Download Pelvic girdle

Appendicular Skeleton
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Pelvic Girdle
Thigh (Leg)
(Lower) Leg
Foot
The lower appendages are attached to the
axial skeleton via the pelvic girdle
Bones of the Pelvic Girdle
• Pelvic girdle  2 coxal bones + sacrum
– Coxal bones are three pairs of fused bones
1. Ilium
2. Ischium
3. Pubis
• Bony pelvis  2 coxal bones + sacrum + coccyx
© 2015 Pearson Education, Inc.
Function of the Pelvic Girdle
• protects several organs
– Reproductive organs
– Urinary bladder
– Part of the large intestine
• Bears weight of the upper body
© 2015 Pearson Education, Inc.
Figure 5.26a The bony pelvis.
Articulates with axial skeleton at the sacrum = sacroiliac joint
Iliac crest
Sacroiliac
joint
Ilium
Coxal bone
(or hip bone)
Sacrum
Pubis
Pelvic brim
Coccyx
Ischial spine
Acetabulum
Ischium
(a)
Pubic symphysis
Pubic arch
Figure 5.26b The bony pelvis.
Ilium
Ala
Posterior
superior
iliac spine
Posterior
inferior
iliac spine
Greater sciatic
notch
Ischial body
Iliac crest
Anterior superior
iliac spine
Anterior inferior
iliac spine
Acetabulum
Body of pubis
Ischial spine
Pubis
Ischial
tuberosity
Ischium
(b) Ischial ramus
Inferior pubic
ramus
Obturator
foramen
Gender Differences of the Pelvis
• The female’s pelvis:
– Inlet is larger and more circular
– Pelvis as a whole is shallower, and the bones are
lighter and thinner
– Ilia flare more laterally
– Sacrum is shorter and less curved
– Ischial spines are shorter and farther apart; thus,
the outlet is larger
– Pubic arch is more rounded because the angle of
the pubic arch is greater
© 2015 Pearson Education, Inc.
Figure 5.26c The bony pelvis.
False pelvis
Inlet of
true
pelvis
Pelvic brim
Pubic arch
)
(less than 90°
False pelvis
Inlet of
true
pelvis
Pelvic brim
(c)
Pubic arch
)
(more than 90°
Bones of the Lower Appendages
• Femur—thigh bone
– heaviest, strongest bone in the body
– Proximally, the head articulates with the
acetabulum of the (hip) bone
• This creates a ball-and-socket joint
– Distally, the lateral and medial condyles articulate
with the tibia in the lower leg
© 2015 Pearson Education, Inc.
Figure 5.27a Bones of the right thigh and leg.
Neck
Head
Intertrochanteric
line
Lateral
condyle
Patellar
surface
(a)
Lesser
trochanter
Figure 5.27b Bones of the right thigh and leg.
Greater
trochanter
Head
Lesser
trochanter
Intertrochanteric
crest
Gluteal
tuberosity
Intercondylar
fossa
Medial
condyle
(b)
Lateral
condyle
Bones of the Lower Limbs
1. Tibia—shinbone; larger and medially
oriented
– Medial and lateral condyles articulate proximally
with the femur to form the knee joint
2. Fibula—thin and sticklike; lateral to the tibia
– Not part of the knee joint
• (Patella- a sesamoid (short) bone that lies
anteriorly in the knee joint; called kneecap)
© 2015 Pearson Education, Inc.
Figure 5.27c Bones of the right thigh and leg.
Intercondylar
eminence
Medial
condyle
Lateral
condyle
Head
Tibial
tuberosity
Proximal
tibiofibular
joint
Interosseous
membrane
Anterior
border
Fibula
Tibia
Distal
tibiofibular
joint
Lateral
malleolus
(c)
Medial
malleolus
Bones of the Foot
• Tarsals—Two largest tarsals
• Calcaneus (heel bone)
• Talus
• Metatarsals—form the sole of the foot
• Phalanges—form the toes
– Big toe is the hallux
– All have 3 bones; hallux has 2
© 2015 Pearson Education, Inc.
Figure 5.28 Bones of the right foot, superior view.
Phalanges:
Distal
Middle
Proximal
Tarsals:
Medial
cuneiform
Intermediate
cuneiform
Navicular
Metatarsals
Tarsals:
Lateral
cuneiform
Cuboid
Talus
Calcaneus
Arches of the Foot
• Bones of the foot are arranged to form three
strong arches
– Two longitudinal
• Medial and laterally located
– One transverse
© 2015 Pearson Education, Inc.
Figure 5.29 Arches of the foot.
Medial longitudinal arch
Transverse arch
Lateral longitudinal
arch