Skeletal
Organization
Bone Function
Function
(cont.)
Bone
(cont.)
(See Table 7.1, p. 141)
Two major portions of skeletons:
• Axial skeleton
• Consists of bony and
cartilaginous parts that support
and protect the organs of the
head, neck, and trunk.
• Skull: 8 cranial & 14 facial
bones
• Middle ear bones: 3 bones per
ear
• Hyoid bone: 1 bone
• Vertebral column: 26 vertebrae
• Thoracic cage: 25 bones
Skeletal
Organization
Bone Function
Function
(cont.)
Bone
(cont.)
(See Table 7.1, p. 141)
Two major portions of skeletons:
• Appendicular Skeleton
• Consists of the bones of the
upper and lower limbs and the
bones that anchor the limbs to
the axial skeleton.
• Pectoral girdle(shoulder): 2
bones per shoulder
• Upper limbs(arms and hands):
30 bones per arm and hand
• Pelvic girdle (hips): 1 bone per
hip
• Lower limbs (legs and feet): 30
bones per leg and foot
Terms
Skeletal Structures
(See Table 7.2, p.142)
Bonefor
Function
(cont.)
Bone
Function
(cont.)
Facet
• A small, nearly flat surface.
• Example: rib facet of thoracic vertebrae
Condyle
• Rounded process that usually
articulates with another bone.
• Example: medial and lateral condyles
of the femur
Foramen
• An opening through a bone that is
usually a passageway for blood
vessels, nerves, or ligaments.
• Example: foramen magnum of the
occipital bone of the skull
Terms
Skeletal Structures
(See Table 7.2, p.142)
Bonefor
Function
(cont.)
Bone
Function
(cont.)
Fontanel
• A soft spot in the skull where
membranes cover the spaces
between bones.
• Example: anterior fontanel between
frontal and parietal bones.
Head
• An enlargement on the end of the
bone.
• Example: head of the femur
Sinus
• A cavity within a bone.
• Example: frontal sinus within frontal
bone
Terms
Skeletal Structures
(See Table 7.2, p.142)
Bonefor
Function
(cont.)
Bone
Function
(cont.)
Spine
• A thornlike projection
• Example: spine of scapula
Tubercle
• A small, knoblike process
• Example: greater tubercle of
humerus
Tuberosity
• A knoblike process usually larger
than a tubercle
• Example: deltoid tuberosity of
humerus
The
BoneSkull
Function (cont.)
(cont.)
Bone
Function
• Consists of 22 bones that,
except for the lower jaw,
are interlocked along
sutures.
– 8 bones make up the
cranium.
– 14 bones make up the
face.
• The only moveable bone
in the skull is the lower
jaw (called the mandible)
and is held to the cranium
by ligaments.
The
BoneCranium
Function (cont.)
(cont.)
Bone
Function
• Encloses and protects the
brain
• Surface provides attachments
for muscles that make chewing
and head movements possible
• Contain air-filled cavities called
paranasal sinuses which are
lined with mucous membranes
and connected by passageways to the nasal cavity.
• Sinuses function to:
– Reduce skull weight
– Increase voice intensity by
serving as a resonance
chamber
The
BoneCranium
Function (cont.)
(cont.)
Bone
Function
• Frontal bone (1)
– Forms the anterior portion of the
skull above the eyes
– Contains 2 frontal sinuses, one
above each eye near the midline
– Marked by a supraorbital foramen
through which blood vessels and
nerves pass to the forehead.
• Parietal bones (2)
– Located on each side of the skull
just behind the frontal bone
– Form the bulging sides and roof
of the cranium
– Fused at the midline along the
sagittal suture
– Meet the frontal bone along the
coronal suture.
The
BoneCranium
Function (cont.)
(cont.)
Bone
Function
• Occipital bone (1)
– Joins the parietal bones along
the lambdoid suture
– Forms the back of the skull
and the base of the cranium
– Foramen magnum is the large
opening through which the
brain joins the spinal cord
– Rounded processes called
occipital condyles, located on
either side of the foramen
magnum, articulate with the
first vertebra (called the atlas)
of the vertebral column.
