Muscles and Movement

Question 1

What are the three types of muscle tissue in the body?

Answer 1

Skeletal, Cardiac, and Smooth muscle

Question 2

which type of muscle is responsible for voluntary movement

Answer 2

skeletal

Question 3

where is the cardiac muscle found

Answer 3

found in the heart and moves blood through thecirculatory system

Question 4

what is the main function of smooth muscle

Answer 4

controls movement of substance in internal organs and tubes, such as blood vessels and the digestive system

Question 5

which types f muscle are under involuntary control

Answer 5

cardiac and smooth m

Question 6

what is the basic structural unit of skeletal muscle

Answer 6

The sarcomere

Question 7

which two proteins are responsible for muscle contraction

Answer 7

actin and myosin

Question 8

What are the names of the three connective tissue layers surrounding muscle fibers?

Answer 8

Epimysium, Perimysium, and Endomysium

Question 9

what is the function of the sarcoplasmic reticulum in muscle cells

Answer 9

stores and releases calcium ions for muscle contraction

Question 10

what is the role of transverse tubules (t-tubules)

Answer 10

allows action potentials to penetrate into the muscle fibers

Question 11

what is the name of the model that describes how muscles contract

Answer 11

sliding filament theory

Question 12

What happens to the sarcomere during contraction?

Answer 12

It shortens as actin filaments slide past myosin filaments

Question 13

Which regulatory proteins control muscle contraction?

Answer 13

Troponin and Tropomyosin

Question 14

What causes the myosin binding sites on actin to be exposed?

Answer 14

Calcium ions bind to troponin, moving tropomyosin

Question 15

What is the function of ATP in muscle contraction?

Answer 15

ATP provides energy for cross-bridge cycling and detachment of myosin from actin

Question 16

what is the neuromuscular junction

Answer 16

the synapse between the motor neuro and the muscle fiber

Question 17

Which neurotransmitter is released at the neuromuscular junction?

Answer 17

Acetylcholine

Question 18

How does calcium trigger muscle contraction?

Answer 18

Calcium binds to troponin, shifting tropomyosin to expose myosin-binding sites on actin

Question 19

what ion is essential for muscle relaxation

Answer 19

Calcium must be pumped back into the sarcoplasmic reticulum for relaxation to occur

Question 20

What enzyme breaks down acetylcholine to stop muscle contraction?

Answer 20

Acetylcholinesterase

Question 21

in cardiac muscle what are intercalated discs

Answer 21

gap junctions allowing electrical signals to pass between cardiac cells

Question 22

How does cardiac muscle differ from skeletal muscle in contraction?

Answer 22

Cardiac muscle has pacemaker cells and is myogenic, meaning it contracts without neural input

Question 23

What is the role of calcium-induced calcium release in cardiac muscle?

Answer 23

Extracellular calcium enters through DHP receptors, triggering additional calcium release from the sarcoplasmic reticulum

Question 24

Why does cardiac muscle have a longer refractory period?

Answer 24

To prevent tetanus and allow the heart to fill with blood between beats

Question 25

What are the two types of smooth muscle, and how do they differ?

Answer 25

Single-unit smooth muscle contracts as a syncytium via gap junctions, while multi-unit smooth muscle contracts independently

Question 26

how is smooth muscle contraction regulated differently from skeletal muscle

Answer 26

smooth muscle uses calmodulin instead of tropine to regulate contraction

Question 27

which enzyme activates myosin in smooth muscle

Answer 27

myosin light chain kinase

Question 28

which type of muscle contraction generates force without shortening the muscle

Answer 28

isometric contraction

Question 29

what adaptations do frogs have that allow them to jump long distances

Answer 29

powerful skeletal muscles and tendon storage of elastic energy

Question 30

what can hummingbirds fly backwards and hover

Answer 30

they have unique wing muscle adaptations and high frequency wings beats

Question 31

which muscle types can contract the fastest

Answer 31

skeletal

Question 32

which muscle type contracts the slowest but can retain force for long durations

Answer 32

smooth muscle

Question 33

Why do cardiac muscle cells have a longer refractory period than skeletal muscle cells?

Answer 33

To prevent sustained contractions that would stop the heart from pumping

Question 34

What role does acetylcholinesterase play in muscle contraction?

Answer 34

Breaks down acetylcholine to stop the signal for contraction

Question 35

What would happen if T-tubules were absent in muscle fibers?

Answer 35

Action potentials would not efficiently reach deep muscle fibers, reducing contraction efficiency

Question 36

How does the recruitment of motor units affect muscle force generation?

Answer 36

More motor units activated = greater force production

Question 37

What is the difference between neurogenic and myogenic muscle contraction?

