muscles