Muscular system intro lecture 70

Question 1

Do skeletal muscle cells exhibit individual neuromuscular junctions?

Answer 1

yes, at A-I junctions

Question 2

Does smooth muscle exhibit individual neuromuscular junctions?

Answer 2

yes, but only in multi-unit junctions

Question 3

How many functions does skeletal muscle have? What are they?

Answer 3

movement, posture, joint stabilization and heat generation

Question 4

Each skeletal muscle contains what kind of tissue?

Answer 4

connective

Question 5

The outer skeletal muscle tissue sheath is the

Answer 5

epimysium

Question 6

The middle skeletal muscle tissue sheath is the

Answer 6

perimysium (surround fascicles of individual fibers)

Question 7

Which muscles show striations?

Answer 7

skeletal - cardiac has some

Question 8

T or F: cardiac muscle is self-excitatory

Answer 8

true

Question 9

Which muscle tissue contracts in all directions?

Answer 9

smooth

Question 10

All three muscle types work by interaction of

Answer 10

myofilaments composed of actin and myosin

Question 11

The endomysium is surrounded by what kind of tissue?

Answer 11

connective composed of reticular fibers

Question 12

If only course control is required,

Answer 12

one motor neuron may innervate many fibers (large ratio)

Question 13

If fine control is required,

Answer 13

there are more motor neurons to fiber innervation

Question 14

What are biarticular muscles?

Answer 14

skeletal muscles that span 2 or more joints

Question 15

Which type of fibers do not exist in humans?

Answer 15

slow oxidative

Question 16

What are the three types of skeletal muscle fibers?

Answer 16

slow and fast oxidative and fast glycolytic

Question 17

Calf muscles use what kind of skeletal muscle fibers and when?

Answer 17

glycolytic for short sprints, oxidative for long distance, slow oxidative to maintain standing position

Question 18

Cardiac muscle arranged in bundles forms the

Answer 18

myocardium

Question 19

Cardiac muscle cells are branched and join together at

Answer 19

intercalated discs

Question 20

Are cardiac muscle cells innervated?

Answer 20

no, individual cells contract simultaneously (self excitatory)

Question 21

Which layer is found in cardiac muscle?

Answer 21

the endomysium

Question 22

What is the key mediator of smooth muscle cells?

Answer 22

calcium (mechanism not understood)

Question 23

How many nuclei are contained in smooth muscle cells?

Answer 23

only one; and smooth muscle is composed of separate cells

Question 24

How many nuclei are contained in cardiac muscle?

Answer 24

1 to 2, and cardiac muscle is composed of single cells

Question 25

Is smooth muscle low or high energy?

Answer 25

low energy, therefore few mitochondria (think - you don’t get tired from digestion - you don’t even think about it!)

Question 26

Lastly - study table

Answer 26

do it!