Download Appendicular Skeleton Lab

Appendicular Skeleton Lab
(Revised 10/07)
EXAMINING AND IDENTIFYING BONES OF THE APPENDICULAR SKELETON
Examine each of the bones described in this exercise and identify characteristics of bone markings of each. The
markings help you determine whether a bone is the right or left member of its pair.
BONE OF THE PECTORAL GIRDLE
The paired pectoral, or shoulder girdles (Figure 5.20
page 139) each consists of two bones – a clavicle and
a scapula. The shoulder girdles anchor the upper
limbs to the axial skeleton and provide attachment
points for man trunk and neck muscles.
The clavicle, or collarbone, is a slender doubly
curved bone. Its medial end attaches to the sternum.
The lateral end of the clavicle is flattened where it
articulates with the scapula. The clavicle serves as a
brace, or strut, to hold the arm away from the top of
the thorax.
The scapula, or shoulder blade, are generally
triangular. The scapula has no direct attachment to
the axial skeleton but is loosely held in place by trunk
muscles.
ARM
The arm consists of a single bone – the humerus, a
typical long bone (Figure 5.21 (a & b) page 140).
Proximally it attaches to the scapula. The distal end
of the humerus articulates with the ulna of the
forearm.
FOREARM
Two bones, the radius and the ulna (Figure 5.21 (c)
page 140), form the skeleton of the forearm. In the
anatomical position, the radius is in the lateral
position. Proximally, the radius attaches to the
humerus.
The ulna is the medial bone of the forearm.
Proximally, it attaches to the humerus and distally
attaches to the carpal bones.
THE HAND
The skeleton of the hand (Figure 5.22 page 141) includes three groups of bones: the carpals , metacarpals, and
phalanges.
The carpal, or wrist bone, is made up of eight bones arranged in two irregular rows of four bone each. Study
Figure 5.22 to study the names and the arrangements of the carpals.
The metacarpals, numbered 1 to 5 from the thumb side of the hand, radiate out from the wrist like spokes to
form the palm of the hand. The bases of the metacarpals articulate with the carpals of the wrist; their heads
articulate with the phalanges of the fingers distally.
Like the bones of the palm, the fingers are numbered from 1 to 5, beginning from the thumb side of the hand.
The 14 bones of the fingers, or digits of each hand, are miniature long bones, called phalanges.
THE PELVIC GIRDLE
The pelvic girdle or hip girdle (Figure 5.23 page
142), is formed by the two coxal bones. The bony
pelvis is made up of the pelvic girdle together with
the sacrum and the coccyx.
Each coxal bone is a result of the fusion of three
bones – the ilium, ischium, and pubis. The ilium, a
large flaring bone, forms most of the coxal bone. It
connects posteriorly with the sacrum.
The ischium, forming the inferior portion of the
coxal bone, is the “sit-down” bone. It receives
majority of the weight of the body when we sit.
The pubis is the most anterior part of the coxal bone.
Two pubic bones meet anteriorly.
The ilium, ischium, and pubis unite at the deep
hemispherical socket called the acetabulum, which
receives the head of the thigh bone.
The female pelvis is modified for childbearing.
Generally speaking, the female pelvis is wider,
shallower, lighter, and rounder than that of the male.
THE THIGH
The femur, or thigh bone (Figure 5.24 (a & b), is
the only bone of the thigh. It is the heaviest,
strongest bone in the body. Its ball-like head
articulates with the hop bone via the acetabulum.
Distally, the femur articulates with the tibia below.
The femur’s anterior surface attaches to the patella
(kneecap).
THE LEG
Two bones, the tibia and the fibula (Figure 5.24 (c)),
form the skeleton of the leg.
The tibia, or shinbone, is the larger and more medial bone. At the proximal end, the tibia articulates with the
distal portion of the femur. Distally, the tibia articulates with the tarsal bones that make up the ankle bones.
The sticklike fibula, which lies parallel to the tibia, takes no part in forming the knee joint. Its proximal end
articulates with the lateral head of the tibia. The fibula is not a weight-bearing bone.
THE FOOT
The bones of the foot include 7 tarsal bones forming the ankle, 5 metatarsals which forms the sole of the foot,
and 14 phalanges which form toes (Figure 5.25 page145).
IDENTIFY BONES: Go around the room, find the numbered bones, and identify the bones.
1. ____________________
2. ____________________
3. ____________________
4. ____________________
5. ____________________
6. ____________________
7. ____________________
8. ____________________
9. ____________________
10. ____________________
11. ____________________
12. ____________________
13. ____________________
14. ____________________
15. ____________________
16. ____________________
17. ____________________