Exam 4C Flashcards
cutaneous innervation of the sole of the foot
medial calcaneal branches of tibial nerve supply most of the heel
medial plantar nerve (terminal branch of tibial nerve): supplies medial ⅔ of sole of foot and medial 3½ toes
lateral plantar nerve (terminal branch of tibial nerve): supplies lateral ⅓ of sole of foot and lateral 1½ toes
small area along medial border of foot is supplied by saphenous nerve
small area of lateral heel and lateral border of foot is supplied by sural nerve (lateral calcaneal and lateral dorsal cutaneous branches)
plantar aponeurosis
attaches posteriorly to calcaneal tuberosity
distally, it divides into 5 digital bands, become continuous with fibrous flexor (digital) sheaths of corresponding toes
digital bands are connected to each other by transverse fibers at the level of metatarsal heads, superficial transverse metatarsal ligaments
functions: gives firm attachment to overlying skin, protects deeper structures (vessels, nerves, tendons, etc.), assists in maintaining longitudinal arches of foot
fibrous flexor sheaths
begin at level of metatarsal heads and extend to bases of distal phalanges
together with inferior surfaces of phalanges, interphalangeal joints and metatarsophalangeal joints, create osteofibrous tunnels on inferior (plantar) aspects of toes
osteofibrous tunnel of great toe contains tendon of flexor hallucis longus
osteofibrous tunnels of lateral 4 toes contain tendons of flexor digitorum longus and flexor digitorum brevis
within tunnels, tendons are surrounded by synovial sheaths
1st layer muscles of sole of foot
abductor hallucis
flexor digitorum brevis
abductor digiti minimi
2nd layer muscles of sole of foot
tendon of flexor hallucis longus
tendons of flexor digitorum longus
4 lumbricals
quadratus plantae
3rd layer muscles of sole of foot
flexor hallucis brevis
adductor hallucis
flexor digiti minimi brevis
4th layer muscles of sole of foot
3 plantar interossei
4 dorsal interossei
tendon of fibularis longus
tendon of tibialis posterior
actions of the muscles of the sole of the foot
actions of muscles of sole of foot are not very important individually because fine control of individual toes is not important to most people
muscles of sole of foot function primarily as a group in posture and locomotion
help to maintain arches of foot, resist forces that tend to flatten arches of foot
adductor hallucis
most medially located in 1st layer
adductor hallucis origin
medial tubercle of calcaneal tuberosity
adductor hallucis insertion
medial side of base of proximal phalanx of great toe
adductor hallucis innervation
medial plantar nerve
adductor hallucis action
abduction of proximal phalanx of great toe
flexor digitorum brevis
central muscle of 1st layer, located immediately deep (superior) to plantar aponeurosis
flexor digitorum brevis origin
medial tubercle of calcaneal tuberosity
flexor digitorum brevis insertion
muscle belly gives rise to 4 tendons for lateral 4 toes; tendons split into 2 slips to allow passage of tendons of flexor digitorum longus; slips insert into sides of middle phalanges of lateral 4 toes (similar arrangement to flexor digitorum superficialis in hand)
flexor digitorum brevis innervation
medial plantar nerve
flexor digitorum brevis action
flexion of middle and proximal phalanges of lateral 4 toes
abductor digiti minimi
most laterally located in 1st layer
abductor digiti minimi origin
medial and lateral tubercles of calcaneal tuberosity
abductor digiti minimi insertion
lateral side of base of proximal phalanx of little toe
abductor digiti minimi innervation
lateral plantar nerve
abductor digiti minimi action
abduction proximal phalanx of little toe
(4) lumbricals origin
tendons of flexor digitorum longus
lumbricals insertion
medial side of extensor expansions of lateral 4 toes
lumbricals innervation
1st lumbrical: medial plantar nerve;
2nd, 3rd and 4th lumbricals: lateral plantar nerve
lumbricals action
flexion of metatarsophalangeal joints and extension of interphalangeal joints of lateral 4 toes
quadrates plantae origin
flexor digitorum accessorius
