1. The Skeleton

2. Skeleton The word skeleton comes from a Greek work meaning “dried up”
Infants are born with about 350 bones which fuse resulting in 206 bones that provide the framework for our structure
177/206 is for voluntary movement

3. Functions Protection: Blood Production: Storage: Movement:
Soft tissues and vital organs i.e. brain, heart lungs, and spinal cord
Blood Production:
Red blood cells (manufactured by red marrow)
Storage:
- Calcium and phosphorous
Movement:
Act as levers for muscle activity

4. Skeleton Organization
Two Divisions:
Axial Skeleton: protection of internal organs
Appendicular Skeleton: movement

5. Axial Skeleton 80 bones Forms the vertical axis of the body: Skull
Vertebral Column
Thoracic Cage:
Ribs
Sternum

6. Appendicular Skeleton
126 bones
Forms the appendages and their attachments to the appendicular skeleton:
Upper Limbs
Lower Limbs
Shoulder Girdle
Pelvic Girdle

7. Skull
Bones that support the head, neck, and trunk, and protects the brain and spinal cord:
- Cranial bones, facial bones, auditory ossicles, and hyoid bone
Cranial Bones: enclose and protect the brain
Facial Bones: forms the framework of the face

8. Skull
Hyoid bone:
Only bone that does not articulate with any other bone
Suspended above the larynx (voice box) where it is anchored by ligaments to the styloid process of the temporal bone
Helps to support the tongue
Serves as an attachment point for muscles to help elevate the larynx during swallowing

9. Skull Auditory Ossicles:
Stapes (stirrup), Incus (anvil), Malleus (hammer)
Named for their shape
Three smallest bones in the human body
Located in the middle ear
Transmit sound

10. Thoracic Cage 25 bones (page 4): Sternum and 24 Ribs Ribs:
Encases heart, lungs, and organs
Attached posteriorly to T1-T12
Ribs 1-7 are True Ribs and attach anteriorly to manubrium and body of sternum
Ribs 8-10 are False Ribs, their cartilage joins the 7th rib anteriorly
Ribs 11 and 12 are Floating Ribs and do not attach to the sternum

12. Coccyx: Tailbone 26 Bones (pg. 3) 7 cervical vertebrae
Vertebral Column
26 Bones (pg. 3)
7 cervical vertebrae
12 Thoracic Vertebrae
5 Lumbar Vertebrae
Sacrum
5 fused vertebrae
Coccyx: Tailbone

13. Cervical Vertebrae
Begins at the base of the skull
Seven cervical vertebrae-C1-C7
Smaller in size than rest of vertebrae
Most moveable vertebrae
Protect the spinal cord, support the skull, and provide movement (i.e., rotation)
Eight pairs of cervical nerves which control breathing and upper body muscles (C3 controls diaphragm)
C1 is called the Atlas (ring shaped; no body and spinous process)
C2 is called the Axis (has a body, spinous process, and dens)

15. Thoracic Vertebrae 12 Thoracic Vertebrae-T1-T12 Located in the chest
Very little movement due to attachment to Ribs and
Sternum
Protect internal organs
1 Vertebral Body
2 Spinous Process
3 Transverse Process
4 Pedicle
5 Foramen
6 Lamina
7 Superior Facet

16. Lumbar Vertebrae 5 Lumbar Vertebrae-L1-L5
Designed to carry most of the body’s weight
Largest vertebrae
More range of motion than thoracic vertebrae, but less than cervical vertebrae

17. Sacrum Located behind the pelvis Connects the spine to the pelvis
Five fused bones-S1-S5
Below the sacrum are five additional fused bones which form the coccyx (tailbone)

18. Curvature of the Spine
Acts like a spring to absorb shock, maintain balance, and allow range of motion
Cervical Spine:
Curves slightly inward
Inward curve of the spine
is called Lordosis
Thoracic Spine:
Curves outward
Outward curve of the
spine is called Kyphosis
Lumbar Spine:
Curves slightly inward-Lordosis

19. Intervertebral Disks
In between the vertebrae are intervertebral discs made of fibrous cartilage that act as shock absorbers and allow the back to move.
As a person ages, these discs compress and shrink, resulting in a distinct loss of height (generally between 0.5 and 2.0cm) between the ages of 50 and 55.

20. Axial Skeleton Summary
Vertebral column
7 cervical vertebrae
12 thoracic vertebrae
5 lumbar vertebrae
Sacrum
Coccyx
Skull
Cranial bones
Facial bones
Auditory ossicles
Hyoid bone
Thoracic Cage
24 ribs
Sternum

21. Shoulder Girdle (pages 4-5)
Pectoral or Shoulder Girdle
Clavicle (2): collarbone
Scapula (2): shoulder blade

22. Upper Extremities (pages 5-7)
Humerus (2): arm bone
Radius (2): forearm (thumb side)
Ulna (2): forearm (pinky side)
Carpals (16): wrist bones 8 in each wrist
Metacarpals (10): hand bones
Phalanges (28): Fingers
2 in each thumb and 3 in each finger

23. Pelvic Girdle (pg. 80)
Attaches the lower limbs and transmits the weight of the upper body to the lower limbs
Ilium: upper portion of the pelvis
Ischium: what we sit on (butt bones)
Pubis: Lower most anterior part of pelvis

24. Lower Extremities (pages 81-83)
Femur (2): largest, longest and strongest bone (Thigh bone)
Patella (2): Kneecap
Tibia (2): Large shin bone
Fibula (2): Thin shin bone
Tarsals (14): ankle bones
Metatarsals (10): foot bones
Phalanges (28): Toes 2 in big toe and 3 in all other toes

25. Appendicular Skeleton Summary
Shoulder Girdle
Clavicle
Scapula
Upper Extremities
Humerus
Radius
Ulna
Metacarpals
Carpals
Phalanges
Pelvic Girdle
Ilium
Ischium
Pubis
Lower Extremities
Femur
Patella
Tibia
Fibula
Tarsals
Metatarsals
Phalanges

26. Bone Markings
Passageways, joint formations, and attachment points for muscles, tendons, and ligaments
Foramen: rounded hole or opening
Foramen Magnum is the large hole in the skull

27. Bone Markings Process: projection Spinous Process of Vertebrae
Fossa: shallow or hollow surface
Iliac Fossa of Pelvis
Crest: a prominent ridge
Iliac Crest of Pelvis

28. Bone Markings Condyle: smooth or rounded projection
Lateral and Medial Condyles of the Femur
Epicondyle: projection located above a condyle
Medial and Lateral Epicondyles of the Humerus

29. Bone Markings Trochanter: a large rough projection
Greater Trochanter of Femur
Tuberosity: a small rounded projection
Tibial Tuberosity