PL Origins, Insertions and Actions

Question 1

semitendinosus

Answer 1

Origin

ischiatic tuberosity

Insertion

medial surface of tibial body

tuber calcanei via common calcanean tendon

Action

extend hip; flex stifle; extend hock

Question 2

semimembranosus

Answer 2

Origin

isciatic tuberosity

Insertion

distal and medial aspect of the caudal femur and medial condyle of the tibia

Action

extend hip

extend or flex stifle depending on limb position

Question 3

sartorius

Answer 3

Origin

crest of ilium & thoracolumbar fascia

ventral border of ilium

Insertion

patella and cranial border of tibia

Action

flex hip; extend stifle (weight bearing);

flex stifle (not weight bearing)

Question 4

gracilis

Answer 4

Origin

pelvic symphysis via symphysial tendon

Insertion

cranial border of tibia;

tuber calcanei via common calcanean tendon

Action

adduct limb; flex stifle; extend hip and hock

Question 5

pectineus

Answer 5

Origin

pubis (pre-pubic tendon and iliopubic eminence)

Insertion

distal end of caudomedial aspect of femur

(medial lip of caudal rough surface)

Action

adduct limb

Question 6

adductor

(magnus et brevis and longus)

Answer 6

Origin

pelvic symphysis via symphysial tendon

ventral surface of pubis and ischium

Insertion

caudolateral aspect of femur

(entire lateral lip of caudal rough surface of femur)

Action

adduct limb; extend hip

Question 7

tensor fasciae latae

Answer 7

Origin

tuber coxae; aponeurosis of middle gluteal m.

Insertion

lateral femoral fascia, a.k.a. fascia lata

Action

tense fascia lata; flex hip; extend stifle

Question 8

superficial gluteal

Answer 8

Origin

sacrotuberous ligament; deep gluteal fascia

Insertion

third trochanter of the femur

Action

extend hip; abduct limb

Question 9

middle gluteal

Answer 9

Origin

crest and gluteal surface of ilium

Insertion

greater trochanter of the femur

Action

extend hip; abduct hip; rotate pelvic limb medially

Question 10

deep gluteal

Answer 10

Origin

body of ilium; ischiatic spine

Insertion

greater trochanter of the femur

Action

extend hip; abduct hip; rotate pelvic limb medially

Question 11

internal obturator

Answer 11

Origin

dorsal surface of ischium and pubis

dorsal pelvic symphysis

Insertion

trochanteric fossa of the femur

Action

rotate pelvic limb laterally

Question 12

gemelli

Answer 12

Origin

lateral surface of ischium, ventral to the lesser ischiatic notch

Insertion

trochanteric fossa of the femur

Action

rotate pelvic limb laterally

Question 13

quadratus femoris

Answer 13

Origin

ventral surface of caudal ischium

Insertion

intertrochanteric crest of the femur

Action

rotate pelvic limb laterally; extend hip

Question 14

external obturator

Answer 14

Origin

ventral surface of pubis and ischium

Insertion

trochanteric fossa of the femur

Action

rotate pelvic limb laterally

Question 15

quadriceps femoris

Answer 15

Origin

ilium (rectus femoris); proximal aspect of femur

Insertion

tibial tuberosity via the patellar ligament

Action

flex hip (rectus femoris); extend stifle (all heads)

Question 16

iliopsoas

Answer 16

Origin

ventral aspect of lumbar vertebrae; cranioventral ilium

Insertion

lesser trochanter of the femur

Action

flex hip

Question 17

cranial tibial

Answer 17

Origin

proximal and lateral aspect of the tibia near the extensor groove

Insertion

proximal plantar surface of metatarsals I and II

Action

flex tarsus; rotate paw laterally so plantar surface faces medially

Question 18

fibularis longus

Answer 18

Origin

lateral collateral ligament; proximal aspect of tibia and fibula

Insertion

tarsal bone IV; plantar aspect of proximal ends of metatarsals

Action

flex tarsus; rotate paw medially so plantar surface faces laterally

Question 19

gastrocnemius

Answer 19

Origin

medial and lateral supracondylar tuberosities of the femur

Insertion

tuber calcanei

Action

extend tarsus; flex stifle

Question 20

superficial digital flexor

Answer 20

Origin

lateral supracondylar tuberosity of the femur (in common with with lateral head of the gastrocnemius m.)

Insertion

tuber calcanei; plantar aspect of the base of the middle phalanx of digits II, III, IV, and V

Action

flex stifle; extend tarsus; flex digits

Question 21

deep digital flexor

Answer 21

Origin

proximal tibia and fibula and adjacent interosseus membrane between the two

Insertion

plantar aspect of the base of the distal phalanx of digits I - V

Action

flex digits; extend tarsus

Question 22

popliteus

Answer 22

Origin

lateral condyle of femur

Insertion

proximal and caudal aspect of the tibia

Action

flex stifle; rotate leg (crus) medially

Question 23

long ditital extensor

Answer 23

Origin

extensor fossa of the femur

Insertion

extensor processes of distal phalanges digits II, III, IV, and V.

Action

extend digits; flex tarsus

Question 24

biceps femoris

Answer 24

Origin

sacrotuberous ligament & ischiatic tuberosity

Insertion

patella, patellar lig., & cranial border of tibia via fascia lata and crural fascia; tuber calcanei via common calcanean tendon

Action

extend hip, stifle, & hock; can flex stifle when not bearing weight