Sem 1 - W - The Hand - Bones/Joints - Aponeurosis - Intrinsic Muscles, Thenar/hypothenar, lumbricals, interossei - arches, Nerve supply Flashcards
- 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
- 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
- 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?
- 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
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?
Ulnar nerve (C8,T1 roots) Median nerve (C8, T1 roots)
As we look at the palm of the hand, immediately beneath the skin is palmar aponeurosis What is the function of the palmar aponeurosis?
The palmar aponeurosis helps protect the structures beneath it and sticks the skin down to the structures essentially helping with grip
What are the two muscles which attach to the palmar aponeurosis?
The palmaris longus and brevis (both are not present in every individual due to variation)
Recap on the anterior compartment of the forearm What is the attachment function and nerve supply of the palmaris longus?
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)
What is the attachment, function and nerve supply of the palmaris brevis?
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)
What is the attachment of the adductor pollicis?
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
What is the function and nerve supply of the adductor pollicis?
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)
What is the attachment, function and nerve supply to the adductor pollicis?
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)
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?
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
Already talked about addcutor pollicis
What are the attachments, function and nerve supply of the abductor pollicis brevis?
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)
What are the attachments, function and nerve supply of the flexor pollicis brevis?
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)
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
This would be the opponens pollicis
What are the attachments, function and nerve supply of the opponens pollicis?
Attachments - trapezium to first metacarpal
Function - opposition of the thumb at the CMC joint
Nerve supply - Recurrent branch of median nerve (C8,T1)
State the attachments, function and nerve supply of the abductor pollicis brevis, flexor pollicis brevis and the opponens pollicis
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
State the nerve supply to the thenar muscles
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
Image shows abductor pollicis brevis most lateral then flexor pollicis brevis Opponens pollicis sits beneath these What are the hypothenar muscles?
Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi
What is the attachment, function and nerve supply of the abductor digiti minimi?
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)
What is the attachment, function and nerve supply of the flexor digiti minimi?
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)
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?
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
State the attachments function and nerve supply of: Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi
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
What are the lumbricals? Where do they arise from and insert into?
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
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?
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)
Which fingers do not have a palmar interossei?
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
Now we know the attachments of the 3 palmar interossie, state their palmar interossie actions again?
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
Which fingers do not need a dorsal interossei?
- 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
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?
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
How does the ulnar artery pass over the wrist into the hand?
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
How does the radial artery enter the hand?
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
The ulnar artery gives of small branches to the fingers known as the digital arteries What aspect of the finger do these run on?
Digital arteries run on the lateral aspect of the finger
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?
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)
What are the palmar and thenar spaces continous with distally?
The lumbrical tunnels
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
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)
NEED TO KNOWN CUTANEOUS SUPPLY TO UPPER LIMB AND DERMATOMES State the cutaneous supply to the hand
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
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
- * 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
