The skeletal system, composed of bones, cartilage, tendons, and ligaments, provides body support, organ protection, and facilitates movement. It stores minerals, produces blood cells, and consists of specialized cells like osteoblasts, osteocytes, and osteoclasts that maintain bone structure through processes of ossification and remodeling. The axial skeleton includes the skull, hyoid bone, and vertebral column, which serve critical functions in protecting the nervous system and supporting bodily weight.

1. SKELETAL
SYSTEM
ERLISON LORENZ M. OGNILLA RN, LPT, MAT
INSTRUCTOR

4. COMPONENTS:
bones
cartilage
tendons
ligaments

6. Functions:
body support
strong and rigid bone-> bearing weight; main
supporting tissue
firm but flexible support -> nose, external ear,
thoracic cage, trachea
ligaments -> hold bones together

7. Functions:
organ protection
body movement
skeletal muscles attach to bones by tendons
contraction of skeletal muscles-> moves
bones-> body movements
joints -> allow movement between bones

8. Functions:
Mineral storage
Calcium and phosphorus
Adipose tissues within bone cavities
Blood cell production
Bone cavities-> red bone marrow -> blood cells
and platelets

9. Cartilage:
Three types:
 Hyaline -> most associated with bone*
 Fibrocartilage
Elastic
{
provide
support

10. Cartilage:
 Hyaline cartilage chondroblasts
secrete a matrix, which surrounds
the chondroblasts
 Once the matrix has surrounded
the chondroblast, it has
differentiated into a chondrocyte.
 Chondrocytes are rounded cells
that occupy a space called a
lacuna within the matrix.
 The matrix contains collagen,
which provides strength, and
proteoglycans, which make
cartilage resilient by trapping
water

11. Cartilage:
 Most cartilage is covered by a
protective connective tissue
sheath called the perichondrium
 The perichondrium is a double-
layered outer layer of dense
irregular connective tissue
containing fibroblasts. The inner,
more delicate layer has fewer
fibers and contains
chondroblasts.
 Blood vessels and nerves
penetrate the outer layer of the
perichondrium but do not enter
the cartilage matrix*

12. Cartilage:
 Articular cartilage, which is
hyaline cartilage that covers the
ends of bones where they come
together to form joints, has no
perichondrium, blood vessels, or
nerves.
There are two types of cartilage growth: (1)
appositional growth and (2) interstitial growth.
In appositional growth, chondroblasts
in the perichondrium add new cartilage to the
outside edge of the existing cartilage. In
interstitial growth, chondrocytes in the center of
the tissue divide and add more matrix in
between the existing cells

13. Bone Matrix:
Bone -> connective tissue = spread-out cells
separated by nonliving material (matrix)
Bone cells produce and get entrapped within
matrix
The cells also break down old matrix so that
new matrix can replace it.
Bone matrix composition is responsible for the
characteristics of bone.

14. Bone Matrix:
by weight, 35% organic (collagen and
proteoglycans) and 65% inorganic
(hydroxyapatite- calcium phosphate crystal)
collagen fibers = flexible strength*
 like concrete, the mineral components give
the matrix weight-bearing strength.

15. Bone Matrix:
(a) Normal bone. (b)
Demineralized bone, soaked in
acid, in which collagen is the
primary remaining component,
can be bent without breaking. (c)
When collagen is denatured,
mineral is the primary remaining
component, making the bone so
brittle that it is easilyshattered.

16. Bone Cells: Osteoblasts
Bone-building cells
 produce collagen and proteoglycans
secrete matrix vesicles -> high concentration
of calcium and phosphate ions -> formation of
hydroxyapatite crystal -> stimulate further
hydroxyapatite formation and mineralization of
the matrix

17. Bone Cells: Osteoblasts
The formation of new bone by osteoblasts is
called ossification or osteogenesis
a) On a preexisting surface, such as cartilage or bone, the cell extensions of different osteoblasts join
together. (b) Osteoblasts have produced bone matrix and are now osteocytes. (c) Photomicrograph of
an osteocyte in a lacuna
with cell extensions in the canaliculi. (c)

18. Bone Cells: Osteocytes
Osteoblasts become osteocytes
once the osteoblasts have
secreted sufficient bone matrix
They account for 90–95% of bone
cells and are very long-lived, with
a lifespan of up to 25 years
Osteocyte cell bodies are housed
within the bone matrix in spaces
called lacunae

19. Bone Cells: Osteoclasts
bone-destroying cells
break down old or damaged bone cells
Bone reabsorption*
This breakdown is important for mobilizing
crucial Ca2+ and phosphate ions for use in
many metabolic processes.

