Anatomy

1. SKELETAL SYSTEM
Mrs Musyimi J.M

2. SKELATAL SYSTEM
• Bone tissues makes up about 18% of the total
human body weight.
• The skeletal system supports and protects the
body while giving it shape and form.
• Osteology: It is the branch of science that
deals with the study of the skeletal system,
their structure and functions.

3. SKELETAL SYSTEM
• COMPOSED OF:
-Bones
-Cartilage
-Joints
-Ligaments

4. FUNCTIONS OF SKELETALSYSTEM
• SUPPORT: Hard framework that supports and anchors the
soft organs of the body.
• PROTECTION: Surrounds organs such as the brain and
spinal cord.
• MOVEMENT: Allows for muscle attachment therefore the
bones are used as levers.
• STORAGE: Minerals and lipids are stored within bone
material.
• BLOOD CELLFORMATION: The bone marrow is
responsible for blood cell production.

5. DIVISIONS OF THE SKELETAL
SYSTEM
• The human skeleton consists of 206 named bones
• Bones of the skeleton are grouped into two principal
divisions:
– Axial skeleton
• Skull bones, auditory ossicles (ear bones), hyoid bone,ribs,
sternum (breastbone), and bones of the vertebralcolumn
– Appendicular skeleton
• Consists of the bones of the upper and lower limbs(extremities),
plus the bones forming the girdles that connect the limbs to the
axial skeleton

6. DIVISIONS OF THE SKELETAL
SYSTEM

7. CLASSIFICATION OF BONE BASED
ON SHAPE
• Bones can be classified into five types based on
shape:
• Long
• Short
• Flat
• Irregular
• Sesamoid

8. CLASSIFICATION OF BONE BASED ON
SHAPE
• Long Bones
– Greater length than width and are slightly curved for strength
– Femur, tibia, fibula, humerus, ulna, radius, phalanges
• Short bones
– Cube-shaped and are nearly equal in length and width
– Carpal, tarsal
• Flat bones
– Thin and composed of two nearly parallel plates of compact bone
tissue enclosing a layer of spongy bone tissue
– Cranial, sternum, ribs, scapulae
• Irregular bones
– Complex shapes and cannot be grouped into any of the previous
categories
– Vertebrae, hip bones, some facial bones, calcaneus
• Sesamoid bones
– Protect tendons from excessive wear and tear
– Patellae, foot, hand

9. THE AXIALSKELETON
The axial skeleton consists of :
1. Skull.
2. Vertebral column (spinal column).
3. Thoracic cage.
4. Sternum.

10. THE AXIALSKELETON
Skull
• The skull is situated on the upper end of vertebral
column and its bony structure is divided into 2 parts.
1. The cranium
2. The face

11. THE AXIALSKELETON
A. Cranium:
• It is formed by flat and irregular bones that provides a bony
protection to the brain.
• 1 Frontal Bone
– It forms the forehead, It forms parts of eye sockets
– The coronal suture joins the frontal and parietal bones.
• 2 Parietal Bones
– It form the sides and roof of the cranial cavity, it articulates
with each other at the sagittal suture.
– It joins the frontal bone with coronal suture and occipital
bone with lambdoidal suture and the temporal bones at
the squamous suture.
• 2 Temporal Bones
– These bones lie one on each side of the head and form
immovable joints with the parietal, occipital, sphenoid and
zygomatic bones.
– The temporal bone articulates with the mendible at the
tempo-mandibular joint.

12. THE AXIALSKELETON
• 1 Occipital Bone
– It forms back of head and most of the base of the skull.
– It has immovable joints with the parietal, temporal and
sphenoid bones.
• 1 Sphenoid Bone
– It occupies the middle portion of base of skull and it
articulates with the occipital, temporal, parietal and frontal
bones.
• 1 Ethmoid Bone
– It occupies the anterior part of base of the skull and helps to
form the orbital cavity, the nasal septum and the lateral
walls of the nasal cavity.
– It is very delight bone containing many air sinuses that
opens into the nasal cavity.

