Anterior compartment of forearm Flashcards
What are the superficial muscles in the anterior compartment of forearm?
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor digitorum superficialis
- Flexor carpi ulnaris
What are the deep muscles in the anterior compartment of forearm?
- Flexor digitorum profundus
- Flexor pollicis longus
- Pronator quadratus
What is the origin of trapezius muscle?
External occipital protuberance and superior nuchal line of the back of the skull – ligamentum nuchae – spine processes of all thoracic vertebra T1 to T12
What is the insertion of deltoid?
Deltoid tuberosity
Actions of teres major
Adduction & medial rotation of the humerus
Origin of supraspinatus
Supraspinous fossa scapula
Where does the blood supply to the hand come from?
- Superficial palmar arterial arch
- Deep palmar arterial arch
Where do finger flexor tendons lie?
Ulna bursae
Where do thumb flexor tendons lie?
Radial bursae
Where is the nerve supply to all the Intrinsic muscles of the hand from?
From the ulnar nerve (C8,T1)
What are the thenar muscles supplies by?
Median nerve
Where are constant creases present?
Where skin and superficial fatty layer bound to deep fibrous tissue
What is skin of palm bound to and why?
To deep fascia and thick to permit grasping
How can you remember the attachments of the flexor retinaculum?
STOP
- Scaphoid
- Trapezium
- HOck of hamate
- Pisiform
What does the flexor retinaculum form?
The fibro-osseous carpal tunnel
What does the osseo-fascial carpal tunnel cover?
10 tendons and a nerve
Name the tendons and nerve that the osseo-fascial carpal tunnel cover
- FDS - 4
- FDP - 4
- FCR - 1
- FPL1
- Median nerve
- The radial and ulna bursae
What is the flexor retinaculum crossed superficially by?
- Ulnar nerve & artery (Guyon’s tunnel)
- Palmar cutaneous branch of ulnar nerve
- Palmar cutaneous branch of median nerve
- Tendon of palmaris longus
- Superficial palmar branch of Radial Artery
What does the flexor retinaculum give attachment to superficially?
Thenar and hypothenar muscles
What attaches the palmar aponeurosis to underlying skin?
Fibrous septa
What is palmar aponeurosis in relation to thenar and hypothenar muscles?
Thin layer of deep fascia over thenar and hypothenar muscles.
What is the palmar aponeurosis?
A strong centrally placed triangular thickening of deep fascia
What does the palmar aponeurosis cover/
- Superficial palmar arch artery
- Long flexor tendons
What does the proximally point of triangle blend with?
Flexor retinaculum & gives attachment to PL
What are the fibrous flexor sheaths in continuity with?
With slips from the palmar aponeurosis
What do fibrosseous tunnels attach to?
To the sides of the phalanges arching over the flexor tendon sheaths
Where do fibrosseous tunnels extend from and to?
From base of proximal phalanx to base of the distal phalanx (all fingers and thumb)
What are the fibrous flexor tunnels strengthened by?
By additional annular and cruciate fibres (pulleys)
Where are annular pulleys placed?
Anterior to 1st MCP (A1), middle third proximal phalanx (A2), proximal interphalangeal joint (A3) and middle third of middle phalanx (A4)
What are in between fibrous flexor sheaths?
The cruciate pulleys (C1, C2, C3)
What do the cruciate pulleys consist of?
Weaker crossing fibres
How many annular pulley are in the thumb?
Two
Where are the annular pulleys of the thumb?
A1 anterior to the MCPJ and A2 pulley proximal to
the interphalangeal joint
Where is the oblique pulley of the thumb?
Over middle third proximal phalanx.
What do fibrous flexor sheaths, palmar aponeurosis and flexor retinaculum prevent?
Prevent bow-stringing of the
flexor tendons and therefore increase the effectiveness of the grip
What are the three thenar muscles?
OAF
- Opponens pollicis
- Abductor pollicis brevis
- Flexor pollicis brevis
What is the most superficial thenar muscle?
Abductor Policis Brevis
What is the nerve supply of the thenar muscles?
The recurrent branch of the median nerve
What is the nerve supply of the hypothenar muscles?
Deep branch of ulnar nerve
What are the hypothenar muscles?
OAF
- Opponens digiti minimi
- Abductor digiti minimi
- Flexor digiti minimi
What are the attachments of the abductor digiti minimi?
Pisiform bone -> ulnar side of base proximal phalanx
What are the attachments of opponens digiti minimi?
- Hook of hamate
- Flexor retinaculum
What are the attachments of the flexor digiti minimi?
- Hook of hamate
- Flexor retinaculum
Where do the muscles of lumbricals lie?
In own fascial tunnel
Where do the tendons of lumbricals lie and attach?
Pass anteriorly to MCP joints and then posteriorly to attach to laterally side of dorsal extensor expansion of the digits
What are the actions of lumbricals?
Flexion of MCP joints as and then assist extension of the interphalangeal joints by tensioning the extensor expansion
What is the nerve supply of the 1st and 2nd lumbricals?
Median nerve
What is the nerve supply of the 3rd and 4rd lumbricals?
Ulnar nerve
What lies deep to flexor digitorum superficialis?
Flexor digitorum profundus
What happens to tendons of flexor digitorum superficials that were lying over eachother in the carpal tunnel? (palm)
They fan out in the palm
What are flexor tunnels in the deep fascial fibrous flexor tunnels covered by?
