muscle anatomy

content from anatomy topic on muscles

muscular system function

muscular system function

responsible for maintenance of posture, locomotion and control of various circulatory systems

contractility

ability to generate force/create tension

extensibility

ability to be stretched beyond its normal resting length

elasticity

ability to return to resting length after it has been stretched

atrophy

a decrease in myofibrils/muscle size

hypertrophy

an increase in myofibrils/muscle size

controlled by nerve stimuli and fed by capillaries

generate force when stimulated by a nerve

3 types of muscle

smooth, cardiac and skeletal

smooth muscle

• lines walls of hollow internal structures

• involuntary control

• non-striated

cardiac muscle

• heart muscle

• striated

• involuntary control

skeletal muscle

• voluntary control

• striated

structure of skeletal muscle

epimysium, perimysium, endomysium, muscle fibre, myofibral, sacromere, actin, myosin

epimysium

outer most layer that surrounds entire muscle

perimysium

surrounds bundles of muscle fibres (fascicle)

endomysium

surrounds individual muscle fibres

muscle fibre

individual fibres containing many myofibrils

myofibril

bundle of contractile fibres within muscle cells

sarcomere

functional contractile unit of myofibril of striated muscle

origin

attachment of a muscle tendon to a stationary bone

insertion

attachment of a muscle tendon to a moveable bone

anterior muscles

deltoid, pectoralis, biceps brachii, external obliques, abdominus rectus, illiopsoas, sartorius, quadriceps (rectus femoris, vastus intermedialis, vastus medialis, vastus lateralis), tibialis anterior

posterior muscles

trapezius, erector spinae, latissimus dorsi, triceps brachii, gluteus maximus, hamstrings (biceps femoris, semiteninosus, semimembranosis), gastrocnemius, soleus

DOMS

• delayed onset muscle soreness

• phenomenon of muscle soreness/pain/stiffness felt 24-48 after exercise

what causes DOMS

eccentric contractions of muscles causing little tears, inflammatory reaction iwthin the muscle and overstretching or overtraining

how to reduce DOMS

• reducing eccentric component of muscle actions in early training

• start at low intensity and increase

• warm up and cool down

explain reciprocal inhibition

muscles work in pairs where as one contracts the other relaxes to allow movement