The skeletal system consists of 206 bones that provide structure, protect organs, allow movement, and store minerals. Bones are classified by shape and composition. The skull is formed from flat cranial and facial bones, including the occipital, sphenoid, ethmoid, frontal, parietal, and temporal bones. The vertebral column consists of cervical, thoracic, lumbar, sacral and coccyx vertebrae. The rib cage includes ribs and the sternum. The appendicular skeleton includes the shoulder girdle, long bones of the arms and legs, wrist/ankle bones, and phalanges of the fingers and toes.

1. THE SKELETAL SYSTEM
VINNCI ANGELICA G. DELA CRUZ

2. THE SKELETAL SYSTEM
COMPOSED OF 206 BONES
NEW BORN: 350 BONES
INFANCY: 275 BONES
ADULT: 206 BONES

3. FUNCTIONS:
1.SUPPORT
2.PROTECTION
3.MOVEMENT
4.STORAGE > STOREHOUSE FOR
MINERALS
5.BLOOD CELL FORMATION
(HEMATOPOIESIS)

4. CLASSIFICATION OF BONES:
1.COMPACT BONES
> ARE PACKED TIGHTLY
TOGETHER TO FORM WHAT
APPEARS TO BE SOLID
MASS.

5. CLASSIFICATION OF BONES:
2. SPONGY (CANCELLOUS)
BONES
> COMPOSED OF SMALL
NEEDLELIKE PIECES OF
BONE & LOTS OF OPEN
SPACES.

6. CLASSIFICATION OF BONES:

7. 4 SHAPES OF BONES:
1. LONG BONE
>FOUND IN LIMBS

8. LONG BONE

9. 4 SHAPES OF BONES:
2. SHORT BONE
> EX: KNEE-CAP

10. SHORT BONE: PATELLA (KNEECAP)

11. 4 SHAPES OF BONES:
3. FLAT BONE
> EX: SKULL, RIBS,
STERNUM

12. FLAT BONE: SCAPULA (SHOULDER BLADE)

13. 4 SHAPES OF BONES:
4. IRREGULAR BONE
> EX:VERTEBRAE

14. IRREGULAR BONE: VERTEBRAE

15. STRUCTURE OF A LONG BONE:
1.DIAPHYSIS/ SHAFT
COMPOSED OF COMPACT BONE.
PERIOSTEUM > A FIBROUS CONNECTIVE
TISSUE THAT COVER AND PROTECT THE
DIAPHYSIS.
PERFORATING/SHARPEY’S FIBERS
> CONNECTIVE TISSUE FIBERS THAT
SECURE THE PERIOSTEUM TO THE
UNDERLYING TISSUE.

16. STRUCTURE OF A LONG BONE:
2. EPIPHYSES (PROXIMAL AND DISTAL)
 END PART OF A LONG BONE.
ARTICULAR CARTILAGE > COVERS THE
EPIPHYSES AND PROVIDE A SMOOTH,
SLIPPERY SURFACE THAT DECREASES
FRICTION AT JOINT SURFACES.

17. STRUCTURE OF A LONG BONE

18. SKELETON IS DIVIDED INTO 2 PARTS:
1.AXIAL SKELETON
FORMS THE LONGITUDINAL AXIS OF
THE BODY. (SKULL, VERTEBRAL
COLUMN, AND RIB CAGE)
2. APPENDICULAR SKELETON
BONES OF THE ARMS AND LEGS AND
THE SHOULDER AND PELVIC GIRDLES.

19. THE AXIAL AND APPENDICULAR SKELETON

20. THE AXIAL AND APPENDICULAR SKELETON

21. AXIAL SKELETON
SKULL
IS FORMED BY 2 SETS OF
BONES:
CRANIUM AND FACIAL BONES.

22. SKULL

23. CRANIUM
1.FRONTAL BONE
2.PARIETAL BONES
> THEY MEET IN THE MIDLINE OF
THE SKULL AT THE SAGITTAL
SUTURE AND FORM THE CORONAL
SUTURE WHERE THEY MEET WITH
THE FRONTAL BONE.

24. FRONTAL BONE

25. PARIETAL BONES

26. SAGITTAL AND CORONAL SUTURES

27. CRANIUM
3. TEMPORAL BONES
> LIES INFERIOR TO THE PARIETAL
BONE, THEY JOIN THEM AT THE
SQUAMOUS SUTURES.

28. TEMPORAL BONE AND SQUAMOUS SUTURE

29. CRANIUM
IMPORTANT BONE MARKINGS:
A.EXTERNAL ACOUSTIC (AUDITORY)
MEATUS
> A CANAL THAT LEADS TO THE
EARDRUM AND MIDDLE EAR.

