1.2 Muscular Anatomy Flashcards
Characteristics common to muscle tissue
Contractility, extensibility, elasticity,
atrophy, hypertrophy, controlled by nerve stimuli, fed by capillaries
Contractility
Ability of muscle to contract and generate force
Extensibility
Ability of muscle to be stretched beyond its normal resting length
Elasticity
Ability of muscle to return to its original resting length after stretch is removed
Atrophy
Decrease in muscle mass (due to decrease in number of myofibrils)
Hypertrophy
Increase in muscle mass (due to increase in number of myofibrils)
Fed by capillaries
Provide the muscle with oxygen, nutrients and calcium; remove waste products
Types of muscle
Skeletal, cardiac, smooth
Skeletal
Under voluntary control; striated appearance
Has tendons (attach bone to muscle) Main function of skeletal muscle = move the skeleton
Cardiac
(heart muscle)
Under involuntary control; striated appearance
Smooth
Under involuntary control; not striated appearance
Lines the walls of blood vessels + hollow organs
e.g. stomach, intestines
Striated
Alternating dark and light bands that are visible when seen under a microscope (due to myofibrils)
Voluntary control
Contracts with the individual consciously thinking about it (controlled by nerve stimuli - operated by somatic nervous system)
Involuntary control
Contracts without the individual consciously thinking about it (controlled by nerve stimuli - operated by automatic nervous system)
Structure of skeletal muscle
Epimysium, perimysium, endomysium,
Muscle fibre, myofibril, sarcomere,
Actin and myosin
Origin and insertion of muscles
Origin: the attachment of a muscle tendon to a
stationary bone
Insertion: the attachment of a muscle tendon to a
moveable bone
Location of skeletal muscles - the anterior
Deltoid, pectoralis, biceps brachii Abdominus rectus, external obliques Iliopsoas, sartorius Quadriceps femoris (rectus femoris, vastus intermedius, vastus medialis, vastus lateralis) Tibialis anterior
Location of skeletal muscles - the posterior
Trapezius, latissimus dorsi, triceps brachii,
Erector spinae
Gluteus maximus
Hamstrings (biceps femoris, semitendinosus,
semimembranosus)
Gastronemius, soleus
Controlled by nerve stimuli
Nerves (motor neurons) bring impulses from the central nervous system to the muscle
Neurons release neurotransmitters into the blood which stimulate the muscle to contract and produce force
Epimysium
Fascia (a band/sheet of connective tissue fibers); outer layer which covers the entire muscle
Perimysium
Fascia (a band/sheet of connective tissue fibres); surrounds bundles of muscle fibres or fascicles
Fascicles (bundle of skeletal muscle fibres) are long, cylindrical and vary in length
Endomysium
Fascia (a band/sheet of connective tissue fibres); surrounds the individual muscle fibres
Muscle fibre
Type of cell found in muscle tissue; long, tubular cells
Myofibril
Long, highly organized bundle of actin, myosin
Sacromere
The contractile unit of a myofibril
Actin, Myosin
Contractile proteins responsible for movement
