1. Integumentary and Skeletal Systems
Test Notes

2. Skeletal System The skeletal system consists of:
Bones
Cartilage
Tendons
Ligaments
Bone maintains the shape of the body, protects internal organs, is a lever system for muscles to act upon, and is a site of mineral storage and blood-cell formation.
Cartilage forms a fetal model of bone, covers the ends of bones, and provides a firm, flexible support.
Tendons attach muscle to bone.
Ligaments attach bone to bone.
To help you remember: LLL, TTT (ligaments are like to like, tendons are two types)

3. Skeletal System (Tendons and Ligaments)
extracellular matrix of tendons and ligaments is made up of primarily collagen fibers which makes them very tough like ropes or cables.
ligament

4. Skeletal System (Cartilage)
Three types of cartilage:
Hyaline
Elastic
Fibrocartilage
Hyaline cartilage is most intimately associated with bone function and development
hyaline
elastic
fibrocartilage

5. Skeletal System (Bone)
Bone Tissue Types:
Cancellous (Spongy)
Compact
Cancellous Bone:
Located mainly in the epiphyses of long bones & the interior of all other bones.
Consists of a lacy network of bone with many small, marrow-filled spaces.
Compact Bone:
Mostly solid matrix and cells.
Forms most of the diaphysis of long bones & the thinner surfaces of all other bones.
cancellous
compact

6. Skeletal System (Bone)
Bone is composed of an organic matrix (mostly collagen) that provides flexible strength and an inorganic matrix (hydroxyapatite) that provides compressional strength (weight bearing).
Hydroxyapatite are calcium phosphate crystals
Bone is formed in thin sheets of extracellular matrix called lamellae
Compact bone consists of cells called osteocytes located within spaces in the matrix called lacunae

7. Skeletal System (Bone)
Ossification is the formation of bone by osteoblasts
Intramembranous ossification occurs when osteoblasts begin to produce bone in connective tissue membranes (primarily in bones of the skull)
Endochondral ossification is the process that produces most of the skeleton, occurs when bones develop from cartilage models, and occurs when osteoblasts invade the spaces left by dying cartilage cells

8. Skeletal System (Bone)
Four types of bone, based on their shape:
Long
Short
Flat
Irregular

9. Skeletal System (Bone Shapes)
Long bones are longer than they are wide (bones of upper & lower limbs).
Short bones are approximately as broad as they are long (bones of ankle & wrist).
Flat bones have a relatively thin flattened shape (some skull bones, ribs, & sternum).
Irregular bones do not fit in the other shape categories (vertebrae & facial bones).
Long bones
Short bones
Flat bones
Irregular bones

10. BONE STRUCTURE - Long Bone
Epiphysis
Diaphysis
Hyaline (Articular) Cartilage
Periosteum

11. Skeletal System (Bone)
a long bone has a diaphysis (shaft) and an epiphysis (each end)
the epiphyseal plate (growth plate), is the site of growth in length of a long bone, and is found between each epiphysis and the diaphysis
a long bone has a medullary cavity (filled with yellow marrow) in the diaphysis, has cancellous bone at the ends (filled with red marrow)
has an endosteum lining the medullary cavity
outer surface covered by a connective tissue layer- periosteum

12. Structure of a Long Bone
Figure 6.3a-c

13. Medullary Cavity – hollow chamber filled with bone marrow
Inside the Long Bone
Medullary Cavity – hollow chamber filled with bone marrow
Red Marrow (blood)
Yellow Marrow (fat)
Endosteum
– lining of the medullary

14. Compact (wall of the diaphysis) Spongy (cancellous, epiphysis)
Types of Bone Tissue
Compact (wall of the diaphysis)
Spongy (cancellous, epiphysis)

15. Review the Structure of a Long Bone
Matching quiz at

16. Microscopic Structure
MATRIX - where the bone cells live
OSTEOCYTES  - mature bone cells, enclosed in tiny chambers called LACUNAE
OSTEOCYTES form rings (LAMELLAE) around a HAVERSIAN CANAL which houses blood vessels
Osteocytes are linked by CANALICULI
Haversian Canals are linked by VOLKMAN's CANALS

17. Compact Bone

19. BONE DEVELOPMENT & GROWTH
Intramembranous bones – flat, skull
 Endochondral bones – all other
ALL BONES START AS HYALINE CARTILAGE, areas graduallly turn to bone
         
PRIMARY OSSIFICATION CENTER (shaft)
        
SECONDARY OSSIFICATION CENTER (ends)

20. Bone Development & Growth
EPIPHYSEAL DISK  (growth plate) is a band of cartilage between the epiphysis and diaphysis
These areas increase bone length as the cells ossify
Cartilage becomes OSTEOBLASTS become OSTEOCYTES

21. RESORPTION
OSTEOCLASTS - dissolve bone tissue to release minerals,  process is called RESORPTION

22. Bone Growth

23. Bone Growth