by 2 heads from medial surface and lateral border of inferior (plantar) surface of calcaneus
Insertion:
quadrates plantae insertion
posterolateral border of tendon of flexor digitorum longus
quadrates plantae innervation
lateral plantar nerve
quadrates plantae action
assists flexor digitorum longus in flexing lateral 4 toes (straightens its line of pull/corrects for obliquity of tendon of flexor digitorum longus)
flexor hallucis brevis origin
cuboid, lateral cuneiform and tendon of tibialis posterior
flexor hallucis brevis insertion
distally, muscle belly divides into 2 heads (medial and lateral), insert into medial and lateral sides of base of proximal phalanx of great toe, there is a sesamoid bone within tendon of each head
tendon of flexor hallucis longus runs between medial and lateral heads of flexor hallucis brevis
flexor hallucis brevis innervation
medial plantar nerve
flexor hallucis brevis action
flexion of proximal phalanx of great toe
adductor hallucis origin
oblique head: bases of 2nd, 3rd and 4th metatarsals
transverse head: plantar ligaments of 3rd, 4th and 5th metatarsophalangeal joints
adductor hallucis insertion
lateral side of base of proximal phalanx of great toe
adductor hallucis innervation
lateral plantar nerve
adductor hallucis action
adduction of proximal phalanx of great toe; assists in maintaining transverse arch of foot
flexor digiti minimi brevis origin
base of 5th metatarsal
flexor digiti minimi brevis insertion
lateral side of base of proximal phalanx of little toe
flexor digiti minimi brevis innervation
lateral plantar nerve
flexor digiti minimi brevis action
flexion of proximal phalanx of little toe
interossei
axis for abduction/adduction of toes passes through 2nd toe
plantar interossei: adductors of toes (PAD)
dorsal interossei: abductors of toes (DAB)
plantar and dorsal interossei also flex metatarsophalangeal joints and extend interphalangeal joints
plantar interossei (3)
Origin: 3rd, 4th and 5th metatarsals
Insertion: medial side of bases of proximal phalanges of 3rd, 4th and 5th toes and their extensor expansions
Nerve supply: lateral plantar nerve
dorsal interossei (4)
Origin: each dorsal interosseous originates by 2 heads from sides of 2 adjacent metatarsals
Insertion: 1st and 2nd medial and lateral sides of base of proximal phalanx of 2nd toe; 3rd and 4th lateral side of bases of proximal phalanges of 3rd and 4th toes (all dorsal interossei also insert into extensor expansions of corresponding toes)
Nerve supply: lateral plantar nerve
medial plantar artery
smaller terminal branch of posterior tibial artery
enters sole of foot deep to abductor hallucis muscle, runs anteriorly between abductor hallucis and flexor digitorum brevis muscles (accompanied by medial plantar nerve), ends distally by supplying medial side of great toe
gives off numerous muscular and cutaneous branches along its course
lateral plantar artery
larger terminal branch of posterior tibial artery
enters sole of foot deep to abductor hallucis muscle, runs anteriorly and laterally between flexor digitorum brevis and quadratus plantae muscles (along its course, it is accompanied by lateral plantar nerve)
at base of 5th metatarsal, it curves medially (passing deep to oblique head of adductor hallucis muscle) to form (deep) plantar arch
plantar arch terminates at proximal end of 1st interosseous (intermetatarsal) space (between 1st and 2nd metatarsals), where it anastomoses with deep plantar artery (branch of dorsalis pedis artery)
lateral plantar artery branches
numerous muscular and cutaneous branches along its course
perforating branches: originate from (deep) plantar arch, pass dorsally, between metatarsals, to anastomose with dorsal metatarsal arteries (on dorsum of foot)
plantar metatarsal arteries: originate from (deep) plantar arch, run distally and give off plantar digital arteries that supply toes
medial plantar nerve
terminal branch of tibial nerve
enters sole of foot deep to abductor hallucis muscle, runs anteriorly between abductor hallucis and flexor digitorum brevis muscles (accompanied by medial plantar artery)
