The femur, also known as the thigh bone, is the longest bone of
the human skeleton and is located between the hip bone and the
knee.LEARNING OBJECTIVE Describe the femur
KEY POINTS The femur is one of the strongest bones in the human
skeleton. It functions in supporting the weight of the body and
allowing motion of the lower extremity. The femur makes up part of
the hip joint and thekneejoint.
TERM condyleA smooth prominence on a bone where it forms a joint
with another bone.Give us feedback on this content:FULL TEXTThe
femur, or thigh bone, is the most proximal (closest to the center
of the body) bone of the leg intetrapodvertebrates capable of
walking or jumping, such as most land mammals, birds, many reptiles
such as lizards, and amphibians such as frogs . In vertebrates with
four legs such as dogs and horses, the femur is found only in the
rear legs. The head of the femur articulates with the acetabulum in
the pelvic bone to form the hip joint, while thedistalpart of the
femur articulates with thetibiaandpatellato form the knee joint. By
most measures, the femur is the strongest bone in the body.
Anterior Position of the Human FemurThe femurs are outlined in
red.The femur is the longest bone of the human skeleton and is
located between the hip bone and the knee. It is the only bone in
the thigh. This bone is also one of the strongest bones in the
human skeleton. It functions in supporting the weight of the body
and allowing motion of the lower extremity.The head (at the
proximal extremity) of the femur articulates with the acetabulum of
thepelvisto form the hip joint . The lower extremity of the femur
(or distal extremity), which is larger, is somewhat cuboid in form
and consists of two oblong eminences known as thecondyles. The
articular surface of the lower end of the femur occupies the
anterior, inferior, andposteriorsurfaces of the condyles. The front
or anterior portion is the patellar surface and articulates with
the patella. The lower and posterior parts articulate with the
corresponding condyles of the tibia to form the knee joint.
FemurThe anterior surface of the femur with parts labeledThe
lower and posterior parts of the articular surface constitute the
tibial surfaces forarticulationwith the corresponding condyles of
the tibia and menisci.
The patella, also known as the knee cap, is a triangular shaped
bone found between the femur and the tibia.LEARNING OBJECTIVE
Identify the purpose of the patella
KEY POINTS The primary functions of thepatellaare protection of
thekneejoint and legextension. The lower part of
theposteriorsurface hasvascularcanaliculi filled and is filled by
fatty tissue, which is the infrapatellar fat pad. The patella is
the largest sesamoid bone in the body. A sesamoid bone is a bone
that is embedded within atendon.
TERMS patellaThe sesamoid bone of the knee; the kneecap.
exostosesAn exostosis (plural:exostoses) is a benign bony growth,
often covered withcartilage, on the surface of a bone or tooth.Give
us feedback on this content:FULL TEXTThe patella, also known as the
knee cap, is a triangular-shaped bone found between the femur and
thetibia. The patella is the largest sesamoid bone in the body. A
sesamoid bone is embedded within a tendon.
PatellaHuman left patellaThe patella is roughly triangular in
shape with itsbasefacing proximally (towards the torso) and its tip
(apex patellae) facing distally (towards the feet). Its anterior
and posterior surfaces are joined laterally (left/right) by a
thinner margin and medially (towards center) by a thicker
margin.The anterior surface can be divided into three parts: The
upper third is coarse, flattened, and rough; it serves for the
attachment of the tendon of thequadricepsand often has exostoses.
The middle third has numerous vascular canaliculi. The lower third
includes thedistalapex, which serves as theoriginof the patellar
ligament.The posterior surface is divided into two parts.The upper
three-quarters articulates with the femur and is subdivided into a
medial and alateralfacet by a vertical ledge which varies in
shape.Four main types of articular surface can be distinguished.
Most commonly, the medial articular surface is smaller than the
lateral. Sometimes both articular surfaces are virtually equal in
size. Occasionally, the medial surface is hypoplastic or the
central ledge is only indicated. In an adult, the articular surface
is about 12 cm2(1.9 sq in) and covered by cartilage, which can
reach a maximal thickness of six mm (0.24 in) in the center at
about 30 years of age. The lower part of the posterior surface has
vascular canaliculi and is filled by fatty tissue, which is the
infrapatellar fat pad.The patella protects the knee joint, but its
primary functional role is knee extension . The patella increases
the leverage that the tendon can exert on the femur by increasing
the angle at which it acts.
