Human AP Exam 2 Chapter 6 Review

Osteology

Study of bones

Components of the Skeletal System

Bones, cartilage, ligaments, tendons

Functions of the Skeletal System

Support, protection, movement, mineral storage, blood cell production, fat storage

Classes of Bones

Long, short, flat, irregular, sesamoid, sutural

Types of Bone

Compact bone, spongy bone

Proximal epiphysis

End of the bone closest to the trunk

Proximal metaphysis

Area between epiphysis and diaphysis

Diaphysis

Shaft of the bone

Distal metaphysis

Area between diaphysis and epiphysis at the far end

Distal epiphysis

End of the bone farthest from the trunk

Articular cartilage

Covers joint surfaces, reduces friction

Medullary cavity

Hollow space inside diaphysis, contains marrow

Diploe

Spongy bone layer between compact bone layers in flat bones

Parts of the Osteon

Central canal, lamellae, lacunae, osteocytes, canaliculi

Cells of Bone Tissue

Osteoblasts (build bone), osteoclasts (break down bone), osteocytes (maintain bone), osteoprogenitor cells (stem cells)

Periosteum

Outer covering of bone, contains blood vessels and nerves

Endosteum

Inner lining of bone, involved in bone growth and repair

Hyaline cartilage

Joints, nose, ribs; reduces friction

Fibrocartilage

Intervertebral discs, meniscus; absorbs shock

Elastic cartilage

Ear, epiglottis; provides flexibility

Appositional

Bone grows in width

Interstitial

Bone grows in length

Intramembranous Ossification

Bone forms directly from mesenchyme (e.g., skull bones)

Endochondral Ossification

Bone forms from cartilage (e.g., long bones)

Primary Ossification Center

First site of bone formation in the diaphysis

Secondary Ossification Center

Forms in the epiphyses, later in development

Epiphyseal plate

Growth plate in children

Epiphyseal line

Hardened plate in adults after growth stops

Gland

Parathyroid gland

Hormone

Parathyroid hormone (PTH), calcitonin

Cell

Osteoclasts (increase calcium), osteoblasts (decrease calcium)

Minerals needed for Bone Health

Calcium, phosphorus, magnesium, fluoride

Vitamins Needed for Bone Health

Vitamin D (calcium absorption), Vitamin C (collagen), Vitamin A (osteoblast activity), Vitamin K & B12 (bone protein production)

Articular Cartilage

Covers joint surfaces to reduce friction and absorb shock

Osteoporosis

Bone disease causing weak, brittle bones due to decreased bone mass

Acromegaly

Excess growth hormone in adulthood, causing enlarged bones

Yellow marrow

Fat storage, found in medullary cavity

Red Marrow

Blood cell production, found in spongy bone

Open (compound)

Bone breaks through skin

Closed (simple)

Bone breaks but does not pierce skin

Greenstick

Partial break, common in children

Comminuted:

Bone shatters into pieces

Spiral

Twisting force causes a break

Epiphyseal fracture

Break at growth plate

Compression fracture

Bone is crushed

Step one of Fracture Repair

Hematoma forms (blood clot)

Step two of Fracture Repair

Soft callus forms (cartilage)

Step three of Fracture Repair

Hard callus forms (spongy bone)

Steps four of Fracture Repair

Bone remodeling (compact bone replaces spongy bone)