Muscles Flashcards
Iliopsoas
Composed of iliacus and psoas muscle
Psoas Major
Origin: transverse process & bodies of lumbar vertebrae
Insertion: less trochanter femur
Action: hip flexion, lateral rotation, flex trunk on hip (sitting position)
Iliacus
Origin: iliac fossa
Insertion: lesser trochanter femur
Action: hip flexion, lateral rotation, flex trunk on hip (sitting position)
Adductors
Origin: pubic bone
Insertion: medial/proximal femur
Action: hip addiction & medial rotation
Sartorius
O: anterior superior iliac spine
I: medial and proximal surface tibia
A: flexes knee, flexes/abducts & laterally rotates thigh at hip joint (crossing of legs)
Quadriceps
Vastus lateralis
Vastus medialis
Vastus intermedius
Recuts femoris
Vastus lateralis
O: greater trochanter & proximal lateral femur
I: tibial tuberosity through patellar ligament
A: knee extension
Vastus medialis
O: proximal & medial femur
I: tibial tuberosity through patellar ligament
A: knee extension
Vastus intermedius
O: anterior & lateral surface of femur
I: tibial tuberosity through patellar ligament
A: knee extension
Rectus femoris
O: anterior inferior iliac spine of ilium
I: tibial tuberosity through patellar ligament
A: knee extension & hip flexion
Crosses two joints
Tibialis anterior
O: lateral condyle & proximal tibia
I: first metatarsal & first cuneiform
A: dorsifelxion ankle & inversion foot
Extension digitorum longus
O: lateral condyle of tibia & anterior surface tibia
I: middle & distal phalanges 2-5
A: ankle dorsiflexion, extends toes
Fibularis (peroneus) longus
O: head & body of fibula & lateral condyle of tibia
I: first metatarsal & 1st cuneiform
A: ankle plantarfelxion & foot eversion
Gluteus Maximus
O: iliac crest, sacrum, coccyx
I: iliotibial tract of tensor fascia lata & gluteal tuberosity
A: hip extension & lateral rotation
Gluteus medius
O: ilium
I: greater trochanter of femur
A: hip abduction, medial rotation
Hamstrings-biceps femoris
O:
LONG HEAD: ischial tuberosity
SHORT HEAD: proximal femur
I: head of fibula & lateral condyle tibia
A: flexes knee and hip extension
*two heads of origin & crosses two joints
Hamstrings semimembranosis
O: ischial tuberosity
I: medial condyle of tibia
A: flexes knee and hip extension
*crosses two joints
Hamstrings semitendinosis
O: ischial tuberosity
I: proximal & medial tibia
A: Flexes knee and hip extension
*crosses two joints
Gastrocnemius
O: lateral & medial condyle femur
I: calcaneus through achilles tendon
A: plantarflexion & knee flexion
*crosses two joints
Soleus
O: head of fibula & medial tibia
I: calcaneus through achilles tendon
A: plantarflexion
Skeletal muscle
Most skeletal muscles fibres are attached by tendons to bones
Large, cigar shaped and multinucleate
Aka striated muscle because of its stripes
Aka voluntary muscle because it’s the only muscle tissue subject to conscious control
Connective tissues
Endomysium
Perimysium
Episyium
Endomysium
Encloses a single muscle fibre
Perimysium
Wraps around a facicle (bundle) of muscle fibres
Epimysium
Covers the entire skeletal muscle
-fascia= on the outside of the epismysium
Connective tissue attachment
Tendons
Aponeuroses
Tendons
Cordlike structures
Mostly collagen fibers
Often cross a joint bc of their toughness & small size
Aponeuroses
Sheetlike structures
Attach muscles indirectly to bones, cartilages, or connective tissue coverings
Muscle functions
Maintain posture & body position
Stabilize joints
Generate heat
Microscopic anatomy of skeletal muscles
Sacrolemma
Myofibrils
Sacrolemma
Specialized plasma membrane
Layer under Endomysium
Myofibrils
Long organelles inside muscle cell
Light (i) and dark (a) bands that give the muscle it’s striated appearance
Sacromere
Contractile unit of a muscle fibre
Structural and functional unit of skeletal muscles