13. THE AXIALSKELETON

14. THE AXIALSKELETON
B. The Face (Facialbones)
• Nasal Bones
– Form the bridge of the nose
• Maxillae
– Form the upper jawbone
– Form most of the hard palate
• Separates the nasal cavity from the oral cavity
• Zygomatic Bones
– commonly called cheekbones, form the prominences of the cheeks
• Lacrimal Bones
– Form a part of the medial wall of each orbit
• Palatine Bones
– Form the posterior portion of the hard palate
• Inferior Nasal Conchae
– Form a part of the inferior lateral wall of the nasalcavity

15. THE AXIALSKELETON
• Vomer
– Forms the inferior portion of the nasal septum
• Mandible
– Lower jawbone
– The largest, strongest facial bone
– The only movable skull bone
• Nasal Septum
– Divides the interior of the nasal cavity into right and leftsides
– “Broken nose,” in most cases, refers to septal damage rather thanthe
nasal bones themselves
• Orbits
– Eye socket
• Foramina
– Openings for blood vessels , nerves , or ligaments of theskull

16. THE AXIALSKELETON

17. THE AXIALSKELETON
Mandible

18. THE AXIALSKELETON
• The vertebral column:
• Also called the spine, backbone, or spinal column
• Functions to:
– Protect the spinal cord
– Support the head
– Serve as a point of attachment for the ribs, pelvic girdle,
and muscles
• The vertebral column is curved to varying degrees
in different locations
– Curves increase the column strength
– Help maintain balance in the upright position
– Absorb shocks during walking, and help protect the
vertebrae from fracture

19. THE AXIALSKELETON- VERTEBRAL COLUMN

20. THE AXIALSKELETON-VERTEBRAL COLUMN
The vertebral column:
• Composed of a series of bones called vertebrae
• In Adults there are 26vertebrae:
– 7 cervical are in the neck region
– 12 thoracic are posterior to the thoracic
cavity
– 5 lumbar support the lower back
– 1 sacrum consists of five fused sacral
vertebrae
– 1 coccyx consists of four fused coccygeal
vertebrae

21. THE AXIALSKELETON
Intervertebral Discs:
• Found between the bodies of adjacent vertebrae
• Functions to:
– Form strong joints
– Permit various movements of the vertebral column
– Absorb vertical shock
• Vertebrae typically consist of:
– A Body (weight bearing)
– A vertebral arch (surrounds the spinal cord)
– Several processes (points of attachment for muscles)

23. THE AXIALSKELETON-THORAX
Thorax: (Thoracic cage)
• Thoracic cage is formed by the:
– Sternum
– Ribs
– Costal cartilages
– Thoracic vertebrae
• Functions to:
– Enclose and protect the organs in the thoracic and
abdominal cavities
– Provide support for the bones of the upper limbs
– Play a role in breathing

24. THE AXIALSKELETON
• Sternum
– “Breastbone” located in the center of the thoracic
wall
– Consists of the manubrium, body, xiphoid process
• Ribs
– Twelve pairs of ribs give structural support to the
sides of the thoracic cavity
• Costal cartilages
– Costal cartilages contribute to the elasticity of the
thoracic cage

25. THE AXIALSKELETON-THORACIC CAGE

27. END OF PART 1
THANK YOU

28. THE APPENDICULAR SKELETON

29. THE APPENDICULAR SKELETON
 The appendicular skeleton is made up of the bones
of the limbs and their girdles
 Pectoral girdles attach the upper limbs to the body
trunk
 Pelvic girdle secures the lower limbs

30. PECTORAL GIRDLES (SHOULDER GIRDLES)
 The pectoral girdles consist of th clavicles
nateriorly and the scapulae posteriorly.
 They attach the upper limbs to the axial skeleton in
a manner that allows for maximum movement
 They provide attachment points for muscles that
move the upper limbs

31. Pectoral Girdles (Shoulder Girdles)

32. Clavicles (Collarbones)
 Slender, doubly curved long bones lying across the
superior thorax
 The acromial (lateral) end articulates with the
scapula, and the sternal (medial) end articulates
with the sternum
 Provide attachment points for numerous muscles,
and act as braces to hold the scapulae and arms out
laterally away from the body

33. Clavicles (Collarbones)

34. Scapulae (Shoulder Blades)
 Triangular, flat bones lying on the dorsal surface of
the rib cage, between the second and seventh ribs
 Scapulae have three borders and three angles
 Major markings include the suprascapular notch,
the supraspinous and infraspinous fossae, the
spine, the acromion, and the coracoid process

35. Scapulae (Shoulder Blades)

36. Scapulae (Shoulder Blades)

37. Scapulae (Shoulder Blades)

38. The Upper Limb
 The upper limb consists of the arm (brachium),
forearm (antebrachium), and hand (manus)
 Thirty-seven bones form the skeletal framework of
each upper limb

39. Arm
 The humerus is the sole bone of the arm
 It articulates with the scapula at the shoulder, and
the radius and ulna at the elbow

40. Arm
 Major markings
 Proximal humerus includes the head, anatomical
and surgical necks, greater and lesser tubercles,
and the intertubercular groove
 Distal humerus includes the capitulum, trochlea,
medial and lateral epicondyles, and the coronoid
and olecranon fossae
 Medial portion includes the radial groove and the
deltoid process

