Comparison of smooth muscle contraction and skeletal muscle contraction.

Question 1

difference 1

Answer 1

APPEARANCE

skeletal muscle
- striated appearance due to actin-filament arrangement forming sarcomere

smooth muscle
- non-striated appearance due to actin-filament not in regular arrangement

Question 2

difference 2

Answer 2

FUNCTION

skeletal - movement/ posture/ balance

smooth - CURRD examples

Question 3

difference 3

Answer 3

FATIGUE

skeletal muscle
- fast twitch fibres = fast fatigue
- slow twitch fibres = slow fatigue

smooth muscles
- less likely to fatigue

Question 4

difference 4

Answer 4

INNERVATON

skeletal muscle innervated by motory units + sensory units

smooth muscle innervated by sympathetic + parasympathetic nervous system

Question 5

difference 5

Answer 5

METABOLISM

skeletal
- anaerobic + aerobic

smooth
- aerobic = slow ATP

Question 6

difference 6

Answer 6

REGENERATION

skeletal muscles = prefer to undergo fibrosis scarring by satellite cells

smooth muscles = cell division

Question 7

difference 7

Answer 7

ACTION

skeletal muscles require all or nothing stimulus to reach threshold to generate AP

smooth muscle receives stimulus and then begins contraction mechanism = graded response

Question 8

difference 8

Answer 8

STIMULI

skeletal muscle stimuli = only nerve impulse

smooth muscle stimuli = chemical/ electrical/ mechanical etc

Question 9

difference 9

Answer 9

LOCATION

skeletal muscles - attached to bones by tendons across joints

smooth muscle - hollow organs

Question 10

difference 10

Answer 10

CONTROL

skeletal muscle controlled by voluntary + conscious mechanisms by somatic nervous system

smooth muscle controlled involuntary + autonomous mechanisms by autonomic nervous system

Question 11

difference 11

Answer 11

CELLS

skeletal muscles = cylindrical cells + mutlinucleated

smooth muscles = spindle shaped cells + single nucleus

Question 12

difference 12

Answer 12

CONTRACTION

skeletal muscle
- neuromuscular junction action
- sarcomere depolarisation
- excitation-coupling mechanism
- rapid process due Ca2+ / ATP

smooth muscle
- depolarisation
- contraction
- latch phase
- relaxation
- slow process due to ATPase activity + sustained calcium influx

Question 13

difference 13

Answer 13

CONTRACTION TYPES

skeletal:
- isotonic
- isometric
- twitch = single rapid contraction then relaxation
- tetanic = sustained contraction due to high frequency sequence of APs

smooth
- tonic = sustained contraction w/o fatigue in blood vessels
- phasic = rhymic contractions during peristalsis

Question 14

difference 14

Answer 14

CALCIUM SOURCE

skeletal - intracellular only

smooth - extracellular + intracellular