CHP 6 BONE TISSUE AND SKELETAL SYSTEM
SUTURAL BONES
Small, irregular bones Found between the flat bones of the skull
OSTEOCYTE
mature bone cell
EPIPHYSIS
wider section at each end of the bone
STAGES IN FRACTURE REPAIR
1. hematoma forms 2. fibro-cartilaginious callus forms, new blood vessels 3. bony callus forms 4. bone remodeling
FUNCTIONS OF THE SKELTAL SYSTEM
1.Support 2.Storage of minerals (calcium) & lipids (in the yellow marrow) 3.Blood cell production (in the red marrow) 4. Protection 5.Movement
BONE MARKINGS
BONE LANDMARKS Display projections, depressions, and openings that serve as sites of muscle, ligament, and tendon attachment, as joint surfaces, or as conduits for blood vessels •Tuberosity—rounded projection •Crest—narrow, prominent ridge •Trochanter—large, blunt, irregular surface •Line—narrow ridge of bone •Tubercle—small rounded projection •Epicondyle—raised area above a condyle •Spine—sharp, slender projection •Process—any bony prominence •Condyle—rounded articular projection •Ramus—armlike bar
OSTEOCLAST
Bone-destroying cells
YELLOW BONE MARROW
Contains adipose tissue; Triglycerides stored in the adipocytes of the tissue can serve as a source of energy
LONG BONES
Cylindrical in shape, being longer than it is wide. Arms (humerus, ulna, radius) Legs (femur, tibia, fibula) Fingers (metacarpals, phalanges) Toes (metatarsals, phalanges).
Main function of the skeletal and bones systems
Enable body movement
ANATOMY OF A LONG BONE
Diaphysis, epiphysis, epiphyseal plates, epiphyseal line
OSSEOUS TISSUE (BONE)
Hard, dense connective tissue Forms most of the adult skeleton Support structure of the body
MEDULLARY CAVITY
Hollow region in the diaphysis, filled with yellow marrow
CALCITONIN
Inhibits osteoclast activity and stimulates calcium uptake by bones
BONE DEPRESSIONS AND MARKINGS
Meatus •Canal-like passageway Sinus •Cavity within a bone Fossa •Shallow, basin-like depression Groove •Furrow Fissure •Narrow, slit-like opening Foramen •Round or oval opening through a bone
ENDOSTEUM
Membraneous cavity where bone growth, repair, and remodeling occur. •Incomplete cell layer •Lines the medullary cavity •Covers trabeculae of spongy bone
The body deposits calcium in the bones when blood levels get too high, and it releases calcium when blood levels drop too low (is this positive or negative feedback?!?).
NEGATIVE FEEDBACK LOOP Regulated with PTH, Vitamin D and Calcitonin
CALCIUM
Needed to make calcium phosphate and calcium carbonate, which forms hydroxyapatite crystals that give bone its hardness
IRREGULAR BONES
Odd shaped bone thats not easily classified Found in vertebrae, pelvic, and facial bones
CARTILAGE
Semi-rigid form of connective tissue, Provides flexibility and smooth surfaces for movement.
SESAMOID BONES
Small, round bones found near joints Shaped like a sesame seed Feet, hands, patella
SYNTHESIS OF VITAMIN D
Sunlight activates a precursor to vitamin D Enzymes in the liver and kidneys transform that molecule into calcitriol (most active form of vitamin D) Necessary vitamin for absorption of calcium from food in the gastrointestinal tract
PATHWAYS IN CALCIUM HOMEOSTASIS
The body regulates calcium homeostasis with two pathways; 1. Signaled to turn on when blood calcium levels drop below normal 2. Signaled to turn on when blood calcium levels are elevated.
Examples of how bones SUPPORT the body?
The cranium protects the brain. The vertebrae protects the spinal cord. the rib cage/sternum protects the heart/lungs.
CALCIFICATION
The deposition of calcium salts within a tissue
Bones support Movement which means?
They act as "Levers"
FLAT BONES
Thin, flat, slightly curved Sternum, scapulae, ribs, most skull bones Serve as points of attachment for muscles and protect internal organs.
TYPES OF FRACTURES
Transverse-Occurs straight across the long axis of the bone Oblique- Occurs at an angle that is not 90 degrees Spiral- Bone segments are pulled apart as a result of a twisting motion Comminuted- Several breaks result in many small pieces between two large segments Impacted- One fragment is driven into the other, usually as a result of compression Greenstick- A partial fracture in which only one side of the bone is broken Open (or compound)- A fracture in which at least one end of the broken bone tears through the skin; carries a high risk of infection Closed (or simple)- A fracture in which the skin remains intact
ARTICULAR CARTILAGE
a thin layer of cartilage that reduces friction and acts as a shock absorber.
PROJECTION
an area of a bone that projects above the surface of the bone
HOLE
an opening or groove in the bone that allows blood vessels and nerves to enter the bone.
OSTEOBLAST
build bone cells
COMPACT BONE
dense, hard layers of bone tissue that lie underneath the periosteum
HEMATOPOIESIS
formation of blood cells
OSSIFICATION
formation of bone
OSTEOGENESIS
formation of bone
OSTEOGENIC CELLS
give rise to osteoblasts which give rise to osteocytes
EPIPHYSEAL PLATE
growth plate
VITAMIN D
needed for calcium absorption
CANALICULI
pathways for nutrient & waste exchange
Red Bone Marrow
produces red and white blood cells and platelets
EPIPHYSEAL LINE
remnant of the epiphyseal plate, seen in adult bones
PTH
stimulates osteoclastic activity
VITAMIN K
supports bone mineralization and may have a synergistic role with vitamin D
CALCITRIOL
the active form of vitamin D (secreted by the kidneys) that promotes absorption of calcium from foods in the GI tract into the blood, helping to further increase blood calcium level
DIAPHYSIS
the tubular shaft that runs between the proximal and distal ends of the bone.
PAGETS DIESEASE
viral infection of bone that deforms (porous and curved) the skeleton due to the acceleration of bone loss
ARTICULATION
where two bones come together
SHORT BONES
wrist and ankle
PERIOSTEUM
•Isolates bone •Provides a route for circulatory & nervous supply •Participates in bone growth & repair