Lecture Exam #2: Skeletal And Bone Features Flashcards
What is a part of the axial skeleton?
Skull, vertebrae, sternum, ribs, sacrum, hyoid
What is part of the appendicular skeleton?
Pectoral girdle, upper/lower limbs, pelvic girdle
What is articulation?
Consisting of segments united by joints
Auditory ossicles (SKULL)
3 in each ear in the middle: malleus, incus, stapes
Hyoid Bone:
Between chin & larynx, doesn’t articulate w/ any bone, suspended by muscle
Infant Skull
Fontanels: spaces between unfused bones
Metopic Suture: fusing of the frontal bones
Reaches full size by 8 or 9
Spine Vertebraes
33 TOTAL
Cervical: 7
Thoracic: 12
Lumbar: 5
Sacral: 5
Coccygeal: 4
Functions of Spine
-supports skull/trunk
-allows movement
-protects spinal cord
-absorbs stress
-provides attachment for limbs, thoracic cage, postural muscles
Types of Curvature:
- Newborn Curvature: C shape (thoracic/lumbar)
- Adult Curvature: S shape (cervical/pelvic)
- Abnormal Curvature: scoliosis, kyphosis, lordosis
Explain Scolosis
Abnormal lateral curvature in thoracic region, particularly in adolescent girls
Explain Kyphosis
Exaggerated thoracic curvature, caused by wrestling/weightlifting in young boys (hunchback)
Explain Lordosis
Exaggerated lumbar curvature, caused by pregnancy/obesity (sway back)
When you go down the spine vertebrae get…..
Larger
C1-ATLAS
supports head, has no body, allows yes nodding motion
C2-AXIS
dens projects into atlas, allows “no” nodding motion
Intervertebral Discs
binds vertebra, supports weight of body, absorbs shock
intervertebral foramen
holes seen from lateral views when vertebrae are connected, passage way for spinal nerves
vertebral foramen
hole in between body and spinous process
describe cervical vertebrae
bifid spinous process, only type with transverse foramen
describe a thoracic vertebrae 
spinous process is angled down and pointy, has costal facets for ribs
Describe the thoracic cage
has sternum/ribs/thoracic vertebrae, costal margin: downward arc of the ribs
what are the true ribs
ribs 1-7, direct attachment to dternum
what are the false ribs
ribs 8-10, join together then go to sternum
what are the floating ribs
ribs 11/12, still false, don’t attach at all
Describe the lumbar vertebrae
thick/stout body, blunt squarish spinous process
Compare male and female pelvis
male has a more narrow pelvic brim and pubic arch is 90° while a female has a wide pelvic brim in the pubic arch is 120° for childbirth
What are the four shapes of bones and give examples of each
Long: femur, short: talus, Flat: sternum, irregular: vertebra
 explain the parts of compact bone
osteon: Basic structural, concentric lamellae: Layers of matrix around central canals,
Perforating canals: Diagonal passages coming off the central canal
Nutrient foramina on surface
circumferential lamellae: Boundaries of dense bone
Interstitial lamellae: Remains of old osteons that broke down as bone grew & remodeled
explain the medullary (marrow) cavity
hollow part of bone that contains bone marrow
explain the makeup of spongy (cancellous) bone
spicules: slivers of bone
trabeculae: thin plates of bone
- red bone marrow fills spaces
- few osteons
- no central canals
what is the diaphysis on a bone
Cylinder of compact bone called the shaft
what is the epiphysis on a bone
end parts of bone that are separated by epiphyseal plates until fully connected to shaft when plate turns into line
where is articular cartilage on a bone what does it do
covers the epiphysis and creates joints when bones connect
what is periosteum
external sheath that covers bone, outer fibrous layer of collagen with inner osteogenic layer of bone forming cells
What is the epiphyseal plate
Area of hyaline cartilage that separates marrow spaces of epiphysis and diaphysis, AKA growth plate, transition zone where cartilage is replaced by bone (metaphysis)
what is the endosteum
thin layer of reticular connective tissue lining the marrow cavity
what is nutrient foramina
little holes on surface that allows blood vessels and nerves to enter the bone 
What’s the function of osteogenic cells
stem cells that differentiate and become osteoblasts
What is the function of osteoblasts
bone forming cells that line up as a single layer of cells under the endosteum and periosteum that then turn into osteocytes
what is the function of osteocytes
osteoblasts that form the lacunae (matrix cocoon),
- maintains bone matrix
- When stressed they send signals for aged bone remodeling
What is the function of osteoclasts

bone dissolving cells found on the bone surface, remodels
What does the matrix consist of
1/3 organic matter (synthesized by osteoblasts, collagen/carbohydrate/protein complexes)
2/3 inorganic matter (85% hydroxyapatite, 10% calcium carbonate, other minerals)
What is rickets
soft bones due to deficiency of calcium salts (more organic than inorganic matter)