1. Skeleton is divided into
Skeletal Organization
Skeleton is divided into
two divisions!
Axial (the center or “axis”)
Appendicular (legs and arms)

3. Axial skeleton
1. Skull (28 bones including auditory ossicles)
2. Hyoid bone (1 bone)
3. Vertebral column (26 bones)
a. Cervical (7 vertebrae)
b. Thoracic (12 vertebrae)
c. Lumbar (5 vertebrae)
d. Sacrum (1 – 5 fused vertebrae)
e. Coccyx (1 -~4 fused vertebrae)
4. Thoracic Cage (25 bones)
a. Ribs (24)
b. Sternum (1 – 3 parts)
80 total bones in axial skeleton

4. The Skull – 28 bones Braincase – encloses cranial cavity
Surrounds & protects brain
6 bones, 8 when paired
Facial bones – forms facial structure
8 bones, 14 when paired
Auditory ossicles – form the middle ear
These bones transmit vibration to eardrum
Malleus, incus, & stapes

5. Braincase bones – 8 bones
2 parietals
2 temporals
1 frontal
1 occipital
1 sphenoid
1 ethmoid

6. Braincase Parietals (wall) Most of sides & roof of cranial cavity
Joined to temporal by squamous suture (scale-like)
Joined to frontal by coronal suture (crown)
Joined to occipital by lambdoid suture ()
Sagittal suture joins two parietals

7. Braincase Temporals (time)
Inferior part of cranium & part of cranial floor
Joined to occipital and parietal by squamous suture
External auditory meatus – sound waves travel through to eardrum
Mastoid process – neck muscle attachment for head rotation
Other landmarks:
Zygomatic Process – articulates with zygomatic
Mandibular Fossa – articulates with mandible
Styloid Process – muscle attachment for tongue, hyoid, & pharynx movement

8. Braincase Occipital (back of head) Sphenoid (wedge-shaped)
Posterior part & prominent portion of the base of the cranium
Joined to parietals by lambdoid suture
Occipital bone landmarks:
Foramen Magnum – passage of spinal cord (connects to brain)
Occipital Condyles – articulate with vertebral column
Sphenoid (wedge-shaped)
Connects to all other cranial bones
Sella turcica (next slide) – contains pituitary gland

9. Braincase
Ethmoid
Light, spongy bone that increases surface area of nasal cavity
Moistens & warms inhaled air
Anterior floor of the cranium between the orbits
Composes much of nasal cavity & part of nasal septum
Ethmoid bone landmarks:
Crista Galli
Perpendicular Plate – part of nasal septum (with vomer)
Superior Nasal Conchae & Middle Nasal Conchae – form lateral walls of nasal cavity

11. Facial bones – 14 bones 2 maxillae 2 zygomatic 2 palatine 2 nasals
2 lacrimals
2 inferior nasal conchae
1 mandible
1 vomer

12. Facial Bones Zygomatic bones cheek bones
form the floor & outer walls of the orbits
Zygomatic bone landmarks:
Temporal processes
Zygomatic arches (temporal & zygomatic)
Muscle attachment for moving the mandible

13. Facial Bones Maxillae paired bones forming upper jaw (holds teeth)
articulate with every bone of the face except the mandible
Maxillary bone landmark:
Palatine Processes = horizontal projection forming the anterior 2/3 of the hard palate (palatines form the rest)

14. Facial Bones Mandible Mandible landmarks: Lower jaw (holds teeth)
Largest and strongest bone in the face
the only moveable skull bone
Articulates with the temporal bone to form the Temporal Mandibular Joint (TMJ)
Mandible landmarks:
Ramus = perpendicular portion of bone
Angle
Mandibular condyle = articulates with temporal
Mandibular Notch

15. Facial Bones Nasal bones Lacrimals Palatines Bridge of nose
Forms part of tear duct
Palatines
Posterior 1/3 of hard palate

16. Facial Bones Inferior nasal conchae Vomer
Part of nasal septum (with perpendicular plate of ethmoid)

17. Other Skull Features Orbits Nasal cavity Made by 7 bones!
Orbit landmarks:
Superior orbital fissures & Inferior orbital fissures
Blood vessels & nerves
Optic foramen (optic nerve)
Nasolacrimal canal (tear duct)
Nasal cavity
Nasal septum = vomer + ethmoid (perpendicular plate)
Nasal conchae
Inferior nasal concha – individual bone
Superior & middle nasal conchae – ethmoid bone
Increase surface area

18. Paranasal sinuses Open into nasal cavity
Decrease skull weight & serve as resonating chambers during voice production
Frontal, maxillary, ethmoidal, & sphenoidal

19. Hyoid bone U-shaped Not part of skull
No direct bony attachment to skull (attached by muscles & ligaments)
Attachment site for tongue & larynx muscles (speech & swallowing)

21. Vertebral Column “Backbone” Central axis of skeleton 5 regions:
Cervical vertebrae (neck + to turn) (C1-C7)
Thoracic vertebrae (T1-T12)
Lumbar vertebrae (L1-L5)
Sacral (S)
Coccygeal bone (CO)
4 curves:
Cervical curves anteriorly
Thoracic curves posteriorly
Lumbar curves anteriorly
Sacral & coccygeal curve posteriorly

22. Functions of Vertebral Column
Supports weight of head & trunk
Protects spinal cord
Allows spinal nerves to exit spinal cord
Site for muscle attachment
Permits head & trunk movement

