Download chapter 8 A and P 2017

chapter 8
the skeleton
skull
anatomical features of bones
vertebrae
limbs
206 adult bones
sesamoid bones
sutural (wormian) bones
learn table 8.2
learn the bones of the skull
learn the bones of the vertebral column
learn the bones of the limbs
this is best done with bones in hand
during lab periods
axial = head, thorax, vertebrae
appendicular = pelvic, upper and lower limbs
skull = most complex part of skeleton
sutures = immovable joints fused by connective tissue
skull cavities = cranial, orbit, nasal, oral, otic, aural,
skull sinuses = sphenoid, frontal, ethmoid, maxillary
cranial & facial bones = 29 bones
8 cranial bones
1 frontal, 2 parietal, 2 temporal, 1 occipital, 1 sphenoid, 1 ethmoid
frontal – forehead to coronal suture
parietal – right and left, part of roof and walls
temporal – wall and floor of cranium, complex bone
occipital – rear and base, foramen magnum
sphenoid – complex shape, behind nasal cavity
ethmoid – ant. between eyes, median wall of orbit, roof & walls of nasal cavity
facial bones – 14 bones
2 maxillae, palatine, zygomatic, lacrimal, nasal, inferior nasal conchae,
1 vomer & mandible
maxillae – upper jaw
palatine – posterior nasal cavity
zygomatic – angles of cheeks, inferolateral and lateral orbit walls
lacrimal – smallest bones of skull, medial wall of orbit
nasal – bridge of nose
inferior nasal conchae – in nasal cavity
vomer – inferior half of nasal septum
mandible – strongest of skull,
other bones of the head and skull
malleus, incus, stapes – bones of middle ear, 6 smallest bones
hyoid – adam’s apple
vertebral column
support skull & trunk, allows movement,
protects spinal cord, absorbs stress of walking & running
attachment of muscles, organs, tendons, & ligaments
33 vertebrae
7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 4 coccygeal
4 bends = cervical, thoracic, lumbar, pelvic
vertebral structure
body (centrum) – spongey bone, red marrow, weight bearing
vertebral foramen – opening between neural arch & body,
spinal cord passes through this space
vertebral canal – space occupied by the spinal cord
vertebral arch – formed on the back of the vertebral body by
the pedicles and laminae
pedicle – pillar like stalk
lamina – plate like surface
spinous process – posteriorly directed and downward from canal
transverse process – laterally from where pedicle & lamina meet
vertebral discs ( 23 )
intervertebral disc – cartilage pad between two centrums
nucleus pulposus – inner gelatinous layer of disc
anulus fibrosus – ring of fibrocartilage
hold vertebrae together
support weight of body
absorb shock of body movements
the vertebrae
cervical – small, 1=atlas, 2=axis has dens(odontoid), atlantooccipital joint, atlanto-axial joint, transverse foramen
for vertebral BV for neck
thoracic - 12 for 12 ribs, spinous process points downward,
large centrum, costal facets & transverse costal
facets for ribs
lumbar - large thick centrum, blunt spinous process, articular
facets inf & sup face medially to resist twisting
sacrum - bony plate, 4 pelvic foramina, sacral canal with spinal
nerve roots, sacroiliac joint, sacral promontory
coccyx - 4 or 5 fuse to tailbone, pelvic muscles attach
the thoracic cage
vertebrae, sternum, ribs
protects heart, lungs, spleen, liver,
attach pectoral & upper limb muscles
sternum – manubrium, body(gladiolus), xiphoid process
manubrium – broad superior portion, suprasternal notch,
clavicular notch
gladiolus – attachments for ribs C2-C7
xiphoid – abdominal muscles attach
the ribs 12 pairs
- proximal(posterior) end attached to vertebral column
- anterior end (of most) attached to sternum by costal cartilage
- head, neck, tubercle, shaft, superior & inferior articular facet
tubercle – attachment to transverse costal facet
superior articular facet – joins inf costal facet of above vertebrate
inferior articular facet – joins sup costal facet of vertebrate below
costal groove – path of blood vessels and nerves
false ribs - 8 -12, 11-12 = floating ribs,
the upper limb (30 bones per limb)
brachium – humerus (1)
antebrachium – radius (1) and ulna (1)
carpus – 8 carpal bones
manus – 19 bones (5 metacarpals, 14 phalanges)
humerus
- proximal head into glenoid cavity
- adjacent to the anatomical neck are greater & lesser tubercles and an intertubercular
sulcus to which tendons of the biceps attach
- below the surgical neck is a deltoid tuberosity where the deltoid inserts
- distal end has 2 condyles - lateral capitulum and medial trochlea
- bone flares to form lateral & medial condyles
- next to epicondyles are lateral & medial supracondylar ridges - forearm muscles attach