The
BoneCranium
Function (cont.)
(cont.)
Bone
Function
• Temporal bones (2)
– Located on either side of the skull
forming parts of the sides and base
of the cranium
– Joins the parietal bones along the
squamous suture
– Near the inferior margin is an
opening called the external acoustic
(or auditory) meatus, which leads
inward to parts of the ear.
– Below the meatus are 2 projections:
a rounded mastoid process and a
long, pointed styloid process.
– The zygomatic process projects
anteriorly to join the zygomatic bone
to form the prominence of the
cheek.
The
BoneCranium
Function (cont.)
(cont.)
Bone
Function
• Sphenoid bone (1)
– Wedged between several other
bones in the anterior cranium
– Helps form the base of the
cranium, the sides of the skull,
and the floors and sides of the
orbits
– Along the midline within the
cranial cavity, a portion of the
sphenoid bone indents to form
the saddle-shaped sella turcica
– The pituitary gland also contains
2 sphenoidal sinuses (along the
sides of the nose on the face)
The
BoneCranium
Function (cont.)
(cont.)
Bone
Function
• Ethmoid bone (1)
– Located in front of the sphenoid
bone inside the cranium
– 2 masses on either side of the nasal
cavity are joined together by
cribriform plates which form part of
the roof of the nasal cavity
– Projecting upward into the cranial
cavity between the cribriform plates
is a triangular process called the
crista galli
– Portions of the ethmoid bone form
parts of the cranial floor, the orbital
walls, and the nasal cavity walls
– A perpendicular plate projects down
to form most of the nasal septum
The
BoneCranium
Function (cont.)
(cont.)
Bone
Function
• Ethmoid bone (1)
– Delicate scroll-shaped plates called
the superior nasal conchae and the
middle nasal conchae project inward
from the lateral part of the ethmoid
bone toward the perpendicular
plate.
– The lateral portions of the ethmoid
bone contain small air spaces called
the ethmoidal sinuses (found
between the eyes on the face)
The
BoneFace
Function (cont.)
(cont.)
Bone
Function
• Consists of 13 immoveable bones and 1 moveable lower jaw
• Forms the basic shape of the face
• Provide attachments for muscles that move the jaw and
control facial expressions
The
BoneFace
Function (cont.)
(cont.)
Bone
Function
• Maxillae (singular maxilla) (2)
– Forms the upper jaw, portions of the
anterior roof of the mouth (the hard
palate), the floors of the orbits, and the
sides and floors of the nasal cavity.
– Contain the sockets of the upper teeth
– Lateral to the nasal cavity are 2 maxillary
sinuses, the largest of the sinuses.
– During development, parts of the
maxillae called palantine processes
grow together and fuse along the midline
to form the anterior hard palate
– The inferior border of each maxillary
bone projects downward, forming horseshoe shaped alveolar or dental arch
– Teeth occupy cavities in the dental arch
The
BoneFace
Function (cont.)
(cont.)
Bone
Function
• Cleft palate
– Results from incomplete fusion of
the palatine processes of the
maxillae
– Infants with a cleft palate may
have trouble nursing because of
the opening between the oral and
nasal cavities.
– Temporary prosthetics may be
inserted in to the mouth or special
bottle nipples may be used until
surgery can be performed to
correct the condition.
– Cleft palate is sometimes
accompanied by a second
malformation called a cleft lip or
“harelip”.
The
BoneFace
Function (cont.)
(cont.)
Bone
Function
• Palatine bones (2)
– L-shaped bones located behind
the maxillae
– Horizontal portions form the
posterior hard palate and the floor
of the nasal cavity
– Perpendicular portions help form
the lateral walls of the nasal
cavity
• Lacrimal bones (2)
– Thin, scale-like structure located
in the medial wall of each orbit
between the ethmoid bone and
the maxilla
– Bony structure that surrounds the
tear ducts and allow tears.