41. Humerus of the Arm

42. Forearm
 The bones of the forearm are the radius and ulna
 They articulate proximally with the humerus and
distally with the wrist bones
 They also articulate with each other proximally
and distally at small radioulnar joints
 Interosseous membrane connects the two bones
along their entire length

43. Bones of the Forearm

44. Ulna
 The ulna lies medially in the forearm and is
slightly longer than the radius
 Forms the major portion of the elbow joint with the
humerus
 Its major markings include the olecranon, coronoid
process, trochlear notch, radial notch, and the
styloid process

45. Radius
 The radius lies opposite (lateral to) the ulna and is
thin at its proximal end, widened distally
 The superior surface of the head articulates with
the capitulum of the humerus
 Medially, the head articulates with the radial notch
of the ulna
 Major markings include the radial tuberosity, ulnar
notch, and styloid process

46. Radius and Ulna

47. Hand
 Skeleton of the hand
contains wrist bones
(carpals), bones of the
palm (metacarpals),
and bones of the
fingers (phalanges)

48. Carpus (Wrist)
 Consists of eight bones
 Scaphoid, lunate, triquetral, and pisiform
proximally
 Trapezium, trapezoid, capitate, and hamate distally

49. Metacarpus (Palm)
 Five numbered (1-5) metacarpal bones radiate
from the wrist to form the palm
 Their bases articulate with the carpals proximally,
and with each other medially and laterally
 Heads articulate with the phalanges

50. Phalanges (Fingers)
 Each hand contains 14 miniature long bones called
phalanges
 Fingers (digits) are numbered 1-5, beginning with
the thumb (pollex)
 Each finger (except the thumb) has three phalanges
– distal, middle, and proximal
 The thumb has no middle phalanx

51. PELVIC GIRDLE (HIP)
 The hip is formed by a pair of hip bones (Ilium,
Ischium and Pubic bones)
 Together with the sacrum and the coccyx, these
bones form the bony pelvis

52. Pelvic Girdle (Hip)
 The pelvis
 Attaches the lower limbs to the axial skeleton with
the strongest ligaments of the body
 Transmits weight of the upper body to the lower
limbs
 Supports the visceral organs of the pelvis

53. Pelvic Girdle (Hip)

54. Ilium
 The ilium is a large flaring bone that forms the
superior region of the coxal bone
 It consists of a body and a superior winglike
portion called the ala
 The broad posterolateral surface is called the
gluteal surface

55. Ilium
 The auricular surface articulates with the sacrum
(sacroiliac joint)
 Major markings include the iliac crests, four
spines, greater sciatic notch, iliac fossa, arcuate
line, and the pelvic brim

56. Ilium: Lateral View

57. Ilium: Medial View

58. Ischium
 The ischium forms the posteroinferior part of the
hip bone
 The thick body articulates with the ilium, and the
thinner ramus articulates with the pubis
 Major markings include the ischial spine, lesser
sciatic notch, and the ischial tuberosity

59. Pubis
 The pubic bone forms the anterior portion of the
hip bone
 It articulates with the ischium and the ilium

60. Pubis: Lateral View

61. Pubis: Medial View

62. Comparison of Male and Female Pelvic
Structure
 Female pelvis
 Tilted forward, adapted for childbearing
 True pelvis defines birth canal
 Cavity of the true pelvis is broad, shallow, and has
greater capacity

63. Comparison of Male and Female Pelvic
Structure
 Male pelvis
 Tilted less forward
 Adapted for support of heavier male build and
stronger muscles
 Cavity of true pelvis is narrow and deep

64. Comparison of Male and Female Pelvic
Structure

65. Characteristic Female Male
Bone thickness Lighter, thinner, and smoother
Heavier, thicker, and more
prominent markings
Pubic arch/angle 80˚–90˚ 50˚–60˚
Acetabula Small; farther apart Large; closer together
Sacrum
Wider, shorter; sacral curvature is
accentuated
Narrow, longer; sacral
promontory more ventral
Coccyx More movable; straighter
Less movable; curves
ventrally
Comparison of Male and Female Pelvic
Structure

66. The Lower Limb
 The three segments of the lower limb are the thigh,
leg, and foot
 They carry the weight of the erect body, and are
subjected to exceptional forces when one jumps or
runs

67. Femur
 The sole bone of the thigh is the femur, the largest
and strongest bone in the body
 It articulates proximally with the hip and distally
with the tibia and fibula
 Major markings include the head, greater and
lesser trochanters, lateral and medial condyles and
epicondyles, patellar surface, and the intercondylar
notch

