Unit 3 Part 2 Notes

Unit 3 Part 2

 

  • 206 Total bones (Axial – 80, Appendicular 126)
 
I.  Axial Skeleton

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)

 

B.  Cranial Bones
 
 
  • 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.
C.  Cranial Sutures

  • 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.
D.  Ear Bones

         

  • Malleus – Hammer
  • Incus – Anvil
  • Stapes - Stirrup
E.  Facial Bones

 

  • 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
 
 
 
 
G.  Bones of the Thorax

  • 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.
 
H.  Hyoid Bone

  • Only bone of the skeleton not articulated to another bone
  • Supported by the muscles of the neck
  • Supports the root of the tongue
 
II.  Appendicular Skeleton
  • 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)

 

  • Lateral Longitudinal – Outer foot (Pigeon toe)

 

  • Transverse (Metatarsal) – Left to right in middle of foot. (Flat-footedness)
 
III.  Joints (Articulations)
  • All bones are connected to other bones, except hyoid bone (tongue attachment).
 
A.  Joints are classified according to degree of movement.

  

  •  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).

          ballandsocket.gif (37701 bytes)     

      • 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.

           pivot.gif (42790 bytes)                                                        

      • 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)
 
A.  Fractures of Bone
  • 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.
C.  Factors Affecting Repair of Fractures
  • 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.