20. Spongy Bone
appears porous, has less bone
matrix and more space than
compact bone
consists of interconnecting rods
or plates of bone called
trabeculae
Between the trabeculae are
spaces, which in life are filled with
bone marrow and blood vessels.

21. Compact Bone
solid, outer layer
surrounding each
bone.
It has more matrix
and is denser with
fewer pores than
spongy bone.

22. Compact Bone
Osteon or haversian
system- functional unit
of long bone
composed of
concentric rings of
matrix which surround
a central tunnel and
contain osteocytes

23. Compact Bone
 Perforating canals (Volkmann
canals) deliver blood to the central
canals of the osteons
 They contain blood vessels from the
periosteum or medullary cavity.
 Nutrients in the blood vessels are
delivered to the osteocytes.
 Because the osteocytes are in
contact with each other through
the canaliculi, nutrients are passed
from osteocyte to osteocyte of each
osteon.

24. Structure of a Long Bone
Diaphysis-center portion
of the bone. It is composed
primarily of compact bone,
surrounding a hollow
center called the
medullary cavity. Some
spongy bone can be found
lining the medullary cavity.

25. Structure of a Long Bone
The ends of a long bone
are called epiphyses. The
epiphyses are mostly
spongy bone, with an outer
layer of compact bone.
Within joints, the end of a
long bone is covered with
hyaline cartilage called
articular cartilage

26. Structure of a Long Bone
During bone formation
and growth, bones develop
from centers of ossification
The primary ossification
center is in the diaphysis.
The epiphysis develops
from different centers of
ossification from the
diaphysis

27. Structure of a Long Bone
The epiphyseal plate,
or growth plate, is
located between the
epiphysis and the
diaphysis.
Growth in bone length
occurs at the epiphyseal
plate.

28. Structure of a Long Bone
The cavities of spongy
bone and the medullary
cavity are filled with
marrow.
Red marrow is the site
of blood cell formation,
and yellow marrow is
mostly adipose tissue*

29. Structure of a Long Bone
 The periosteum is a connective
tissue membrane covering the
outer surface of a bone
 The outer fibrous layer is dense
irregular collagenous connective
tissue that contains blood vessels
and nerves.
 The inner layer is a single layer of
bone cells, including osteoblasts,
osteoclasts, and osteochondral
progenitor cells

30. Structure of a Long Bone
 Endosteum is a single cell layer
of connective tissue that lines
the internal surfaces of all
cavities within bones, such as
the medullary cavity of the
diaphysis and the smaller
cavities in spongy and compact
bone
 The endosteum includes
osteoblasts, osteoclasts, and
osteochondral progenitor cells.

31. Structure of a Flat Bone
Flat bones contain an
interior framework of
spongy bone
sandwiched between
two layers of compact
bone

32. Structure of a Short and Irregular
Short and irregular bones have a composition
similar to the epiphyses of long bones—
compact bone surfaces surrounding a spongy
bone center with small spaces that are usually
filled with marrow.
Short and irregular bones are not elongated
and have no diaphyses.

33. Structure of a Short and Irregular
Short bones are roughly cube
shaped with vertical and horizontal
dimensions approximately equal.
They consist primarily of spongy
bone, which is covered by a thin
layer of compact bone.
Short bones include the bones of
the wrist and ankle.

34. Structure of a Short and Irregular
Bones that are not in any of
the above three categories are
classified as irregular bones.
They are primarily spongy
bone that is covered with a
thin layer of compact bone.
The vertebrae and some of
the bones in the skull are
irregular bones.

35. Axial Skeleton: Skull
The skull consists of 8 cranial bones and 14
facial bones, a total of 22 bones
The cranial bones, or cranium house and
protect the brain
The cranial bones are connected by
immovable joints called sutures. There are four
principal sutures: (1) coronal, (2) sagittal, (3)
lambdoid, and (4) squamous

36. Coronal
suture Sagittal
suture
Lambdoid
suture
Squamous
suture

37. Axial Skeleton: Skull
The 8 bones of the cranium include:
(1) the frontal bone,
(2) the 2 parietal bones,
(3) the 2 temporal bones,
(4) the occipital bone,
(5) the sphenoid bone, and
(6) the ethmoid bone.