68. Femur

69. Leg
 The tibia and fibula form the skeleton of the leg
 They are connected to each other by the
interosseous membrane
 They articulate with the femur proximally and with
the ankle bones distally
 They also articulate with each other via the
immovable tibiofibular joints

70. Tibia
 Receives the weight of the body from the femur
and transmits it to the foot
 Major markings include medial and lateral
condyles, the tibial tuberosity, anterior crest, and
medial malleolus,

71. Tibia and Fibula

72. Fibula
 Sticklike bone with slightly expanded ends located
laterally to the tibia
 Major markings include the head and lateral
malleolus

73. Foot
 The skeleton of the foot
includes the tarsus,
metatarsus, and the
phalanges (toes)
 The foot supports body
weight and acts as a
lever to propel the body
forward in walking and
running
Figure 7.31a

74. Tarsals
 Composed of seven bones that form the posterior
half of the foot
 Body weight is carried primarily on the talus and
calcaneus
 Talus articulates with the tibia and fibula
superiorly, and the calcaneus inferiorly

75. Tarsals

76. Calcaneus
 Forms the heel of the foot
 Carries the talus on its superior surface
 Point of attachment for the calcaneal (Achilles)
tendon of the calf muscles

77. Metatarsals and Phalanges
 Metatarsals
 Five (1-5) long bones that articulate with the
proximal phalanges
 The enlarged head of metatarsal 1 forms the “ball
of the foot”
 Phalanges
 The 14 bones of the toes
 Each digit has three phalanges except the hallux,
which has no middle phalanx

78. Metatarsals and Phalanges

79. THE END OF PART 2

80. JOINTS
Mrs Musyimi J.M

82. JOINTS
Ajoint can be defined as follows:
Ajoint or place of articulation is formed where 2 or more
bones come in close contact in the body and are attached
to each other by ligaments or cartilage.

83. TYPES OF JOINTS: FIBROUS
• Fibrous (or Immovable)
Joints.
• Held together by a thin
layer ofstrong
connective tissue.
• No movement between the
bones.
• Sutures of the skull,
teeth in their sockets.

84. TYPES OF JOINTS: CARTILAGENOUS
Cartilagenous Joints.
The articular surfaces of the
bones forming the joints are
attached to each other by
white fibro-cartilaginous
discs
Limited degree of movement.
Vertebral discs, the pubic
symphysis.

85. TYPES OF JOINTS: SYNOVIAL
Freely movable joints.
The ends of the bones are
covered with a layer of
smooth hyaline cartilage.
Enclosed by a bag-like capsular
ligament which holds the
joint together and contains
the synovial fluid.

86. TYPES OF JOINTS: SYNOVIAL
Lined with a Synovial
membrane. This membrane
secretes synovial fluid. The
synovial fluid lubricates the
joint.
The bones are also attached by
ligaments. They prevent
dislocation during normal
movement.

87. CARTILAGE
Is a tough, generally smooth
fibrous connective tissue
found at the end of
bones and between
joints.
It protects bones by helping
to absorb the impacts
experienced during
movement and physical
activity

88. LIGAMENTS
A strong, fibrous
band of
connective
tissue that
holds
together two
or more
moveable
bones or
cartilage.
“Connects bone
to bone”

89. TENDONS
Are very strong and
inflexible connective
tissue that allow
movement to occur
by helping muscles
pull on bones.
“Tendons connect
muscles to bones”

91. BALL-AND-SOCKET JOINTS.
These joints are
formed where the
rounded head of
one bone fits into
the hollow, cup-
shaped socket of
another bone.
Freedom of
movement in all
directions.
Hip, shoulder.

92. HINGE JOINTS.
Movement is
possible in one
plane only.
Knee and the
Elbow joints.
Hinge joints have
ligaments mainly
at the sides of
the joints.

93. GLIDING JOINTS.
Allow for gliding
movements
between flat
surfaces as they
slide over one
another.
Only a limited
amount of
movement is
allowed
The joints between
the carpal bones,
the joints between
the tarsal bones

94. PIVOT JOINTS.
These joints occur where:
a bony ring rotates round the
pivot (axis) of another bone
such as the ring-like atlas
rotating around the
odontoid process of the
axis, allowing the head to
turn from side to side.
The end of one bone rotates
round the axis of another
bone such as the end of the
radius rotating around the
ulna as the palm of the
hand is turned inwards or
outwards.

95. SADDLE JOINTS
Two saddle-like
structures allowing
backwards,
forwards and
sideways
movements.
Thumb (between
carpals and
metacarpals)
Ankle (between fibula,
tibia and tarsals)

96. CONDYLOID JOINT
Oval shaped head of
bone in a shallow
cavity, allowing
backwards,
forwards and
sideways
movement
Wrist (between radius
and ulna and
carpals)