Bones and joints of the upper limb
Scapula and clavicle
formof
thethe
shoulder
girdle,limb
holding up the axial skeleton.
Bones
upper
clavicle
scapula
humerus
ulna
radius
Clavicle (collar bone) is an unusual long bone. The only bone that sits
horizontally. It develops from intra-membranous ossification. It does not have a
medullary cavity in the middle that characterise long bones.
clavicle
Superior
Superior – smooth surface
Inferior– rough surface
Lateral end –
flattened
Acromion end
Articulates with
scapula
Medial end –
round
Sternal end
Articulates with
sternum
Medially curves
forwards
The lateral end is called the acromion end because it articulates with the
chromion of the scapula. Acromioclavicular joint.
The medial round end articulated with the sternum and so is called the sternal
end. Sternoclavicular joint.
The curvature changes between 2/3 and 1/3 and this is the weakest point – most
likely to fracture.
When bones change from round to flat, this is appoint of fracture.
Scapula is an irregular bone.
Flat bone in a triangular shape.
The lateral and medial border meet at a medial angle.
Greys anatomy.
Scapula
Posterior
Anterior
Corocoid process
Superior
Acromion
Subscapular
fossa
Supraspinous
fossa
Glenoid
fossa
Infraspinous
fossa
Medial
Lateral
Glenoid
fossa
lateral
Humerus. Also called the funny bone.
Long bone, has a head with an anatomical neck and the surgical neck (where
breakages occur).
The greater tubercle is more lateral.
The greater and lesser tubercles are created by pressure.
The grove between the tubercles is the intertubercular groove or sulcus.
Most medial bump on the distal head of the humerus is the medial epicondyle.
the flexors come form here. The one on the other side is the later epicondyle and
is where the extensors come from.
The trochlear is the pulley where the ulna articulates.
Capitulum is lateral. It articulates with the radius.
Humerus
Anterior
head
Greater tubercle
anatomical neck
surgical neck
Lesser tubercle
Intertubercular
groove
Lateral
epicondyle
Medial epicondyle
Capitulum
Trochlear
Ulna is in line with the 5th digit. It is more medial than the radius. It articulates
with the trochlea at the trochlea notch. The most proximal point is olecranon.
The head of the ulna is at the bottom, the radius is the reverse. Head is distal.
At the base there is the olecranon at the very top, which extends posteriorinferiorally; then the trochlear notch, coronoid process and the ulnar tuberosity.
The head (inferioally) is the styloid process.
Bones are separated by interosseous membrane.
Ulna and Radius
Anterior
PROXIMAL
head
neck
Olecranon
Trochlear notch
Coronoid process
Ulnar tuberosity
radial tuberosity
Interosseous
membrane
(fibrous joint)
Radius
(lat)
BASE
Styloid
process
Ulna
(med)
HEAD
Styloid process
Ulnar notch
The radius articulates with the capitulum. It is shorter and more lateral. It’s
head is proximal. It is circular – controls rotation.
It has a head and then a thinned neck. It has a bulge, called the radial tuberosity.
The styloid process articulates with the carpal bones.
It articulates with the ulna in the proximal radial-ulna joint. With the ulnar notch.
In-between the radius and the ulna is the interosseous membrane which is a
fibrous joint.
The hand
Radius and ulna.
Carpus – wrist of hand. 2 rows of 4 very short bones. It forms a tunnel shape
(carpal tunnel syndrome).
Some Lovers Try Positions that they can’t handle.
Metacarpals.
Are numbered laterally to medially. 1-5.
The head of these bones are the knuckles.
There are 14 phalanges in the hand.
There is a proximal, middle and distal phalanges. The thumb (first digit) doesn’t
have a middle phalange.
JOINTS
Joint means articulation.
1. fibrous joints.
2. cartilaginous joints
3. synovial joints
Tissues that lies between the articulating surfaces is synovium, which
increases the range of movement. Lined by articular or hyaline cartilage.
Inside the joint capsule is the synovial cavity, filled with oil like synovial
fluid. Then there are ligaments.
Ligament – joins bone to bone.
Uniaxial joint – movement in only one plane. Eg. gliding joint between carpal
bones. They are synovial, gliding joints. Two flat surfaces that glide on each
other.
Or hinge joints, like between the ulna and humerus.
Biaxial – two. Eg. condyloid joints between radius and the carpal bones or in the
metacarpal bones.
Multiaxial – more than two. Eg. ball and socket joints at humerus and scapula.
Also saddle joints, between first metacarpal and other carpal bones. The only one
in the body,
Elbow is a hinge joint. Between the capitulum and trochlea with radius and ulna.
Proximal radial ulna joint and distal radio-ulna joint.
Need to know basic movement.