Chapter 6

Skeletal tissue

3 types of cartilage

Hyaline, fibrocartilage, elastic

Hyaline cartilage

Provides support, flexibility, resilience/joints, ribs, larynx

Elastic cartilage

Contains elastic fibers/ ear, epiglottis

Fibrocartilage

Thick collagen fibers, has great tensile strength/knee, vertebrae discs

Bone functions

Support, protection, movement, mineral + growth, hematopoiesis, triglyceride, hormone production

Major cells of cartilage

Chondrocytes

Axial skeleton

Skull, ribs, vertebrae

Appendicular skeleton

Limbs, girdles

4 classes of bone

Long, short, irregular, flat

Long bone

Longer than wide/limbs

Short bone

Cubes/wrist, patella

Flat

Ribs

Irregular

Vertebrae, hips

Diaphysis

Shaft

Epiphysis

Ends

Red bone marrow

Produces blood cells

Yellow bone marrow

Stores fat

Periosteum

Lines outside of compact bone, secures membrane to bone

Endosteum

Line inside of compact bone

3 bone markings

Projection, depression, opening

Projection

Outward bulge

Depression

Bowl/groove

Opening

Hole

Osteon

Structural unit of compact bone

2 organic components of bones

Cells, extra cellular matrix

Intramembranous ossification

Skull, clavicle/ fibrous connective tissue

Endochondral ossification

Long bones, appendicular, replace hyaline cartilage

What bone growth happens at epiphyseal plate

Longitudinal growth

Bone growth that creases thickness

Appositional growth

Cells of bone tissue

osteogenic, osteoblasts, osteocytes, bone-lining cells, osteoclasts

Osteoblasts

Bone forming cells

Osteocytes

mature bone cells in lacunae, communicate information to osteoblasts and osteoclasts for bone remodeling

Bone-lining cells

mature bone cells, maintains bone matrix like osteocytes

Osteoclasts

bone-resorting cell

Growth hormone

stimulates epiphyseal plate activity in infancy and childhood

Thyroid hormone

modulates activity of growth hormone, ensures proper proportions

Testosterone and estrogens at puberty

promote adolescent growth spurts, end growth by inducing epiphyseal plate closure

2 Triggers of bone remodeling

mechanical stresses, changes in blood concentrations of calcium or phosphate

Osteoblasts in bone remodeling

Deposit new bone matrix

Osteoclasts in bone remodeling

break down bone e to release calcium

Position of bone’s ends breaks

nondisplaced: ends retain normal position

Displaced: ends are out of normal alignment

Completeness of break

complete: broken all the way through

Complete: not broken all the way through

Penetration of skin

Open: skin is penetrated

Closed: skin is not penetrated

2 types of fracture treatment

Reduction, immobilization

4 stages of bone repair

1. Hematoma forms 2. Fibrocartilage 3. Bony callus forms 4. Bone-remodeling occurs

Rickets

vitamin d deficiency, low calcium

Manifestations of rickets

bowed legs, bone deformities because bone ends are abnormal and long

Osteoporosis

insufficient exercise, age, sex, estrogen, testosterone, smoking, genetics, alcohol, poor diet