shayan study

Question 1

What is excitability/ irritability in muscles?

Answer 1

Ability to respond to stimuli.

Question 2

What is contractility in muscles?

Answer 2

Ability to contract and generate force.

Question 3

What is extensibility in muscles?

Answer 3

Ability to lengthen in response to stimuli

Question 4

What is elasticity in muscles?

Answer 4

Ability to return to original shape after stretching.

Question 5

What are the characteristics of smooth muscle?

Answer 5

Involuntary, non-striated, found in organs (e.g., intestines, blood vessels).

Question 6

What are the characteristics of cardiac muscle?

Answer 6

Involuntary, striated, found in the heart.

Question 7

What are the characteristics of skeletal muscle?

Answer 7

Voluntary, striated, attached to bones.

Question 8

What is the parallel arrangement of muscle fibres?

Answer 8

Fibres run along the length (e.g., biceps brachii).

Question 9

What is the pennate arrangement of muscle fibres?

Answer 9

fibres arranged at oblique angles
(e.g., deltoids).

Question 10

What is the convergent arrangement of muscle fibres?

Answer 10

Broad origin, fibres converge (e.g., pectoralis major).

Question 11

What is the circular arrangement of muscle fibres?

Answer 11

Form rings (e.g., around mouth).

Question 12

What is the muscle belly?

Answer 12

Whole muscle.

Question 13

What are fascicles?

Answer 13

Bundles of muscle fibres.

Question 14

What are muscle fibres?

Answer 14

Individual muscle cells.

Question 15

What are myofibrils?

Answer 15

Contractile elements.

Question 16

What are myofilaments?

Answer 16

Actin: Thin filament. Myosin: Thick filament.

Question 17

What is the neuromuscular junction (NMJ)?

Answer 17

Synapse where a motor neuron communicates with a muscle fibre.

Question 18

What is an action potential?

Answer 18

Electrical impulse that triggers muscle contraction.

Question 19

What is motor unit recruitment?

Answer 19

Increasing the number of motor units activated for more force.

Question 20

What is the all-or-none principle?

Answer 20

Muscle fibres in a motor unit contract fully or not at all.

Question 21

What is the role of ATP in excitation-contraction coupling?

Answer 21

Powers myosin head movement and detachment.

Question 22

What is myosin ATPase?

Answer 22

Enzyme that breaks down ATP for energy.

Question 23

What is the role of calcium in muscle contraction?

Answer 23

Binds to troponin, allowing actin-myosin interaction.

Question 24

What is a powerstroke?

Answer 24

Myosin pulls actin filament, causing contraction.

Question 25

What is the sliding filament theory?

Answer 25

Myosin heads bind to actin, forming cross-bridges. Myosin pulls actin inward (powerstroke). ATP is required to detach myosin heads and reset the cycle.

Question 26

What are slow twitch muscle fibres?

Answer 26

High endurance, aerobic, fatigue-resistant. (Marathon runner legs)

Question 27

What are fast twitch Type IIa muscle fibres?

Answer 27

Intermediate, moderate endurance and power. (Quad’s of Cyclist)

Question 28

What are fast twitch Type IIb muscle fibres?

Answer 28

High power, anaerobic, fatigues quickly. (Gastrocnemius of sprinter)

Question 29

What are tonic muscles?

Answer 29

High endurance, postural.

Question 30

What are phasic muscles?

Answer 30

Quick, powerful movements.

Question 31

What are the biochemical properties of muscle fibres?

Answer 31

Different fibre types have specific enzymes (e.g., oxidative enzymes in Type I).

Question 32

What energy systems do muscle fibres rely on?

Answer 32

Type I relies on aerobic metabolism; Type IIb relies on anaerobic glycolysis.

Question 33

What determines force production in skeletal muscles?

Answer 33

Determined by fibre type and recruitment.

Question 34

What is the speed of contraction in muscle fibres?

Answer 34

Faster in Type II fibres.

Question 35

What is fatigue resistance in muscle fibres?

Answer 35

High in Type I fibres.

Question 36

What is a muscle twitch?

Answer 36

Single contraction from one stimulus.

Question 37

What is summation in muscle contraction?

Answer 37

Increased force with rapid stimuli.

Question 38

What is tetanus in muscle contraction?

Answer 38

Sustained contraction with no relaxation.

Question 39

How is force regulated in muscle?

Answer 39

Motor Unit Recruitment: Activating more units increases force. Frequency of Stimulation: Higher frequency produces greater force. Length-Tension Relationship: Optimal length for maximum force.

Question 40

What is hypertrophy?

Answer 40

Increase in muscle cell size due to training. (Anabolism)

Question 41

What is hyperplasia?

Answer 41

Increase in the number of muscle fibre (rare in humans).

Question 42

What is atrophy?

Answer 42

Decrease in muscle cell size due to inactivity or disease. (Catabolism)

Question 43

What is the role of a prime mover (agonist)?

Answer 43

Main muscle causing movement.

Question 44

What is the role of an antagonist?

Answer 44

Opposes the agonist.

Question 45

What is the role of synergists?

Answer 45

Assist the prime mover.

Question 46

What is the role of stabilizers (fixators)?

Answer 46

Stabilize a joint during movement.

Question 47

What is an isometric contraction?

Answer 47

Muscle contracts without changing length. (Hold the dumbbell half way)

Question 48

What is a concentric contraction?

Answer 48

Muscle shortens during contraction. (Curling a dumbbell up)

Question 49

What is an eccentric contraction?

Answer 49

Muscle lengthens under tension. (Curling a dumbbell down)