Comparison of the pelvis in females and males
Table 5.1
Point of comparison
General structure
False (greater) pelvis
Pelvic inlet
Acetabulum
Obturator foramen
Pubic arch
Female
Light and thin
Shallow
Larger and more oval
Small and faces anteriorly
Oval
Greater than 90° angle
Male
Heavy and thick
Deep
Smaller and heart-shaped
Large and faces laterally
Round
Less than 90° angle
False (greater)
pelvis
Pelvic brim (inlet)
Acetabulum
Obturator
foramen
Pubic arch (greater than 90°)
Pubic arch (less than 90°)
Anterior views
The pelvic inlet—the superior opening into the bony
pelvis—is heart-shaped in males and oval in females.
The sacrum is wider and more posteriorly placed in the
female than in the male.
All bones of the lower body are shown in Figure 5.12 on
the next page.
its rounded distal end and forms a joint with the talus of
the ankle. The ankle bones, or
tarsals
, consist of 7 bones.
Two of these bones, the
talus
(
TA-lus
) and the
calcaneus
(
kal-KA-ne-us
), are on the posterior part of the foot. The
talus is part of the ankle joint, while the calcaneus forms
the heel of the foot. The rest of the tarsals are anterior to
these and attach to the metatarsals.
The Design of the Lower Limb Is
Similar to That of the Upper Limb
Like the upper limb, the lower limb is composed of a single
bone proximally with increasing numbers of bones as one
moves distally. Attached to each coxal bone is a
femur
(thigh
bone), the longest single bone in the body (see Figure 5.12a).
Like the humerus, the femur has a rounded, proximal head
where it fits into the acetabulum of the pelvis. The femur
bends medially and attaches distally to the
patella
(knee
cap) and the tibia.
The
tibia
is the large medial bone of the shin and
bears most of the weight. It attaches proximally with the
femur and fibula and distally with the fibula and the talus
of the ankle. The patellar ligament, which holds the patel-
la in place, attaches to the tibia at the
tibial tuberosity
.
The lateral bone of the shin is called the
fibula
. The
proximal end of the fibula articulates with the tibia and
Foot Structure Helps Disperse
Body Weight and Absorb Shock
The
metatarsals
(5) are like the metacarpals of the hand.
Attached to the metatarsals are the phalanges (toes), which
have a structure similar to the phalanges in the hand (Figure
5.12d). The calcaneus forms the posterior portion of the foot.
The foot has two raised bends, or
arches
, in it (Figure 5.12e).
The
longitudinal arch
spreads from anterior to posterior, while
the
transverse arch
goes from side to side. The arches are flex-
ible and springy. They absorb shocks, distribute body weight
over the foot, and provide leverage while walking.
CONCEPT CHECK
1.
What
is the pubic symphysis?
2.
How
does the thigh attach to the leg?
3.
What
are the functions of the arches of the foot?
Bones of the Lower Body Form the Pelvic Girdle and Legs
133
previous page 168 Craig Freudenrich, Gerard J  Tortora   Visualizing Anatomy and Physiology   2011 read online next page 170 Craig Freudenrich, Gerard J  Tortora   Visualizing Anatomy and Physiology   2011 read online Home Toggle text on/off