Sem 1 - W - The Hand - Bones/Joints - Aponeurosis - Intrinsic Muscles, Thenar/hypothenar, lumbricals, interossei - arches, Nerve supply

Question 1

• What are the joints between the carpals known as?
• What are the joints between the carpal and metacarpal joints known as?
• What are the joints between the metacarpals and phalanges known as?
• What are the joints between phalnges known as?

State the type of joint for each

Answer 1

• Carpals - intercarpal joints - synovial plane
• Carpals and metacarpals - carpometacarpal (CMC) joints - synovial plane joints apart from 1st CMC joint which is a synovial saddle joint (thumb)
• Metacarpals and phalnges - metacarpophalyngeal (MCP) joints - synoivial condyloid joints
• Phalnges - interphalnygeal joints - synovial hinge joints

Question 2

• So Intercarpal joints are synovial plane
• CMC joints are synovial plane joints apart from 1st CMC joints which is synovial saddle joint (thumb)
• MCP joints are synovial condyloid joints
• Interphalnygeal joints are synovial hinge

What movements do each of these joints allow for?

Answer 2

• Intercarpal and CMC (2nd to 5th digit) - synoival plane - some gliding
• 1st CMC (thumb) - synovial saddle - flexion, extension, abduction, adduction and opposition
• MCP - synovial condyloid - flexion, extension, abduction, adduction & circumduction
• Interphalgeal - synovial hinge - flexion & extension

Question 3

The intrinsic muscles of the hand. These include the adductor pollicis, palmaris brevis, interossei, lumbricals, thenar and hypothenar muscles. There are two other muscles in the palm that are not lumbricals or interossei and do not precisely fit in the hypothenar or thenar compartments: - these are the palmaris brevis and adductor pollicis (technically thenar eminence) What is the nerve supply and roots to all the intrinsic hand muscles?

Answer 3

Ulnar nerve (C8,T1 roots) Median nerve (C8, T1 roots)

Question 4

As we look at the palm of the hand, immediately beneath the skin is palmar aponeurosis What is the function of the palmar aponeurosis?

Answer 4

The palmar aponeurosis helps protect the structures beneath it and sticks the skin down to the structures essentially helping with grip

Question 5

What are the two muscles which attach to the palmar aponeurosis?

Answer 5

The palmaris longus and brevis (both are not present in every individual due to variation)

Question 6

Recap on the anterior compartment of the forearm What is the attachment function and nerve supply of the palmaris longus?

Answer 6

Attachment - attaches from the medial epicondyle of the humerus to the palmar aponeurosis

Function - tenses the palmar aponeurosis and assists in wrist flexion

Nerve supply - Median nerve (C7,8)

Question 7

What is the attachment, function and nerve supply of the palmaris brevis?

Answer 7

Attachment - Palmar aponeurosis and flexor retinaculum to dermis on medial margin of the hand

Function - tenses the palmar aponeurosis and improves grip

Nerve supply - Ulnar nerve Superficial branchC8,T1)

Question 8

What is the attachment of the adductor pollicis?

Answer 8

Two heads Transverse head from 3rd metacarpal Oblique head from capitate and 2nd/3rd metacarpals Both to the base of the proximal phalnyx of the thumb

Question 9

What is the function and nerve supply of the adductor pollicis?

Answer 9

Adduction of the CMC joint Flexion of the MCP joint as it crosses the front of the joint Nerve supply - Ulnar nerve (deep, C8,T1)

Question 10

What is the attachment, function and nerve supply to the adductor pollicis?

Answer 10

Attachment - Transverse head - 3rd metacarpal Oblique head - capitate and 2nd/3rd metacarpals To the base of the proximal phalnyx of the thumb

Function - Adduction at the CMC joint of the thumb Flexion at the MCP joint of the thumb

Innervation - Deep branch of ulnar nerve (C8,T1)

Question 11

All the intrinsic muscles of the hand supplied by the ulnar nerve come from the deep branch of the ulnar nerve apart from the palmaris brevis which comes from the superficial branch of the ulnar nerve

Lets talk about the thenar eminence

What are the muscles of the thenar eminence?

