Interossei muscles, fibrous flexor sheath, synovial flexor sheath, digital attachments of the long tendons (dave's notes) Flashcards
What are the two groups of interossei?
Palmar and dorsal
Describe the palmar group of interossei. What do they arise from? What is their action? What is the exception?
The palmar interossei are smaller and arise from their own metacarpal bone. These adduct toward the middle finger (which has no adductor).
Describe the dorsal group of interossei. What do they arise from? What is their action? What are the exceptions?
The dorsal interossei are larger and arise front eh adjacent metacarpal bones of the space in which they lie. These abduct and are more powerful. There is none to 1 and 5. One on each side of 3.
There are four in total each arising from two heads; one on each side of the spar.
Where do the tendons of the dorsal and the palmar interossei all pass?
To the posterior side of the deep transverse ligament
What is the nerve supply to the interossei?
The deep branch of the ulnar nerve
What is the fibrous flexor sheath?
What are its strong and weak areas?
A strong unyielding fibrous sheath that passes from the MC heads to the distal phalanges of all five digits.
Strong over the shaft and lax over the joint.
What occupies the thumb fibrous flexor sheath?
The FPL tendon
What occupies the finger’s fibrous flexor sheaths?
Tendons of the superficial and deep flexors
What is the synovial flexor sheath?
The flexor tendons are invested with a synovial sheath from the lower forearm to the insertion into the terminal phalanx
Palmar spaces web spaces pulp spaces
READ
Where does FDS tendon enter the fibrous flexor sheath?
On the palmar surface of FDP, then divides into two which spiral around FDP
What happens to FDP and FDS after FDS has divided and spiralled around FDP?
FDP then passes distally to reach the base of the terminal phalanx, and the superficial tendon is attached to the sides of the whole shaft of the middle phalanx