Knee JointThis image shows the position of the patella relative
to the articulation of the femur and the tibia.
Tibia and Fibula (Leg)READPROPOSE A
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ReadingView QuizViewPowerPointTemplateThe tibia and the smaller
fibula bones comprise the lower leg and articulate at the knee and
ankle.LEARNING OBJECTIVE Contrast the fibula with the tibia
KEY POINTS Thetibia, also known as the shinbone, is a long bone
of the lower leg, found between thepatellaand the ankle.
Thefibulais a long, thin bone running parallel to the tibia. Like
the femur, the tibia bears much of the body's weight and plays an
essential role in movement and locomotion. The fibula, along with
the tibia and the tarsals, forms the ankle.
TERMS fibulaThe smaller of the two bones in the lower leg, the
calf bone. tibiaThe inner and usually the larger of the two bones
of the leg or hind limb below theknee.Give us feedback on this
content:FULL TEXTTibia and Fibula (Leg)The TibiaThe tibia, also
known as the shin bone, is a long bone of the lower leg found
between the patella and the ankle. It is the larger and stronger of
the two bones in the leg below the knee in vertebrates (the other
being the fibula), and connects the knee with the ankle bones. The
tibia is named for the Greek aulos flute. It is commonly recognized
as the strongest weight-bearing bone of the body. It forms the
medial part of the ankle joint and is the second largest bone next
to the femur. Like the femur, the tibia bears much of the body's
weight and plays an essential role in movement and locomotion. In
the male, its direction is vertical and parallel with the bone of
the opposite side. In the female, it has a slightly oblique
direction downward and laterally, to compensate for the greater
obliqueness of the femur. The tibia is prismoid in form, which
means it is polyhedron-like in shape with parallel planes
containing an equal number of points. It is wider at the top, where
it enters into the knee-joint, contracted in the lower third, and
again enlarged but to a lesser extent towards the ankle joint.The
tibia derives its arterialbloodsupply from two sources: the
nutrientartery(main source) and the periosteal vessels derived from
the anterior tibial artery.The superior tibiofibulararticulationis
an arthrodial joint between thelateralcondyleof the tibia and the
head of the fibula. The inferior tibiofibular articulation
(tibiofibular syndesmosis) is formed by the rough, convex surface
of the medial side of the lower end of the fibula, and a rough
concave surface on the lateral side of the tibia. The tibia is
connected to the fibula by aninterosseous membrane, forming a type
of joint called a syndesmosis. The forward flat part of the tibia
is called the fibia, often confused with the fibula.The FibulaThe
fibula, also known as the calf bone, is a long, thin bone running
parallel to the tibia. Its upper extremity is small, placed toward
the back of the head of the tibia, below the level of the
knee-joint, and excluded from the formation of this joint. Its
lower extremity inclines a little forward so that it is on a plane
anterior to that of the upper end. It projects below the tibia
forming the lateral part of the ankle joint.The fibula has the
following components: Body of fibula Lateral malleolus;
Interosseous membrane connecting the fibula to the tibia, forming
asyndesmosesjoint; The superior tibiofibular articulation is an
arthrodial joint between the lateral condyle of the tibia and the
head of the fibula; The inferior tibiofibular articulation
(tibiofibular syndesmosis) is formed by the rough, convex surface
of the medial side of the lower end of the fibula, and a rough
concave surface on the lateral side of the tibia.The blood supply
to the fibula is important for planning free tissue transfer
because the fibula is commonly used to reconstruct themandible. The
shaft is supplied in its middle third by a large nutrient vessel
from the fibular artery. It is also perfused from its periosteum
which receives many small branches from the fibular artery. The
proximal head and the epiphysis are supplied by a branch of the
anterior tibial artery. In harvesting the bone, the middle third is
always taken and the ends preserved (4 cm proximally and 6 cm
distally).In addition, in the tibia, ossification, which is the
formation of the bone, starts from three centers; one in the shaft
and one in each extremity, while the fibula is ossified from three
centers, one for the shaft and another for either end. For the
fibula, ossification begins in the body about the eighth week of
fetallife, and extends toward the extremities. At birth the ends
are cartilaginous. Ossification commences in the lower end in the
second year, and in the upper end around 4 years old. The lower
epiphysis, the first to ossify, unites with the body around 20
years old and the upper epiphysis joins around 25 years old.