The
BoneFace
Function (cont.)
(cont.)
Bone
Function
• Zygoma or Zygomatic bones
– Form the prominances of the
cheeks below and to the sides of
the eyes
– Help form the lateral walls and the
floors of the orbits
– Each bone has a temporal
process that extends posteriorly
to join the zygomatic process of
the temporal bone
– Together the temporal and
zygomatic processes form the
zygomatic arch.
The
BoneFace
Function (cont.)
(cont.)
Bone
Function
• Nasal Bones (2)
– Form the bridge of the nose
– Have a long, thin, and nearly
rectangular shape
– Lie side by side and are fused at the
midline
• Vomer Bone (1)
– Located along the midline of the
nasal cavity
– Joins the perpendicular plate of the
ethmoid bone posteriorly to form the
nasal septum
– Has a thin, flat shape
The
BoneFace
Function (cont.)
(cont.)
Bone
Function
• Inferior Nasal Conchae (2)
– Fragile, scroll-shaped bones
attached to the lateral walls of
the nasal cavity
– Found below the superior and
middle nasal conchae, which
are part of the ethmoid bone
– Function to support mucous
membranes within the nasal
cavity
The
BoneFace
Function (cont.)
(cont.)
Bone
Function
• Mandible
– Forms the lower jaw
– Horizontal, horse-shoe shaped body
with a flat portion projecting upward
at each end
– Upward projection has 2 processes:
• Posterior mandibular condyle
which articulates with the
mandibular fossa of the temporal
bones
• Anterior coronoid process which
provides attachment for muscles
used in chewing.
– Curved bar of bone on the superior
border (the alveolar arch) contains
the hollow sockets for the lower
teeth.
The
BoneVertebral
FunctionColumn
(cont.)
Bone
Function
(cont.)
• Extends from the skull to the pelvis
• Forms the vertical axis of the
skeleton
• Supports the head and trunk of the
body
• Protects the spinal cord which
passes through a vertebral canal
formed by openings in the vertebrae.
• Composed of bony parts called
vertebrae that are separated by
masses of fibrocartilage called
intervertebral discs
• Vertebrae are connected to one
another by ligaments
The
BoneVertebral
FunctionColumn
(cont.)
Bone
Function
(cont.)
• Typical vertebrae:
– Drum-shaped body which forms
the anterior portion of the bone.
• A longitudinal column of these
bodies supports the weight of the
head and trunk.
– 2 short stalks called pedicles
project posteriorly from each
vertebral body
– 2 plates called laminae arise from
the pedicles and fuse in the back
to become a spinous process.
– The pedicles, laminae, and
spinous process together form the
vertebral arch around the vertebral
foramen.
– The spinal cord passes through
the vertebral foramen.
The
BoneVertebral
FunctionColumn
(cont.)
Bone
Function
(cont.)
• Typical vertebrae:
– Between the pedicles and laminae
is a transverse process which
projects laterally and posteriorly.
– Projecting upward and downward
from each vertebral arch are
superior and inferior articular
processes which have facets by
which each vertebrae is joined to
the one above and below.
– Intervertebral foramina are
openings found on the lower
surfaces of the pedicles. These
openings provide passageways for
spinal nerves.
(continued)
The
BoneVertebral
FunctionColumn
(cont.)
Bone
Function
(cont.)
• Spina bifida
– Caused by the failure of the
laminae of the vertebrae to close
or unite during development
– Causes the contents of the
vertebral canal to protrude
outward
– Occurs most commonly in the
lumbosacral region
– Associated with folic acid
deficiency in certain genetically
susceptible individuals.
– The higher the spina bifida on the
individual, the more of the body is
affected, the lower the spina bifida,
the less of the body is affected.
(continued)
Cervical
Vertebrae
Bone Function
Function
(cont.)
Bone
(cont.)
• Comprise the bony axis of
the neck
• There are 7 cervical
vertebrae, labeled C1 – C7
(top to bottom)
• Distinctive features:
– Have transverse foramina
which are passageways for
arteries leading to the brain.
