4TH LAYER O/I

Question 1

Plantar Interossei Muscles origin

Answer 1

plantar aspect of the bases and medial aspect of the shafts of the 3rd, 4th and
5th metatarsals; ex. the 1st plantar interosseous muscle arises from the
plantar base and medial shaft of the 3rd metatarsal, the 2nd plantar
interosseous muscle arises from the plantar base and medial shaft of the
4th metatarsal and the 3rd plantar interosseous muscle arises from the
plantar base and medial shaft of the 5th metatarsal

Question 2

Plantar Interossei Muscles insertion

Answer 2

medial aspect of the base of the proximal phalanx and extensor expansion of the respective digit;

ex. the 3rd plantar interosseous muscle inserts medially onto the proximal phalanx and laterally to the extensor expansion
of the 5th toe, the 2nd plantar interosseous muscle inserts medially onto the proximal phalanx and laterally to the extensor expansion of the 4th digit,
and the 1st plantar interosseous muscle inserts medially onto the proximal
phalanx and laterally to the extensor expansion of the 3rd toe

• the tendons pass deep to the extensor expansion

Question 3

dorsal Interossei Muscles origin

Answer 3

adjacent areas of the metatarsal shafts (one muscle is located in each intermetatarsal space), ex. the 1st dorsal interosseous muscle originates from the lateral aspect of the 1st metatarsal shaft and the medial aspect of the 2nd metatarsal shaft, the 2nd dorsal interosseous muscle originates from the lateral shaft of the 2nd metatarsal and the medial shaft of the 3rd metatarsal, the 3rd dorsal interosseous muscle originates from adjacent aspects of the 3rd and 4th
metatarsal shafts, and the 4th dorsal interosseous muscle originates from adjacent surfaces of the 4th and 5th metatarsal shafts

Question 4

dorsal Interossei Muscles insertion

Answer 4

first - medial aspect of the 2nd proximal phalangeal base

second, third and fourth - lateral aspect of the base of the proximal phalanx of
the respective toe ex. the 2nd dorsal interosseous muscle inserts onto the lateral aspect of the 2nd proximal phalangeal base, the 3rd dorsal interosseous muscle inserts onto the lateral aspect of the proximal phalangeal base of the 3rd toe, and the 4th dorsal interosseous muscle inserts onto the lateral aspect of the base of the proximal phalanx of the 4th toe

• tendons pass within the extensor expansion