Answer 11

Abductor pollicis brevis

Flexor pollicis brevis

Opponens pollicis

Already talked about addcutor pollicis

Question 12

What are the attachments, function and nerve supply of the abductor pollicis brevis?

Answer 12

Scaphoid and trapezium to the base of the proximal phalnyx

Function - Abduction of the thumb at the CMC joint

Nerve - recurrent branch of the median nerve (C8,T1)

Question 13

What are the attachments, function and nerve supply of the flexor pollicis brevis?

Answer 13

Attachments - flexor retinaculum, capitate and trapezium to the base of the proximal phalnyx of the thumb Function - CMC joint flexion Nerve supply - Recurrent nerve branch of median nerve, some texts also say ulnar nerve (C8,T1)

Question 14

What muscle is found if pushing the flexor pollicis brevis and abductor pollicis brevis to the side? This muscle allows for pincer grip Flexor pollics longus was in the deep compartment of the anterior forearm Abductor pollicis longus was in the deep compartment of the posterior forearm

Answer 14

This would be the opponens pollicis

Question 15

What are the attachments, function and nerve supply of the opponens pollicis?

Answer 15

Attachments - trapezium to first metacarpal

Function - opposition of the thumb at the CMC joint

Nerve supply - Recurrent branch of median nerve (C8,T1)

Question 16

State the attachments, function and nerve supply of the abductor pollicis brevis, flexor pollicis brevis and the opponens pollicis

Answer 16

Abductor pollicis brevis - Scaphoid & trapezium to the base of the proximal phalnyx of the thumb, abducts the thumb at the CMC joint, Recurrent branch of median nerve (C8,T1)

Flexor pollicis brevis - Flexor retinaculum, capitate and trapezium to the base of the proximal phalynx of the thumb, CMC joint of the thumb flexion, recurrent branch of median nerve (some texts also say ulnar nerve)

Opponens pollicis - trapezium to first metacarpal, opposition at CMC joint, recurrent branch of median nerve

Question 17

State the nerve supply to the thenar muscles

Answer 17

Abductor pollicis brevis - recurrent branch of median nerve

Flexor pollicis brevis - recurrent branch of median nerve, some texts also say ulnar nerve

Opponens pollicis - recurrent branch of the median nerve

Adductor pollicis - deep branch of the ulnar nerve

Question 18

Image shows abductor pollicis brevis most lateral then flexor pollicis brevis Opponens pollicis sits beneath these What are the hypothenar muscles?

Answer 18

Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi

Question 19

What is the acronym used to remember the thenar and hypothenar muscles? State the muscles

Answer 19

• * Abductor digiti minimi
• * Flexor digiti minimi
• * Opponens digiti minimi
• * Adductor pollicis
• * Opponens pollicis
• * Flexor pollicis brevis
• * Abductor pollicis brevis

All For One (hypothenar) And One For All (thenar)

Question 20

What is the attachment, function and nerve supply of the abductor digiti minimi?

Answer 20

Abductor digit minimi Pisifororm to the base of the 5th proximal phalnyx Abduction and flexion of the MCP joint Deep branch of the ulnar nerve (C8,T1)

Question 21

What is the attachment, function and nerve supply of the flexor digiti minimi?

Answer 21

Flexor digiti minimi Hamate and flexor retinaculum to the base of the 5th proximal phalnyx Flexes the MCP joint of the little finger Deep branch of the ulnar nerve (C8,T1)

Question 22

What is the attachment, function and nerve supply of the opponens digiti minimi? Where does this muscle lie in relation to the other hypothenar muscles?

Answer 22

Opponens digiti minimi - Attaches from hamate and flexor retinaculum to the 5th metacarpal Weak opposition of the finger Just as the opponens pollicis lies deep to the other thenar muscles, the opponens digiti minimi lies deep to the other hypothenar muscles

Question 23

State the attachments function and nerve supply of: Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi

Answer 23

Innervation - deep branch of ulnar nerve (C8,T1)

• Abductor digiti minimi - pisiform to base of the 5th proximal phalnyx- abducts and flexes the MCP joint of the little finger
• Flexor digiti minimi - hamate and flexor retinaculum to base of 5th proximal phalnyx - flexes MCP joint of the little finger
• Opponens digiti minimi - hamate and flexor retinaculum to 5th metacarpal - weak opposition of little finger

