Chapter 6: Bones And Bone Tissue Flashcards
Long bones
Bones: greater in length than width
Number of bones in adult body
206
Physiology of bones
Shape: give body it’s structure
Support: bones of the legs, pelvis and vertebral column supports the body and hold upright
Protection: protect delicate internal organs
Movement: movement of arms legs and ability to breathe a result from interaction between bones and muscles
Electrolyte balance: stores and releases minerals
Blood cell production: bone marrow produces RBC, WBC and platelets
Acid-base balance: absorbs and releases alkaline salts to help maintain a stable pH
Short bones
Bones: cube shaped
Flat bones
Bones: thin, but protective
Irregular bones
Bones: complex shapes
Four major microscopic bone cell types
Osteogenic cells
Osteoblasts
Osteocytes
Osteoclast
Diaphysis
Long main portion of the bone
Epiphysis
The distal and proximal ends of the bone
Metaphysis
Region where the diaphysis joins epiphysis
Articular cartilage
Thin Hyaline cartilage that covers the Epiphysis, reduces friction and absorbs shock
Periosteum
Dense irregular connective tissue covering the bone except where articular cartilage is present. It provides a point of attachment for ligaments and tendons
Medullary cavity
Hollow cylindrical space in the diaphysis. Contains yellow bone marrow
Endosteum
Thin membrane that lines medullary cavity, contains bone-forming cells
Osteogenic cells
Unspecialized stem cells, they undergo cell division and resulting cells develop into osteoblasts
Osteoblast
Bone-building cells, they synthesize and secrete collagen fibers
Deposition
Osteocytes
Mature bone cells, maintain daily metabolism
Osteoclasts
Release enzymes and acids which breakdown bone
Resorption
Compact bone tissue
Contains osteons (Havershan systems) with a little space between
Makes up most of bone tissue and the diaphysis
Functionally compact bone, protects supports and resists stress
Spongy bone tissue
Consists of trabeculae surrounding red bone marrow
Located in short, flat, irregular bones and the epiphysis of long bones
Functionally stores red bone marrow and provide some support
Two hormones involved in maintaining blood calcium levels
Parathyroid hormone
Calcitonin
Parathyroid hormone
Secreted from parathyroid glands
Released when blood calcium levels are low
Increases the number and activity of osteoclasts
Thereby releasing calcium from bone into blood
Calcitonin
Secreted from thyroid, decreases osteoclast activity, released when blood calcium is elevated
Yellow bone marrow
Saturated with fat giving it a yellowish color