Muscles Flashcards
What are fascicles?
- bundle of muscle fibres that run parallel to each other
- arrangement tells the action of the muscle and determines the ROM and power
Skeletal muscle fibres shorten to ____ % of resting length
70%
How is the power of a muscle determined?
-by the number and length of fibres
What kind of tissue divides limb muscles into compartments?
dense regular connective tissue
What are muscle compartments?
groups of muscles that arose from common embryonic origin
Anterior compartment muscles of the arm ______ while posterior compartment muscles _______
- flex shoulder and elbow
- extend shoulder and elbow
Anterior compartment muscles of the thigh ______ while posterior compartment muscles _______
- flex the hip and extend the knee
- extend the hip and flex the knee
Medial compartment muscles of the thigh______ while lateral compartment muscles _______
- adduct thigh
- abduct thigh
How are skeletal muscles named?
- location
- shape
- relative size
- direction of fascicles and muscle fibres
- location of attachments
- number of orgins
- action
The muscles of the chest, shoulder, and back are involved with __________ of the scapula
elevation/ depression
medial/ lateral rotation
protraction/ retraction
The muscles of the chest, shoulder, and back are involved with __________ of the humerus
flexion/ extension
adduction/ abduction
medial/ lateral rotation
What are the muscles of the rotator cuff?
- subscapularis (medial rotator of humerus)
- supraspinatous (abduction)
- infraspinatous (lateral rotation of humerus)
- teres minor (lateral rotation of humerus)
Muscles of the arm are involved with ______________ of the forearm
flexion, extension, and supination
What are the chief forearm flexors?
brachialis and biceps brachii
bicep brachii also supinates
What acts as a synergist and stabilizes the elbow during flexion?
brachioradialis
What is the prime mover of forearm extension?
triceps brachii
Muscles of the hip and gluteal region are involved with _________ of the femur
flexion/ extension
adduction/ abduction
-medial/ lateral rotation
Which muscles flex the thigh? What is their origin?
iliacus and psoas major; iliopsoas, and sartorius
originate on the pelvis or vertebral column
What is the role of the muscles that originate on the pelvis or sacrum?
gluteus maximus- extends thigh
gluteus medius and minimus- abduct thigh
Which muscles adduct the thigh?
medial compartment muscles
adductor longus/ brevis/ magnus, pectineus, and gracilis
Which muscle of the major lateral rotator of the thigh?
piriformis
What are the four powerful knee extensors?
rectus femoris
vastus lateralis/ medialis/ intermedius
What is the role of the tensor fasciae latae?
steadies the trunk on thigh by making IT band taut
What muscles are the prime movers of hip extension and knee flexion?
hamstrings
Which muscles share a common origin on the ischial tuberosity?
hamstrings
biceps femoris
semitendinosus
semimembranosus
What muscles are responsible for plantar flexion?
gastrocnemius and soleus
