bones a&P 1 lecture test

Support

Framework for body and organs.

Protection

Shields vital organs.

Movement

Muscles pull on bones as levers.

Mineral Storage

Calcium and phosphate for electrolyte balance.

Blood Cell Formation

Red marrow produces blood cells.

Fat Storage

Yellow marrow stores triglycerides.

Hyaline Cartilage

Most abundant; smooth, glassy appearance; found in articular surfaces, nose, trachea.

Elastic Cartilage

Flexible; found in ear and epiglottis.

Fibrocartilage

Tough, absorbs shock; found in intervertebral discs, pubic symphysis, menisci.

Long Bone

Example: femur.

Short Bone

Example: carpals.

Flat Bone

Examples: frontal, sternum.

Irregular Bone

Example: vertebra.

Sesamoid Bone

Example: patella.

Diaphysis

Shaft of compact bone with medullary cavity.

Epiphysis

Ends of spongy bone with red marrow.

Periosteum

Outer membrane of bone.

Endosteum

Inner lining of bone.

Articular Cartilage

Hyaline cartilage covering the ends of bones.

Compact Bone

Dense osteons with central canals, resists compression.

Spongy Bone

Trabeculae with marrow spaces, lightweight, resists forces from many directions.

Organic Bone Composition

Collagen and osteoid provide flexibility.

Inorganic Bone Composition

Hydroxyapatite provides hardness.

Osteogenic Cells

Stem cells that develop into bone cells.

Osteoblasts

Cells that build bone.

Osteocytes

Cells that maintain bone.

Osteoclasts

Cells that break down bone.

Intramembranous Ossification

Develops from mesenchyme; flat bones of skull, clavicle.

Endochondral Ossification

Develops from hyaline cartilage; long bones.

Fontanels

Soft membranous spaces between fetal skull bones that allow brain growth and skull compression during birth.

Longitudinal Growth

Occurs at epiphyseal plate; zones of cartilage proliferate, hypertrophy, calcify, and ossify.

Appositional Growth

Bone added under periosteum, increases width.

Bone Remodeling

Osteoblasts deposit bone, osteoclasts resorb bone.

PTH

Raises blood calcium by stimulating osteoclasts and kidney reabsorption.

Calcitonin

Lowers calcium by inhibiting osteoclasts and increasing excretion.

Growth Hormone

increases chondrocyte activity.

Thyroxine

supports metabolism.

Sex Hormones

stimulate growth, close plates.

Vitamin D

increases calcium absorption.

Fracture Repair Steps

1. Hematoma forms. 2. Soft (fibrocartilaginous) callus forms with hyaline cartilage. 3. Hard (bony) callus replaces cartilage. 4. Remodeling restores original bone shape.

Reduction

realignment of broken bone ends (closed or surgical).

Osteoporosis

low bone density.

Rickets/Osteomalacia

vitamin D deficiency.

Gigantism

GH excess before puberty.

Acromegaly

GH excess after puberty.

Dwarfism

low GH or achondroplasia.

Marfan's

connective tissue defect (long limbs).

Axial Skeleton

skull, vertebrae, ribs, sternum.

Appendicular Skeleton

limbs, pectoral and pelvic girdles.

Male Pelvic Girdle

narrower, heart-shaped inlet, pubic arch < 90°.

Female Pelvic Girdle

wider, shallower, larger inlet, pubic arch > 100° for childbirth.

Bone Markings

• Projections (tuberosity, spine, process) - for muscle attachment. • Depressions (fossa, groove) - for vessels or nerves. • Openings (foramen, canal) - passageways.

Intervertebral Discs

Fibrocartilage pads between vertebrae: outer annulus fibrosus, inner nucleus pulposus.

Herniated Disc

nucleus pulposus protrudes, compressing spinal nerves.

Foot Arches

Arches (medial, lateral, transverse) distribute weight and absorb shock.

Fallen Arches

occur when ligaments/tendons stretch, flattening the arch.

Deviated Septum

vomer & ethmoid.

Cleft Palate

maxilla & palatine.

Scoliosis

lateral curve.

Kyphosis

thoracic hump.

Lordosis

lumbar curve.

Carpal Tunnel

inflammation compresses median nerve.

Joint Classification

Structural: Fibrous (sutures), Cartilaginous (symphysis), Synovial (freely movable). Functional: Synarthrosis - immovable, Amphiarthrosis - slightly movable, Diarthrosis - freely movable.

Synovial Joint Structure

Includes articular cartilage (hyaline), synovial cavity, capsule, ligaments, tendons, bursae, and synovial fluid.

Specific Joints

• Shoulder & Hip - ball-and-socket, multiaxial. • Elbow - hinge, flexion/extension. • Knee - modified hinge, flexion/extension. • Atlas/Axis - pivot, rotation.

Joint Disorders & Injuries

Osteoarthritis - wear & tear. Rheumatoid Arthritis - autoimmune inflammation. Gout - uric acid buildup. Bursitis/Tendonitis - inflamed bursae/tendons. Sprain - stretched ligament. Dislocation - bones forced out of alignment. Separated Shoulder - clavicle/scapula disarticulation.