1. Skeletal System Class Notes
Imagine yourself in a foreign country where you do not speak the language. Even simple conversations would be difficult. For example, what if you need
to explain how to sew a dress to someone who does not know what certain words like baste, zipper, and stitch mean? No matter how intelligent you are, you would look pretty silly making sounds and gestures to explain simple sewing procedures.
Each profession has its own language and jargon that makes it difficult for others to fully understand what is being said. (Comic) It is important to realize, however, that this specialized language is needed in order to communicate accurately and concisely. You have chosen to pursue an interest in the medical profession and it is important that you learn to “speak the lingo.”
Unit 6.4 (6th Edition)
Chapter 7.4 (7th Edition)

2. Fun Facts About the Human Skeleton
Adult humans have 206 bones
You are born with 300 bones
Bones fuse together as you age
As human develops in mother’s womb, majority of
skeleton is cartilage, not yet ossified bone
The strongest and longest bone in the femur (thigh)
The smallest bone is the stapes bone in the ear
Ounce for ounce, bone is stronger than steel and
reinforced concrete
However, in a given year, doctors around the world
treat tens of millions of broken bones!
One out of 20 people have an extra rib

3. 26 bones in head eventually fuse together with the exception of the mandible.

4. Cervical Rib – attaches posteriorly at C7 and can be floating
Or attach anteriorly to the first rib.

5. Bone Functions (Physiology)
Framework
support the body’s muscles, fat, and skin
Protection
surround vital organs to protect them
Levers
muscles attach to bones to help
provide movement
Blood Cell Production
produce red and white blood cells and platelets
Storage
store most of calcium supply of body

6. Bone Cells - Specialization
Osteoclast –multi-nuclei, Mitochondria are numerous, there is little rough endoplasmic reticulum and many lysosomes FXN: destroy bone
Osteoblast –Single nuclei, many rough endoplasmic reticulum FXN: make b
Osteocyte -long branches for increased SA. FXN: sense mechanical strain on the bone and can secrete growth factors to direct bone growth in response to the environment 
Lining cells – old osteoblasts which have become flat and pancake-shaped and  line the entire surface of the bone.  FXN: release of calcium from the bone if the blood calcium is too low.  They also have receptors for hormones and factors that initiate bone remodeling.

7. Types of Bones

8. Bone Anatomy Diaphysis long shaft of bone
medullary cavity contains yellow
marrow (fat cells)
Epiphysis
ends of long bone
contains red marrow
Red Marrow
produces red blood cells
produces platelets
some white blood cells
used to diagnose blood diseases
Periosteum
tough membrane on outside of bone
aids in bone growth, repair, nutrition

9. Bone Anatomy

10. Two Divisions of the Skeleton
Axial Skeleton
main trunk of body
skull
spinal column
ribs
breastbone
Appendicular Skeleton
extremities of body
shoulder girdle
arm bones
pelvic girdle
leg bones

11. Bones of the Skeleton

12. Joints Joints areas where 2+ bones join Ligaments
connective tissue bands
help hold long bones at joints
Tendons
tough connective tissue cords
one way skeletal muscles attach to bone
Four Main Types of Joints
classified according to degree of movement
arthr/o = joint
diarthroses- moveable (hip, elbow, knee)
amphiarthroses- partially moveable (ribs to vertebrae)
synarthroses- immoveable (cranium)

13. Diathroses (Moving) Joints
Three Major Joint Parts
articular cartilage
bursa (joint capsule)
synovial (joint cavity)
Ball and Socket
shoulders, hips
Hinge
knees, elbows
Pivot
radius, ulna
Gliding
vertebrae

14. Diseases & Abnormal Conditions
Arthritis
inflammation of the joints
Osteoarthritis
most common form of arthritis
chronic disease due to aging
commonly affects knees and hips
symptoms are stiffness, pain, aching, limited range of motion
no cure, but treatments include: anti-inflammatory medications, heat/
cold application, steroid injections, and rest
Rheumatoid arthritis
affects joints and connective tissues
3 times more common in women than men
occurs between 35 and 45 years of age
can case scar tissue formation and atrophy
of bone and muscle tissue
results in deformity and immobility
rest, anti-inflammatory medications, and surgery

15. Diseases & Abnormalities Continued
Bursitis
inflammation of bursae (small, fluid-filled sacs surrounding joints)
common in shoulders, elbows, hips, or knees
Dislocation
when bone is forcibly displaced from a joint
common in shoulders, fingers, knees, and hips
Sprain
twisting action tears ligaments at joint
common in wrists and ankles
Osteomyelitis
bone inflammation usually caused by pathogenic organism
abscess is formed within the bone and accumulation of pus
Osteoporosis
increased porosity or softening of bones caused by hormone deficiency
lack of calcium, and sedentary lifestyle
Ruptured (Herniated) Disk
occurs when an intervetrebral disk ruptures/protrudes out of place

16. Skeletal System Class Notes
Bone Fractures
Skeletal System Class Notes
Definition
crack or break in a bone
Greenstick
bone bends & is split causing a crack/incomplete break common in kids
Simple or Closed
complete break of the bone with no damage to skin
Compound or Open
bone breaks and ruptures through the skin with increased infection risk
Impacted
broken bone ends jam into each other
Comminuted
bone fragments/splinters into 2+ pieces
Spiral
bone twists and results in one or more breaks
Depressed
broken piece of skull bone moves inward
Colles
breaking and dislocation of distal radius that causes bulge at wrist

17. Bone Fractures Continued
Skeletal System Class Notes