38. Axial Skeleton: Skull
The frontal bone is connected to the two
parietal bones by the coronal suture
Forehead
 It forms the roof of both the orbit of the eye
and the nasal cavity
Internally, the frontal bone forms the anterior
cranial fossa, which supports the frontal lobes
of the brain

41. Axial Skeleton: Skull
The parietal bone form nearly half of the
superior portion of the skull.
 The two parietal bones are joined medially by
the sagittal suture and are connected to the
occipital bone by the lambdoid suture.
Along with the temporal bones, the parietal
bones make up the majority of the lateral
portion of the skull

43. Axial Skeleton: Skull
Temporal bones are
connected to the skull by
the squamous sutures
The temporal bone is
subdivided into three main
regions: (1) the squamous
part, (2) the tympanic part,
and (3) the petrous part.

44. Axial Skeleton: Skull
The squamous part of each
temporal bone meets the parietal
bone superiorly.
The zygomatic process extends
from the squamous part
anteriorly toward the zygomatic
bone of the face. It joins with the
temporal process of the zygomatic
bone to form the zygomatic arch,
a bridge across the side of the
skull

45. Axial Skeleton: Skull
The tympanic part of
the temporal bone has
the prominent external
acoustic meatus

46. Axial Skeleton: Skull
 The petrous part of the temporal
bone extends posterolaterally
from the center of the sphenoid
bone
 The petrous part and sphenoid
bone make up the middle cranial
fossa which contains the temporal
lobes of the brain.
 The petrous part is a thick, bony
ridge (petrous; rocky), is hollow,
and houses the middle and inner
ears.

47. Axial Skeleton: Skull
 Externally, the mastoid process is
a large, bony inferior projection
that can be seen and felt just
posterior to the external ear.
 Styloid process projects from the
inferior of the petrous part of the
temporal bone. It serves as an
attachment site for three muscles
necessary for movement of the
tongue, hyoid bone, and pharynx

48. Axial Skeleton: Skull
The occipital bone makes up the
majority of the skull’s posterior
wall and base.
Its most prominent feature is the
foramen magnum (large hole),
the opening where the brainstem
connects to the spinal cord
It forms the posterior cranial
fossae that support the
cerebellum of the brain.

50. Axial Skeleton: Skull
Although appearing to be two
bones, one on each side of the
skull anterior to the temporal
bone, the sphenoid bone is
actually a single bone that
extends completely across the
skull
When viewed as a whole, the
sphenoid bone somewhat
resembles a butterfly with four
distinct parts.*

51. Axial Skeleton: Skull
The ethmoid bone is a
porous, fragile bone.
It is centrally located
in the skull, forming the
nasal septum (wall), a
large portion of the
nasal cavity, as well as
the medial wall of the
orbits.

52. Axial Skeleton: Skull
The 14 facial bones of the skull include
(1) the 2 zygomatic bones,
(2) the 2 maxilla bones,
(3) the 2 palatine bones,
(4) the 2 lacrimal bones,
(5) the 2 nasal bones,
(6) the mandible,
(7) the vomer bone, and
(8) the 2 inferior nasal conchae

54. Axial Skeleton: Skull
The zygomatic bones, commonly known as the
cheekbones, are anterior to the sphenoid bone.
There they form part of the inferiolateral
border of the orbits
As previously discussed, the temporal process
of the zygomatic bone articulates with the
zygomatic process of the temporal bone to form
the zygomatic arch.

55. Axial Skeleton: Skull
Each maxilla is anterior and inferior to the
zygomatic bones and the two maxillae are
fused medially
The maxillae are two of the three jaw bones,
and form (1) the upper jaw, (2) the majority of
the roof of the mouth, and (3) the center
portion of the face

57. Axial Skeleton: Skull
The palatine bones
have horizontal plates
that fuse medially to
form the posterior
portion of the hard
palate as described
earlier with the
maxillae.

58. Axial Skeleton: Skull
The lacrimal bones are
the smallest of the skull
bones and house the
depression through which
the nasolacrimal duct
enters the nasolacrimal
canal, joining the orbits
and nasal cavity

59. •The nasal bones,
along with the frontal
processes of the
maxillae, form the
bridge of the nose.

60. Axial Skeleton: Skull
The mandible is the only
skull bone that is freely
movable relative to the
other skull bones.
It is inferior to the maxillae
and attaches posteriorly to
the temporal bone via the
mandibular fossa

61. Axial Skeleton: Hyoid Bone
important for speech and
swallowing.
Some tongue muscles as well
as neck muscles that elevate
the larynx attach to the hyoid
The hyoid bone has the unique
distinction of being the only
bone in the body not directly
attached to another bone.*

63. Axial Skeleton: Vertebral Column
performs five major functions:

64. Axial Skeleton: Vertebral Column
performs five major functions:
(1) It supports the weight of the head and
trunk, (2) it protects the spinal cord, (3) it
allows spinal nerves to exit the spinal cord, (4)
it provides a site for muscle attachment, and
(5) it permits movement of the head and
trunk.

