Anatomy Lecture-Exam 2 Content

How many carpal bones in each wrist and what are their names? What’s the mnemonic to remember them and where they are?

• 8 carpal bones

  • Scaphoid

  • Lunate

  • Triquetrum

  • Pisiform

  • Trapezium

  • Trapezoid

  • Capitate

  • Hamate

•“Sally Left the Party, To Take Cathy Home”

Which carpal bone is most commonly fractured?

scaphoid

Which carpal bone has a prominence that can be palpated deep to the hypothenar eminence?

hamate

Can you palpate the pisiform?

• yes

  • anterior aspect of medial border of wrist (medial aspect of most distal wrist crease)

  • most mobile when wrist is flexed

Which carpal bone is the largest?

capitate (keystone)

How many metacarpals in each hand?

5

How many phalanges in each hand?

• 14

  • each finger has 3 except thumb, which has 2

On your hand, show me where sensation is supplied by the superficial radial nerve, the ulnar nerve, and the median nerve.

The ulnar artery and nerve pass __________ to the pisiform.

lateral

What is Guyon’s canal? Why is this structure important in batting sports, cycling and prolonged driving?

• AKA Ulnar canal

• Semi rigid longitudinal canal in the wrist that allows for passage of the ulnar artery and ulnar nerve into the hand

• Spans over pisiform and hook of hamate

• Entrapment of ulnar nerve in this canal can lead to tingling in the ring and little fingers before progressing to loss of sensation and/or impaired motor function of the intrinsic muscles of the hand (innervated by the ulnar n.)

• Compression of ulnar n. more common in cyclists
  
  

  

What does the flexor retinaculum have to do with the carpal tunnel?

What are the contents of the carpal tunnel?

Demonstrate the arrangement of the FDS tendons in the carpal tunnel. Visualize on cross-section, the arrangement of the tendons passing thru the carpal tunnel.

What structure forms the roof of the carpal tunnel?

What does palmaris longus insert upon? If there is a palmaris longus, there must be a palmaris brevis. Where is it? How many lumbricals in each hand? O, I, A, N of them.

What are the muscles of the thenar eminence?

• adductor policis brevis

• flexor pollicis brevis

• opponens pollicis

Opponens pollicis: origin

Flexor retinaculum and tubercles of scaphoid and trapezium

Opponens pollicis: insertion

Lateral side of 1st metacarpal

Opponens pollicis: action

To oppose thumb, it draws 1st metacarpal medially to center of palm and rotates it medially

Opponens pollicis: innervation

Recurrent branch of median nerve (C8, T1)

Abductor pollicis brevis: origin

Flexor retinaculum and tubercles of scaphoid and trapezium

Abductor pollicis brevis: insertion

Lateral side of base of proximal phalanx of thumb

Abductor pollicis brevis: action

Abducts thumb; helps oppose it

Abductor pollicis brevis: innervation

Recurrent branch of median nerve (C8, T1)

Flexor pollicis brevis: origin

Flexor retinaculum and tubercles of scaphoid and trapezium

Flexor pollicis brevis: insertion

Lateral side of base of proximal phalanx of thumb

Flexor pollicis brevis: action

flexes thumb

Flexor pollicis brevis: innervation

Recurrent branch of median nerve (C8, T1)

Adductor Pollicis: Origin

Oblique Head: Bases of 2nd and 3rd metacarpals, capitate, and adjacent carpals

Transverse Head: Anterior surface of shaft of 3rd metacarpal

Adductor Pollicis: Insertion

Medial side of base of proximal phalanx of thumb

Adductor Pollicis: Action

Adducts thumb toward lateral border of palm

Where are the ulnar and radial collateral ligaments? What are the parts of the radial and ulnar collateral ligaments?

Radial collateral ligament extends from the lateral epicondyle of the humerus and blends distally with the annular ligament of the radius

Ulnar collateral ligament extends from the medial epicondyle of the humerus to the coronoid process and olecranon of the ulna and consists of anterior cord, posterior cord, oblique band that deepens the socket for the trochlea of the humerus

Adductor Pollicis: Innervation

Deep branch of ulnar nerve (C8, T1)

Abductor Digit Minimi: Origin

pisiform

Abductor Digit Minimi: Insertion

Medial side of base of proximal phalanx of 5th digit

Abductor Digit Minimi: Action

Abducts 5th digit; assists in flexion of its proximal phalanx

Abductor Digit Minimi: Innervation

Deep branch of ulnar nerve (C8, T1)

Flexor digiti minimi: Origin

Hook of hamate and flexor retinaculum

Flexor digiti minimi: Insertion

Medial side of base of proximal phalanx of 5th digit

Flexor digiti minimi: Action

Flexes proximal phalanx of 5th digit

Flexor digiti minimi: Innervation

Deep branch of ulnar nerve (C8, T1)

Opponens digiti minimi: origin

Hook of hamate and flexor retinaculum

Opponens digiti minimi: insertion

Medial border of 5th metacarpal

Opponens digiti minimi: action

Draws 5th metacarpal anterior and rotates it, bringing 5th digit into opposition with thumb

Opponens digiti minimi: innervation

Deep branch of ulnar nerve (C8, T1)

In each hand, how many “layers” of interosseous muscles? How many interosseous muscles in each of these layers?

What is DAB and PAD?

DAB: Dorsal Interossei Muscles Abduct (Dorsal Abduct)

PAD: Palmar Adduct (middle finger does not have PAD because we use it as the midline)

How many arterial arches in each palm? What are they called?