- distal end has 3 deep pits the olecranon fossa (for ulna), coronoid fossa (for ulna), and
radial fossa (for radius head)
Radius and ulna
Radius (distal to body)
humerus end - radius is medial, head rotates on capitulum,
edge spins on radial notch on ulna, narrow neck opens
to radial tuberosity which has the insertion of the distal
tendon of the biceps
distal end - styloid process, 2 articular facets for scaphoid
and lunate bones, & ulnar notch which articulates the
end of ulna
Ulna proximal to body
large C shaped trochlear notch wraps trochlea of humerus,
posterior notch forms a large olecranon (elbow to table)
anterior side has a coronoid process & laterally a radial notch
distal end – styloid processes on radius and ulna (bumps on
your wrist), radius and ulna connect by interosseous
membrane attached to an interosseous ridge (margin), the IM
when the arm is move or rotated disperses the weight to the
elbow joint to spare wear on the radius and ulna, the IM is also
the attachment site for fore arm muscles
carpals and bones of the hand
carpals = 2 rows of 4 bones,
proximal row = scaphoid, lunate, triquetrum, pisiform
distal row = trapezium, trapezoid, capitate, hamate
metacarpals = bones of the palm, proximal base, shaft, and a
distal head (knuckles)
phalanges = bones of fingers, described as proximal, middle,
and distal
pelvic girdle
2 hip (coxal) bones [ossa coxae] and the sacrum
3 distinctive features = iliac crest, acetabulum, obturator foramen
- bowl shaped structure plus ligaments and muscles
- each hip bone is joined to the sacrum at the sacroiliac joint
- anteriorly hip bones join at the interpubic disc (fibrocartilage)
- the anterior medial hip bones plus disc = pubic symphysis
- greater pelvis - between hips, pelvic inlet
- lesser pelvis – close to symphysis – pelvic outlet
-
- adult hip bone is a fusion of the ilium, ischium, and pubis
- anterior superior and posterior superior spines of ilium
- anterior inferior and posterior inferior spines of ilium
- greater sciatic notch, iliac fossa for iliacus muscle onto ilium
- ischium heavy bone (you sit on it), ischial tuberosity
- lesser sciatic notch of ischium, ramus joins pubis
- pubis is most anterior, bowl for bladder, triangular,
- superior & inferior rami, sexually dimorphic, meet at symphysis
the lower limbs
- adapted for weight bearing and locomotion
- 4 regions with 30 bones per limb
- femoral – femur and patella, hip to knee
- crural – tibia and fibula, knee to ankle
- tarsal (tarsus) – union of crural to foot
- pedal (pes) – foot, 7 tarsal, 5 metatarsal, 14 phalanges in toes
femur
- longest and strongest bone, 25% of body height
- ball and socket joint with acetabulum of the pelvis
- head, neck, greater and lesser trochanters
- intertrochanteric crest and line
- shaft – posterior linea aspera becomes spiral pectineal line
and gluteal tuberosity (gluteus maximus attaches)
- at low end linea becomes medial & lateral supracondylar lines
- widest part at medial & lateral epicondyles for attachment of
thigh and leg muscles and knee ligaments
- distally large medial & lateral condyles for knee movements
- anterior smooth depression articulates with the patella
- posteriorly there is a depression the popliteal surface
patella (kneecap)
- triangular sesamoid bone embedded in the knee tendons
- broad base, pointed apex, 2 shallow articular facets
- tendon of quadriceps femoris muscle extends to the patella
and continues as the patellar ligament from the patella
to the tibia
tibia and fibula
- a thick tibia (weight bearing) and a slender fibula
- superior head has flat articular medial & lateral condyles
separated by a intercondylar eminence
- tibial tuberosity (attachment of thigh muscles) can be felt
below the patella
- shaft has an angular border (shin),
- medial (tibia) & lateral malleoli form bony knobs at the ankle
- a thin fibula, stabilizes the ankle, interosseous membrane and
ligaments at the superior and inferior ends
The ankle and foot
- ankle bones modified for weight bearing role
- calcaneous (largest tarsal bone), forms heel, attachment of
calcaneous (Achilles) tendon from calf muscle
- 2nd largest is talus, 3 articular surfaces, for calcaneous, tibia,
and navicular
- distally a row of 4 bones – medial, intermediate, & lateral
cuneiforms and the cuboid
- metatarsals 1-5, toe bones are phalanges, big toe = hallux
-
- feet are like hands which have been turned palms down
- feet do not normally rest flat but have an arch
- the arch is held in place by 3 springy arches
- medial and lateral longitudinal and transverse arches
medial from calcaneous to hallux
lateral from heel to little toe
transverse from cuboid to proximal metatarsals