Anatomy 28 Flashcards
What are the radius and ulna bones connected by?
Interosseous membrane
What does the trochlea notch of the ulna articulate with?
The trochlea of the humerus
What does the radial head articulate with?
Capitellum of the humerus
What movements occur at the elbow joint?
Flexion and extension
Where do the radius and ulna articulate with each other at?
Proximal and distal radioulnar joints
What movement do the radioulnar joints allow?
Pronation and supination of the forearm and hand
What types of muscles does the anterior compartment of the forearm contain?
2 muscles that act as pronators
What forms the radiocarpal joint?
The radius articulates with two of the small bones of the wrist, or carpus
What movements occur at the wrist joint?
Flexion, extension, abduction and adduction
What muscles help achieve movements at the wrist joint?
Muscles in the anterior and posterior forearm
What is the carpus comprised of?
8 small bones that articulate with each other at small
joints
What are the bones in the carpus arranged in?
2 rows of 4 bones, one proximal, one distal
What forms the radiocarpal joint?
The distal radius articulates with two of the bones in the proximal row – the scaphoid and lunate
What bones does the proximal row of the carpal comprise of?
From lateral to medial:
the scaphoid, lunate, triquetral and the pisiform
What is the pisiform?
Not a true carpal bone, but rather is a small bone that develops in the tendon of flexor carpi ulnaris
What bones does the distal row of the carpal comprise of?
Form lateral to medial:
the trapezium (base of the thumb), trapezoid, capitate (located centrally and is the largest carpal bone) and the hamate.
What is the hamate?
Bears a bony process anteriorly (the hook), which is obvious on the bone and is palpable on examination
What is the most commonly fractured carpal bone?
Scaphoid – usually by a fall on to an outstretched hand.
A scaphoid fracture has potentially serious consequences
Where do the metacarpals lie?
Distal to the carpus
What are the bones of the digit?
Phalanges; there are three phalanges in each finger and two phalanges in the thumb.
What is the cubital fossa and what is it bounded by?
Triangular-shaped region anterior to the elbow, bounded by brachioradialis laterally and pronator teres medially
What is the pronator teres?
Anterior forearm muscle which we’ll look at in the next section
What is the superior border of the cubital fossa formed by?
A line drawn between the medial and lateral epicondyles of the humerus
What 4 important structures are found in the cubital fossa?
- Biceps tendon
- Median nerve
- Brachial artery which bifurcates into the radial and ulnar arteries
- Superficial veins lie in the subcutaneous tissue over the cubital fossa and are key sites for IV access