Basic structure and function of skeletal muscles

Question 1

Give some examples of function of muscles

Answer 1

Provides us with our ability to move
Regulate organ volumes
Allow us to communicate with one another
Consumes ATP in order to produce body heat
Maintains posture

Question 2

Name the 3 types of muscles

Answer 2

Smooth, skeletal and cardiac

Question 3

Where would you find smooth muscle

Answer 3

On the walls of internal organs

Question 4

Where would you find cardiac muscle

Answer 4

In the heart

Question 5

Where would you find skeletal muscle

Answer 5

Attached to the skeleton via tendons or indirectly via a connective tissue called aponeurosis

Question 6

Order of the grouping of skeletal muscle

Answer 6

Bundles of muscle fascicles
Bundles of muscle fibres
Bundles of myofibrils
Bundles of myofilaments

Question 7

What are myofibrils composed of

Answer 7

Protein filaments

Question 8

What are myofilaments responsible for

Answer 8

Muscle contraction

Question 9

What are the 3 layers of connective tissue that muscles are organised into?

Answer 9

Endomysium, perimysium and epimysium

Question 10

What does endomysium surround

Answer 10

Each muscle fibre

Question 11

What doe perimysium surround

Answer 11

Groups muscle fibres into muscle fascicles

Question 12

What is the function of perimysium?

Answer 12

To prevent any damage to the muscle fascicles

Question 13

Why is there a nutrient storage in perimysium?

Answer 13

It has vascularity - it contains capillaries and nerve fibres

Question 14

What does epimysium surround

Answer 14

An entire skeletal muscle

Question 15

What does epimysium seperate

Answer 15

The muscle from surrounding connective tissue and muscles

Question 16

What is a muscles sarcolemma

Answer 16

The plasma membrane of a muscle fibre

Question 17

Describe the sarcolemma’s role in action poteionals

Answer 17

Recieves electrical stimuli and conducts an action potential to the muscles internal structures

Question 18

Describe transverse tubules

Answer 18

Forms where the sarcolemma is invaginated,

Question 19

How do transverse trabeculae recieve stimuli from the sarcolemma?

Answer 19

They penetrate through the muscle fibre

Question 20

What does the sarcoplasmic reticulum contain?

Answer 20

A calcium storage

Question 21

How are terminal cisternae formed?

Answer 21

When the s. reticulum becomes enlarged and forms bonds that wrap around the muscle fibre on either side of the t tubule

Question 22

What is the function of the terminal cisternae

Answer 22

To release calcium from the s. reticulum

Question 23

What do terminal cisternae trigger?

Answer 23

The contraction of myofibrils

Question 24

Are mucles single or multi nucleated?

Answer 24

Multinucleated

Question 25

What does the sarcoplasm contain?

Answer 25

glycogen and myofibrils

Question 26

What are myofibrils made of?

Answer 26

Composed of myofilaments that are organised into sarcomeres

Question 27

Define a sarcomere

Answer 27

The basic functional unit of a myofibril

Question 28

What is found at the I band

Answer 28

Actin

Question 29

What is found at the z line

Answer 29

titin - marks the end of sarcomere

Question 30

What is found at m line

Answer 30

myosin

Question 31

What do you not find at the h zone

Answer 31

actin

Question 32

What does myosin allow

Answer 32

Coupling hydroylis of ATP to conformational changes to the head region of the filament that enables it to bind and move along the actin filaments

Question 33

What structual protein is found at the m-line of a sarcomere

Answer 33

myomesin

Question 34

What structual protein is found at actin filaments

Answer 34

nebulin

Question 35

What tructual protein links actin to the sarcolemma

Answer 35

dyotrophin

Question 36

Name the 2 regulatory proteins of muscle contraction

Answer 36

Tropomyoin and troponin

Question 37

What does tropomyosin regulate

Answer 37

uncovers myosin head during excitation and contraction

Question 38

What is the role of troponin

Answer 38

binds to calcium forming a crossbridge link

Question 39

Are skeletal muscles straited or non striated

Answer 39

striated

Question 40

Are cardiac muscles straited or non striated

Answer 40

striated

Question 41

Are smooth muscles straited or non striated

Answer 41

non striated

Question 42

Are skeletal muscles voluntary or involuntary

Answer 42

voluntary

Question 43

Are smooth muscles voluntary or involuntary

Answer 43

involuntary

Question 44

Are cardiac muscles voluntary or involuntary

Answer 44

involuntary

Question 45

In muscles where is acetyl cholinerase found

Answer 45

Acetyl cholinesterase is found in the synapse between nerve cells and muscle cells

Question 46

Define muscle spindles

Answer 46

Muscle spindles are sensory receptors within the belly of a muscle

Question 47

What is the function of muscle spindles

Answer 47

Muscle spindles primarily detect changes in the length of muscle.

Question 48

What part of the sarcomere does not shorten during mucle contraction?

Answer 48

A band

Question 49

How do leukocytes move to the site of injury

Answer 49

by diapedis

Question 50

What is the function of titin

Answer 50

Maintains the alignment of thick filaments in the middle of the sarcomere