skeletal system Flashcards
what makes up the skeletal system?
bones and joints
what is the skeletal system responsible for?
providing support and protection allowing movement generating blood cells storing fat, iron, and calcium guiding the growth of the entire body
2 parts of the skeletal system
axial and appendicular
axial skeleton consist of…
80 bones placed along the body’s midline axis and grouped into the skull, ribs, hyoid bone, sternum and vertebral column
appendicular skeleton consist of…
126 bones grouped into the upper and lower libs and the pelvic and pectoral girdles. they anchor muscles and allow for movements
on the cellular level, the bone consists of two distinctively different parts:
the matrix and living bone cells
bone matrix..
the non-living part of the bone, which is made out of water, collagen, protein, calcium phosphate, and calcium carbonate crystals
living bone cells
- also called osteocytes
- found at the edges of the bones and throughout the bone matrix in small cavities
- plays vital part in the growth, development, and repair of bones, and can be used for the mineral they store
periosteum
- topmost layer of bone, acting as layer of connective tissue
- contains collagen fibers that anchor the tendons and the muscles
- holds the stem ad the osteoblast cells that are necessary for growth and repair of the bones
- nervous tissue, nerve endings and blood vessels
compact bone of cortical
Tightly packed cells. Strong, dense, and rigid
cancellous bone
- aka spongy bone
- consist of trabeculae- network of girders with open spaces filled with red bone marrow.
the functional unit of cancellous bone is the…
trabecula; holds red bone marrow and provides structural support
ossification
process where new bone is formed by osteoblasts; occurs in fetal development and is ongoing as bones grow and repair themselves
osteoclasts
type of bone cell; responsible for breaking down bone tissue; located on the surface of bones and help balance the body’s calcium levels by degrading bone to release stored calcium
where is bone marrow located in bones?
medullar cavity of the bones
hematopoiesis
occurs in the red bone marrow; when white and red blood cells are made from stem cells;
what happens to red bone marrow at puberty?
red bone marrow declines at the end of puberty; as a significant part of it is replaced by the yellow bone marrow
what are the five types of bone?
long, short, flat, irregular, and sesamoid bones
long bones…
- major bones of the limbs.
- longer than wide
- responsible for most out height
long bones divide into 2 regions…..
epiphyses- located at the ends of the bone
diaphysis- located in the middle (contains a hollow medullary cavity that stores bone marrow
short bones…
- long as they are wide
- generally cube shaped or round
- include carpal bones of the wrist and foot
flat bones…
- do not have medullary cavities because they are thin
- ribs, hip bones, and frontal, parietal, and occipital bones of the skull
irregular bones…
- do not fit criteria to be classified as long short, or flat
- vertebrae, sacrum, among others
how many bones is they skull composed of?
22 bones
skulls purpose?
protects the brain and the sense organs for vision, hearing, smell, taste, and balance.