1. The Skeletal System

2. The Skeletal System
Structure and function of bone
Organization of the Skeleton
Joints

3. THE ANATOMICAL POSITION
The body in an upright, standing position,
face and feet pointing forward,
arms at the side
forearms fully supinated (palms forward).

4. Anatomical Planes The body moves in relation to 3 planes:
Frontal (Coronal) –
divides the body into anterior (front) and posterior (back) segments.
Transverse –
divides the body into superior and inferior segments.
Sagittal –
divides the body into medial and lateral segments.

6. Functions of bone (skeleton)
Support and protection
Blood cell formation
Mineral storage (calcium especially)
Site for muscle attachmentbody movement

7. Role of the Skeleton Protection
1. They protect vital organs and structures from trauma. The brain is packaged in a hard shell filled with cerebral spinal fluid, which helps absorb shock. Lungs and heart protected by the rib cage.
Framework
1. Structural support for soft tissue, including muscles and viscera.
Movement
1. Muscles attach to bones by tendons. Muscles contract and move bones to facilitate movement.
Storehouse for Essential Nutrients
1. The bones store calcium and phosphorus for the body.
Blood Cell Formation
1. Red blood cells and platelets are made in bones.

8. About Bone…
Composed of 50% H2O and 50% organic and inorganic material.
Elements include:
phosphorus, zinc, calcium, magnesium, flourine, iron, and chlorine.
Resists compression and tension.
Bounded by joints – through ligaments.
Muscles attach to bones by tendons, this produces movement.

9. Classification of Bones
5 Types of bones classified according to their shape.
1. Long Bones: found in the arms and legs. Femur is a long bone.
2. Short Bones: most common in the wrists and ankles.
3. Flat Bones: are flat and thin and often protect vital organs from injury. (Skull Bones)
4. Irregular Bones: odd looking bones . (Vertebrae)
5. Sesamoid Bones: are unusual bones that are small and flat wrapped within tendons that move over bony surfaces. (patella)

10. Bones classified by shape:
Long
Short
Flat
Irregular
Round

11. Bone enclosed in periosteum, which is continuous
with tendons and ligaments
blood vessels in periosteum
Epiphysis- ends
spongy bone contains red marrow
compact bone, articular cartilage
Diaphysis- middle
compact bone
medullary cavity- contains yellow marrow (fat)
lined with endosteum (squamous epithelium)

12. ANATOMY OF A LONG BONE
1. Epiphysis: Very ends of long bones, made up of compact bone. The part where the bone articulates with other bones. It is covered with cartilage.
2. Diaphysis: The shaft of the bone.
3. Articulating Cartilage: Located on both ends of long bones. It allows smooth movement within joints.
4. Periosteum: Outer connective tissue that covers the entire length of the bone. Helps connect bone to bone and bone to muscle.
5. Medullary Cavity: Found inside the shaft of the bone and is filled with red and yellow bone marrow. Red marrow forms red blood cells. Yellow is fat.
6. Compact Bone: Dense part of the bone. Structural Integrity.
7. Spongy Bone: Filled with marrow. Strengthens with specific exercises. (Cancellous Bone)

14. Compact bone
osteocytes within lacunae
arranged in concentric circles called lamellae
This surround a central canal; complex is called
Haversian system
Canaliculi connect osteocytes to central canal and
to each other

16. 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

19. BONE FORMATION AND REMODELLING
Osteocytes: Bone cells
Osteoblasts: Bone building cells.
Osteclasts: Bone destroying cells.
Ossification of Bone is the growth of bones. Short bones have a single ossification center in the middle. Long bones of the arms and legs have 3, one at the center and one at each end.
Growth continues until the epiphyseal plate has ossified and longitudinal growth is no longer possible.
Bone Remodelling: During early growth, new deposits of bone replace old deposits so growth can continue.

