chapter 10, muscle

Question 1

What type of muscle is voluntary and striated, attached to bones?

Answer 1

Skeletal muscle

Skeletal muscle is responsible for body movements.

Question 2

What type of muscle is involuntary and striated, found in the heart?

Answer 2

Cardiac muscle

Cardiac muscle is responsible for pumping blood.

Question 3

What type of muscle is involuntary and non-striated, found in walls of hollow organs?

Answer 3

Smooth muscle

Examples include intestines and blood vessels.

Question 4

What is one of the main functions of muscular tissue?

Answer 4

Movement

Skeletal muscles move the body; smooth muscles move substances.

Question 5

What is the function of muscles in maintaining posture?

Answer 5

Stability

Muscles stabilize joints and maintain body posture.

Question 6

How do muscles contribute to heat production?

Answer 6

Muscles generate heat through contraction

Example: shivering increases body temperature.

Question 7

What is the ability of muscle tissue to respond to stimuli called?

Answer 7

Excitability

This characteristic allows muscles to react to signals.

Question 8

What is the ability of muscle tissue to shorten and generate force?

Answer 8

Contractility

This property is essential for muscle function.

Question 9

What is the connective tissue surrounding each muscle fiber called?

Answer 9

Endomysium

Endomysium provides support to individual muscle fibers.

Question 10

What connective tissue surrounds muscle fascicles?

Answer 10

Perimysium

Perimysium binds groups of muscle fibers together.

Question 11

What is the connective tissue surrounding the entire muscle?

Answer 11

Epimysium

Epimysium encases the muscle as a whole.

Question 12

What is the structure of a single muscle cell called?

Answer 12

Muscle fiber

Muscle fibers are the basic units of muscle tissue.

Question 13

What is the cell membrane of a muscle fiber known as?

Answer 13

Sarcolemma

Sarcolemma plays a key role in muscle contraction.

Question 14

What are the long protein structures inside muscle fibers responsible for contraction?

Answer 14

Myofibrils

Myofibrils contain the contractile proteins actin and myosin.

Question 15

What is the functional unit of muscle contraction?

Answer 15

Sarcomere

Sarcomeres are the repeating units in myofibrils.

Question 16

What is the role of the sarcoplasmic reticulum (SR) in muscle fibers?

Answer 16

Stores calcium for muscle contraction

Calcium release from SR triggers muscle contraction.

Question 17

What are the extensions of the sarcolemma that carry electrical impulses into the muscle?

Answer 17

T-tubules (Transverse tubules)

T-tubules help synchronize muscle contraction.

Question 18

What is the thin filament in muscle fibers called?

Answer 18

Actin

Actin interacts with myosin during muscle contraction.

Question 19

What is the thick filament in muscle fibers called?

Answer 19

Myosin

Myosin heads bind to actin to facilitate contraction.

Question 20

What is the regulatory protein that binds calcium and controls muscle contraction?

Answer 20

Troponin

Troponin’s binding to calcium initiates contraction.

Question 21

What blocks myosin binding sites on actin when the muscle is relaxed?

Answer 21

Tropomyosin

Tropomyosin prevents contraction in the relaxed state.

Question 22

What model explains how muscles contract by filaments sliding past each other?

Answer 22

Sliding filament theory

This theory is fundamental to understanding muscle contraction.

Question 23

What is a motor unit?

Answer 23

A motor neuron and all the muscle fibers it controls

Motor units vary in size depending on muscle function.

Question 24

What neurotransmitter triggers muscle contraction?

Answer 24

Acetylcholine (ACh)

ACh is released at the neuromuscular junction.

Question 25

What is the space between the neuron and muscle fiber called?

Answer 25

Synaptic cleft ## Footnote The synaptic cleft is where neurotransmission occurs.

Question 26

What enzyme breaks down acetylcholine, stopping contraction?

Answer 26

Acetylcholinesterase (AChE) ## Footnote AChE regulates muscle contraction duration.

Question 27

What molecule stores energy for quick ATP regeneration?

Answer 27

Creatine phosphate ## Footnote Creatine phosphate serves as an energy reserve in muscle cells.

Question 28

What type of respiration produces ATP without oxygen?

Answer 28

Anaerobic respiration ## Footnote This process can lead to lactic acid buildup.

Question 29

What type of respiration uses oxygen to produce ATP and is more efficient?

Answer 29

Aerobic respiration ## Footnote Aerobic respiration is the preferred method for ATP production.

Question 30

What is muscle fatigue?

Answer 30

Inability to maintain contraction due to lack of ATP or lactic acid accumulation ## Footnote Muscle fatigue can affect performance.

Question 31

What are slow oxidative (SO) fibers known for?

Answer 31

Fatigue-resistant, high endurance, aerobic metabolism ## Footnote SO fibers are typically found in postural muscles.

Question 32

What are fast glycolytic (FG) fibers known for?

Answer 32

Fatigue quickly, powerful, anaerobic metabolism ## Footnote FG fibers are used in short bursts of intense activity.

Question 33

What type of muscle contraction occurs when the muscle changes length while maintaining constant tension?

Answer 33

Isotonic contraction ## Footnote Isotonic contractions include both concentric and eccentric types.

Question 34

What is a concentric contraction?

Answer 34

Muscle shortens ## Footnote Example: lifting a weight.

Question 35

What is an eccentric contraction?

Answer 35

Muscle lengthens while maintaining tension ## Footnote Example: lowering a weight.

Question 36

What is an isometric contraction?

Answer 36

Muscle does not change length but maintains tension ## Footnote Example: holding a plank.

Question 37

What is muscular dystrophy?

Answer 37

Genetic disorder causing muscle degeneration ## Footnote This condition leads to progressive weakness.

Question 38

What is myasthenia gravis?

Answer 38

Autoimmune disorder affecting ACh receptors, leading to muscle weakness ## Footnote Myasthenia gravis can significantly impact daily activities.

Question 39

What is rhabdomyolysis?

Answer 39

Breakdown of muscle tissue releasing harmful proteins into the bloodstream ## Footnote Rhabdomyolysis can occur from severe muscle damage.

Question 40

What is fibromyalgia?

Answer 40

Chronic muscle pain with unknown cause ## Footnote Fibromyalgia can be challenging to diagnose and treat.