BIO122 Spring, 2010

Laboratory 5

The Forearm and wrist

OBJECTIVES

At the end of this laboratory you should:

1. Know the osteological features of the elbow (review), forearm and wrist and be able to identify these parts on skeletal material and in radiographs and living subjects. (Humerus: medial epicondyle, lateral epicondyle, trochlea, capitulum, olecranon fossa, groove for ulnar nerve; Radius: head, neck, radial tuberosity, styliod process, ulnar notch; Ulna: olecranon, trochlear notch, coranoid process, ulnar tuberosity, styloid process, radial notch).

2. Be able to name and demonstrate all of the movements that occur at the elbow, wrist, thumb and fingers and know the contribution of the flexor forearm muscles to each motion.

3. Know the course and distribution (i.e. muscles innervated) of the median, ulnar and radial nerves in the forearm and the sensory and motor deficits that would occur if one or any combination of the nerves were lesioned. At this time, concentrate on deficits created by the paralysis of forearm muscles rather than the intrinsic muscles of the hand. Know the cutaneous areas that are only innervated by one nerve (i.e.: autonomous zones) and their significance.

4. Know the major muscles on the flexor and extensor surfaces of the forearm and know the functions and distinguishing characteristics of each.

5. Know the position, course and distribution of the radial and ulnar arteries at the elbow, in the forearm and at the wrist.

6. Be able to palpate and identify the extensor tendons of the wrist, fingers and thumb. Understand the anatomical arrangement of tendons forming the anatomical snuff box (abductor pollicis longus & extensor pollicis brevis laterally, and extensor pollicis longus dorsally) and the bones that form the floor of this area.

7. Know the attachments and function of the flexor retinaculum, and the other structures that contribute to the boundaries of the carpal tunnel.

8. Learn the names and positions of the bones of the wrist (carpals).

PRELAB PREPARATION

1. Read the sections in your textbook dealing with the osteology, musculature, nervous innervation and blood supply of the forearm and the elbow joint (M&D 2006, pp. 801-826, 866-872; MD&A 2010, 744-771; 800-807).