20. Adults continually break down and build up bone
Osteoclasts remove damaged cells and release
calcium into blood
Osteoblasts remove calcium from blood and build
new matrix. They become trapped
osteoclasts

21. Axial skeleton
skull (cranium and facial bones)
hyoid bone (anchors tongue and muscles
associated with swallowing)
vertebral column (vertebrae and disks)
thoracic cage (ribs and sternum)
Appendicular skeleton
pectoral girdle (clavicles and scapulae)
upper limbs (arms)
pelvic girdle (coxal bones, sacrum, coccyx)
lower limbs (legs)

23. Axial skeleton-
supports and protects organs
of head, neck and trunk
Appendicular skeleton-
bones of limbs and bones
that anchor them to the axial
skeleton
Articulation-
where joints
are formed

24. 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

25. The skull
8 sutured bones in cranium
Facial bones: 13 sutured bones, 1 mandible
Cranium
encases brain
attachments for muscles
sinuses

27. Allows for
growth

28. Vertebra

29. Vertebral column
7 cervial vertebrae
12 thoracic
5 lumbar
1 sacrum (5 fused
1 coccyx (4 fused)
Vertebrae vary in size and morphology

31. Thoracic cage
ribs
thoracic vertebrae
sternum
costal cartilages
True ribs are directly attached to the sternum
(first seven pairs)
Three false ribs are joined to the 7th rib
Two pairs of floating ribs

33. Clavicles and scapulae
Help brace shoulders
Attachment sites for muscles

35. Bones of upper limb
Humerus (upper arm)
Radius
Ulna
Carpals
Metacarpals
Phalanges

36. Bones of lower limb
Femur
Patella
Tibia
Fibula
Tarsals
Metatarslas
Phalanges

38. Joints
Immovable (synarthoses) bones sutured together
by connective tissue: skull
Slightly movable (amphiarthoses) connected by
fibrocartilage or hyaline cartilage:
vertebrae, rib/sternum joint, pubic
symphysis
Freely movable (diarthroses)- separated
ligaments- hold bones together
tendons- muscle to bone
lined by synovial membrane

41. Types of freely movable joints
Saddle: carpal and metacarpal bones of thumb
Ball and socket: shoulder and hip joints
Pivot- rotation only: proximal end of radius and ulna
Hinge- up and own movement in one plane:
knee and elbow
Gliding- sliding and twisting: wrist and ankle
Condyloid- movement in different planes but not
rotations: btw metacarpals and phalanges

42. When muscle contracts, it shortens and causes
movement
Skeletal muscles attached to bones by tendons
Insertion- attachment to more movable bone
Origin- less movable
Flexors and extensors act on the same joint
to produce opposite actions

44. Types of Movement Flexion Extension Abduction Adduction Rotation
Suppination
Pronation
Circumduction
Inversion
Eversion
Elevation

45. flexion- move lower leg toward upper
extension- straightening the leg
abduction- moving leg away from body
adduction- moving leg toward the body
rotation- around its axis
supination- rotation of arm to palm-up position
pronation- palm down
circumduction- swinging arms in circles
inversion- turning foot so sole is inward
eversion- sole is out
elevation and depression- raising body part up
or down

49. Aging and bones
both bone and cartilage tend to deteriorate
cartilage: chondrocytes die, cartilage
becomes calcified
osteoporosis; bone is broken down faster
than it can be built
bones get weak and brittle; tend to fracture
easily

51. Risk factors for osteoporosis
Inadequate calcium
Little weight-bearing exercise
Drinking alcohol, smoking
Being female: decreased estrogen secretion
after menopause
Small frame
Caucasian or Asian

53. Skeleton and other systems
Skin makes vitamin D which enhances calcium
absorption
Skeleton stores calcium for muscle contraction,
nervous stimulation, blood clot formation
Red marrow- site of blood cell formation
Calcium levels regulated by
parathyroid hormone and calcitonin
kidneys (can help provide vitamin D)
digestive system (can release calcium
into blood

55. 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
childhoodgigantism
In adulthood- acromegaly. Bones can’t grow
but soft tissue can

57. Types of bone fractures
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

62. Sports Medicine
Anatomy

67. Displaced fracture of the fifth metacarpal head Caused by softball.

72. 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

74. Breaks

75. Repair

77. Clavicle Fracture Repair

78. Total Knee Replacement