The LegTibia and fibula in anatomical position with parts
labeled.Give us feedback on this content:
Tarsals, Metatarsals, and Phalanges (Foot)READPROPOSE A
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ReadingView QuizViewPowerPointTemplateThe human ankle and foot
bones include tarsals (ankle), metatarsals (middle bones), and
phalanges (toes).LEARNING OBJECTIVE Distinguish the subdivisions of
the foot
KEY POINTS The human foot and ankle are strong and complex
mechanical structures containing more than 26 bones
(tarsals/ankle,metatarsals/mid-bones, andphalanges/toes), 33
joints, and more than a hundred muscles,tendons, and ligaments. The
foot can be subdivided into the hindfoot, the midfoot, and the
forefoot. The hindfoot is composed of the talus or ankle bone and
the calcaneus or heel bone. The five irregular bones of the midfoot
(the cuboid, navicular, and three cuneiform bones) form the arches
of the foot. The forefoot is composed of five toes and the
corresponding five proximal long bones forming themetatarsus. The
human foot has two longitudinal arches and a transverse arch
maintained by the interlocking shapes of the foot bones, strong
ligaments, and pulling muscles during activity.
TERMS metatarsusThe part of the foot between the toes and the
ankle, especially its five bones. tarsusThe part of the foot
between thetibiaandfibulaand the metatarsus. phalangeOne of the
bones of the finger or toe, also called phalanx.Give us feedback on
this content:FULL TEXTThe human foot and ankle are strong and
complex mechanical structures containing more than 26 bones
(tarsals/ankle, metatarsals/mid-bones, and phalanges/toes ), 33
joints (20 of which are actively articulated), and more than a
hundred muscles, tendons, and ligaments.
Main parts of footFoot (anatomic): 1 - ankle, 2 - heel bone, 3 -
instep, 4 - metatarsus, 5 - toe.The foot can be subdivided into the
hindfoot, the midfoot, and the forefoot.The hindfoot is composed of
the talus or ankle bone and the calcaneus or heel bone. The two
long bones of the lower leg, the tibia and fibula, are connected to
the top of the talus to form the ankle. Connected to the talus at
the subtalar joint, the calcaneus (the largest bone of the foot) is
cushioned inferiorly by a layer of fat.The five irregular bones of
the midfoot (the cuboid, navicular, and three cuneiform bones) form
the arches of the foot which serve asshockabsorbers. The midfoot is
connected to the hind- and fore-foot by muscles and
theplantarfascia.The forefoot is composed of five toes and the
corresponding five proximal long bones forming the metatarsus .
Similar to the fingers of the hand, the bones of the toes are
called phalanges. The big toe has two phalanges, while the other
four toes have three phalanges. The joints between the phalanges
are called interphalangeal; those between the metatarsus and
phalanges are called metatarsophalangeal (MTP).
Arches of the FootSkeleton of foot. Lateral aspect.Both the
midfoot and forefoot constitute the dorsum (the area facing upwards
while standing) and the planum (the area facing downwards while
standing).The human foot has two longitudinal arches and a
transverse arch maintained by the interlocking shapes of the foot
bones, strong ligaments, and pulling muscles during activity. The
slight mobility of these arches when weight is applied to and
removed from the foot makes walking and running more economical in
terms of energy. As can be examined in a footprint, the medial
longitudinal arch curves above the ground. This arch stretches from
the heel bone over the "keystone" ankle bone to the three medial
metatarsals. In contrast, thelaterallongitudinal arch is very low.
With the cuboid serving as its keystone, it redistributes part of
the weight to the calcaneus and thedistalend of the fifth
metatarsal. The two longitudinal arches serve as pillars for the
transverse arch which run obliquely across the tarsometatarsal
joints. Excessive strain on the tendons and ligaments of the feet
can result in fallen arches or flat feet.
MetatarsalThe metatarsus or metatarsal bones are a group of five
long bones in the foot located between the tarsal bones of the
hind- and mid-foot and the phalanges of the toes.