242
UNIT TWO
b. They articulate with the humerus of each upper
limb and provide attachments for muscles of the
upper limbs and chest.
7.10
UPPER LIMB (PAGE 226)
Limb bones form the framework and provide the
attachments for muscles that move the limb.
1. Humerus
a. The humerus extends from the scapula to the
elbow.
b. It has a head, greater tubercle, lesser tubercle,
intertubercular groove, anatomical neck, surgical
neck, deltoid tuberosity, capitulum, trochlea,
epicondyles, coronoid fossa, and olecranon fossa.
2. Radius
a. The radius is on the thumb side of the forearm
between the elbow and wrist.
b. It has a head, radial tuberosity, styloid process,
and ulnar notch.
3. Ulna
a. The ulna is longer than the radius and overlaps the
humerus posteriorly.
b. It has a trochlear notch, olecranon process,
coronoid process, head, styloid process, and radial
notch.
c. It articulates with the radius laterally and with a
disc of F
brocartilage inferiorly.
4. Hand
a. The wrist has eight carpals.
b. The palm has F
ve metacarpals.
c. The F ve F
ngers have fourteen phalanges.
7.11
PELVIC GIRDLE (PAGE 231)
The pelvic girdle consists of two hip bones that articulate
with each other anteriorly and with the sacrum
posteriorly. The sacrum, coccyx, and pelvic girdle form
the pelvis. The girdle provides support for body weight
and attachments for muscles and protects visceral organs.
1. Hip bones
Each hip bone consists of an ilium, ischium, and
pubis, fused in the region of the acetabulum.
a. Ilium
(1) The ilium, the largest portion of the hip bone,
joins the sacrum at the sacroiliac joint.
(2) It has an iliac crest with anterior and posterior
superior iliac spines and iliac fossae.
b. Ischium
(1) The ischium is the lowest portion of the hip
bone.
(2) It has an ischial tuberosity and ischial spine.
c. Pubis
(1) The pubis is the anterior portion of the hip
bone.
(2) Pubis bones are fused anteriorly at the
symphysis pubis.
2. Greater and lesser pelves
a. The greater pelvis is above the pelvic brim; the
lesser pelvis is below it.
b. The greater pelvis helps support abdominal
organs; the lesser pelvis functions as a birth canal.
3. Thoracic vertebrae
a. Thoracic vertebrae are larger than cervical
vertebrae.
b. Their transverse processes project posteriorly at
sharp angles.
c. Their long spinous processes slope downward, and
facets on the sides of bodies articulate with the ribs.
4. Lumbar vertebrae
a. Vertebral bodies of lumbar vertebrae are large and
strong.
b. Their transverse processes project laterally, and
their spinous processes project posteriorly nearly
horizontal.
5. Sacrum
a. The sacrum, formed of F
ve fused vertebrae, is a
triangular structure that has rows of dorsal sacral
foramina.
b. It is united with the hip bones at the sacroiliac
joints.
c. The sacral promontory provides a guide for
determining the size of the pelvis.
6. Coccyx
a. The coccyx, composed of four fused vertebrae,
forms the lowest part of the vertebral column.
b. It acts as a shock absorber when a person sits and
is an attachment for muscles of the pelvic fl
oor.
7.8
THORACIC CAGE (PAGE 222)
The thoracic cage includes the ribs, thoracic vertebrae,
sternum, and costal cartilages. It supports the pectoral
girdle and upper limbs, protects viscera, and functions in
breathing.
1. Ribs
a. Twelve pairs of ribs are attached to the twelve
thoracic vertebrae.
b. Costal cartilages of the true ribs join the sternum
directly; those of the false ribs join indirectly or not
at all.
c. A typical rib has a shaft, head, and tubercles that
articulate with the vertebrae.
2. Sternum
a. The sternum consists of a manubrium, body, and
xiphoid process.
b. It articulates with costal cartilages and clavicles.
7.9
PECTORAL GIRDLE (PAGE 225)
The pectoral girdle is composed of two clavicles and two
scapulae. It forms an incomplete ring that supports the
upper limbs and provides attachments for muscles that
move the upper limbs.
1. Clavicles
a. Clavicles are rodlike bones that run horizontally
between the sternum and shoulders.
b. They hold the shoulders in place and provide
attachments for muscles.
2. Scapulae
a. The scapulae are broad, triangular bones with
bodies, spines, acromion processes, coracoid
processes, glenoid cavities, supraspinous and
infraspinous fossae, superior borders, axillary
borders, and vertebral borders.
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