divisions of the skeletal system Flashcards
(30 cards)
axial skeleton
forms the vertical, central axis of the body and includes all bones of the head, neck, chest, and back
- protect the brain, spinal cord, heart, and lungs
-attachment site for muscles that move the head, neck, and back, and for muscles that act across the shoulder and hip joints to move their corresponding limbs.
appendicular skeleton
- all bones of the upper and lower limbs
- plus bones that attach each limb to the axial skeleton
only moveable bone of the skull
mandible
new born skull
The bones of the newborn skull are not fully ossified and are separated by large areas called fontanelles, which are filled with fibrous connective tissue. The fontanelles allow for continued growth of the skull after birth. At the time of birth, the facial bones are small and underdeveloped, and the mastoid process has not yet formed.
what are fontanelles in an infants skull
large areas of dense connective tissue between skull bones “soft spots”
maxillary bone
paired bones that form the upper jaw and anterior portion of the hard palate.
mandible
Unpaired bone that forms the lower jaw bone; the only moveable bone of the skull
three bones in middle ear
malleus, incus, stapes
- transfer vibrations from eardrum to the inner ear
hyoid bone
- small Ushaped bone located in upper neck
- attached to the larynx below and the pharynx posteriorly
- held in position by series of small muscles that move hyoid up/down, forward/back
- movements are coordinated with movements of tongue, larynx, pharynx during swelling or speaking
vertebral column
Together, the vertebrae and intervertebral discs form the vertebral column. It is a flexible column that supports the head, neck, and body and allows for their movements. It also protects the spinal cord, which passes down the back through openings in the vertebra.
Cervical (Neck)
7 cervical vertebrae labeled C1 to C7
- C1 (atlas) connects to the skull and C2 (axis) allows the head to turn
thoracic (mid-back)
- 12 thoracic vertebrae
- labelled T1-T12
lumbar (lower back)
5, L1-L5
Sacrum
- 5 vertebra that fuse together to form single bone
coccyx
- tailbone
- formed from fusion of 4 small vertebrae
in adult, this fetal curvature is retained into regions of the vertebral column
- thoracic curve (involved thoracic vertebrae)
- sacrococcygeal curve (sacrum and coccyx)
vertebral body
- front part of each vertebra
- supports body weight
- vertebral bodies get bigger down the spine
intervertebral disc
- bodies of adjacent vertebrae are separated and connected by intervertebral discs
vertebral arch
back part of each vertebra
vertebral foramen
- space between vertebral arch and body is called vertebral foramen
- contains spinal cord
vertebral canal
- vertebral foramen of all vertebrae align to form vertebral canal
- protects and allows passage of the spinal cord
intervertebral foramen
- opening allows spinal nerves to exit the vertebral column
true ribs
ribs 1-7
- vertebrosternal ribs
- attach via their costal cartilage directly to the sternum
ribs 8-12
- false ribs
- vertebrochaondral ribs
- costal cartilage either attaches indirectly to the sternum via the costal cartilage of the next higher rib or does not attach to the sternum at all.