– Spinous processes of C2-C7
are forked or bifid to provide
attachments for muscles.
– Smallest bodies
Cervical
Vertebrae
Bone Function
Function
(cont.)
Bone
(cont.)
• C1 is also called the atlas
– has 2 facets that articulate with occipital condyles
• C2 is also called the axis
– has a tooth-like odontoid process or dens
– As the head turns from side to side, the atlas pivots around the dens.
Thoracic
Vertebrae
Bone Function
Function
(cont.)
Bone
(cont.)
• 12 pairs, labeled T1 – T12
• Larger than cervical
vertebrae
• Distinctive features:
– Have the longest spinous
processes
– Have facets on the sides of the
vertebral body which articulate
with ribs.
• Beginning with the third
thoracic vertebrae and
moving inferiorly, the bodies
increase in size to bear
increasing loads of body
weight.
Lumbar
Vertebrae
Bone Function
Function
(cont.)
Bone
(cont.)
• 5 pairs, labeled L1 – L5
• Found in the small of the back
• Distinctive features:
– Have the largest and strongest bodies to support more weight than
the vertebrae above them
– Have short, stubby spinous processes
Sacrum
Bone Function
Function (cont.)
(cont.)
Bone
• Triangular structure that forms the base of
the vertebral column
• Composed of 5 fused vertebrae
• Spinous processes of fused bones form a
ridge of tubercles
• Lateral to the tubercles are rows of
openings called the posterior sacral
foramina, through which nerves and blood
vessels pass
• Vertebral foramina of the sacral vertebrae
form the sacral canal, which continues
through the sacrum to an opening at the
inferior tip called the sacral hiatus
• On the ventral surface, 4 pairs of anterior
sacral foramina provide passageways for
nerves and blood vessels.
Coccyx
Bone Function
Function (cont.)
(cont.)
Bone
• Also called the tailbone
• Most inferior part of the vertebral
column
• Composed of 4 fused vertebrae
• Attached to the sacral hiatus by
ligaments.
Spinal
Curvature
Disorders
Bone Function
Function
(cont.)
Bone
(cont.)
• Lordosis
– Also called swayback,
– Characterized by a significant curve
inward at the lower back.
• Kyphosis
– Extreme cases can be called
hunchback
– Characterized by an abnormally
rounded upper back (more than 50
degrees of curvature).
• Scoliosis
– Characterized by a sideways curve
to their spine.
– The curve is often S-shaped or Cshaped.
Thoracic
Cage (cont.)
Bone Function
Function
(cont.)
Bone
• Includes:
–
–
–
–
the ribs,
the thoracic vertebrae,
the sternum,
the costal cartilages that
attach the ribs to the sternum
• Functions:
– Support the pectoral girdle
and the upper limbs
– Protect the viscera in the
thoracic and upper abdominal
cavities
– Plays a role in breathing
Ribs
Bone Function
Function (cont.)
(cont.)
Bone
• 12 pairs or 24 total ribs
• Each pair of ribs is attached to
each of the thoracic vertebrae
• Typical rib:
– Slender shaft which curves
around the chest and slopes
downward
– On the posterior end is an
enlarged head by which the rib
articulates with a facet on the
body of its vertebra and the body
of the next higher vertebra
– A tubercle close to the head of the
rib articulates with the transverse
process of the vertebra
Ribs
Bone Function
Function (cont.)
(cont.)
Bone
• The first seven pairs are called true
ribs or vertebrosternal ribs because
they are attached to the sternum
anteriorly and the vertebrae
posteriorly
• The next five pairs are called false
ribs
– Pairs 8-10 are called
vertebrochondral ribs because they
do not reach the sternum directly and
are attached to the cartilage of the 7th
ribs
– Pairs 11-12 are called floating or
vertebral ribs because they have no
cartilaginous attachments to the
sternum.
Sternum
Bone Function
Function (cont.)
(cont.)