What is a mallet (baseball) finger?

What do you suppose is “opened” to relieve compression on the median nerve in CTR surgery?

What small nerve needs to be carefully identified so that it is not accidentally cut in CTR surgery and the resulting deformity if it is injured is called what?

What are ulnar impaction?

What bones make up the true elbow? What parts of those bones?

Elbow joint = articulation of the distal humerus and the proximal ulna and radius

Humeroulnar joint = Trochlear notch of the ulna articulates with the trochlea of the humerus

Humeroradial joint = Head of the radius articulates with the capitulum of the humerus

Proximal radioulnar joint = The proximal articulation of the head of the radius and the radial notch of the ulna

Bony features of radius and ulna

• Radius:

  • head

  • radial tuberosity

  • interosseous border

  • pronator tubercle

  • ulnar notch

  • radial styloid process

• Ulna:

  • olecranon

  • coronoid process

  • trochlear notch

  • radial notch

  • supinator crest

  • ulnar styloid process

What motion do each of the ligaments of the elbow resist?

What are the 3 radioulnar (RU) joints?

1. Proximal radio ulnar joint: pivot type of synovial joint, allows movement of the head of the radius on the ula

2. Distal radio-ulnar joint: pivot synovial joint, the radius moves around the relatively fixed distal end of the ulna

What is the interosseous membrane?

A strong, fibrous membrane that firmly ties the forearm bones together, allowing for pronation and supination. It is also the proximal attachment for various deep forearm muscles

pronator teres origin

Ulnar head: coronoid process

Humeral head: medial epicondyle of humerus

pronator teres insertion

middle of convexity of lateral surface of radius

pronator teres action

Pronates and flexes forearm (at elbow)

pronator teres innervation

Median nerve (C6, C7)

flexor carpi radialis origin

Medial epicondyle of humerus

flexor carpi radialis insertion

Base of 2nd metacarpal

flexor carpi radialis action

Flexes and abducts hand (at wrist)

flexor carpi radialis innervation

Median nerve (C6, C7)

palmaris longus origin

Medial epicondyle of humerus

palmaris longus insertion

Distal half of flexor retinaculum and apex of palmar aponeurosis

palmaris longus action

Flexes hand (at wrist) and tenses palmar aponeurosis

palmaris longus innervation

Median nerve (C7, C8)

flexor carpi ulnaris origin

Humeral head: Medial epicondyle of humerus

Ulnar head: olecranon and posterior border of ulna (via aponeurosis)

flexor carpi ulnaris insertion

Pisiform, hook of hamate, 5th metacarpal

flexor carpi ulnaris action

Flexes and adducts hand (at wrist)

flexor carpi ulnaris innervation

Ulnar nerve (C7, C8)

flexor digitorum superficialis origin

Humero-ulnar head: medial epicondyle and coronoid process

Radial head: superior half of anterior border

flexor digitorum superficialis insertion

Shafts of middle phalanges of medial four digits

flexor digitorum superficialis action

Flexes middle phalanges at proximal interphalangeal joints of middle four digits; also flexes proximal phalanges at metacarpophalangeal joints

flexor digitorum superficialis innervation

Median nerve (C7, C8, T1)

flexor digitorum profundis origin

Proximal three quarters of medial and anterior surfaces of ulna and interosseous membrane

flexor digitorum profundis insertion

Medial part: bases of distal phalanges of 4th and 5th digits

Lateral part: bases of distal phalanges of 2nd and 3rd digits

flexor digitorum profundis action

Medial part: flexes distal phalanges 4 and 5 at interphalangeal joints

Lateral part: flexes distal phalanges 2 and 3 at distal interphalangeal joints

flexor digitorum profundis innervation

Medial part: ulnar nerve (C8, T1)

Lateral part: anterior interosseous nerve, from median nerve (C8, T1)

Flexor pollicis longus origin

Anterior surface of radius and adjacent interosseous membrane

Flexor pollicis longus insertion

Base of distal phalanx of thumb

Flexor pollicis longus action

Flexes phalanges of 1st digit (thumb)

Flexor pollicis longus innervation

anterior interosseous nerve, from median nerve (C8, T1)

pronator quadratus origin

Distal quarter of anterior surface of ulna

pronator quadratus insertion

Distal quarter of anterior surface of radius

pronator quadratus action

Pronates forearm; deep fibers bind radius and ulna together

pronator quadratus innervation

anterior interosseous nerve, from median nerve (C8, T1)

Forearm Flexors: superficial, intermediate, and deep group

• Superficial:

  • pronator teres

  • flexor carpi radialis

  • palmaris longus

  • flexor carpi ulnaris

• Intermediate:

  • flexor digitorum superficialis

  • flexor digitorum profundis

• Deep:

  • flexor pollicis longus

  • pronator quadratus

The brachial A enters the cubital fossa and bifurcates into the _________ and __________ arteries.

radial, ulnar

Just above the wrist, ulnar A’s pulse can be felt _______________ to the flexor carpi ulnaris.

The radial A’s pulse, just above the wrist is felt ___________ to the flexor carpi radialis

Which muscles in the superficial and deep flexors of the forearm are NOT innervated by the Median N?

flexor carpi ulnaris, flexor digitorum profundus (medial part)

Which muscles does the ulnar nerve innervate in the forearm?

Flexor carpi ulnaris, flexor digitorum profundis (medial part)