Deck 12: Microscopic Anatomy and Organization of Skeletal Muscle

Question 1

The thick and thin filaments are made up of _, respectively.

A) the dark and light bands
B) the H zone and the Z disc
C) T tubules and terminal cisterns
D) myosin and actin

Answer 1

D

Question 2

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

A) fiber, myofibril, myofilament
B) myofibril, myofilament, fiber
C) myofilament, myofibril, fiber
D) myofilament, fiber, myofibril

Answer 2

A

Question 3

Tendons differ from ligaments in that .

A) tendons attach to bone and ligaments do not
B) tendons bind muscle to bone and ligaments bind bone to bone
C) they are formed from different tissue types
D) tendons are broad and flat and ligaments are like cords

Answer 3

B

Question 4

The function of the neuromuscular junction is to .

A) convey a signal from the nervous system to skeletal muscle
B) stimulate or inhibit the activity of skeletal muscles
C) link nerve endings to muscle, to protect the nerve structurally
D) connect sensory neurons directly to muscle

Question 5

This contractile protein forms the thin filaments.

A) dystrophin
B) myosin
C) titin
D) actin

Question 6

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?

A) functional group of muscles: endomysium
B) fascicle: perimysium
C) entire muscle: epimysium
D) muscle fiber: deep fascia

Question 7

At the neuromuscular junction, the electrical signal of the nerve .

A) causes the axon terminal to release Na+ and K+
B) stimulates formation of the neurotransmitter acetylcholine (ACh)
C) causes the axon terminal to release acetylcholine (ACh)
D) is sent directly to muscle

Question 8

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

A) fiber, fascicle, muscle
B) muscle, fiber, fascicle
C) fascicle muscle, fiber
D) muscle, fascicle, fiber

Question 9

An aponeurosis is .

A) similar to a tendon in function
B) a structural part of the interior of muscle cells
C) a covering of the myoneural region
D) a disease of the neuromuscular junction

Question 10

This contractile protein is shaped like a golf club.

A) troponin
B) myosin
C) tropomyosin
D) actin

Question 11

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

A) T tubule
B) terminal cisterns
C) triad
D) sarcoplasmic reticulum

Question 12

A muscle fiber is _ .

A) a rod-like structure consisting of sarcomeres placed end to end
B) an arrangement of actin and myosin filaments deep within a muscle cell
C) the elaborate arrangement of smooth endoplasmic reticulum inside a muscle cell
D) a muscle cell

Question 13

The neuromuscular junction consists of .

A) a nerve touching a muscle
B) a nerve coming into close proximity to a muscle fiber
C) the end branch of a single nerve fiber touching a muscle
D) the axon terminal coming into close proximity to a muscle fiber

Question 14

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

A) myoneural junction
B) motor unit
C) fascicle
D) synaptic cleft

Question 15

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

A) ligament
B) tendon
C) deep fascia
D) myofibril

Question 16

Sarcomeres consist of _.

A) a network of sarcoplasmic reticulum
B) bands of tissue wrapped around the sarcolemma
C) orderly arrangements of actin and myosin
D) myofibrils arranged one after the other

Question 17

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

A) sarcoplasmic reticulum
B) thick filaments
C) sarcomeres
D) myofibrils

Question 18

The dark band of skeletal muscle consists of .

A) T tubules
B) only thick filaments
C) both thick and thin filaments
D) only thin filaments

Question 19

Terminal cisterns _.

A) store acetylcholine
B) carry the action potential deep into the muscle cell
C) are made of smooth endoplasmic reticulum
D) are an important link between the nervous system and the muscle cell

Question 20

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

A) aponeurosis cleft
B) nerve gap
C) muscle gap
D) synaptic cleft

Question 21

The I-band consists of .

A) thin filaments
B) H zone
C) M line
D) thick filaments

Question 22

A triad consists of _ .

A) sarcomeres and T-tubules
B) myofibrils and terminal cisterne
C) terminal cisternae and T-tubules
D) sarcomeres and terminal cisternae

Question 23

Acetylcholine (ACh) is the neurotransmitter of axon terminals at the neuromuscular junction. It .

A) binds to receptors on the muscle membrane
B) ultimately causes the motor neuron to depolarize
C) diffuses into the muscle cell
D) binds to receptors on the motor neuron