30. EXTERNAL AUDITORY MEATUS

31. CRANIUM
IMPORTANT BONE MARKINGS:
B. STYLOID PROCESS
>ATTACHMENT POINT FOR SOME
NECK MUSCLES.

32. CRANIUM
IMPORTANT BONE MARKINGS:
C. MASTOID PROCESS
>ATTACHMENT SITE FOR SOME
MUSCLES OF THE NECK

33. STYLOID PROCESS AND MASTOID PROCESS

34. CRANIUM
IMPORTANT BONE MARKINGS:
D. JUGULAR FORAMEN
>ALLOWS PASSAGE OF THE
JUGULAR VEIN

35. JUGULAR FORAMEN

36. CRANIUM
IMPORTANT BONE MARKINGS:
E. INTERNAL ACOUSTIC MEATUS
>TRANSMITS CRANIAL NERVE VII
AND VIII (FACIAL AND
VESTIBULOCOCHLEAR NERVES)

37. INTERNAL ACOUSTIC MEATUS

38. CRANIUM
IMPORTANT BONE MARKINGS:
F. CAROTID CANAL
> IT IS WHERE THE INTERNAL
CAROTID ARTERY RUNS,
SUPPLYING BLOOD TO MOST OF
THE BRAIN.

39. CAROTID CANAL AND CAROTID ARTERY

40. CRANIUM
4. OCCIPITAL BONE
THE MOST POSTERIOR BONE OF
THE CRANIUM. IT FORMS THE
FLOOR AND BACK WALL OF THE
SKULL.
*lambdoid suture > joins the
parietal bones anteriorly

41. OCCIPITAL BONE AND LAMBDOID SUTURE

42. CRANIUM
OCCIPITAL BONE
A.FORAMEN MAGNUM
> A LARGE OPENING THAT ALLOWS THE
SPINAL CORD TO CONNECT TO THE
BRAIN.

43. FORAMEN MAGNUM

44. CRANIUM
OCCIPITAL BONE
B. OCCIPITAL CONDYLES
> LIES ON THE FIRST VERTEBRA OF THE
SPINAL COLUMN.

45. OCCIPITAL CONDYLE

46. CRANIUM
5. SPHENOID BONE
> FORMS THE PART OF THE FLOOR
OF THE CRANIAL CAVITY.

47. SPHENOID BONE

48. CRANIUM
SPHENOID BONE
A.SELLA TURCICA/ TURK’S SADDLE
> HOLDS THE PITUITARY GLAND IN
PLACE.

49. SELLA TURCICA

50. CRANIUM
SPHENOID BONE
B. FORAMEN OVALE
> A LARGE OVAL OPENING THAT
ALLOWS FIBERS OF CRANIAL
NERVE V (TRIGEMINAL NERVE) TO
PASS TO THE CHEWING MUSCLES
OF THE LOWER JAW (MANDIBLE).

51. FORAMEN OVALE

52. CRANIUM
SPHENOID BONE
C. OPTIC CANAL
> ALLOWS OPTIC NERVE TO PASS
TO THE EYE.

53. OPTIC CANAL

54. CRANIUM
SPHENOID BONE
D. SUPERIOR ORBITAL FISSURE
> ALLOWS CRANIAL NERVES III, IV,
VI RESPONSIBLE FOR
CONTROLLING EYE MOVEMENTS.

55. SUPERIOR ORBITAL FISSURE

56. CRANIUM
SPHENOID BONE
E. SPHENOID SINUSES
>CAVITIES OF THE SPHENOID BONE

57. SPHENOID SINUSES

58. CRANIUM
6. ETHMOID BONE
> FORMS THE ROOF OF
THE NASAL CAVITY

59. ETHMOID BONE

60. CRANIUM
ETHMOID BONE
A. CRISTA GALLI
> THE OUTERMOST COVERING
OF THE BRAIN ATTACHES TO
THIS PROJECTION.

61. CRANIUM
ETHMOID BONE
B. CRIBIFORM PLATE
>HOLEY AREAS THAT ALLOW NERVE
FIBERS CARRYING IMPULSES
FROM THE OLFACTORY (SMELL)
RECEPTORS OF THE NOSE TO
REACH THE BRAIN.

62. CRANIUM
ETHMOID BONE
C. SUPERIOR AND MIDDLE
NASAL CONCHAE
> FORM PART OF THE LATERAL
WALLS OF THE NASAL CAVITY
AND INCREASE THE
TURBULENCE OF AIR FLOWING
THROUGH THE NASAL
PASSAGES.

