Quiz 3

Question 1

Which filament will block the cross-bridge formation and limit the ability of muscles to contract?

Answer 1

tropomyosin

Question 2

What is a characteristic of a motor neuron?

Answer 2

A motor neuron and all of the muscle fibres it innervates

Question 3

Where do sympathetic ganglia originate?

Answer 3

in the lumbar and thoracic regions of the spine

Question 4

What term is used to describe the location where a muscle-tendon connects to the distal end of the bone, and the starting location of a muscle?

Answer 4

insertion; origin

Question 5

What are three differences between smooth and skeletal muscle?

Answer 5

1. smooth muscle runs in several different directions, while skeletal muscles run in only one direction
2. smooth muscle is controlled by the autonomic nervous system, while skeletal muscle is controlled by the somatic nervous system.
3. smooth muscle can contract for much longer without getting tired, while skeletal muscle can only contract for short periods of time before fatigue sets in.

Question 6

What are 2 characteristics that describe pacemaker cells?

Answer 6

oscillations in membrane potential that depolarize to create a rhythm of contraction.
cardiac muscle cells that fire action potentials spontaneously

Question 7

If you are examining a muscle fibre under a microscope and you notice that the cell has a striped appearance, what assumptions would you make?

Answer 7

• that the muscle fibre is striated,
• the muscle fibre is either from skeletal or cardiac muscle
• the muscle fibre is arranged in sarcomeres

Question 8

The bicep brachii and tricep brachii muscles are what type of muscle group?

Answer 8

antagonist muscle group

Question 9

What are two characteristics that explain cross bridges?

Answer 9

• When ATP attaches to myosin, the crossbridge detaches,

- When the power stroke occurs, actin slides towards the M-line

Question 10

When the sympathetic nervous system is activated …

Answer 10

• Heart rate speeds up
• Pupils dilate
• intestinal` motility is inhibited

Question 11

Tyler took some medication for their flu symptoms. Later, Tyler began to feel a little faint because the medication caused their heart to beat more slowly and their blood pressure to fall. What system was likely activated by the medication?

Answer 11

parasympathetic

Question 12

Z-Disk

Answer 12

Attachment site for thin filaments

Question 13

I-Band

Answer 13

Contains thin filaments only

Question 14

A-band

Answer 14

length of the thick filament

Question 15

H-zone

Answer 15

the central region between thick filaments

Question 16

M-Line

Answer 16

attachment site for thick filaments

Question 17

Compared to skeletal muscle, cardiac muscle cells are:

Answer 17

smaller

Question 18

Which neurotransmitter is used in the neuromuscular junction

Answer 18

Acetylcholine

Question 19

What is the organization of a muscle from largest to smallest?

Answer 19

Muscle, Fascicle, muscle fiber, myofibrils, myofilaments

Question 20

What are three classifications of smooth muscle?

Answer 20

• Location
• Contraction pattern
• communication