65. Axial Skeleton: Vertebral Column
The 26 bones, called
vertebrae, which can be divided
into five regions: 7 cervical
vertebrae, 12 thoracic
vertebrae, 5 lumbar vertebrae,
1 sacral bone, and 1 coccygeal
bone.

66. Axial Skeleton: Vertebral Column
The adult vertebral column has
four major curvatures
The cervical region curves
anteriorly, the thoracic region
curves posteriorly, the lumbar
region curves anteriorly, and the
sacral and coccygeal regions
together curve posteriorly.

67. Axial Skeleton: Vertebral Column
Each vertebra consists of (1)
a body, (2) a vertebral arch,
and (3) various processes.
The vertebral body, the solid
bony disk of each vertebra,
supports the body’s weight.
The vertebral arch, along
with the body, protects the
spinal cord.

68. Axial Skeleton: Vertebral Column
The vertebral arch
projects posteriorly from
the body. Together, the
vertebral arch and the body
form a complete bony circle
enclosing the vertebral
foramen, which is occupied
by the spinal cord in a living
person

69. Axial Skeleton: Vertebral Column
The spinous
processes can be
seen and felt as a
series of rounded
projections down the
midline of the back.

70. Axial Skeleton: Vertebral Column
The intervertebral foramina
are the locations where two
vertebrae meet
Each intervertebral foramen
is formed by intervertebral
notches in the pedicles of
adjacent vertebrae. These
foramina are where spinal
nerves exit the spinal cord.

71. Axial Skeleton: Vertebral Column
In a living person, vertebrae are
separated by intervertebral disks.
Intervertebral disks are
composed of fibrocartilage*, and
are located between the bodies
of adjacent vertebrae
The intervertebral disks provide
support and cushion the
vertebral bodies.

73. Axial Skeleton: Vertebral Column
Cervical vertebrae are
located in the vertebral
column region with the
greatest range of motion.
These vertebrae support and
move the head.*
Most cervical vertebrae have
bifid (split) spinous processes.

74. Axial Skeleton: Vertebral Column
 The first two cervical vertebrae include
(1) the atlas (C1) and (2) the axis (C2).
 The atlas and axis are heftier than the
other five cervical vertebrae since they
directly support the weight of the head
and control its movements.

75. Axial Skeleton: Vertebral Column
The thoracic region is the
least moveable of the five
regions due to the
articulation of the thoracic
vertebrae with the ribs.
It supports the thoracic
cage, which houses and
protects the heart and lungs

76. Axial Skeleton: Vertebral Column
These vertebrae have the
longest spinous processes,
which project inferiorly.
Their transverse processes
are longer than others and
the first 10 possess articular
facets for the tubercles of
the ribs.

77. Axial Skeleton: Vertebral Column
The bodies have articular
facets for the heads of the
ribs. The head of most ribs
articulates with the inferior
articular facet of one
vertebra and with the
superior articular facet for
the rib head on the next
vertebra down.

78. Axial Skeleton: Vertebral Column
Lumbar vertebrae support
the majority of the body’s
weight
They have massive bodies
and heavy, rectangular
transverse and spinous
processes.

79. Axial Skeleton: Vertebral Column
The sacrum is located between
the two hip bones.
 It articulates with each hip
bone by way of the auricular
surfaces, forming the sacroiliac
joint.
The sacrum is part of the pelvic
girdle, which provides stable
support for our lower limbs.

80. Axial Skeleton: Vertebral Column
The coccyx is commonly
referred to as the tailbone.
It is the terminal portion
of the vertebral column.

81. Axial Skeleton: Thoracic cage
 Thoracic cage, commonly called
the rib cage, protects the heart
and lungs within the thorax.
 It forms a semirigid chamber,
which can increase and decrease
in volume during respiration.
 It consists of (1) the thoracic
vertebrae, (2) the ribs with their
associated costal (rib) cartilages,
and (3) the sternum

82. Axial Skeleton: Thoracic cage
There are 12 pairs of ribs.
Ribs are classified as either
true ribs or false ribs.
Ribs 1–7 are called true ribs.
True ribs attach directly
through costal cartilage to the
sternum.
Ribs 8–12 are called false ribs
because they do not attach
directly to the sternum.

