Skeletal System (1)

framework

The skeletal system is the ___ that provides support, protection, and structure for the body.

bones cartilage joints

The skeletal system consists of ___, ___. and ___.

support portection movement hemopoiesis mineral and energy storage

Five functions of the skeletal system:

soft tissues organs

Support:

The skeleton forms a rigid framework to which are attached the ___ ___ and ___ of the body

skull vertebral rib pelvic

Protection:

The ___, ___ column, ___ cage, and ___ girdle enclose and protect vital organs

levers

Movement:

Bones act as ___ when attached muscles contract, causing movement about joints.

blood

Hemopoiesis:

Sites for ___ cell production are protected with in the hollow centers of certain bones.

red bone marrow

___ ___ ___ of an adult produces white and red blood cells and platelets.

yellow bone marrow

___ ___ ___ stores lipids in adipose cells for energy.

calcium phosphorus

Mineral and Energy storage:

The matrix of bone is composed primarily of ___ and ___.

These minerals can be withdrawn in small amounts if needed elsewhere in the body.

Lesser amounts of magnesium and sodium are also stored in bone tissue.

long bones

The length of the bone is longer than width.

ex) in appendages

short bones

The shape is close to cubical.

ex) in confined spaces

flat bones

The major role of this bone is protection.

ex) skull and ribs

irregular bones

These are odd-shaped bones.

ex) vertebrae and certain skull bones.

diaphysis epiphysis

A long bone consists of a ___ or shaft in the center and an ___ on either end.

medullary cavity endosteum

Within the diaphysis is a ___ ___ that is lined with a thin layer of connective tissue, the ___.

spongy compact

The epiphysis consist of ___ bone surrounded by ___ bone,

spongy

Red bone marrow is found within the pores of the ___ bone.

epiphyseal plate linear

Separating the diaphysis and epiphysis is an ___ ___, a region of mitotic activity responsible for ___ growth.

line

An epiphyseal ___ replaces the plate when bone growth is completed.

periosteum

___ of dense regular connective tissue covers the bone and is the site of tendon-muscle attachment.

diametric

Periosteum (+endosteum) is the site of ___ bone growth.

compact bone

It is dense and hard, forming the outer layer of bones.

strength protection

Compact bone provides ___ and ___.

sponge bone

It is less dense and found inside the compact bone.

red bone marrow

Sponge bone provides support and flexibility while containing ___ ___ ___ for blood cell production.

mesenchymal cells

Multipotent stem cells found in bone marrow which develop into connective tissue, blood vessels, and lymphatic tissue:

osteogenic cells

Cells drived from primitive mesencymal cells.

osteogenic cells

Progenitor cells that give rise to all bone cells:

osteoblasts

The principal bone-building cells:

matrix

Osteoblasts synthesize the unmineralized bone ___ (=osteoid) including collagenous fibers.

mineralization

Osteoblasts promote ___ during ossification.

osteocytes

Osteoblasts develop into ___ that maintain the bone tissue.

osteoclasts

Bone-destroying cells that contain lysosomes and phagocytic vacuoles that demineralize bone tissue.

ossification

Bone formation begins during the fourth week of prenatal development.

endochondral cartilaginous stage

During ___ ossification, bone development first goes through a ___ ___.

hyaline cartilage model

During endochondral ossification, bone forms from a ___ ___ ___ and occurs in most bones including long bones and irregular bones.

primary center chondrocytes cartilage matrix

Endochondral ossification of a long bone begins in a ___ ___ in the shaft of the  cartilage model with hypertrophy of ___ and calcification of the ___ ___.

intramembranous 

During ___ ossification, bone form directly.

mesenchymal

During intramembranous ossification, compact and spongy bones develop directly from sheets of ___ tissues.

fibrous membrane

During intramembranous ossification, bone forms from ___ ___ (from mesencymal tissues) and occurs mostly in flat bone such as the cranial bones and clavicles.