Unit 3 Part 2
- 206 Total bones (Axial – 80, Appendicular 126)
A. Consists of bones from:
AXIAL SKELETON APPENDICULAR SKELETON
- Skull (Cranium, Ear bones, and Facial Bones)
- Spine (Vertebrae)
- Thorax (Ribs and Sternum)
- Hyoid bone (Tongue attachment)
- Frontal (1) – Forehead, Upper eye sockets
- Parietal (2) - Topsides of cranium
- Temporal (2) – Lower sides of cranium, middle and inner ear, mastoid process, external auditory canal, and styloid process.
- Occipital (1) – Back of skull, Foramen magnum
- Sphenoid (1) – Central floor of cranium
- Ethmoid (1) – Floor of cranium, side walls and roof of nose.
Suture – Synarthrotic (immovable) joint
- Lambdoidal – Between parietal and occipital bones.
- Squamosal – Between parietal and temporal and part of sphenoid bone.
- Coronal – Between parietal and frontal bones.
- Malleus – Hammer
- Incus – Anvil
- Stapes - Stirrup
- Nasal (2) – Bridge of nose
- Maxilla (2) – Upper jaw bones, roof of mouth, floor and side of nose, and floor and roof of orbits (eyes).
- Zygomatic (2) – Cheek bones and orbits
- Mandible (1) – Lower jawbone (movable) and condyloid process.
- Lacrimal (2) – Medial wall of eye socket, side wall of nasal cavity.
- Palatine (2) – Back part of mouth roof, floor and side walls of nose. (can't see on above diagram)
- Inferior concha (2) – Curved ledge along inside wall of nose.
- Vomer (1) – Lower back portion of nose
F. Bone of the Spine
Cervical vertebrae (7) – Superior bones of vertebrae.
- Atlas (1st/C1) Axis (2nd/C2)
- Thoracic vertebrae (12) - Attachment site of ribs.
- Lumbar vertebrae (5) – Small of back
- Sacrum (1) – Child – 5 separate bones - Adult – 1 fused bone
- Coccyx (1) – Child – 3-5 separate bones - Adult – 1 fused bone
- True ribs (14) – Upper 7 pair, attached to sternum by costal cartilage.
- False ribs (10) – Lower 5 pair. Last 2 pair are called floating ribs (not attached to sternum)
Sternum (1) – Breast bone
- Manubrium – Top portion
- Gladiolus/Body – Middle portion
- Xiphoid process – Cartilage at inferior end.
- Only bone of the skeleton not articulated to another bone
- Supported by the muscles of the neck
- Supports the root of the tongue
- Upper extremity
- 126 bones
AXIAL SKELETON APPENDICULAR SKELETON
B. Upper Limb (Arm and hand)
Clavicle (collar bone)
- Sternoclavicular joint – Attachment point between sternum and clavicle.
- Scapula (shoulder blade)
- Humerus – Upper arm bone, 2nd longest bone
Radius (thumb side) and Ulna (pinky side) – Forearm bones
- Radius rotates over the top of the ulna bone when hand is supinated
- Carpal – 8 wrist bones
- Metacarpals – 5 palm bones
Phalanges – 14 finger bones
- 27 bones in hand allow for great movement.
C. Lower extremity
Pelvic (hip) girdle
- Connects legs to trunk
Consist of 2 Os Coxa (Separate in infants – Ilium, Ischium, and Pubis) Fused in adults and come together at front forming joint called symphysis pubis.
- Femur (thigh) – Longest and strongest bone in body.
- Patella – Kneecap
- Tibia – Lower weight bearing leg bone.
- Fibula – Lower non – weight bearing bone.
Tarsals (7) – Ankle
- Largest tarsal bone is the calcaneous (heel bone).
- Metatarsals (5) – Top of foot
- Phalanges (14) – Toes
D. Foot Arches
- Medial Longitudinal – Inner foot (Duck-walk)
- All bones are connected to other bones, except hyoid bone (tongue attachment).
- Synarthrotic – No movement
- Connective tissue connects bone.
- Cranial bone
- Amphiarthrotic – Slight movement
- Cartilage connects bone.
- Symphysis pubis, Vertebrae
Diarthrotic – Free movement -
- Contain joint capsule (fibrous connective tissue and synovial membrane), joint cavity, and layer of cartilage.
- Ligaments present to add strength.
Types of Diarthrotic Joints
- Ball and Socket – Ball shaped bone (Head) fits into a concave socket (Fossa).
- 1. Shoulder and Hip
- 2. Greatest amount of movement of any joint
- Hinge – Two directional movement.
- 1. Elbow and Knee
- Pivot – Small projection pivots on another.
- 1. Atlas on axis (Vertebrae)
- 2. Radius over ulna
- Saddle – Allow for great degree of movement.
- 1. Opposable thumb
Gliding – Least moveable
- 1. Joints between vertebrae
IV. Fractures of Bone
- Greenstick – Incomplete break which occurs on convex surface of bend. (Children)
- Fissured/Longitudinal – Incomplete longitudinal break. (Impact to end of bone)
- Comminuted – Complete break resulting in many fragments. (Tremendous force)
- Transverse – Complete break at a right angle. (Impact)
- Oblique – Occurs at other than right angle. (Impact)
- Spiral – Caused by twisting a bone excessively.
- Compression -- Fracture that occurs from a "pinching" that collapses the bone (vertebrae)
- Depression -- Bone that has been pressed inward (ie. = fractured skull bones)
- If bone penetrates skin = Compound fracture
- If bone is covered by skin = Simple fracture
- Break due to injury = Traumatic fracture
- Break due to disease = Spontaneous or Pathologic fracture
B. Repair of a Fracture
- When a bone is broken, blood vessels and periosteum are also broken.
4 steps to repair a fractured bone
- Inflammation: Causes blood to form and escape and creates a hematoma.
- Soft Callus: Fibrocartilage blueprint forms in damaged area
- Hard Callus: Fibrocartilage is replaced by bony callus.
- Remodeling: Osteoclasts smooth callus and recreate the medullary cavity.
- Proximity and number of fractured bones.
- Leg bones take twice as long to heal as any other bone.
- As age increases, so does healing time.