4: Hand Flashcards
What is the palmar fascia?
The fascia of the palm (continous with the forearm), specilises into
- Aponeurosis
- Fibrous digital sheaths
What is the Palmar aponeurosis?
What are its key features?
well-defined region of palmar fascial that overlies the long flexor tendons of the hand
–> proximal continuous with flexor retinaculum and palmaris longus
What is the fibrous digital sheath of the hand?
It is the distal continuation of the fibrous sheaths and contains the flexor tendons and synovial sheaths of each finger
What is the thenar compartment of the hand?
The intrinsic muscles of the hand that move the thumb:
- Abductor pollicis brevis
- Flexor pollicis brevis
- Opponens pollicis
+ (Adductor pollicis)= technically not a thenar muscles but sometimes also counted as one
What are the hypothenar muscles of the hand?
The intrinsic muscles of the hand that move the little finger
- Abductor digiti minimi
- Flexor digiti minimi
- opponens digiti minimi
Which nerves supplies the thenar muscles of the hand?
Recurrent branch of the Median nerve C8-T1
Which nerves supplies the adductor pollicis?
The Ulnar nerve (C8-T1)
Which nerve supplies the hypothenar compartment of the hand?
The Ulnar nerve C8-T1
What is the function of the interossei muscle of the hand?
- The palmar interossei: adduct the digits
- The dorsal interossei: abduct the digits
Which nerves innervates the interossei muscles of the hand?
The deep branch of the Ulnar nerve (C8-T1)
What are the lumbrical muscles of the hand?
What is their function?
Flexion of metacarpalphalangeal joints
Extionsion of proximal and distal interphalangeal joints
What is the innervation of the lumbircal muslces of the hand?
2+3 Median Nerve (C8-T1) (index+ middle finger)
4+5 Ulnar Nerve (C8-T1) (ring+ little finger)
Which bones form the attachment for the flexor retinaculum?
On the lateral side it attaches to the
- Trapezium
- Scarphoid
Medial side
- Pisiform
- Hook of Hamate
What are the structures passing through the carpal tunnel?
- Median Nerve
- Tendons of the
- Flexor digitorium superficialis
- Flexor digitorium profundus
- Flexor Pollicis longus
What are the fibrous digital sheaths in the hand?
Which structures do they contain?
How do you call the fibrous digital sheath together with their structures an the bone?
They are the fibrous tubes around the digits containing
- Flexor tendons (incl. synovial sheaths)
–> together they are called osseo-fibrous tunnels
Explain the organisation of vessels, nerves and tendons in the digits
From Deep to superficial
- Deep: Bone (phalynxes)
- Tendons
- Flexor tendons anteriorly (surrounded by fibrous + synovial sheath)
- Extensor tendons Posteriorly
- Structures form Deep (in this case posteriorly) to superificial (in this case anteriorly), embedden in Skin(Grayson) ligament
- Vein
- Artery
- Nerve
Name the different septa in the hand
- medial septum (to the little finger metacarpal)
- lateral septum (to the middle finger metacarpal)
In which compartements do the septa of the hand devide the hand?
- hypothenar compartment
- central compartment
- thenar compartment
- adductor compartment (contains the adductor pollicis muscle)
Explain the routes of the FDP and the FDS in the hand
- Enter the hand via the Carpal tunnel
- Run together in a common synovial sheath
- Pass into respective digit in digital synovial sheath
- FDS splits around the FDP at the proximal phalanx, attaches to the middle phalanx (picture)
- FDP attaches to the distal phalanx
How are the condensations of the fibrous digital sheath at the fingers called?
They are called pulleys
- Annular pulleys
- Cruciform pulleys
How is the structure at the back of the hand called that fixates all the extensor tendons?
The extensor retinaculum
What is the role and function of the intertendenous bands of the hand?
these bands limit free movement of one extensor tendon independently of the others.
What is the extensor expansion?
The long extensor flattening at level of the metacarpals
What is the function of the extensor expansion?
Involved in movement of the digits
It is an attachment for the interossei and the lumbrical muscles
What type of joint is the carpo-matacarpal joint of the thumb?
Which bones are involved?
It is the joint between the trapezium and the 1st metarcarpal bone
It is a saddle joint (type of synovial joint)
What type of joint are the carpometacarpa joints?
They are synovial elipsoid joints
How are the main ligaments called that stabelise the MCP and IP joints called?
Collateral ligaments, one on each side
- One ulnar collateral ligament
- Radial collateral ligament
What is a mallet finger?
Avulsion of extensor digitorum longus tendon at the base of distal phalanx
The median nerve passes laterally to the tendon of which muscle just before entering the carpal tunnel?
Palmaris Longus