Bone
• Also called the breastbone
• Located along the midline in the
anterior portion of the thoracic cage
• Three main parts:
– Manubrium which is the upper part
• Articulates with the clavicles by facets
on its superior border
– Body or gladiolus which is the middle
part
– Xiphoid process which is the inferior
portion that projects downward
Pectoral
Girdle(cont.)
Bone Function
Function
(cont.)
Bone
• Also called the shoulder
girdle
• Composed of 2 clavicles
and 2 scapulae
• Incomplete ring because it
is open posteriorly between
the scapulae and
separated anteriorly by the
sternum
• Functions:
– To support the upper limbs
– Serves as attachment for
several muscles
Pectoral
Girdle(cont.)
Bone Function
Function
(cont.)
Bone
• Clavicles
– Also called collarbones
– Slender, rod-like bones with an
elongated S shape
– Located at the base of the neck
– Run horizontally between the
manubrium and the scapulae
– Functions:
• Brace the freely moveable
scapulae,
• Help hold the shoulders in place
• Provide attachments for
muscles of the upper limbs,
chest, and back
Pectoral
Girdle(cont.)
Bone Function
Function
(cont.)
Bone
• Scapulae (singular: scapula)
– Also called shoulder blades
– Broad, somewhat triangular bones
located on either side of the upper
back
– A spine divides the posterior surface
into unequal portions
– An acromion process forms the tip of
the shoulder
• Articulates with the clavicle
– A coracoid process curves anteriorly
and inferiorly to the clavicle
– A depression called the glenoid fossa
articulates with the head of the
humerus
Shoulder Structure
Upper
Limb
Bone Function
Function
(cont.)
Bone
(cont.)
• Forms the framework of the arm,
forearm, and hand
• Provide attachments for muscles
• Function as levers that move limb
parts
• Bones include (per arm):
–
–
–
–
–
–
Humerus (1)
Radius (1)
Ulna (1)
Carpals (8)
Metacarpals (5)
Phalanges (14)
Humerus
Bone Function
Function (cont.)
(cont.)
Bone
• Long bone that extends from the
scapula to the elbow
• Smooth rounded head at upper end
fits into the glenoid cavity of the
scapula
• 2 processes below the head provide
attachments for muscles: lateral
greater tubercle and anterior lesser
tubercle
• A narrow depression along the lower
margin of the head separates it from
the tubercles and is called the
anatomical neck
• Below the anatomical neck is a
tapering region called the surgical
neck.
Humerus
(cont.)
Bone Function
Function
(cont.)
Bone
(cont.)
• Near the middle of the shaft is a
rough, V-shaped deltoid tuberosity
which provides an attachment for the
deltoid muscle of the shoulder
• At lower end of humerus are 2 smooth
condyles that articulate with the radius
on the lateral side and the ulna on the
medial side:
– Lateral capitulum
– Medial trochlea
• Above the condyles on either side are
epicondyles which provide
attachments for muscles and
ligaments of the elbow.
• The coronoid and olecranon
processes articulate with the ulna
Radius
Bone Function
Function (cont.)
(cont.)
Bone
• Located on the thumb side of the
forearm and extends from the elbow
to the wrist.
• Crosses over the ulna when the palm
is downward.
• A thick, disc-like head at the upper
end articulates with the humerus and
the radial notch (of the ulna),
allowing the radius to rotate.
• A process called the radial tuberosity
is just below the head, and is an
attachment for the biceps brachii.
• At the distal end, a lateral styloid
process provides attachments for
ligaments of the wrist.
Ulna
Bone Function
Function (cont.)
(cont.)
Bone
• Longer than the radius and overlaps
the humerus posteriorly
• A wrench-like opening called the
trochlear notch articulates with the
humerus
• The olecranon and coronoid
processes provide attachments for
muscles
• At the distal end, a knob-like head
articulates laterally with the ulnar
notch of the radius.
• A medial styloid process at the distal
end provides attachments for wrist
ligaments.
Hand
(Wrist) (cont.)
Bone Function
Function
(cont.)
