Innervation, Vessels, Growth & Healing of

BonesHelena Varys

Innervation & Vessels

• Periosteum

• nerves

• blood & lymph vessels

• large vessel -> small capillaries

Innervation• Peripheral

• Most sympathetic and vasomotor

• Sensory

• Hilton's Law

• Muscle nerve innervates underlining bone

• Accompany vessels

Vessels• nutrient foramina

• perforating (Volkmann) canals

• connect to central (haversian) canals

• canaliculi

Ossification• bone formation

• initial formation

• growth after birth

• remodeling

• fracture repair

• template out of mesenchyme cells

• ossification starts by 6th week

• two different patterns

• Intramembranous

• Endochondral

Growth in Thickness and Length • perichondrium ->

osteoblasts -> osteocytes

• lamellae, new osteons formed at surface

• medullary cavity enlargement slower than growth

• Epiphyseal plate

• thickness stays constant

• chondrocytes divide

• on diaphyseal sides, replaced by bone

• replaced by epiphyseal line

Bone Remodeling • Bone Resorption

(osteoclasts) & Deposition (osteoblasts)

• different rates

• removes injuries

• influenced by exercise, diet change, hormones

Fracture Repair1. phagocytes (osteoclasts) remove dead tissue

2. chondroblasts form fibrocartilage

3. osteoblast convert fibrocartilage into spongy bone

4. spongy bone converted into compact bone

Healing

• takes months

• bone cells slowly divide

• blood supply disrupted

• gradual Ca & P deposits

Summary • Vessels and nerves come from the periosteum

through canals

• Epiphyseal plate is in charge of growth in length

• Periosteum differentiation is in charge of growth in width

• Healing involves cartilage formation and its ossification.

Sources • Tortara, Gerard J., Bryan Derrickson. Introduction to the Human Body The Essentials

of Anatomy and Physiology. New Jersey: John Wiley & Sons, Inc, 2012. Print

• Junqueira, Luiz C., and Anthony L. Mescher. Junqueira's Basic Histology: Text & Atlas. New York: McGraw-Hill Medical, 2010. Print.

• Platzer, Werner. Color Atlas of Human Anatomy, Vol. 1 Locomotor System 6th Edition. New York, 2005. Print

• "nutrient foramen." Medical Dictionary for the Health Professions and Nursing. 2012. Farlex 6 Oct. 2015 http://medical-dictionary.thefreedictionary.com/nutrient+foramen

• Iqbal, Ahsan. Man Anatomy. 2011. Web. 11 October 2015. http://www.mananatomy.com/basic-anatomy/nerve-supply-bones