Lecture 11: Skeletal System

Question 0

Bone classification

Answer 0

Long: femur, humerus
Short: talus, digits
Flat: cranium, scapula
Irregular: vertebrae

Question 1

Functions of skeletal system

Answer 1

Support
Protection
Movement
Blood cell production
Mineral storage
Lipid storage

Question 2

Anatomy of a long bone

Answer 2

Periosteum: CT covering
Epiphysis: ends
Diaphysis: shaft
Epiphyseal plate: cartilage where growth occurs
Articular cartilage: joints
Medullary cavity: inside diaphysis, stores marrow

Question 3

Bone cells

Answer 3

Calcification
Osteoblasts: build then become osteocytes and maintain bone
Osteocytes: mature bone cell
Osteoclasts: break down bone

Question 4

Compact bone tissue

Answer 4

Haversion system (osteon): central canal
Lacunae: space between lamellae that cell sits in
Canaliculi: transports nutrients between osteocytes and Haversion canal
Lamellae: concentric layers surrounding Haversion canal

Question 5

Trabeculae

Answer 5

Boney bars

Question 6

Bone formation

Answer 6

Endochondral ossification: formed cartilage mold
Cartilage model dvlpmt: chondroblasts make cartilage mold
Growth of cartilage model: chondroblasts become chondrocytes and divide
Primary/secondary ossification center: cartilage converted to bone by osteoblasts
Articular cartilage and epiphyseal plate formation: cartilage remains at ends and epiphyseal plates

Question 7

Bone growth

Answer 7

Length (interstitial): cartilage cells divide and turn into bone
Thickness (appositional growth): blood vessels in periosteum are surrounded and become Haversion canal

Question 8

Calcium

Answer 8

Parathyroid hormone (PTH): stimulates osteoclasts, kidneys retain calcium
Calcitrol: released by kidneys, GI tract retains calcium
Calcitonin: inhibits osteoclasts, osteoblasts build faster