Bone
• Made up of the wrist, palm, and
finger bones
Wrist:
• Consists of 8 carpal bones
found in 2 rows of 4 bones
each.
• The compact mass of the wrist
is called a carpus
• The carpus articulates with the
radius and fibrocartilaginous
disc on the ulnar side.
• On the distal surface, the
carpus articulates with the
metacarpal bones.
Hand
(Metacarpals)
Bone Function
Function
(cont.)
Bone
(cont.)
• 5 metacarpal bones form the
framework of the palm or
metacarpus.
• These bones are cylindrical
with rounded distal ends that
form the knuckles of a
clenched fist.
• Metacarpal bones are
numbered 1-5 beginning with
the metacarpal of the thumb.
• Metacarpals articulate
proximally with the carpals and
distally with the phalanges.
Hand
(Phalanges)
Bone Function
Function
(cont.)
Bone
(cont.)
• Phalanges are finger bones
• Each finger has 3 phalanges:
– A proximal phalanx
– A middle phalanx
– A distal phalanx
• The thumb has 2 phalanges:
– A proximal phalanx
– A distal phalanx
Pelvic
Girdle (cont.)
Bone Function
Function
(cont.)
Bone
• Consists of 2 hip or coxal bones
which articulate with each other
anteriorly and with the sacrum
posteriorly
• The sacrum, coccyx, and pelvic
girdle together form the bowlshaped pelvis.
• Functions:
– Supports the trunk of the body
– Provides attachments for the
lower limbs
– Protects the urinary bladder, the
distal end of the large intestine,
and the internal reproductive
organs
Hip
Bones
Bone
Function (cont.)
(cont.)
Bone
Function
• Each hip bone develops
from 3 parts:
– Ilium
– Ischium
– Pubis
• These parts fuse in the
region of a cupshaped cavity called
the acetabulum.
• The acetabulum is a depression found on the lateral surface
of the hip bone, and receives the rounded head of the femur
or thigh bone.
Hip
Bones
– Ilium
Bone
Function
(cont.)
Bone
Function
(cont.)
• Largest and uppermost portion of
the hip bone
• Flares outward forming the
prominance of the hip
• The margin of the prominance is
called the iliac crest.
• Joins the sacrum posteriorly at the
sacroiliac joint.
• The anterior superior iliac spine
can be felt lateral to the groin and
provides attachments for ligaments
and muscles.
Hip
Bones
– Ischium
Bone
Function
(cont.)
Bone
Function
(cont.)
• Forms the lowest portion of the hip
bone
• Is L-shaped, with its angle pointing
posteriorly and downward
• The ischial tuberosity provides
attachments for ligaments and
lower limb muscles, and supports
the weight of the body during
sitting.
• Superior to the ischial tuberosity is
a sharp projection called the ischial
spine.
• The distance between the ischial
spines provides the shortest
diameter of the pelvic outlet.
Hip
Bones
– Pubis
Bone
Function
(cont.)
Bone
Function
(cont.)
• Constitutes the anterior portion of
the hip bone.
• The 2 pubis bones are joined at the
midline by a joint called the
symphysis pubis.
• The angle of the pubis bones below
the symphysis is the pubic arch.
• Between the bodies of the pubis
and the ischium is the largest
foramen in the body: the obdurator
foramen.
• The pelvic brim separates the lower
or true pelvis from the upper or
false pelvis (See p. 159, Figure
7.29a)
Differences
Between
Male and Female Skeletons
Bone Function
Function
(cont.)
Bone
(cont.)
• See Table 7.3, page 159
• Female Skull:
–
–
–
–
Smaller and lighter with less conspicuous muscle attachments,
Facial area is rounder,
Jaw is smaller,
Mastoid process is less prominent than in a male.
• Female Pelvic girdle:
– Hip bones are lighter, thinner, and have less obvious muscle
attachments,
– The obdurator foramina and acetabula are smaller and farther
apart than those of a male,
Differences
Between
Male and Female Skeletons
Bone Function
Function
(cont.)