Synovial sheath
What are the deep muscles of the hand?
- Interossei
- Adductor pollicis
What are the interossei and adductor pollicis supplied by?
Deep branch ulnar nerve
What is a good test for C8/T1 root and ulnar nerve?
Flexion of 1st dorsal interosseous
What are the oblique head attachments of adductor pollicis?
- Palmar surface bases of 2nd & 3rd metacarpals
- Adjacent carpal bones
What are the transverse head attachments of adductor pollicis?
- Palmar surface of shaft of 3rd metacarpal phalange
What are the distal attachments of adductor pollicis?
Ulnar & radial sides of base proximal phalanx of the thumb by small tendons
which both contain sesamoid bones
What are the actions of adductor pollicis?
Adduction and assists opposition of thumb
What are the proximal attachments of the interossei?
3 small palmar interossei arise by 1 head from palmar surface of 1st, 2nd, &
4th MCP’s; and 4 large dorsal interossei arise deeply by 2 heads from adjacent sides of MCP’s
What are the distal attachmetns of the interossei?
Tendons attach to the base of their corresponding proximal phalanx plus to
the dorsal extensor expansion of the fingers
What is the function of the palmar interossei?
Adduct
What is the function of the dorsal interossei?
Abduct
What does the superficial fascia and fatty layer contain?
Dorsal venous network of veins
What is the clinical note for dorsum of hand?
Common site for iv cannulation
What does the deep fascia layer cover?
Covers layer of extensor tendons passing to thumb and extensor expansion of fingers
To what do lumbricals attach in the dorsal extensor expansion of the fingers?
To the lateral side of the extensor expansion
When can lumbricals help to do? (exd)
Can help to extend the interphalangeal joint
What does the dorsal extensor expansion of the fingers consist of?
Consists of a triangular hood over MCP joint to which the main extensor tendons are attached
What emerges from the triangular hood over MCP joint?
A central band and 2 collaterals emerge
Where does the central slip of the dorsal extensor expansion pass over and attach to?
Over the proximal interphalangeal joints and attaches to the base of the middle phalanx
Where do the two collateral slips of the dorsal extensor expansion pass?
They pass either side of the proximal interphalangeal joints merge over the distal middle phalanx and pass
over the distal interphalangeal joint to attach to the base of the distal phalanx
What can the interossei assist the long extensors with?
With finger extension
What is the superficial palmar arterial arch a direct continuation of?
The ulnar artery
What is the deep palmar arterial arch formed by?
The radial artery
What is the superficial palmar compartment arterial arch deep to?
The palmar aponeurosis
What might the superficial palmar arch artery anastomose with?
With the superficial palmar branch of the radial artery.
Where does the superficial palmar arch artery lie?
Across the centre of the palm
What arteries does the superficial palmar arch artery give off?
A digital artery to ulnar side of the little finger and three common palmar digital arteries
What do palmar digital arteries anastomose with?
Dorsal digital arteries supplying dorsum and nail beds
Where does the radial artery cross in the wrist/hand?
It crosses the anatomical snuffbox and passes to the dorsum of the hand
Where does the deep palmar arch artery run?
It runs deeply between the two heads of the first dorsal interosseous muscle.
Where does the deep palmar arch artery give off larges branches to?
- To radial side of index finger
- To thumb
Where does the princeps policis pass?
It passes along the 1st metacarpal
What does the princeps policis divide into?
Divides into two palmar digital branches
Where does the main radial artery pass in hand?
Passes between two heads of adductor pollicis to form the deep palmar arch
What is the deep palmar arch an arterial arcade anastomoses with?
The deep branch of the ulnar artery
Where does the deep branch of the ulnar nerve lie?
Within the concavity of the deep arch.
How many palmar metacarpal arteries does the deep palmar arch artery give off?
Three
What is the function of accompanying veins of the deep palmar arch artery?
They drain most of the blood from the palm into the dorsal venous network
What type of joints are the carpal joints?
Plane synovial
What is the degree of freedom of carpal joints?
1º
What are the ligaments of the carpal joints?
Capsular: formed by many small fibrous bands capsule loose cavity continuous between bones.
What does the synovial membrane of the carpal joints do?
lines non-articular surfaces
Stability of the carpal joint
Stable - dependent on complex set of ligaments both palmar and dorsal & Interosseous Ligaments.
What is the nerve supply of the interosseous
- Anteriorly - Interosseous nerve (median)
- Posteriorly - Interosseous nerve (radial)
What are the articular surfaces of the carpal joints?
Extensive Composite Joint / individual joints are planar - composite joints are condyloid form a continuous space between 1st & 2nd rows of carpal bones many small articular facets.
What type of joint are carpometacarpal joints?
Plane synovial
What is the degree of freedom of carpometacarpal joints?
1º
What are the articular surfaces of carpometacarpal joints?
Distal facets of carpus proximal surfaces bases of metacarpals
What are the ligaments of carpometacarpal joints?
Capsular: continuous cavity thickenings of capsule dorsal & palmar carpometacarpal ligaments
dorsal & palmar metacarpal ligaments
What are the movements of the carpometacarpal joints?
Flexion from 2nd to 5th metacarpal