Question 24

State all the intrinsic muscles of the hand and there innervation (dont include lumbriccals and interossie on this card) The nerve roots for all the intrinsic muscles of the hand are C8 and T1

Answer 24

Palmaris brevis - superficial branch of the ulnar nerve

• Hypothenar eminence
  
  • * Abductor digiti minimi - deep branch of ulnar nerve
  • * Flexor digiti minimi - deep branch of ulnar nerve
  • * Opponens digiti minimi - deep branch ulnar nerve
• Thenar eminence
  
  • * Adductor pollicis - (deep branch of the ulnar nerve)
  • * Opponens pollicis - recurrent branch median nerve
  • * Flexor pollicis brevis - recurrent branch of median nerve (some texts also say ulnar nerve)
  • * Abductor pollicis brevis - recurrent branch of median nerve

Question 25

What are the lumbricals? Where do they arise from and insert into?

Answer 25

These are a group of muscles that flex the metacarpophalyngeal (MCP) joints & extend the interphalyngeal (IP) joints They are 4 small muscles arising from the tedons of the flexor digitorum profundus and insert at the base of the proximal phalanyx & go around the finger to insert into the dorsal expansion

Question 26

If you push the flexor digitorum superficialis tendons to one side, can see the lumbricals attaching to the flexor digitorum profundus tendons What digits do the 4 lumbricals act on and what action do they bring about? What is different about lumbricals 1and2 vs 3and4? What is different about the lumbrical nerve supply?

Answer 26

They cause flexion of the MCP joints and extension of the IP joints Lumbricals 1 (index) and 2 (middle) are unipennate and are innervated by the digital branch of the median nerve (C8,T1) Lumbricals 3 (ring) and 4 (little) are bipenate and are innervated by the deep branch of the ulnar nerve (C8,T1)

Question 27

The interossei muscles are located between the metacarpals. They can be divided into two groups: the dorsal and palmar interossei. What is the function of the interossei?

Answer 27

In addition to adduction (palmar interossei) and abduction (dorsal interossei), both will assist the lumbricals in flexion of the MCP joints and extension of the IP joints

Question 28

Which fingers do not have a palmar interossei?

Answer 28

Middle finger does not have a palmar interossie - since adduction of the finger is moving the fingers towards the middle Thumb does not have a palmar interossei as it already has the adductor pollicis to carry out adduction of the thumb

Question 29

The interossei are the deepest muscle layers in the hand How many palmar interosssie are there and where do they attach?

Answer 29

There are 3 palmar interossei * 1st - 2nd metacarpal to the base of the 2nd proximal phalnyx and dorsal expansion 2 * nd - 4th metacarpal to the base of the 4th proximal phalnyx and dorsal expansion * 3rd - 5th metacarpal to the base of the 5th proximal phalnyx and dorsal expansion

Question 30

Now we know the attachments of the 3 palmar interossie, state their palmar interossie actions again?

Answer 30

Adduction towards the middle finger And as it crosses the MCP to insert at the base of the proximal phalnyx and also runs posteriorly to insert into the dorsal expansion, it will flex the MCP and extend the IP joints

Question 31

Which fingers do not need a dorsal interossei?

Answer 31

* Thumb has its own abductors (abductor pollicis longus and brevis) * Little finger has its own abductor as well (abductor digiti minimi) And therefore these do not have any dorsal interossei

Question 32

What are the attachments of the dorsal interossie and how many are there?

Answer 32

There are 4 dorsal interossei They arise form the sides of 2 adjacent metacarpals * \* 1st - from the 1st and 2nd metacarpals and inserts into the 2nd proximal phalnyx and dorsal expansion * \* 2nd - from the 2nd and 3rd metacarpals and inserts into the 3rd proximal phalnyx and dorsal expansion * \* 3rd - form the 3rd and 4th metacarpals and inserts into the 3rd proximal phalnyx and dorsal expansion * \* 4th - from the 4th and 5th metacarpals and inserts into the 4th proximal phalnyx and dorsal expansion

Question 33

Thumb doesn’t need an adductor or abductor as it has its own muscular supply \* So 1st dorsal interossei will move the index finger \* Middle finger this time has 2 interossei – so the middle finger can abduct either way The ring finger has the 4th interossei Little finger just like the thumb has its own muscular supply (has its own abductor in the hypothenar eminence) What movements does the dorsal interossie allow?

