The skeletal system Flashcards
List three functions of five of the skeletal system
I. Provides structure, support, and protection
II. Crucial for locomotion and movement
III. Site of blood cell formation
IV. Storehouse for some inorganic minerals (ex. calcium)
V. Indicates sex, height, weight, race, and medical history
List the bones of the body by shape
Long, short, flat, irregular, pneumatic, and sesamoid bones
Where are pneumatic bones located and what is their function?
They are bones only of the skull and reduce the weight it
Where are sesamoid bones located and what is their function?
They’re located within a tendon and change the angle of muscle attachment for more mechanical leverage.
Axial VS Appendicular skeleton
- Bones of the skull, hyoid, vertebral column, and rib cage are Axial.
- Bones of the limbs and their attachments to the axial skeleton are appendicular.
Cranial VS Post-Cranial
- Bones of the skull are cranial
- Bones of the rest of the skeleton are post-cranial
Diaphysis
bone shaft; primary ossification center
Epiphysis
Usually an area of articulation or site of high muscle tension; secondary ossification center
Epiphyseal plate (disk)
Separates the diaphysis from epiphysis; made of hyaline cartilage
Periosteum
Dense connective tissue covering outer surface but not articular surfaces
List the two layers of the periosteum
I. Outer fibrous
II. Inner cellular layer
List the components of the periosteum layers
Outer fibrous: type I collagen fibers, fibroblasts, blood vessels, and nerve fibers
Inner Cellular layer: primarily osteoprogenitors and osteoblasts
List the function and components of the Endosteum
It’s a thin layer that covers inner bone surfaces; primarily osteoprogenitors and osteoblasts
What is the medullary cavity (marrow cavity)?
cavity at the center of long bones
Where can articular cartilage be found and what is it composed of?
It covers articular surfaces and is hyaline cartilage
What is the matrix composed of?
Type I collagen fibers and ground substance
What are the fibers of the matrix composed of and what are their functions?
Type I collagen fibers and they provide strength to tensile forces (being stretching)
What is the ground substance of the matrix composed of?
An organic component: proteoglycans (chondroitan and keratan sulfate, and hyaluronic acid) and glycoproteins (osteonectin and osteocalcin)
An inorganic component: hydroxyapatite; a mineral composite that gives strength to resist compressive forces
Osteoprogenitors give rise to what and can be found where?
They give rise to osteoblasts and are found in the cell layers of the periosteum and endosteum.
Osteoblasts give rise to what, can be found where, and do what?
They give rise to osteocytes and are located in central and perforating canals of the periosteum and endosteum. They lay down new bone.
Osteocytes are located where and do what?
They are in lacunae of compact bone, and the bony struts of spongy bone. They maintain bone tissue and regulate mineral content.
What are osteoclasts and what is their function?
large multinucleated cells stemming from several monocytes. They destroy bone cells.
There are two types of bone tissue, list them.
Primary bone tissue (woven bone; immature) and Secondary bone tissue (mature or lamellar bone)
List the characteristics of primary bone
I. Arises during fetal development.
II. Associated with fracture repair
III. Collagen fibers randomly arranged, lower mineral content, has a higher amount of osteocytes
List the components of secondary bone (compact bone)
I. An outer layer of densely packed bone tissue
II. osteons
III. circumferential lamellae
IV. interstitial lamellae
What are osteons?
They are the main unit of compact bones. They are cylindrical and make up the interior layer.