Download Guided Notes for the Appendicular Skeleton

Guided Notes for the
Appendicular Skeleton
1. The clavicle, or collarbone, is a
slender, doubly curved bone. It
attaches to the manubrium of the
sternum medially and to the scapula
laterally, where it helps to form the
shoulder joint. The clavicle acts as a
brace to hold the arm away from the
top of the thorax and prevent
shoulder dislocation.
2. Each scapula, or shoulder blade, has a
flattened body and two important
processes. They are the acromion, which is
the enlarged end of the spine of the
scapula, and the beak-like coracoid
process. The acromion connects with the
clavicle laterally at the acromioclavicular
joint. The coracoid process points over the
top of the shoulder and anchors some of
the muscles of the arm.
Reasons Why the Arm Has Free
Movement:
1. Each shoulder attaches the axial
skeleton at only 1 point.
2. The loose attachment of the scapula
allows it to slide as muscles act.
3. The glenoid cavity is shallow and
poorly reinforced.
4. At the midpoint of the
humerus is a roughened area
called the deltoid tuberosity,
which is where the large, fleshy
deltoid muscle of the shoulder
attaches.
5. The radial groove runs
obliquely down the posterior
aspect of the shaft of the
humerus. This groove marks
the course of the radial nerve.
6. Two bones form the skeleton of the
forearm: the radius and the ulna.
When the body is in the anatomical
position, the radius is the lateral
bone. The ulna is the medial bone.
The two bones are connected along
their length by the flexible
interosseous membrane.
7. The eight carpal bones are
arranged in two irregular
groupings of 4 bones each.
The carpals are bound together
by ligaments that restrict their
movement.
8. Each hand contains 14
phalanges. There are 3 in
each finger, except in the
thumb, which has only two.
How are the phalanges named?
 The 3 phalanges are named
(from the wrist) Proximal,
Medial, and Distal based on
their distance from the wrist
10. The pelvic girdle is formed by 2
coxal bones. Together with the
sacrum and the coccyx, they form
the bony pelvis. The most
important function of the pelvic
girdle is bearing weight because
the total weight of the upper body
rests on the pelvis.
11. Each coxal bone is formed by
the fusion of 3 bones: the
ilium, the ischium, and the
pubis. The pubic bones of each
hip fuse anteriorly to form a
cartilaginous joint called the
pubic symphysis.
12. The ilium, ischium, and
pubis fuse at the deep
socket called the
acetabulum. Its function is
to receive the head of the
thigh bone.
13. The dimensions of the true
pelvis of a woman are very
important because they must
be large enough to allow the
infant’s head to pass during
childbirth.
14. The trochanters and the gluteal
tuberosity of the femur serve as
sites for muscle attachment. The
head of the femur articulates with
the acetabulum of the hip bone in a
deep, secure socket.
15. The tibia and fibula form the
skeleton of the lower leg. They
are connected along their
length by an interosseous
membrane.
16. A process of the tibia called the
medial malleolus forms the inner
bulge of the ankle. The anterior crest
of the tibia, also called the shin, is a
sharp ridge and is easily felt under
the skin because it is unprotected by
muscles.
17. The fibula has no part in
forming the knee joint. Its
distal end, called the lateral
malleolus forms the outer
part of the ankle.
Functions of the Foot:
1) To support the body’s weight
2) To serve as a lever that allows us to
propel our bodies forward
19. Body weight is carried mostly by the
two largest tarsals, the calcaneus, or
heelbone, and the talus. The bones
of the foot are arranged to from three
strong arches. Ligaments and
tendons help to hold the foot in the
arched position but still allow a
certain amount of give or springiness.