63. ETHMOID BONE

64. FACIAL BONES
1. MAXILLAE/ MAXILLARY BONE
 MAIN OR KEYSTONE BONES OF
THE FACE.
 CARRY THE UPPER TEETH WITH
THE ALVEOLAR MARGIN

65. MAXILLA

66. FACIAL BONES
1. MAXILLARY BONE
A.PALATINE PROCESS
HARD PALATE OF THE MOUTH
B. PARANASAL SINUSES
LIGHTEN THE SKULL BONES AND
ACT TO AMPLIFY THE SOUNDS WE
MAKE AS WE SPEAK.

67. FACIAL BONES
2. PALATINE BONES
> CLEFT PALATE RESULTS IF
UNFUSED MEDIALLY.

68. PALATINE PROCESS AND PALATINE BONES

69. FACIAL BONES
3. ZYGOMATIC BONES
> CHEEKBONES

70. ZYGOMATIC BONE

71. FACIAL BONES
4. LACRIMAL BONES
>PASSAGEWAY OF TEARS

72. LACRIMAL BONES

73. FACIAL BONES
5. NASAL BONES
> BRIDGE OF THE NOSE

74. NASAL BONE

75. FACIAL BONES
6. VOMER BONE
>SINGLE BONE IN THE MEDIAN LINE
OF THE NASAL CAVITY.

76. VOMER BONE

77. FACIAL BONES
7. INFERIOR NASAL CONCHAE

78. FACIAL BONES
8. MANDIBLE (LOWER JAW)
> LARGEST AND STRONGEST BONE
OF THE FACE

79. FACIAL BONES
9. HYOID BONE
>SERVES AS A MOVABLE BASE FOR
THE TONGUE AND AN ATTACHMENT
POINT FOR NECK MUSCLES THAT
RAISE AND LOWER THE LARYNX
WHEN WE SWALLOW AND SPEAK.

80. HYOID BONE

81. THE SKELETAL SYSTEM
B. VERTEBRAL COLUMN (spine)
> EXTENDS FROM THE SKULL,
AND IT SUPPORTS, TO THE
PELVIS, WHERE IT TRANSMITS
THE WEIGHT OF THE BODY TO
THE LOWER LIMBS.

82. THE SKELETAL SYSTEM
VERTEBRAL COLUMN (spine)
1.CERVICAL VERTEBRAE (7)
ARE THOSE WITHIN THE NECK.
ATLAS: FIRST VERTEBRAE
AXIS: SECOND VERTEBRAE

83. VERTEBRAE

84. THE SKELETAL SYSTEM
VERTEBRAL COLUMN (spine)
2. THORACIC VERTEBRAE
> FORMS JOINTS AND THE RIBS
ON THE POSTERIOR SIDE OF
THE TRUNK.

85. THE SKELETAL SYSTEM
VERTEBRAL COLUMN (spine)
3. LUMBAR VERTEBRAE
>LARGEST AND STRONGEST
BONES OF THE SPINE

86. THE SKELETAL SYSTEM
VERTEBRAL COLUMN (spine)
4. SACRUM
> PERMITS ARTICULATION OF
THE 2 HIP BONES (SACROILIAC
JOINT)

87. THE SKELETAL SYSTEM
VERTEBRAL COLUMN (spine)
5. COCCYX
>REMNANT OF TAIL VERTEBRAE
AND SOME MUSCLES OF THE
PERINEUM (PELVIC FLOOR) ARE
ANCHORED TO IT.

88. THE SKELETAL SYSTEM
VERTEBRAL COLUMN (spine)
*vertebral canal > a continuous
tunnel within the brain that
contains the spinal cord and
protects it from mechanical
injury.

89. THE SKELETAL SYSTEM
VERTEBRAL COLUMN (spine)
*vertebral canal > a continuous
tunnel within the brain that
contains the spinal cord and
protects it from mechanical
injury.

90. THE SKELETAL SYSTEM
VERTEBRAL COLUMN (spine)
*intervertebral discs > are
fibrous cartilage which
separate the bodies of adjacent
vertebrae.
> cushion and absorb shock
and permits some movement
bet. vertebrae (symphysis
joints)

91. INTERVERTEBRAL DISCS

92. THE SKELETAL SYSTEM
ABNORMALITIES OF THE CURVE OF THE SPINE
1.Scoliosis
> abnormal lateral curvature which may be
congenital, the result of having 1 leg longer
than the other, or the result of chronic poor
posture during childhood while the vertebrae
are still growing. Usually, the thoracic
vertebrae are affected which displaces the rib
cage to one side.

93. SCOLIOSIS

94. THE SKELETAL SYSTEM
ABNORMALITIES OF THE CURVE OF THE SPINE
2. Kyphosis
> Exaggerated thoracic curve; referred to as
hunchback

95. KYPHOSIS

96. THE SKELETAL SYSTEM
ABNORMALITIES OF THE CURVE OF THE SPINE
3. Lordosis
Exaggerated lumbar curve; referred to as
swayback
The pride of pregnancy curve

97. LORDOSIS

98. THE SKELETAL SYSTEM
C. RIB CAGE
>consists of 10 pairs of ribs,
and the sternum or breastbone.

99. THE SKELETAL SYSTEM
*True ribs > first 7 pair of
ribs
*False ribs > next 3 pairs;
their cartilages join the 7th
rib cartilage
*Floating ribs > 2 pairs (last)
because they do not
articulate with the sternum at
all.

