How many bones does the skeleton have?
What does the axial skeleton compose of?
the skull, vertebral column, rib cage
What does the appendicular skeleton compose of?
upper & lower limbs and shoulder & pelvic girdle
What is the skull?
-The skull contains cranial bones that protect the brain joined at sutures. The rest of the skull is made up of facial bones.
-The skull is composed of many cavities and openings, which allow nerves, blood vessels, and organs to function
What is the cranium?
- composed of eight bones, two are paired
- parietal (2), frontal, ethmoid, temporal (2), occipital, and sphenoid
What are the facial bones?
14 facial bones - mandible, maxilla (2), palantine (2), nasal (2), vomer, inferior nasal conchae (2), palantine, zygomatics (2), nasal (2), lacrimal (2)
What are orbits?
cavities that hold the eye and all tissues related to the eye formed by the union of seven bones which also form the lacrimal fossa, optic foramen, and orbital fissures.
What is the nasal cavity?
-made up of bone and cartilage with the topo made by cribiform plate and the bottom made by palantine.
-There are 3 conchaes (shelfs) with 2 made by ethmoid bone and one by the inferior conchae bone.
-Nasal septum divides the nose down the middle
How many bones does the vertebral column make up?
26 (33 techniccally but 9 are fused)
What is the vertebral column?
forms the body's axis, protects spinal cord, articulates with ribs & provides attachment for dorsal muscles & rib muscles
What stabilizes the vertebral column?
anterior & posterior longitudinal ligaments, supraspinous & interspinous ligaments, & the ligamentum flavum
What are intervertebral discs?
composed of fribrocartilage enduring compression & shock absorption. (2 regions: annulus fibrosus & nucleus pulpuses that make up 25% of the height of the column & flatten throughout the day)
What is the spinal column made up of?
cervical (7), thoracic (12), lumbar (5), sacrum (5 fused), coccyx (4 fused)........fused means connected
- - each region has a curve:
- * cervical & lumbar-concave
- *thoracic & sacral-convex
What is the general structure of vertebrae?
all vertebrae except first 2 (atlas & axis) share common characteristics that differ slightly according to region. All vertebrae have a centrum (body), vertebral arch, vertebral foramen, pedicles, laminae, spinous process, transverse process, & inferior/superior articulating facets
What is the regional vertebral characteristics of the 3 vertebrae's and 2 fused ones?
* cervical vertebrae - retangle like containing bifid spinous process, triangular vertebral foramen, has transverse foramen, superior/anterior facets located in slightly opposite positions
* thoracic vertebrae - body is slightly heart shape, has demifacets (for ribs), long spinous process, circular vertebral foramen, transverse processes articulate with ribs, provides most of the rotation
* lumbar vertebrae - bears most of the weight so it has a massive body, short thick pedicles & laminae, triangular vertebral foramen, articulating facets prevent rotation, and short think spinous process
* sacrum - five fused vertebrae that articulates with the bones of the pelvis
* coccyx - 4 (or 3-5) fused vertebrae, also known as the tail bone
What is scoliosis?
lateral curvature that happens most often in thoracic region with the cause sometimes unknown. It can be due to muscle balances (vertebrae deformed and/or other side of muscles is stronger pulling vertebral column to that side) and it can also cause compression of the lung.
What is kyphosis?
a bent on a saggital plane along the thoracic region causing a hunchback that happens most often in women as a result of vertebral fractures do to osteoporosis
What is Lordosis?
over curvature of the lumbar region causing a swayed back often occuring in people carrying a large long in front or spinal tuberculosis or osteomalacia (bone softening)
What is the bony thorax?
rib cage - assist in breathing as well as protecting internal organs
contains the sternum that have 3 sections: manubrium, body, xyphoid process (cartilage) and ribs that have 12 pairs of ribs with the first 7 being true (attach to sternum) and the last 5 floating (false ribs)