Bone
(cont.)
•
Female Pelvic Cavity:
–
–
–
•
Sacrum
–
–
–
•
Wider in all diameters,
Shorter, roomier, and less funnel-shaped,
Distances between ischial spines and ischial tuberosities are
greater than in a male.
Female sacrum is wider
The first sacral vertebrae projects forward to a lesser degree
The sacral curvature is bent more sharply posteriorly than in a
male
Coccyx
–
Female coccyx is more moveable than in a male
Differences
Between
Male and Female Skeletons
Bone Function
Function
(cont.)
Bone
(cont.)
Lower
Limb
Bone Function
Function
(cont.)
Bone
(cont.)
•
•
Bones of the lower limb form
the frameworks of the thigh, leg,
and foot.
Each of the lower limbs contain:
–
–
–
–
–
–
–
1 femur (thigh)
1 patella (knee cap)
1 tibia
1 fibula
7 tarsals
5 metatarsals
14 phalanges
Femur
or Thigh(cont.)
Bone
Bone Function
Function
(cont.)
Bone
•
•
•
•
•
•
•
Longest bone in the body
Extends from the hip to the knee
Large, rounded head at its proximal end
projects medially into the acetabulum of
the hip bone
On the head, a pit called the fovea capitis
marks the attachment of a ligament
Just below the head is a neck, a superior,
lateral greater trochanter, and an inferior,
medial lesser trochanter that provide
attachments for the lower limbs & buttocks
At the distal end, 2 rounded processes
called the lateral and medial condyles
articulate with the tibia of the leg.
A patella, or kneecap, articulates with the
femur on the distal, anterior surface.
Tibia
or
Shin Bone
Bone Function
Function
(cont.)
Bone
(cont.)
•
•
•
•
•
Larger of the 2 leg bones and located
on the medial side
Proximal end is expanded into medial
and lateral condyles which articulate
with the condyles of the femur.
Below the condyles, on the anterior
surface, is a process called the tibial
tuberosity, which provides an
attachment for the patellar ligament
At its distal end, the tibia expands to
form a prominence on the inner ankle
called the medial malleolus.
The inferior surface of the tibia’s distal
end articulates with the talus of the
ankle.
Fibula
Bone Function
Function (cont.)
(cont.)
Bone
•
•
•
•
Long, slender bone located on the
lateral side of the tibia.
Its ends are slightly enlarged into a
proximal head and a distal lateral
malleolus.
The fibula does not enter into the knee
joint and does not bear any of the
body’s weight.
The lateral malleolus articulates with
the ankle and protrudes on the lateral
side.
Foot
Bone Function
Function (cont.)
(cont.)
Bone
Tarsus (or Ankle)
• 7 tarsal bones:
– Talus: moves freely where it joins the
tibia and fibular (B)
– Calcaneus or heelbone: largest of
the tarsals and helps to support body
weight. (A)
– Navicular: anterior to the talus (D)
– Cuboid: lateral to the navicular (C)
– Lateral cuneiform (E)
– Intermediate cuneiform (F)
– Medial cuneiform: anterior to the
navicular bone (G)
Foot
Bone Function
Function (cont.)
(cont.)
Bone
Metatarsals (or Instep)
• 5 elongated bones that articulate with the
tarsus
• Numbered 1-5, starting on medial side
• The heads at the distal ends form the ball of
the foot
• Bound with the tarsals to form the arches of
the foot
– Longitudinal arch extends from heel to
toe
– Transverse arch stretches across the
foot
– Arches provide a stable, shock-absorbing
springy base for the body,
– Fallen arches or flat feet result when
arches are weakened.
Foot
Bone Function
Function (cont.)
(cont.)
Bone
Phalanges (or toes)
• Similar to the bones of the fingers
• Align and articulate with the metatarsals
• Each toe except the big toe has 3
phalanges:
– Proximal phalanx
– Middle phalanx
– Distal phalanx
• The big toe lacks a middle phalanx