INTRODUCTION TO THE SKELETAL SYSTEM

OVERVIEW Histology of Bone Tissue Bone Function and Structure Bone Growth & Development Joints The Axial Skeleton The Pectoral Girdle The Upper Limbs The Pelvic Girdle The Lower Limbs

SOME NUMBERS… 22 bones in skull 6 in middle ears 1 hyoid bone 26 in vertebral column 25 in thoracic cage

4 in pectoral girdle 60 in upper limbs 60 in lower limbs 2 in pelvic girdle

206 bones in all

ACTIVITY – BROKEN BONES Groups of 2 List which bones each of you have broken in your body

on a sheet of paper

We will go through the Powerpoint…the end of the activity will be afterward

BY THE WAY, THIS POWERPOINT WILL BE POSTED ON THE CLASS WEBSITE: http://bushelman-hap.wikispaces.com/ , SO PLEASE DO NOT ASK FOR ME TO SLOW DOWN OR WAIT ON THE SLIDES, BECAUSE I WILL NOT.

BONE GROWTH & DEVELOPMENT Fetal Skeleton

275 BONES

12 WEEKS (6-9 INCHES LONG)

Prenatal development skeleton is mostly cartilaginous

Cartilage cells and then osteoblasts start to deposit minerals

Cartilaginous disk (epiphyseal disk) remains in epiphysis

Cells eventually stop dividing

BONE GROWTH & DEVELOPMENT

BONE GROWTH & DEVELOPMENT

FETAL SKULL

BONE GROWTH & DEVELOPMENT Adults continually break down and build up

bone

Osteoclasts remove damaged cells and releasecalcium into blood

Osteoblasts remove calcium from blood and build new matrix. They become trapped osteoclasts

BROKEN BONES - TYPES OF BONE BREAKS

Simple- skin is not pierced Compound- skin is pierced Complete- bone is broken in half Partial- broken lengthwise but not into twoparts Greenstick- incomplete break on outer arc Comminuted- broken into several pieces Spiral- twisted

BROKEN BONES Types of bone breaks

Simple- skin is not pierced Compound- skin is pierced Complete- bone is broken in half Partial- broken lengthwise but not into two parts Greenstick- incomplete break on outer arc Comminuted- broken into several pieces Spiral- twisted

BROKEN BONES – FRACTURE REPAIR Hematoma- blood clot in space between edges of

break

Fibrocartilage callus- begins tissue repair

Bony callus- osteoblasts produce trabeculae (structural support) of spongy bone and replace fibrocartilage

Remodeling- osteoblasts build new compact bone, osteoclasts build new medullary cavity

BROKEN BONES – FRACTURE REPAIR

BROKEN BONES – TREATMENTS1. Electrical stimulation of the fracture site:• Increases speed and completeness of healing• The e- stimulation inhibits PTH and slow osteoclasts down from

reabsorbing bone

2. Ultrasound treatment:• Daily treatments reduce healing time of broken bones by 25-35%

3. Free vascular fibular graft technique:• Transplant fibula in arm• Gives good blood supply not available in other treatments

4. Bone substitutes:• Crushed bone from cadaver- but risk of HIV and hepatitis• Sea bone- coral• Artificial bone- ceramic

DISEASES OF THE SKELETAL SYSTEM Osteoporosis:

bone reabsorption happens faster than bone deposit;

bones become lighter and fracture easier Factors:

age, gender (more in women) estrogen and testosterone decrease insufficient exercise (or too much) diet poor in Ca++ and protein abnormal vitamin D receptors Smoking Caucasian or Asian ethnicity

DISEASES OF THE SKELETAL SYSTEM Rickets- vitamin D deficiency Osteomalacia- soft bones, inadequate

mineralization in bones, lack of vitamin D

Pagets Disease- spotty weakening in the bones, excessive and abnormal bone remodeling

Rheumatoid arthritis- autoimmune reaction

Growth hormone regulates skeletal growth: stimulates cell division in epiphyseal disks in long bones

Growth stops when epiphyseal disks are converted to bone

When excess growth hormone is produced in childhoodgigantism

In adulthood, bones can’t grow but soft tissue (cartilage) can acromegaly

DISEASES OF THE SKELETAL SYSTEM

ACTIVITY – BROKEN BONES Groups of 2 List which bones each of you have broken in your

body on a sheet of paper

We will go through the Powerpoint…the end of the activity will be afterward

Using the information on the slide about types of bone breaks, list what types of breaks you know (or think) that you had…You have 3 minutes to do so!

WINNERS?!?!

OVERVIEW Histology of Bone Tissue Bone Function and Structure Bone Growth & Development Joints The Axial Skeleton The Pectoral Girdle The Upper Limbs The Pelvic Girdle The Lower Limbs