Transcript Appendicular Skeleton

Appendicular
Skeleton
Pectoral (Shoulder) Girdle
Pectoral Girdle
Attach the bones of
the upper limbs to
the axial skeleton
Consist of two
bones: clavicle and
scapula
The joints are freely
movable in many
directions
Clavicle
Also known as the
collarbone
Long, slender Sshaped bone that is
horizontally above
the first rib
Transmits
mechanical force
from the upper limb
to the trunk
Scapula
Also known as the
shoulder blade
Large, flat triangular
bone situated in the
posterior part of the
thorax
A sharp ridge, the
spine, runs
diagonally across
the back portion of
the scapula body
The lateral end of
the spine is the
acromion, where the
scapula articulates
with the clavicle
The glenoid cavity is
a depression inferior
to the acromion. It
articulates with the
humerus head to
form the shoulder
joint.
The coracoid
process is where
muscles attach.
Upper Limb
Upper Limb
Consists of 30 bones
(all paired up)
Humerus in the arm
Ulna and radius in
the forearm
8 carpals, 5
metacarpals, and 14
phalanges in the
hand
Humerus
Longest and largest
bone of the upper
limb
Articulates with the
scapula at the
shoulder and both
the ulna and radius
at the elbow
Ulna
Located on the
medial side of the
forearm (pinky side)
Longer than the
radius
Radius
Located on the
lateral side of the
forearm (thumb
side)
Humerus Bone Surface
Markings
Proximal end
consists of a head
that articulates with
the scapula’s glenoid
cavity and an
anatomical neck
where the
epiphyseal plate
used to be
The body contains
the deltoid
tuberosity, a
roughened V-shaped
area where the
deltoid muscle
attaches
At the distal end,
the capitulum
articulates with the
head of the radius.
The radial fossa is a
depression that
receives the head of
the radius when the
forearm is bent.
The trochlea is a spoolshaped surface that
articulates with the
ulna.
The coronoid fossa
receives part of the ulna
when the forearm is
bent.
The olecranon fossa is a
depression on the back
of the bone that
receives the ulna when
the forearm is
straightened.
Ulna Bone Surface Markings
The olecranon forms
the prominence of
the elbow on the
proximal end.
The coronoid
process along with
the olecranon
receives the trochlea
of the humerus in
the trochlear notch.
The radial notch is a
depression for the
head of the radius.
A styloid process is
at the distal end.
Radius Bone Surface Markings
Disc-shaped head at the
proximal end articulates
with the capitulum of
the humerus and radial
notch of the ulna
Radial tuberosity is a
raised, roughened area
that is where the biceps
brachii muscle attaches
to the bone
The distal end of the
radius articulates
with three carpal
bones
There’s a styloid
process at the distal
end (similar to the
ulna)
Carpus (Wrist)
8 carpals
Held together by
ligaments with four
bones in each row
Named for their
shapes
Short bones
The carpals in the
top row are the:
Scaphoid, Lunate,
Triquetrum, and
Pisiform
The carpals in the
bottom row are the:
Trapezium,
Trapezoid, Capitate,
and Hamate
Metacarpus (Palm)
5 metacarpals
Each consists of a
proximal base, an
intermediate body,
and a distal head
Numbered I-V
starting with the
thumb
Long bones
Phalanges (Fingers)
14 in each hand
Thumb has two
(proximal and distal)
In each of the other
four digits, there are
three (proximal,
middle, and distal)
Disorders of the Upper Limb
Carpal Tunnel Syndrome
Narrowing of the
carpal tunnel causes
compression of the
median nerve
The nerve
compression causes
pain, numbness,
tingling, and hand
muscle weakness
Rotator Cuff Injury
Tears or
inflammation of
ligaments and
tendons of the
shoulder near the
humerus
Results in pain and
loss of shoulder
mobility
Fractures
Checkpoint Questions
Which bones make up a pectoral girdle? What
is the function of the pectoral girdle?
With which part of the scapula does the
humerus articulate?
What part of the ulna is called the “elbow”?
What part of which bones are commonly
called the “knuckles”?
What bones form the upper limb, from
proximal to distal?