Ch. 6 Bone Tissue Flashcards
Long Bones
- longer than wide; contain more compact bone than spongy bone
- slightly curved to absorb stress of body weight to evenly distribute
- ex. humerus (arm), ulna and radius (forearm bones), femur (thigh), tibia and fibula (leg bones), metacarpals (hand bones), metatarsals (foot bones), phalanges (finger and toe bones)
Short Bones
cube-shaped, similar in length, width and depth; consists mostly of spongy bone
ex. carpal and tarsal
Flat Bones
- thin, contain a layer of spongy bone sandwiched between 2 parallel layers of compact bone
- protection and provide extensive areas for muscle attachment
- ex. cranial bones, sternum and ribs, and scapulae, pelvic girdle
Irregular Bones
- contain varied shapes and many surface features for muscle attachment or articulation
- ex. bones of vertebral column and certain facial bones, and calcaneus
Sesamoid Bones
- protect tendons from excessive wear and tear, and alter direction of pull
- generally small smooth bones that develop within tendons
- ex. patellae, base of big toe
Anatomy of a Long Bone
- Diaphysis: long, cylindrical shaft of the bone
- Epiphysis: proximal and distal end of bone; contain spongy bone (red bone marrow- hemopoiesis)
- Metaphysis: between epiphysis and diaphysis that contains epiphyseal line (chrondocytes cartilagenous is a site of mitotic activity of bone cells)
- Articular cartilage: hyaline cartilage covering the epiphysis; reduce friction and absorbs shock
- Periosteum: dense irregular connective tissue; has blood supply and attaches periosteum to underlying bone by perforating (Sharpey’s) fibers
- Endosteum: thin membrane (dense irregular tissue) that line the medullary cavity and contains bone marrow
- Medullary cavity: within diaphysis that contains yellow bone marrow and numerous blood vessels; inner softer part of spongy bone
Functions of Bones
- support
- protect: eg. cranial bone and vertebral column, rib cage, pectoral & pelvic girdle
- movement
- mineral storage: 90% stored and released by bone; calcium- muscle contraction, blood clotting, and nerve impulse transmission
- blood cell formation (hemopoiesis): stem cell in red bone marrow and adipose tissue in yellow bone marrow
- fat storage: triglyceride storage in adipose cells
Nutrient Foramina
allows passage for blood vessels
Depressions and Openings
form joints or allow the passage of soft tissues
- Fissure, fossa, foramen, sulcus, meatus
Fissure
Narrow slit between adjacent parts of bones through which blood vessels or nerves passes
Foramen
Opening through which blood vessels, nerves, or ligaments pass
Fossa
shallow depression
ex. coronoid fossa of the humerus
Suclus
furrow along a bone surface that accommodates a blood vessel, nerve, or tendon
ex. intertubercular sulcus of the humerus
Meatus
tubelike opening
ex. external and internal auditory meati of the temporal bone
Processes that Form Joints
projections or outgrowths that help form joints
- Condyle: large round protuberance with a smooth articular surface at the end of a bone
- Facet: smooth, flat, slightly concave or convex articular surface
- Head: usually rounded articular projection supported on the neck of a bone
Processes that Form Attachment Points for Connective Tissues
- Crest
- Epicondyle
- Line
- Spinous Processes
- Trochanter
- Tubercle
- Tuberosity
Bone Tissue Cell Types
- Osteogenic cell: develops into an osteoblast
- Osteoblast: forms bone matrix
- Osteocyte: maintains bone tissue
- Osteoclast: functions in reabsorption, the breakdown of bone matrix (limit growth)
Compact Bone
bone surface, high density; contains small spaces, concentric layers near surface, concentric circles or rings (osteons) deeper
Spongy Bone
bone interior, low density; large spaces visible to the naked eye, lamellae arranged into thin columns (trabeculae)
- red bone marrow and yellow bone marrow stored
Periosteal Arteries
small arteries accompanied by nerves, enter the diaphysis and supply the periosteum and outer part of compact bone with blood
Nutrient Artery
enters the diaphysis through the nutrient foramen, and carries blood into proximal and distal regions of the medullary cavity
Metaphyseal and Epiphyseal Arteries
- enter the metaphyses of a long bone and together with the nutrient artery, supply red bone marrow and bone tissue of the matephyses
- enter the epiphyses of a long bone and supply red bone marrow and bone tissue of the epiphyses
Periosteal Veins
drain blood from the periosteum and outer layers of compact bone
Nutrient Veins
accompany respective arteries and drain blood from the proximal and distal regions of the medullary cavity
Metaphyseal and Epiphyseal Veins
drain blood from the ends of long bones and the red bone marrow
