Module 4: Axial and Appendicular System

what consists of the axial skeleton

bones within the long axis of the body

what consists of the appendicular skeleton

bones in the body’s limbs

bones of the axial skeleton

skull, hyoid bone, vertebral column, ribs, sternum

bones of the appendicular skeleton

shoulder girdle, arm, hand, pelvic girdle, leg, foot

functions of cranial bones

surround and protect the brain

attachment of head and neck muscles through surface features

house and protect special sense organs

bones of cranial

singular frontal, occipital, ethmoid, and sphenoid

paired temporal and parietal

functions of facial bones

form underlying scaffold for face

provides passages for air and food

provides anchor site for teeth

provides anchors for face muscles

form cavities for special sense organs

bones of facial

singular mandible and vomer

paired maxillary, sygomatic, nasal, lacrimal, palantine, and inferior nasal conchae

how many cranial bones?

8

feautres of frontal bone

supraorbital margin

supraorbital foramen

glabella

features of parietal bones

sagittal suture

coronal suture

squamous suture

lambdoid suture

features of occipital bone

foramen magnum

occipital condyles

superior and inferior nuchal lines

external occipital protuburance

features of temporal bones

squamous region

tympanic region

mastoid region

petrous region

features of spenoid bone

sella turcica

optic canals

foramen rotundum, ovale, spinosum

superior orbital fissure

pterygoid process

features in ethmoid bone

cribriform plate

cribriform foramina

Crista galli

nasal septum

lateral masses

cranial cavity

largest cavity; surrounds the brain

formed by cranial bones

nasal cavity

contains passages for air and sensory neurons for smell

formed by several bones lined with mucous membranes

orbital cavities

contains eyeballs, blood vessels, muscles, nerves, and lacrimal glands

formed by parts of 7 bones: sphenoid, frontal, sygomatic, ethmoid, lacrimal, maxilla, palatine

oral cavity

contains teeth tongue, passage for food and air, and most salivary glands

first part of GI tract

roof formed by har palate

lacks bony floor and back wall

hyoid bone

onyl bone in the body that doesn’t articulate with any others

position in neck maintained by ligaments

serve as important attachment site for muscles involved in swallowing and phonation

body of vertebra

block-like structure

faces thoracic cavity

primary weight-bearing part of the vertebra

vertebral foramen of vertebra

spinal cord and associated components pass

transverse processes of vertebra

lateral projections off the vertebral arches; attachment site for skeletal muscles

spinous processes of vertebra

project backwards from each vertebra; also serve as attachment sites for skeletal muscles

articular processes of vertebra

contain facets through which adjacent vertebrae articulate

vertebral arch of vertebra

formed by pedicles and laminae; enclose posterior region of vertebral foramen

features of intertebral discs

sit between adjacent bodies

cushion/absorb physical shock

resist grinding between bones

facilitate motion

features of herniated discs

outer ring weakens, allowing inner core to bulge out

occurs due to age, physical trauma/strain, or awkward motions

treatments include bed rest, physical therapy, medications

features of rib cage

formed by 12 pairs of rib bones and their associated anterior costal cartilage

bones of sternum

these stabilize the rib cage and protect vital organs

manubrium

body

xiphoid process

features of pectoral girdle

acts as a brace to resist longitudinal compression

keeps scapula in correct position

anatomy of the scapula

spine

acromion process

glenoid cavity

coracoid process

supraspinous, infraspinous, and subscapular fossae

the pelvis contains 3 main parts, which are the

ilium, ischium, and pubis

features of the pelvis

acetabulum, obturator foramen, ilium, ischium, pubis

features of the upper leg bones

fovea capitis

trochanters

linea apsera

condyles

linea aspera

condyles

patella

features of the lower leg bones: tibia

condyles

intercondylar eminence

tibial tuberosity

anterior crest

Soleil line

features of the lower leg bones: fibula

tibiofibular joints

fibular styloid process

lateral malleoulus

features of ankle and foot

metatarsals, cuneiform bones, talus, calcaneus, cuboid, phalanges

arches of foot

transverse arch, medial longitudinal arch, lateral longitudinal arch

carpal tunnel syndrome

numbness, tingling, and weakness in hand/arm

regional specialization: sacrum

fused sacral ribs:

• sacroiliac joint surface

• anterior and posterior sacral foramina

thoracic and sacral kyphosis is what kind of curvature

primary

cervical and lumbar lordosis are what kind of curvature

secondary

modes of failure: flexion/distraction injury

acute combined axial tension and flexion

soft tissue and bony failure of the lamina and associated processes in tension (tearing)

tearing is directed along the vertebral canal, has lass chance of affecting the dural sac and the spinal cord

modes of failure: fracture dislocation

acute lateral or rotational loading

failure of the intercentral and interarticular joints in shear

shears the vertebral canal, often leading to extensive neurological deficit

modes of failure: spondylolysis

repeated flexion and extension or chronic

lumbar hyperextension together with axial compression

stress fracture of the laminae in between the articular processes

spinous process remains attached to eh next inferior vertebra; superior articular process, pedicles and centrum remain attached to the adjacent superior vertebra

presenting complaints for this injury may be as simple as diffuse lower back pain on extension

modes of failure: spondylolisthesis

allows affected vertebra to slowly slide anteriorly on the intercentral joint

normal lordotic curvature of the lumbar spine & increased axial compression from body weight in the lumbar region = lumbar vertebrae especially vulnerable to spondylolisthesis

why do most clavicular fractures occur in the middle of the bone?

the thinnest part of the shaft, lacks strong muscular or ligamentous support, and is where the bone changes its structural curvature

why do clavicular fractures present similarly?

muscle actions on upper limb without connection to axial skeleton through clavicle