Muscles and Animal Movement

Question 1

What organisms have muscles?

Answer 1

All phyla above porifera

Question 2

By what is muscle performance governed?

Answer 2

Speed of response and efficiency in in converting chemical energy to mechanical energy.

Question 3

What are the three types of of vertebrate muscle tissue?

Answer 3

Skeletal, cardiac and smooth

Question 4

What does muscle tissue contain?

Answer 4

Cells for contraction and force generation.

Question 5

what is the highest frequency of vertebrate locomotor muscles?

Answer 5

25-30Hz

Question 6

How much of the human is muscle?

Answer 6

Around 50%

Question 7

How much of the human body is skeletal muscle for males and females respectively?

Answer 7

40% and 32%

Question 8

What percentage of fish total bodyweight is muscle?

Answer 8

Around 20-50% normally but 55-65% for Barracudas.

Question 9

How is skeletal muscle categorised?

Answer 9

Striated and voluntary.

Question 10

How is cardiac muscle categorised?

Answer 10

Striated and involuntary.

Question 11

How is smooth muscle categorised?

Answer 11

Unstriated and involuntary.

Question 12

How big are skeletal muscle cells?

Answer 12

10-100 um in diameter and 75 cm in length.

Question 13

Why do skeletal muscle cells have multiple nuclei?

Answer 13

From the fusing of myoblasts in development.

Question 14

What are myofibrils?

Answer 14

Specialised contractile elements that extend the entire length of the muscle fibre.

Question 15

What do myofibrils consist of?

Answer 15

Thick and thin filaments

Question 16

Of what are thick filaments made?

Answer 16

Assemblies of myosin

Question 17

Of what are thin filaments comprised?

Answer 17

Actin

Question 18

What are sarcomeres?

Answer 18

The smallest part of the muscle that can contract.

Question 19

Of what do sarcomeres consist?

Answer 19

One A band and two I bands.

Question 20

What are muscles?

Answer 20

Groups of muscle fibres bundled by connective tissue often attached to skeletal elements in antagonistic pairs.

Question 21

What are tendons?

Answer 21

Areas of vertebrate muscle that have extended beyond the muscle.

Question 22

What do muscles attach to in arthropods?

Answer 22

Apodemes

Question 23

What is a muscle twitch?

Answer 23

A brief, weak contraction of a single muscle fibre.

Question 24

What are the two primary factors that are adjusted to accomplish gradation?

Answer 24

The number of muscles contracting and the tension developed by each contracting fibre.

Question 25

What is the number of fibres contracting in vertebrates dependent on?

Answer 25

The extent of motor unit recruitment.

Question 26

What is each muscle innervated by?

Answer 26

A number of different motor neurons.

Question 27

When do vertebrate motor neurons branch?

Answer 27

As they enter the muscle with each axon terminal supplying a single muscle fibre.

Question 28

How many motor neurons are arthropod muscles innervated by?

Answer 28

More than one.

Question 29

What is used in submaximal contractions to prevent fatigue?

Answer 29

Asynchronous recruitment of motor fibres.

Question 30

What determines the number of muscle fibres contracting?

Answer 30

The number of motor units, the number of muscle fibres per motor unit and the number of fibres available to contract.

Question 31

What determines the tension developed by each contracting fibre?

Answer 31

- The frequency of stimulation - The length of the fibre at the onset of contraction - The extent of fatigue - The duration of activity - The type of fibre - The thickness of the fibre - The pattern of neural activity - The amount of testosterone

Question 32

What are the roles of skeleton?

Answer 32

Structural support, protection and facilitation of movement.

Question 33

What are the three types of eukaryotic cytoskeletal filaments?

Answer 33

Microfilaments, intermediate filaments and microtubules.

Question 34

What do fibroblasts secrete?

Answer 34

Collagen in skin cells

Question 35

What do chondrocytes secrete?

Answer 35

A matrix of cartilage

Question 36

What is the function of osteoblasts and osteoclasts?

Answer 36

To model bone

Question 37

What is the structure of prokaryotic flagellum?

Answer 37

They consist of the filament flagellum and have a hook and basal body responsible for motion.

Question 38

How do spirochetes move?

Answer 38

The whole cell moves with a corkscrew motion.

Question 39

How do cyanobacteria adjust their buoyancy?

Answer 39

By adjusting the amount of gas in their gas ventricles.

Question 40

What are the three modes of locomotion in protists?

Answer 40

Amoeboid movement, swimming by means of cilia, swimming by means of flagella.

Question 41

How do ctenophores move?

Answer 41

They have eight rows of cilia bearing plates called ctenes that they use to swim.

Question 42

How do acoelomate planarians move?

Answer 42

They use beating cilia.

Question 43

What are the three skeletal systems in animals?

Answer 43

Hydrostatic, exoskeletal and endoskeletal

Question 44

What constrains the pseudocoelomate body?

Answer 44

A flexible but inelastic chitinous cuticle which resists change in volume.

Question 45

What causes the pseudocoelomate body to ben back and forth?

Answer 45

Contraction of longitudinal muscles against high hydrostatic pressure.

Question 46

How do coelomate worms move?

Answer 46

By extending and shortening sections of the body.

Question 47

What facilitates coelomate movement?

Answer 47

Circular and longitudinal muscle layers and segmental compartments.

Question 48

Of what is the arthropod cuticle comprised?

Answer 48

A layer of proteins and chitin - a strong waterproof polysaccharide.

Question 49

What does the arthropod cuticle act as?

Answer 49

A protective exoskeleton.

Question 50

What are the limitations of the arthropod exoskeleton?

Answer 50

It limits growth and demands new mechanisms of gaseous exchange and locomotion.

Question 51

What are muscles attached to in endoskeleton systems?

Answer 51

To the inside of the exoskeleton.

Question 52

What did the evolution of the endoskeleton allow?

Answer 52

The potential for locomotion.

Question 53

What are the four key features of vertebrates?

Answer 53

- A rigid internal skeleton supported by a vertebral column. - An anterior skull with a large brain - Internal organs suspended in coelom - A well developed circulatory system driven by contractions of a ventral heart

Question 54

What is chitin comprised of?

Answer 54

N-acetylglucosamine