SKELETAL SYSTEM Flashcards
contains collegen, ground substance, and other organic molecules, as well as water and minerals.
EXTRACELLULAR MATRIX
(↑) collagen, (+) proteoglycans but less than that of the cartilage, (↑) hydroxyapatite (calcium phosphate crystals)
Bones
(↑) collagen, (↑) proteoglycans; tough & resilient.
Cartilage
(↑) collagen fibers; tough.
Tendons & Ligaments
2 TYPES OF PROTEIN
COLLAGEN & PROTEOGLYCANS
(35% organic and 65% inorganic material)
- Collagen - flexible strength
- Minerals - weight bearing strength
BONE MATRIX
PLAYS AS A ROLE IN REPAIR AND REMODELING OF THE BONE
OSTEOBLASTS
- MAINTAIN BONE MATRIX; BECOME SURROUNDED BY MATRIX
-RELATIVELY INACTIVE
OSTEOCYTES
-BONE DESTROYING CLLES
-CONTRIBUTE TO BONE REPAIR AND REMODELING BY REMOVING EXISTING BONE, CALLED RESORPTION
OSTEOCLASTS
FOR MOVEMENT OF APPENDAGES
LONG BONE
-HELP TRANSFER FORCE BETWEEN LONG BONE
-BONES OF WRIST AND ANKLE
SHORT BONES
-WELL-SUITED TO PROVIDING A STRONGER BARRIER AROUND SOFT TISSUES
-SKULL BONES, RIBS, SCAPULA, STERNUM
FLAT BONES
TEND TO HAVE SPECIALIZED FUNCTIONS, SUCH AS PROVIDING PROTECTION WHILE ALLOWING BENDING AND FLEXING OF CERTAIN BODY REGIONS
IRREGULAR BONES
CENTRAL SHAFT OF THE BONE
DIAPHYSIS
END OF THE BONE; SEPERATED FROM THE REAMINDER OF THE BONE BY THE EPIPHYSEAL PLATE/LINE
EPIPHYSIS
COVERS THE ENDS OF THE EPIPHYSIS WHERE THE BONE ARTICULATES WITH OTHER BONES
ARTICULAR CARTILAGE
COVERS THE OUTER SURFACE OF BONE EXCEPT WHERE ARTICULAR CARTILAGE IS PRESENT.
PERIOSTEUM
LINES THE INNER CAVITIES OF THE BONE
ENDOSTEUM
-COMPOSED OF CARTILAGE, BETWEEN EACH EPIPHYSIS AND THE DIAPHYSIS
-WHERE THE BONE GROWS IN LENGTH
-REPLACED BY BONE AND BECOMES AN EPIPHYSEAL LINE
EPIPHYSEAL PLATE
Soft tissue that fills the spaces of diaphysis and epiphysis
Bone marrow
consists mostly of adipose tissue
Yellow marrow
consists of blood-forming cells and is the only site of blood formation in adults
Red marrow
- (has spaces between trabeculae;therefore resembles a sponge)
- Appears porous, has less bone matrix and more space than compact bone
- Consists of interconnecting rods or plates of bone called trabeculae
- Between trabeculae are spaces filled with bone marrow and blood vessels
SPONGY BONE
-(more solid; with almost no space)
-Has more bone matrix and less space than spongy bone
COMPACT BONE
Contain an interior framework of spongy bone sandwiched between two layers of compact bone.
FLAT BONES
Have similar composition to the epiphysis of long bones (compact bone surfaces surrounding a spongy center with small spaces that are usually filled with marrow)
SHORT AND IRREGULAR BONES
Formation of bone by osteoblasts (after osteoblast is fully surrounded by bone matrix, it becomes osteocyte)
BONE OSSIFICATION
Formation of bone by osteoblasts (after osteoblast is fully surrounded by bone matrix, it becomes osteocyte)
BONE OSSIFICATION
-(formation within the connective tissue membrane)
- Primarily in the bones of the skull
- Osteoblasts; osteoblasts line up on the surface of connective tissue fibers and begin depositing bone matrix to form trabeculae (ossification centers)
Intramembranous ossification
-(formation inside hyaline cartilage)
- Most of the remaining skeletal system
- Chondrocytes; chondrocytes increase in number. Cartilage model to increase in size. Cartilage matrix to become calcified. Osteoblasts start forming bone.
Endochondral ossification
Osteoblasts deposit a new bone matrix on the surface of bones; bone increases in width, or diameter.
Appositional growth
- Through endochondral ossification
- Chondrocytes increase in number on the epiphyseal plate. Bone will elongate; chondrocytes enlarge and die; cartilage matrix becomes calcified; osteoblasts start forming bone
Interstitial growth
- The removal of existing bone by osteoclasts and the deposition of new bone by osteoblasts.
- Responsible for changes in bone shape, the adjustment of bone to stress, bone repair, and calcium ion regulation in the body fluids
- Important to maintain blood calcium levels within normal limits
BONE REMODELING
Blood released from damaged blood vessels forms a hematoma
- Hematoma formation
The internal callus forms between the ends of the bones, and the external callus forms a collar around the break.
Callus formation
Woven, spongy bone replaces the internal and external calluses
Callus ossification
-Affects the quality and quantity of bone matrix
=Bone matrix in an older bone is more brittle than a younger bone because decreased collagen production results in relatively more mineral and fewer collagen fibers
-Rate of matrix formation by osteoblasts becomes slower than the rate of matrix breakdown by osteoclasts
EFFECTS OF AGING ON THE SKELETAL SYSTEM