23. Vertebral Column Defects
Lordosis – abnormal anterior curvature
Lumbar
Swayback
Kyphosis – abnormal posterior curvature
Usually upper thoracic
Hunchback
Scoliosis – abnormal lateral curvature

24. Vertebral Column Damage
Herniated disk
Compresses nerves
“Broken Tailbone”
Fractured coccyx
Can occur during childbirth and from falls

25. Vertebral Anatomy Body – bears weight
Intervertebral disks – separate bodies; dense fibrous connective tissue
Vertebral arch – forms vertebral foramen
Vertebral foramen – houses spinal cord
Vertebral canal – formed by all vertebral foramina; spinal cord passage/protection
Pedicle – extend from body to transverse process (feet); forms part of vertebral arch
Lamina – extend from transverse process to spinous process; forms part of vertebral arch

26. Vertebral Anatomy
Transverse process – extend laterally from the arch between pedicle & lamina
Spinous process- project dorsally from laminae; can feel externally
Intervertebral foramina- notches formed by adjacent vertebrae; spinal nerves exit here
Articular process – area of vertebral articulation
Articular facet – smooth surface articulates with ribs

27. Differences in Vertebrae
Cervical
small bodies (except atlas)
Transverse foramen on transverse process for vertebral arteries going to brain
Some have split spinous processes
Atlas – 1st vertebra holds up head
Axis – 2nd vertebra allows rotation (dens)

28. Differences in Vertebrae
Thoracic
Long, think spinous processes directed inferiorly
Lateral articular facets for rib articulation
Lumbar
Large, thick bodies
Heavy, rectangular transverse & spinous processes
Medially facing superior articular facets (“locks” vertebrae together for stability)

29. Differences in Vertebrae
Sacrum
5 fused vertebrae
Median sacral crest – spinous processes on 1st 4 vertebrae
Sacral hiatus- inferior end of sacrum without a crest
Site of anesthetic injection prior to childbirth
Sacral promontory- bulge in anterior edge of body of 1st vertebra in sacrum
Palpated before childbirth to determine pelvic opening size
Coccyx (“tailbone”)
4 fused vertebrae
Reduced vertebral bodies
No foramina or processes

30. Thoracic Cage “Rib cage” Functions: Consists of:
Protects vital organs in thorax
Prevents collapse of thorax during respiration
Consists of:
Thoracic vertebrae
Ribs + associated cartilages
Sternum

32. Ribs & Costal Cartilages
12 pairs (24 total)
Articulate with thoracic vertebrae
True ribs – (1-7) superior 7 attach to sternum via cartilage
False ribs – (8-12) inferior 5 do not directly attach to sternum
Floating ribs – (11-12) inferior 2 not attached to sternum at all

33. Sternum “Breastbone” Three parts: Manubrium (handle) Body
Jugular notch – superior to manubrium; between clavicular articulations
Body
Sternal angle – at junction of manubrium & body; locates 2nd rib & used to find apex of heart
Xiphoid process (sword)
Used in CPR alignment

34. Appendicular Skeleton, Joints & Movement
Ch. 6
Appendicular = “to hang something on”

35. Appendicular Skeleton
Pectoral girdle (scapulae & clavicle)
Upper limbs (arm, forearm, wrist, hand)
Pelvic girdle (2 coxae)
Lower limbs (thigh, leg, ankle, foot)

38. Pectoral Girdle 2 scapulae 2 clavicles Articulates with humerus
Articulates with sternum & scapula

39. Upper Limb
Arm
Forearm
Wrist
Hand

40. Upper Limb: Arm
Humerus – region between shoulder and elbow

41. Upper Limb: Forearm
Radius (lateral or thumb side) & Ulna (medial or little finger side)

42. Upper Limb: Wrist & Hand
Wrist – region between forearm and hand
8 carpals
Hand – attached to carpals
5 metacarpals
5 digits
3 phalanges per finger (2 on thumb)

43. Pelvic Girdle
2 coxae
Coxa formed by 3 fused bones: ilium, ischium, pubis
Sex differences: larger pelvic inlet and outlet in females, broader pelvis in females, greater subpubic angle in females (childbirth)

46. Lower Limb
Thigh
Leg
Ankle
Foot

47. Lower Limb: Thigh Femur – region between hip and knee Patella
Articulates with coxa and tibia
Patella

48. Lower Limb: Leg
Tibia (shin) and fibula

49. Lower Limb: Foot & Ankle
Ankle = 7 tarsals; articulates with tibia & fibula; calcaneus forms heel
Foot = 5 metatarsals; 3 phalanges per digit (except great toe – has 2)

50. Joints or “Articulations”
Articulation = place where two bones come together
Classification methods:
Function:
Synarthrosis (non-movable)
Amphiarthrosis (slightly movable)
Diarthrosis (freely movable)
Structure (connective tissue type):
Fibrous (fibrous tissue)
Cartilaginous (cartilage)
Synovial (synovial fluid)

51. Fibrous joints Cartilaginous joints Synovial joints No movement
Sutures in fetal skull
Cartilaginous joints
Slight movements
Epiphyseal plates, costal cartilage
Synovial joints
Free movements
Most joints (wrist, knee, shoulder, hip, etc.)

52. Fibrous Joints

55. Synovial Joints

56. Types of Joint Movements
Flexion vs. extension
Plantar flexion vs. dorsiflexion
Abduction vs. adduction
Pronation vs. supination
Eversion vs. inversion
Rotation
Protraction vs. retraction
Elevation vs. depression
Circumduction
Excursion (mandible moving side to side)
Opposition vs. reposition (thumb & pinky together, then apart)