100. RIB CAGE

101. THE SKELETAL SYSTEM
3 PARTS OF THE STERNUM
1.Manubrium
2.Body
3.Xiphoid process

102. APPENDICULAR SKELETON
A. Shoulder and Arm
1. Scapula > is a large, flat bone
withe several projection
(coracoid process) that
anchor some of the muscles
that move upper arm and the
forearm (shoulder blade)

103. SCAPULA

104. APPENDICULAR SKELETON
A. Shoulder and Arm
*Glenoid fossa > a shallow
depression that forms a ball-and-
socket joint with the
humerus.

105. APPENDICULAR SKELETON
A. Shoulder and Arm
2. Clavicle > act as braces for
the scapulae and prevent the
shoulders from coming too far
forward.

106. APPENDICULAR SKELETON
A. Shoulder and Arm
3. Humerus > long bone of the
upper arm.
Proximal end> is the ball-and-socket
joint
Distal end> hinge joint that permits
the elbow to move in 1 plane ;
restricted lateral mov’t.

107. HUMERUS

108. APPENDICULAR SKELETON
A. Shoulder and Arm
4. Ulna > on the side of the little
finger

109. APPENDICULAR SKELETON
A. Shoulder and Arm
5. Radius >thumbside
Pivot joint> permit turning the
hand palm up and down.

110. APPENDICULAR SKELETON
A. Shoulder and Arm
6. Carpals > are 8 small bones
in the wrist.
Sliding joints> permit a sliding
mov’t.

111. APPENDICULAR SKELETON
A. Shoulder and Arm
7. Metacarpals > 5 bones of the
palm of the hand.
Saddle joints> enables the
thumb to cross over the palm
which permits gripping.

112. APPENDICULAR SKELETON
A. Shoulder and Arm
8. Phalanges > bones of the
fingers.

113. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/
Pelvic Bone)
1. Hip Bones > ilium, ischium
(part that we sit on), and pubis.

114. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/ Pelvic
Bone)
2. Acetabulum>is the socket in the
hip bone that forms a ball-and-socket
with the femur, has much
deeper socket.

115. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/
Pelvic Bone)
3. Femur > long bone of the
thigh.

116. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/
Pelvic Bone)
4. Patella or kneecap>anterior
to the kneejoint.

117. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/ Pelvic
Bone)
5. Tibia > weight-bearing bone of the
lower leg.
Inner malleolus> inner ankle bone
Lateral malleolus> outer ankle bone

118. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/ Pelvic
Bone)
6. Fibula > does not bear much
weight. Help stabilize the tibia.

119. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/
Pelvic Bone)
7. Tarsals >composed of 7 bones
in the ankle
Calcaneus (heelbone) > largest
tarsal
Talus > transmit wt. bet. the
calcaneus and the tibia.

120. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/
Pelvic Bone)
8. Metatarsals> 5 long bones of
each foot.

121. APPENDICULAR SKELETON
B. Hip and Leg (Pelvic Girdle/
Pelvic Bone)
9. Phalanges>bones of the toes.

122. TARSALS, METATARSALS, PHALANGES,
CALCANEUS AND TALUS

123. THE SKELETAL SYSTEM
JOINTS
IS WHERE 2 BONES MEET OR
ARTICULATE.

124. THE SKELETAL SYSTEM
CLASSIFICATION OF JOINTS
1. Synarthrosis > is an
immovable joint, such as a
suture between 2 cranial bones.

125. THE SKELETAL SYSTEM
CLASSIFICATION OF JOINTS
2. Amphiarthrosis > is a slightly
movable joint, such as the
symphysis joint between
adjacent vertebrae.

126. SYNARTHROSIS AND AMPHIARTHROSIS

127. THE SKELETAL SYSTEM
CLASSIFICATION OF JOINTS
3. Diarthrosis > is a freely
movable joint which includes
ball-and-socket joint, the pivot,
hinge, and others.
> is under synovial joints.

128. THE SKELETAL SYSTEM
*articular cartilage > provides a
smooth surface
*joint capsule > made of fibrous
connective tissue which
encloses the joint in a strong
sheath like a sleeve.

129. THE SKELETAL SYSTEM
*synovial membrane > lines the
joint capsule which secretes
synovial fluid into the joint cavity
*synovial fluid > prevents
friction as the bones move.

130. THANK YOU!!! 