Answer 37

Neurogenic contraction requires nervous system input, while myogenic contraction is self-initiated by pacemaker cells)

Question 38

how do muscles generate movement in vertebrates

Answer 38

they contract and pull on bones via tendons

Question 39

what are the three types of skeletal support systems in animals

Answer 39

endoskeleton, exoskeleton and hydrostatic

Question 40

what are the three main energy systems that supply ATP for muscle contraction

Answer 40

immediate, glycolic and oxidative systems

Question 41

which type of muscle fiber is best suited for endurance and which is best for power

Answer 41

type 1=endurance type11b= power

Question 42

what is the main difference between muscle strength and power

Answer 42

strength is ,maximum force and power is force exerted rapidly

Question 43

what factors contribute to muscle fatigue

Answer 43

exercise intensity, metabolism type, muscle composition and fitness level

Question 44

how does motor unit requirement affect muscle force

Answer 44

the more motor units recruited= greater force generated

Question 45

what is the length-tension relationship in muscle contraction

Answer 45

force generation depends on the muscles initial length before contraction

Question 46

how does cross-sectional area affect muscle strength

Answer 46

larger muscle fibers generate more force

Question 47

What is the difference between fusiform and pennate muscle architecture?

Answer 47

Fusiform = parallel fibers, optimized for speed; Pennate = angled fibers, optimized for force

Question 48

Which type of muscle architecture produces the greatest force?

Answer 48

Pennate muscles

Question 49

What is a lever system in biomechanics?

Answer 49

A system where bones and muscles work together to move a load

Question 50

Which class of lever is most common in the human body, and what is its function?

Answer 50

Class III lever; allows for greater range and speed of motion

Question 51

Why do sprinters and marathon runners have different muscle fiber compositions?

Answer 51

Sprinters have more fast-twitch fibers for power, marathon runners have more slow-twitch fibers for endurance

Question 52

How do tendons contribute to efficient movement?

Answer 52

Store and release elastic energy to enhance force production

Question 53

How does calcium trigger muscle contraction?

Answer 53

Binds to troponin, shifting tropomyosin to expose myosin-binding sites on actin

Question 54

Why is ATP required for both muscle contraction and relaxation?

Answer 54

Powers cross-bridge cycling and calcium reuptake into the sarcoplasmic reticulum

Question 55

What is a lever system in biomechanics?

Answer 55

A system where bones and muscles work together to move a load

Question 56

What are the three muscles types in vertebrates?

Answer 56

Skeletal Cardiac Smooth

Question 57

What are the primary muscle types in invertebrates?

Answer 57

transversely striated obliquely striated smooth muscles

Question 58

what is the role of calcium ions in muscle contraction?

Answer 58

they regulate the binding of myosin to actin filaments

Question 59

how do midges achieve 1000Hz wing beats?

Answer 59

they use asynchronous flight muscles, maintaining constant intracellular calcium levels.

Question 60

how do birds and bats differ in flight mechanisms?

Answer 60

birds use large pectoral muscles, while bats rely on elastic skin and smaller muscles for control.

Question 61

what adaption allows hummingbirds to hover and fly backwards?

Answer 61

large pectoral muscles rapid metabolism unique wing angles elongated wings

Question 62

how do squids achieve jet proulsion?

Answer 62

by contracting circumferential muscles in their mantle to expel water forcefully

Question 63

why do crabs move sideways?

Answer 63

their exoskeleton and hinge joints allow lateral movement

Question 64

what is the relationship between locomotion and energy cost?

Answer 64

swimming is the most efficient, followed by flying, and running is most costly.

Question 65

when did the first version of myosin appear and what was its function?

Answer 65

over 2 billion years ago and was to keep intracellular fluids separate from the environment.

Question 66

How did cnidarian and bilaterian muscles evolve independently?

Answer 66

By adding novel proteins to a pre-existing contractile apparatus, resulting in similar muscle structures.

Question 67

What are the two main types of muscle fibers?

Answer 67

Slow-twitch (Type I) for endurance and Fast-twitch (Type II) for rapid force generation.

Question 68

What factors affect the force of muscle contraction?

Answer 68

Cross-sectional area, neural stimulation, muscle fiber type, and energy availability.

Question 69

how does the catch state in mullusks work?

Answer 69

Twitchin protein binds myosin filaments, allowing tension to be maintained with minimal energy use

Question 70

what is the difference between synchronous and asynchronous flight muscles?

Answer 70

Synchronous: One contraction per nerve impulse. Asynchronous: Constant Ca²⁺ levels allow muscles to contract multiple times per impulse.

Question 71

why is asynchronous muscle flight more efficient?

Answer 71

Fewer nerve impulses are needed, and Ca²⁺ pumps are minimised, reducing energy cost.

Question 72

how do hummingbirds rains support their flight activities?

Answer 72

They have a large hippocampus for spatial memory and an enlarged nucleus lentiformis mesencephali for visual processing.

Question 73

what is a hydrostatic skeleton and how does it aid movement?

Answer 73

a fluid filled cavity that muscles contract against enabling motion in worms and other invertebrates

Question 74

why is swimming and flying more energy efficient than running?

Answer 74

gliding and air currents helps reduce energy needed and water supports body weight again reducing energy needed.