MAP HW #14 - Skeletal Muscle (microscope anatomy & physiology)

Question 1

What is the insertion for the anterior fibers of the deltoid muscle?

Answer 1

Deltoid tuberosity of the humerus

Question 2

The prefix ____ means flesh.

Answer 2

Sarco-

Question 3

The prefix ____ means turning, change, or affinity for.

Answer 3

Tropo-

Question 4

The prefix ____ means equal or same.

Answer 4

Iso-

Question 5

The prefix _____ means abnormal, or diseased.

Answer 5

Dys-

Question 6

The prefix _____ means muscle.

Answer 6

Myo-

Question 7

During an exercise where muscles do not shorten, _____, contractions have occurred.

Answer 7

Isometric

Question 8

________ is a missing protein in Duschenne 19s muscular dystrophy.

Answer 8

Dystrophin

Question 9

The two proteins directly involved in muscle contraction are broadly called _______.

Answer 9

Myofilaments

Question 10

The cell membrane of a muscle fiber is the ______.

Answer 10

Sarcolemma

Question 11

__________ has an affinity for myosin binding sites in the absence of calcium.

Answer 11

Tropomyosin

Question 12

Necrotizing fasciitis is a serious bacterial infection. Necrosis is the death of tissues in the body. Considering the organization of the connective tissue sheaths of skeletal muscle, explain how this infection could spread rapidly throughout the body.

Answer 12

Necrotizing fasciitis spreads quickly because the connective tissue sheaths, particularly the epimysium, are all continuous with each other and with the superficial fascia, so there are no physical barriers to stop the spread of the bacteria.

Question 13

The bacterium Clostridium botulinum secretes botulinum toxin, a neurotoxin. The toxin blocks the release of acetylcholine from the axon terminal of a motor neuron. Explain how the toxin binding would change the normal sequence of events at the neuromuscular junction.

Answer 13

Botulinum toxin binds to the motor neuron and prevents the acetylcholine from being released into the synaptic cleft. This prevents the initiation of an end-plate potential because there is no neurotransmitter to bind to the ion-channel receptor on the muscle cell motor end plate.

Question 14

Why are repeat injections of Botox® required over time to control blepharospasm?

Answer 14

PNS motor nerves regenerate

Question 15

Botox® injection directly inhibits which process leading to acetylcholine (ACh) release?

Answer 15

Exocytosis

Question 16

A muscle fiber is ______.

Answer 16

a muscle cell

Question 17

What is the correct order of structures as you move from outside a muscle cell, to deep inside it?

Answer 17

Fiber, myofibril, myofilament

Question 18

The actual contractile units of muscles extend from Z disc to Z disc. They are ________.

Answer 18

Sarcomeres

Question 19

This contractile protein forms thin filaments.

Answer 19

Actin

Question 20

This contractile protein is shaped like a golf club.

Answer 20

Myosin

Question 21

The dark band of skeletal muscle consists of ________.

Answer 21

Both thick and thin filaments

Question 22

This indentation of the sarcolemma carries electrical signals deep into the muscle cells.

Answer 22

T tubule

Question 23

From gross to microscopic, the parts of a muscle are ________.

Answer 23

Muscle, fascicle, fiber

Question 24

Each of the elements that make up a skeletal muscle is surrounded by connective tissue. Which words below correctly pair the connective tissue layer with the corresponding muscle structure?

Answer 24

Fascicle: perimysium

Question 25

This strong, cord-like structure attaches muscles to bones.

Answer 25

Tendon

Question 26

The neuromuscular junction consists of ________.

Answer 26

The axon terminal coming into close proximity to a muscle fiber.

Question 27

The space between the axon terminal and the sarcolemma of a muscle fiber is called the ________.

Answer 27

Synaptic cleft

Question 28

A neuron and all the muscle fibers it stimulates is called a ________.

Answer 28

Motor unit

Question 29

Each muscle cell is surrounded by thin connective tissue called the __________.

Answer 29

Endomysium

Question 30

The junction between an axon and a muscle fiber is called a __________

Answer 30

neuromuscular junction

Question 31

TRUE/FALSE: Larger, more powerful muscles have relatively less connective tissue than smaller muscles.

Answer 31

False

Question 32

Which is NOT true of skeletal muscle?

Answer 32

It is one of the major components of hollow organs

Question 33

TRUE/FALSE: Skeletal muscle cells have more than one nucleus.

Answer 33

True

Question 34

The two contractile proteins that make up the myofilaments of skeletal muscle are __________ and __________.

Answer 34

Actin;myosin

Question 35

A cordlike structure that connects a muscle to another muscle or bone is __________.

Answer 35

A tendon

Question 36

The contractile unit of muscle is the __________.

Answer 36

Sarcomere

Question 37

Because the cells of skeletal muscle are relatively large and cylindrical in shape, they are also known as __________.

Answer 37

Fibers

Question 38

TRUE/FALSE: The neuron and muscle fiber membranes do NOT actually touch but are separated by a fluid-filled gap.

Answer 38

True