Answer 33

Dorsal interossie allows for abduction of the metacarpals away from the midline As well as flexion of the MCP and extension of the IP joints

Question 34

Radial and ulnar arteries anastomose to supply the hand The ulnar artery gives off the common interosseous artery. What does this branch into and to supply what?

Answer 34

Common interosseous artery branches into the anterior interosseous artery which runs on the anterior aspect of the interosseous membrane to supply deep anterior forearm muscles The posterior interosseous artery from the common interosseous pierces the interosseous membrane to supply deep posterior forearm muscles

Question 35

How does the ulnar artery pass over the wrist into the hand?

Answer 35

The ulnar artery passes over the flexor retinaculum (at the pisfiorm) in what is known as Guyon's canal (ulnar canal) - it travels with the ulnar nerve

Question 36

Which artery contributes mostly to the superficial palmar arch and deep palmar arch?

Answer 36

Superficial palmar arch is mainly from the ulnar artery (some from radial) Deep palmar arch is mainly from the radial artery (some from ulnar)

Question 37

How does the radial artery enter the hand?

Answer 37

The radial artery runs in the radial aspect of the anterior forearm before going laterally through the floor of the anatomical snuffbox to enter posterior aspect of the hand It then passes through the heads of the adductor pollicis - to contribute mainly to the deep palmar arch and a little for the superficial palmar arch

Question 38

The ulnar artery gives of small branches to the fingers known as the digital arteries What aspect of the finger do these run on?

Answer 38

Digital arteries run on the lateral aspect of the finger

Question 39

Superficial palmar arch passes directly beneath the palmar aponeurosis What bones does the radial artery pass over? What branches does it give off to supply the thumb and finger?

Answer 39

Radial artery passes over the scaphoid and trapezium (floor of anatomical snuffbox) before giving off two arteries The princeps pollicis artery (main artery to the thumb) The raidalis indicis artery (radial artery of index finger)

Question 40

What are the palmar and thenar spaces continous with distally?

Answer 40

The lumbrical tunnels

Question 41

Median and ulnar nerves in the hand both have sensory and motor components Radial nerve only has sensory innervation once it passes into the hand \* What branches does the median nerve give off once it passes through the carpal tunnel? \* What branches does the ulnar nerve give as it passes over the carpal tunnel? Radial nerve splits after passing by the lateral epicodnyle of the humerus into deep and superficial branches

Answer 41

Median nerve gives off digital and recurrent branches (recurrent to thenar eminence) Ulnar nerve gives off digitial and superficial and deep branches (deep supply hypothenar muscles and adductor pollicis, superficial supplies palmaris brevis and cutaneous)

Question 42

NEED TO KNOWN CUTANEOUS SUPPLY TO UPPER LIMB AND DERMATOMES State the cutaneous supply to the hand

Answer 42

Ulnar nerve to little and half of ring finger and palm/dorsum of hand Median nerve to half of ring finger up to base of proximal phalnyx of thumb on palmar side, on dorsal side tips of thumb to half of ring finger Radial nerve - inferolateral thenar eminence on pamar side, anatomical snuffbox and to half of ring finger proximally on dorsum

Question 43

Dermatomes are an expression of one spinal level on the skin Dermatomal maps can change dependent on which book/site as you can see above In the torso it is just stripes going straight across and therefore dermatomes are easy, for upper and lower limb gets difficult due to the limb rotation State the following dermatomal levels Nipple, Umbilicus, Thumb, Middle & Little finger, Anatomical snuffbox, Badge patch, Shoulder, Medial arm, Axilla

Answer 43

* \* Nipple - T4 * \* Umbilicus - T10 * \* Thumb - C6 * \* Middle finger - C7 * \* Little finger - C8 * \* Anatomical snuffbox - C6 * \* Badge patch - C5 * \* Shoulder - C4 * \* Medial arm - T1 * \* Axilla - T2