83. Axial Skeleton: Thoracic cage
Ribs 8–10 are joined by a
common cartilage to the
costal cartilage of rib 7,
which in turn is attached to
the sternum.
Two of the false ribs, ribs
11 and 12, are also called
floating ribs because they do
not attach to the sternum

84. Axial Skeleton: Thoracic cage
Costal cartilages are
flexible and permit the
thoracic cage to expand
during respiration

85. Axial Skeleton: Thoracic cage
 Most ribs attach to the thoracic
vertebrae in two locations.
 First, the head of the rib articulates
with the bodies and intervertebral
disks of two adjacent vertebrae.
 These sites of articulation are called
the inferior articular facet on the
superior vertebra and the superior
articular facet on the inferior vertebra.
 Second, the tubercle of the rib
articulates with the transverse process
of the inferior vertebra

86. Axial Skeleton: Thoracic cage
The sternum, or
breastbone, has been
described as sword
shaped and has three
parts: (1) The
manubrium; (2) the body,
and (3) the xiphoid
process

87. Appendicular Skeleton
The pectoral girdle consists
of two pairs of bones that
attach each of the upper
limbs to the body:
Each pair is composed of a
scapula, commonly known
as the shoulder blade and a
clavicle, commonly known as
the collarbone

88. Appendicular Skeleton
The acromion process has
three functions: (1) to form
a protective cover for the
shoulder joint, (2) to form
the attachment site for the
clavicle, and (3) to provide
attachment points for some
of the shoulder muscles.

89. Appendicular Skeleton
The smaller coracoid
process provides
attachments for some
shoulder and arm muscles.
A glenoid cavity, located in
the superior lateral portion
of the bone, articulates with
the head of the humerus.

90. Appendicular Skeleton

91. Appendicular Skeleton
The clavicle is a long bone with
a slight sigmoid (S-shaped)
curve.
It articulates with the scapula
and the sternum.
On the lateral end it articulates
with the acromion process. On
the medial end it articulates
with the manubrium of the
sternum.

92. Appendicular Skeleton
The humeral head articulates
with the glenoid cavity of the
scapula.
The proximal end of the
humerus has two prominent
landmarks, both sites of muscle
attachment: (1) Laterally, it is
the greater tubercle. (2)
Anteriorly, it is the lesser
tubercle.

93. Appendicular Skeleton
The diaphysis of the
humerus has a noticeable
lateral landmark.
The deltoid tuberosity is
the site of attachment of
the deltoid muscle.

94. Appendicular Skeleton
 Laterally, the humerus articulates with
the radius. This location is called the
capitulum.
 Medially, the humerus articulates
with the ulna. This location is called
the trochlea.
 Forearm muscles attach to the
humerus just superior to the
capitulum and trochlea.
 The attachment sites are the medial
epicondyle and the lateral epicondyle.

96. Appendicular Skeleton
The forearm has two
bones: (1) the ulna and (2)
the radius.
The ulna is medial, the
same side as the little
finger, and the radius is
lateral, the same side as
the thumb

97. Appendicular Skeleton
The trochlear notch rotates over
the trochlea of the humerus
when bending the elbow.
The coronoid process inserts
into the coronoid fossa of the
humerus when the elbow is bent
The olecranon process inserts
into the olecranon fossa of the
humerus when the elbow is
straightened

98. Appendicular Skeleton
Radial notch where the
head of the radius rotates.
The head of the ulna
articulates with both the
radius and the wrist bones
styloid process- where
ligaments of the wrist
attach

99. Appendicular Skeleton
 The head of the radius articulates
with the humerus and rotates over
the capitulum of the humerus
when bending the elbow.
 radial tuberosity is the site of
attachment for the biceps brachii
muscle of the arm
 The styloid process of the radius is
lateral and also serves as an
attachment location for wrist
ligaments.

100. Appendicular Skeleton
 The wrist is composed of eight
carpal bones arranged into two
rows of four each.
 The proximal row of carpal bones,
lateral to medial, includes (1) the
scaphoid, which is boat-shaped;
(2) the lunate, which is moon-
shaped; (3) the three-cornered
triquetrum; and (4) the pea-
shaped pisiform, which is located
on the palmar surface of the
triquetrum.

101. Appendicular Skeleton
 The distal row of carpal bones,
from medial to lateral, includes
1 hamate which has a hooked
process on its palmar side; (2)
the head-shaped capitate; (3)
the trapezoid, four-sided
geometric form with two
parallel sides; and (4) the
trapezium, four-sided geometric
form with no two sides parallel.

