SKELETAL (bones and joints) Flashcards
are bone-building cells. These cells have an extensive endoplasmic reticulum and numerous ribosomes.
Osteoblasts
The hydroxyapatite crystals act as templates that stimulate further hydroxyapatite formation and mineralization of the matrix. The formation of new bone by osteoblasts is called
osteocytes
once the osteoblasts have secreted sufficient bone matrix
osteocytes
Osteocyte cell bodies are housed within the bone matrix in spaces called
lacunae
Osteocyte cell extensions are housed in narrow, long spaces called
canaliculi
are bone-destroying cells. These cells break down bone.
Osteoclasts
Mature bone is called. It is organized into thin, concentric sheets or layers, called lamellae
lamellar bone
consists of interconnecting rods or plates of bone called trabeculae
Spongy bone
The functional unit of compact bone, composed of concentric rings of matrix, which surround a central tunnel and contain osteocytes
Osteon
In cross section, an osteon resembles a circular target; the bull’s-eye of the target is the
central canal
The ends of a long bone are called e
epiphyses
It is the center portion of the bone. It is composed primarily of compact bone tissue, surrounding a hollow center called the medullary cavity.
diaphysis
Within joints, the end of a long bone is covered with hyaline cartilage called
articular cartilage
is located between the epiphysis and the diaphysis
epiphyseal plate
When bone stops growing in length, the epiphyseal plate becomes ossified and is called the
epiphyseal line
is the site of blood cell formation
Red marrow
is mostly adipose tissue.
yellow marrow
is a connective tissue membrane covering the outer surface of a bone
periosteum
is a single cell layer of connective tissue that lines the internal surfaces of all cavities within bones, such as the medullary cavity of the diaphysis and the smaller cavities in spongy and compact bone
endosteum
Skeletal System Functions
- Support
- Protect
- Movement
- Storage
- Blood cell production
bones are longer than they are wide;
examples are upper and lower limb bones.
Long bones
bones are approximately as wide as they
are long; examples are the bones of the wrist and ankle.
short bones
bones have a relatively thin, flattened shape;
examples are bones of the skull and sternum.
flat bones
include the vertebrae and facial
bones, which have shapes that do not fit readily
into the other three categories.
Irregular bones
covers epiphyses
reduces friction
Articular cartilage
site of growth between diaphysis and epiphysis
Epiphyseal plate
center of
diaphysis red or
yellow marrow
Medullary cavity
membrane around
bone’s outer
surface
Periosteum
membrane that
lines medullary
cavity
Endosteum
Bones contain cavities, such as the large
medullary cavity in the diaphysis, as well as
smaller cavities in the epiphyses of long bones
and in the interior of other bones.
Bone Marrow