The Upper Limb aka The Arm

This is going to take some studying!

Bones of the upper limb (30/per limb)

Arm and Forearm• Humerus• Radius • Ulna

Wrist (8) • Scaphoid• Lunate • Triquetral• Pisiform• Trapezium• Trapezoid• Capitate• Hamate

– Just call them carpals!

Palm/Hand• Metacarpals (5)• Phalanges (14)• Proximal• Middle• Distal

Humerus

• Largest bone of upper limb

• Articulates with radius and ulna distally

• Proximally articulates with scapula at shoulder

AFV

Humerus

Points to know • Head – meets glenoid cavity

Posterior view

Humerus

Points to know • Greater tuberosity – Lateral tuberosity– Muscle attachment!

Posterior view

Humerus

Points to know • Lesser tuberosity – medial point of muscle

attachment

Posterior view

Humerus

Points to know • Deltoid tuberosity– Roughened site for rotator

cuff attachment

Posterior view

Humerus

Points to know • Trochlea – Articulation for the ulna

Posterior view

Humerus

Points to know • Capitulum– “ball like” attachment for

radius

Posterior view

Humerus

Points to know • Epicondyles– Ulnar n. runs behind medial

epicondyle

Posterior view

Humerus

• Coronoid fossa – Anterior fossa allows for

ulna to articulate when flexion happens

• Olecranon fossa – Posterior fossa allows

for ulna to articulate when extension happens

Antebrachium or Forearm

• Proximally articulate with humerus

• Distally articulate with carpal bones

• Radius and Ulna• Attach twice at

radioulnar joints • Interosseous membrane

between the two

UlnaWhat comes after L?

• The Ulna Forms Elbow• Olecranon process back • Coronoid process– Together form the hinge

joint with humerus

Bow!

Ulna info

• While a large part of elbow, very little influence on wrist

• Separated by fribrocartilaginous disc from wrist

• Distally ends in head and styloid process

• Where else did we see styloid process?

Radiusmajor forearm bone

• That at proximal end wide distally– (Opposite ulna)

• Very little contribution to elbow

• Large influence on wrist!

• Meaning: You move the radius, the hand will move!

Radius markings

• Head like a nail

Radius markings

• Head like a nail• Radial tuberosity –

anchors bicep

Radius markings

• Styloid process is distall – anchors ligaments to wrist

Radius markings

• Head like a nail• Radial tuberosity –

anchors bicep• Styloid process is distall

– anchors ligaments to wrist

“Getting a Grip” questions

1. According to the author, what made Richard Owen a genius?

2. What is the theme of this book?3. What pattern does Owen recognize?4. What does Darwin claim is responsible for

the similarities in animal limbs?5. What about the lung fish is not a coincidence

at all?6. Why is Ichthyostega a “let down?”