L12_The Forearm and Hand (1) Flashcards
General aspects of the anterior compartement of the forearm
- “flexor compartment” flexors and pronators of the wrist and flexors of the digits
- Innervated by Median and Ulnar nerves
Explain the movement of supination
- when the bone are parallel to one another
- palm is facing forward (up)
what are the ligaments limiting the movement of the wrist joint?
Radial collateral ligament: between the radius and the carpal bones (prevent too much ulnar deviation)
Ulnar collateral ligament: between the styloid process of ulna and the carpal bones (prevent too much radial deviation)
Describe the metacarpophalangeal joint (MCP) Joints I-V (classification, articulation, functions)
Classification: Synovial, condyloid/ellipsoid joint
Articulation: between the metacarpal and proximal phalange
Functions: flexion/extension, abduction/adduction
Superficial layer of the anterior compartment of the forearm
Describe the pronator teres muscle (origin, insertion, functions, innervation)
Origin: Medial epicondyle of the humerus
Insertion: Lateral Radius
functions: Pronation of the forearm
Innervation: Median nerve (C6-C7)
The median nerve gives innervation to which muscles?
- anterior compartment of the forearm
- Except : medial 1/2 of FDP and FCU
Superficial layer of the anterior compartment of the forearm
Describe the Palmaris longus muscle (origin, insertion, functions, innervation)
Origin: medial epicondyle of the humerus
Insertion: palmar aponeurosis
functions: flexion of the hand at the wrist
Innervation: median nerve (C8)
The Ulnar nerve gives innervation to which muscles?
- flexor carpu ulnaris (FCU)
- medial 1/2 of FDP
(minority innervation)
The anterior interosseous of the median nerve gives innervation to which muscles?
Deep muscles:
- FDP lateral 1/2
- Flexor Pollicis Longus
- Pronator Quadratus
Explain the movement of pronation
- The radius will turn and it’s going to crisscross over top of the ulna
- the bones aren’t parallel anymore
- the palm is facing down
Describe the Carpometacarpal (CMC) joint II-V (classification, articulations, functions)
classification: synovial condyloid/ellipsoid joints
articulations: distal row of carpal bone and metacarpals II-V
Functions: movement very limited - CMC IV and V facilitate opposition of thumb
Name the bones identified by the numbers and the triangle (9)
So= 1. Scaphoid -> Common wrist injury (scaphoid fractures)
Long= 2. Lunate
To= 3. Triquetrum
Pinky= 4. Pisiform
Here= 5. Hamate
*Hook of hamate
Comes= 6. Capitate
The= 7. Trapezoid
Thumb= 8. Trapezium
- Triangular Fibrocartilagenous Disc
Deep layer of the anterior compartment of the forearm
Describe the Flexor digitorum Profundus (FDP) muscle (origin, insertion, functions, innervation)
Origin: Anterior proximal ulna and interosseous membrane
Insertion: Four tendons to base of distal phalanges of digits II-V
Functions: Flexion of the wirst, MCP, DIP and PIP joints
Innervation: Ulnar nerve -> medial 1/2 (Digit V + half of IV)
Anterior interosseous of the median nerve -> lateral 1/2
FDP runs deep to FDS (under it)
Deep layer of the anterior compartment of the forearm
Describe the Flexor pollicis longus muscle (origin, insertion, functions, innervation)
Origin: anterior radius and interosseous membrane
Insertion: base of 1st dital phalanx of digit 1 (thumb)
pollicis=thumb
Functions: flexion of the wrist amd MCP joint, and IP joints of the thumb
Innervation: anterior interosseous of median nerve (C8-T1)
Describe the Proximal Radioulnar joint (classification, articulations, reinforcing ligaments and structures, function)
Classification: synovial pivot joint
Articulations: Heah of the radius and radial notch of ulna
Reinforcing structures and ligaments: annular ligament, quadrate ligament, synovial membrane
Functions: Pronation/Supination and flexion/extension
Superficial layer of the anterior compartment of the forearm
Describe the Flexor carpi radialis muscle (origin, insertion, functions, innervation)
Origin: medial epicondyle of the humerus
Insertion: base of metacarpals II-III
Functions: flexion and abduction (radial deviation) of the hand and wrist
Innervation: median nerve (C6-C7)
Describe the Distal Radioulnar joint (classification, articulations, reinforcing ligaments and structures, function)
Classification: Synovial pivot joint
Articulations: head of the ulna and ulnar notch of radius
Reinforcing structures and ligaments: palmar and dorsal radioulnar ligaments, articular disc, radial collateral ligament at the wrist joint, ulnar collateral ligament at the wrist joint
Functions: pronation/supination and flexion/extension
Describe the Intercarpal Joints (classification, articulations, functions)
Classification: Synovial plane joint plane and gliding
Articulations: between carpal bones
Functions: slight gliding motion
Name the structures identified by the numbers
- Head
- Body
- Base
- Distal part of the phalange
- Middle part of the phalange (not present on digit 1)
- Base of the phalange
- Metacarpal
- Phalange
Describe the Carpometacarpal (CMC) joint I (classification, articulations, functions)
Classification: Synovial saddle joint
Articulations: between the metacarpal bone and the trapezium
functions: flexion/extension, adduction/abduction
Superficial layer of the anterior compartment of the forearm
Describe the flexor carpi ulnaris muscle (origin, insertion, functions, innervation)
Origin: medial epicondyle of the humerus
Insertion: pisiform, hamate, base of metacarpal V
Functions: flexion and adduction (ulnar deviation) of the hand at the wrist
Innervation: Ulnar nerve (C7-C8)
Intermediate layer of the anterior compartment of the forearm
Describe the Flexor digitorum superficialis (FDS) muscle (origin, insertion, functions, innervation)
Origin: Medial epicondyle of the humerus, head and middle 1/3 of the radius
Insertion: body of middle phalanges of digits II-V
Functions: flexion of the wrist and at the MCP and PIP joints
Innervation: median nerve (C7-T1)
Deep layer of the anterior compartment of the forearm
Describe the Pronator Quadratus muscle (origin, insertion, functions, innervation)
Origin: anterior distal ulna
Insertion: anterior distal radius
Functions: pronation
Innervation: anterior interosseous of median nerve (C8-T1)
General aspects of the posterior compartement of the forearm
- “extensor compartment” extensors and supinators of the wrist and extensor of the digits
- Innervated by the radial nerve (deep branch)
Describe the Middle Radioulnar joint (classification, articulations, reinforcing ligaments and structures, function)
Classification: Solid syndesmosis joint
Articulations: Shaft of radius and ulna
Reinforcing ligaments: Radius and Ulna joined by interosseous membrane
Functions: pronation/supination and flexion/extension
Describe the wrist (radiocarpal) joint (classification, articulations, functions)
Classification: Synovial condyloid/ellipsoid joint
Articulations: between the distal radius, triangular fibrocartilage (TFC) disc and proximal row of carpal bones (except pisiform)
Functions: flexion/extension, abduction (radial deviation)/adduction (ulnar deviation)
-> circumduction
Describe the interphalangeal (IP) joint (classification, articulations, functions)
Classification: synovial hinge joint
Articulations: between proximal and middle phalanges (PIP) and between middle and distal phalanges (DIP)
Functions: Flexion/extension