102. Appendicular Skeleton
Five metacarpal bones are
attached to the carpal
bones and make up the
central portion of the hand.
 They are numbered one
to five, starting with the
most lateral metacarpal
bone, at the base of the
thumb.

103. Appendicular Skeleton
 The five digits of each hand
include one thumb (pollex) and
four fingers.
 Each digit consists of small
long bones called phalanges.
 The thumb has two phalanges,
called proximal and distal.
 Each finger has three
phalanges, designated
proximal, middle, and distal.

104. Appendicular Skeleton
The pelvic girdle is formed
by the two hip bones (coxal
bones) and the sacrum.
The hip bones join each
other anteriorly and connect
with the sacrum posteriorly
forming a complete circle of
bone.
The pelvis includes the
pelvic girdle and the coccyx

105. Appendicular Skeleton
The pelvic girdle is formed
by the two hip bones (coxal
bones) and the sacrum.
The hip bones join each
other anteriorly and connect
with the sacrum posteriorly
forming a complete circle of
bone.
The pelvis includes the
pelvic girdle and the coccyx

106. Appendicular Skeleton
 Each hip bone is formed from
three separate bones fused
into a large bony plate: (1) the
ilium, (2) the ischium, and (3)
the pubis
 The three individual bones
converge near the center of
the hip socket, called the
acetabulum where lower limbs
articulate with the pelvic girdle

107. Appendicular Skeleton
The pelvic girdle serves as
the place of attachment for
the lower limbs, supports the
weight of the body, and
protects internal organs.
In women, it protects
developing fetus and forms a
passageway through which
the fetus passes during
delivery.

108. Appendicular Skeleton
The anterior superior
iliac spine is an
important anatomical
landmark used, for
example, to find the
correct location for
giving gluteal injections
into the hip.

109. Appendicular Skeleton
Posterior thigh muscles
attach to the ischial
tuberosity and its the
portion of the pelvis on
which a person sits.
The two pubic bones are
joined by the pubic
symphysis, a thick pad of
fibrocartilage

111. Appendicular Skeleton
The thigh, like the arm,
contains a single bone,
the femur.
The femur has a
prominent, rounded
head, where it
articulates with the
acetabulum

112. Appendicular Skeleton
The proximal shaft
exhibits two projections:
a greater trochanter and
lesser trochanter.
Both trochanters are
attachment sites for
muscles that fasten the
hip to the thigh.

113. Appendicular Skeleton
 The femur articulates with the tibia to
form the knee.
 There are two smooth rounded
projections that rotate on the superior
surface of the tibia when we bend our
knee. These two rounded projections
are (1) the medial condyle and (2) the
lateral condyle.
 Just superior to the medial and lateral
condyles are two large ligament
attachment sites. These are (1) the
medial epicondyle and (2) the lateral
epicondyle

114. Appendicular Skeleton
The patella, or kneecap, is a large
sesamoid bone located within the
tendon of the quadriceps femoris
muscle group, which is the major
muscle group of the anterior thigh
The patella articulates with the
patellar groove of the femur to
create a smooth articular surface
over the anterior distal end of the
femur.

115. Appendicular Skeleton
Like the forearm, leg is
consists of two bones: (1)
the medial, tibia, or
shinbone, and (2) the
lateral fibula.
The tibia is the larger of
the two and is the major
weight-bearing bone of the
leg.

116. Appendicular Skeleton
The tibial tuberosity is the
point of attachment for the
quadriceps femoris muscle
group.
The fibula does not
articulate with the femur,
but its head articulates
with the proximal end of
the tibia.

117. Appendicular Skeleton
The ankle consists of the
distal ends of the tibia and
fibula forming a partial
socket that articulates
with a bone of the foot
(the talus).

118. Appendicular Skeleton
A prominence can be
seen on each side of the
ankle. These are the
medial malleolus of the
distal tibia and the lateral
malleolus of the distal
fibula.

119. Appendicular Skeleton
There are seven tarsal
(foot) bones. It includes:
(1) the talus (ankle), (2)
the calcaneus (heel), (3)
the navicular, (4–6) the
medial, intermediate, and
lateral cuneiforms, and (7)
the cuboid

120. Appendicular Skeleton
The metatarsal bones
and phalanges of the foot
are arranged in a manner
very similar to that of the
metacarpal bones and
phalanges of the hand,
with the great toe (hallux)
comparable to the thumb