its distribution is similar to that of median nerve in hand
medial plantar nerve muscular innervation
abductor hallucis, flexor digitorum brevis, 1st lumbrical and flexor hallucis brevis
medial plantar nerve cutaneous innervation
medial ⅔ of sole of foot and plantar aspects of medial 3½ toes (also supplies nail beds and tips of corresponding toes)
lateral plantar nerve
terminal branch of tibial nerve
enters sole of foot deep to abductor hallucis muscle, runs anteriorly and laterally between flexor digitorum brevis and quadratus plantae muscles (accompanied by lateral plantar artery), at base of 5th metatarsal, it divides into superficial and deep branches (deep branch accompanies [deep] plantar arch)
its distribution is similar to that of ulnar nerve in hand
lateral plantar nerve muscular innervation
abductor digiti minimi, quadratus plantae, 2nd, 3rd and 4th lumbricals, adductor hallucis, flexor digiti minimi brevis and all plantar and dorsal interossei
lateral plantar nerve cutaneous innervation
lateral ⅓ of sole of foot and plantar aspects of lateral 1½ toes (also supplies nail beds and tips of corresponding toes)
cutaneous innervation of the dorsum of the foot
skin is thin, hairy and freely movable on underlying structures
superficial fibular nerve divides into medial and intermediate dorsal cutaneous branches, supply dorsum of foot, medial side of great toe and adjacent sides of 2nd to 5th toes
medial branch of deep fibular nerve, supplies adjacent sides of great and 2nd toes
saphenous nerve, supplies skin along medial border of foot as far as ball of great toe (1st metatarsophalangeal joint)
sural nerve continues in foot as lateral dorsal cutaneous nerve, supplies skin along lateral border of foot and lateral aspect of little toe
dorsal venous arch
lies in subcutaneous tissue (superficial fascia)
dorsal digital veins drain into dorsal metatarsal veins: dorsal metatarsal veins drain into dorsal venous arch
dorsal venous arch drains on medial side into great saphenous vein
dorsal venous arch drains on lateral side into small saphenous vein
extensor digitorum brevis origin
anterior part of superior surface of calcaneus
extensor digitorum brevis insertion
muscle belly gives rise to 4 tendons that pass anteriorly and medially over dorsum of foot, most medial tendon inserts into base of proximal phalanx of great toe (this tendon with its proximal muscle belly is sometimes considered a separate muscle, extensor hallucis brevis), lateral 3 tendons join tendons of extensor digitorum longus for 2nd, 3rd and 4th toes
extensor digitorum brevis innervation
deep fibular nerve
extensor digitorum brevis action
extension of proximal phalanx of great toe
assists extensor digitorum longus in extending 2nd to 4th toes
dorsalis pedis artery
begins distal to ankle, as a continuation of anterior tibial artery
runs superficially on dorsum of foot, with medial branch of deep fibular nerve, between tendon of extensor hallucis longus (medial to artery) and tendons of extensor digitorum longus (lateral to artery); pulsations of artery can be felt in this location
terminates at proximal end of 1st interosseous (intermetatarsal) space (space between 1st and 2nd metatarsals) by dividing into 1st dorsal metatarsal artery and deep plantar artery
dorsalis pedis artery branches
medial and lateral tarsal arteries
arcuate artery: runs laterally, deep to tendons of extensor digitorum longus and brevis, across bases of metatarsals, gives off 2nd to 4th dorsal metatarsal arteries, give rise to dorsal digital arteries for lateral part of 2nd toe and both sides of 3rd to 5th toes
1st dorsal metatarsal artery: gives off dorsal digital arteries for both sides of great toe and medial side of 2nd toe
deep plantar artery: passes inferiorly (into sole of foot) between 2 heads of 1st dorsal interosseous muscle, completes (deep) plantar arch on medial side
deep fibular nerve
enters dorsum of foot on lateral side of dorsalis pedis artery, divides into medial and lateral branches
lateral branch: supplies extensor digitorum brevis
medial branch: supplies skin of adjacent sides of great toe and 2nd toe
