1. HESS 510 PPT Series 1B Foundations of Structural Kinesiology

2. Body Regions (skeletal mass)
The skeletal mass is subdivided into two basic components: The Axial and the Appendicular Skeleton
Appendicular
Upper limbs
Lower limbs
Axial
Cephalic (head)
Cervical (neck)
Trunk

3. Osteology (Bone the study of)
Adult skeleton has approximately 206 bones (FYI). Exact number of bones as well as their specific features occasionally varies from person to person
Axial skeleton
Contains 80 bones (FYI)
Appendicular skeleton
Contains 126 bones (FYI)

4. Skeletal Functions
Protection – Which systems and organs are protected by the skeletal mass?
Posture – How does the skeletal mass promote stability and posture?
Movement – How does the skeletal mass promote movement (muscles and levers)?
Storage of minerals (calcium and phosphorus)
Hemopoiesis –blood cell production… see next slide

5. Skeletal Functions
Hemopoiesis – FYI not on test for discussion only

6. Types of Bones
Bones vary in shape and size and are classified into five major categories:
Long bones
Short bones
Flat bones
Irregular bones
Sesamoid bones

7. Types of Bones – Long Bones
Composed of a long cylindrical shaft with relatively wide, protruding ends. The shaft contains the medullary cavity
Examples pictured - Femur, Radius, Ulna

8. Types of Bones – Short Bones
Small cube-shaped, solid bones that usually have a proportionally large articular surface in order to articulate with more than one bone
Examples Pictured– Capitate (carpal bone) and Talus (tarsal bone)

9. Types of Bones – Flat Bones
Usually have a curved surface and vary from thick, (where tendons attach), to very thin. Flat bones generally provide protection.
Examples Pictured – Scapula, Sternum = (manubrium, body, xiphoid process)

10. Types of Bones – Irregular Bones
Irregular shaped bones serve a variety of purposes Irregular bones are found throughout the entire body.
Examples Pictured: Sphenoid (found in craniofacial skeleton, and a thoracic vertebra.

11. Types of Bones -Sesamoid Bones
Small bones embedded within tendon of a musculotendinous unit that provide protection and improve mechanical advantage (more discussion on mechanical advantage p.72, text) of musculotendinous units.
Examples Pictured – Patella, Sesamoid of Great Toe

12. Typical Bony Features - Terms
Diaphysis – (dia = through; physis = something the grows / develops) Long cylindrical shaft
Cortex – (word origin = bark, shell, husk) Hard, dense and compact bone forming walls of the diaphysis
Periosteum – (peri = about or around; osteum = bone) Dense, fibrous membrane covering the outer surface of the diaphysis

13. Typical Bony Features - Terms
Endosteum – (Endo = within) Fibrous membrane that lines the inside of the cortex
Medullary (word origin = marrow, pith) cavity
Lies between the walls of the diaphysis
Contains yellow or fatty marrow

14. Typical Bony Features - Terms
Epiphysis (Epi= at or near; physis = something that grows / develops)
Appears at the ends of long bones
Formed from cancellous (word origin = lattice) bone. Cancellous bone is also called spongy or trabecular (word origin = little beam) bone
Epiphyseal plate (also called growth plate)
Thin cartilage plate that separates the diaphysis and the epiphysis

15. Typical Bony Features - Terms
Articular (word origin = pertaining to joints) cartilage (word origin = gristle)
Covers the epiphysis to provide a cushioning effect and reduces friction

16. Bone Growth Endochondral bones (endo = within)
Develop from hyaline (word origin = glass) cartilage. Hyaline cartilage is found between many bone articulations (hip/knee)
Hyaline cartilage masses grow rapidly into structures as humans develop from an embryo.

17. Bone Growth
Grow rapidly into structures shaped similar to the bones that they will eventually become
Growth continues, and cartilage gradually undergoes significant change to develop into long bone

18. Bone Growth
Longitudinal growth continues as long as the epiphyseal plates are open
Around adolescence, plates begin closing and disappear
Note growth in both vertical and longitudinal directions. As bone continues to develop the medullary cavity forms and bone diameter increases with an increase in the diaphysis.

19. Bone Growth
Most close by age 18, but some may be open until age 25
Growth in diameter continues throughout life as the internal layer of periosteum builds concentric layers on older layers.
Simultaneously, bone around the medullary cavity is resorbed so that the diameter is continually increased

20. Bone Growth
New bone is formed by specialized cells called osteoblasts (blast = bud, sprout)
Cells that remove (resorb) old bone tissue are called osteoclasts (clast = to cut)
Activity of both permit bone remodeling

21. Bone Properties
Composed of calcium carbonate, calcium phosphate, collagen, and water
60–70% of bone weight = Minerals: Calcium carbonate and calcium phosphate
25–30% of bone weight = Water
Collagen (word origin: colla = glue; -gen = that which produces) provides some flexibility and strength in resisting tension
Aging causes progressive loss of collagen and increases bone brittleness

22. Bone Properties
Most outer bone is cortical; cancellous bone is underneath
Cortical bone - 5%–30% of volume is porous (low porosity)
Cancellous bone (trabecular )- Spongy with 30 to 90% of its volume being porus
Cortical bone is stiffer and can withstand greater compression stress, but less strain, than cancellous bone
Cancellous bone is spongier and can undergo greater strain (deformation) before fracturing

23. Bone Properties Wolff’s law
Bone size and shape are influenced by the direction and magnitude of forces that are habitually applied to them
Bones reshape themselves based on the stresses placed upon them
Bone mass increases over time with increased stress

24. Bone Markings Bone Markings may be defined in two major categories:
Processes (including elevations and projections)which either form joints or serve as a point of attachment for muscles, tendons, or ligaments.
Cavities (word origin = hollow) which include openings and groves that contain tendons, vessels, nerves, and spaces for other structures.
Study all terms in Table 1.4, p. 15
End PPT Series 1B