Skeletal and nervous tissue

Question 1

What are the characteristics of skeletal muscles?

Answer 1

They are striated, strong, quick, voluntary, multinucleated and large

Question 2

What is the arrangement of muscles? from smallest to largest grouping

Answer 2

sacromere–> myofibrils–> muscle fiber–> fascicle–> muscle

Question 3

What is a sacromere?

Answer 3

A contractile unit of muscle that is made of actin and myosin myofilaments

Question 4

What surrounds the muscle fibers?

Answer 4

endomysium

Question 5

What surrounds the fascicles?

Answer 5

perimysium

Question 6

What surrounds the muscle?

Answer 6

epimysium

Question 7

What composes the myosin component of a sacromere?

Answer 7

2heavy chains with globular heads- there are actin binding sites with ATPase domains
2 light chains

Question 8

What holds the myosin of a sacromere in place?

Answer 8

They are held by Titin proteins to the z-disk

Question 9

What composes the actin component of the sacromere?

Answer 9

f-actin monomers(globular) that bind together and form double stranded chains
nebulin will determine length of filament
tropomyosin strands wrap between actin strands and troponin sits on these strands to cover actin binding sites

Question 10

What are the 5 components of the sacromere?

Answer 10

The m-line, z-disk, H band, A band and I band

Question 11

What is the m-line?

Answer 11

found in the sacromere and is the attachment site for myosin

Question 12

What is the z-disk?

Answer 12

found in the sacromere- this is the site between sacromeres where actin and titin bind

Question 13

What is the H band?

Answer 13

Found in the sacromere- The space on either side of the m-line where there is no actin

Question 14

What is the A band?

Answer 14

Found in the sacromere- Distance from the end of one myosin head to the head of the opposite myosin

Question 15

What is the I band?

Answer 15

Found in the sacromere- Space on either side of the z-disk where there is no myosin

Question 16

What is the only band in the sacromere that will not change distance?

Answer 16

The A band since the actin is sliding along the myosin to create contraction

Question 17

How does muscle contraction work?

Answer 17

Myosin must bind to actin- Calcium is released from the SR and will bind to troponin to induce a confirmational change and allows actin to bind to myosin heads and slide past eachother

Question 18

What is the sarcolemma?

Answer 18

membrane around each muscle cell

Question 19

What is the transverse tubules?

Answer 19

membrane system penetrating the muscle cell to convey electrical impulses from sacrcolemma into the cell

Question 20

What is a multipolar neuron?

Answer 20

multiple dendrites and one axon

Question 21

What is a bipolar neuron?

Answer 21

single dendrite (multiple extensions) with one axon

Question 22

What is a pseudounipolar neuron?

Answer 22

One cell process with a single dendrite branch and one axon branch

Question 23

What is the arrangement of neurons?

Answer 23

Axon–> fascicle–>nerve

Question 24

What surrounds the axon?

Answer 24

endoneurium

Question 25

What surrounds the neuron fascicle?

Answer 25

perineurium

Question 26

What surrounds the nerve?

Answer 26

epineurium

Question 27

What is a schwann cell?

Answer 27

surounds axon and creates myelin sheath in the PNS - will wrap around one part of one axon

Question 28

What is an oligodendrocyte?

Answer 28

surrounds axon and creates myelin sheath in the CNS- will wrap around a part of many axons

Question 29

What is the myelin sheath?

Answer 29

circumferential layers of myelin allowing for faster signal conduction velocity

Question 30

What is the neuromuscular junction?

Answer 30

Skeletal muscles innervated by peripheral a-motor neurons from the anterior horn of spine