Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

045. MSK Test 2 > Skeletal Muscle and Nerve Tissue Histology > Flashcards

Skeletal Muscle and Nerve Tissue Histology Flashcards

1
Q

What is the main function of skeletal muscle?

A

generate force for movement by turning ATP into mechanical energy, voluntary movements and postural stability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the key characteristics of skeletal muscle?

A

The muscle is striated and multinucleated, located in the periphery (not center)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a sacromere?

A

a contractile unit of muscle made of actin and myosin myofilaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do chains of sacromeres link together form? and what do those form?

A

Sacromere chains linked together form myofibrils, which form the myofiber (which is the muscle cell)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What fascial covering surrounds myofibrils?

What fascial covering surrounds a group of myofibers (fascicle)?

What fascial covering surrounds a group of fascicles (muscle)?

A

Endomysium

Perimysium

Epimysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List from one to four, the formation of muscle

A
  1. Groups of sacromeres form myofibrils
  2. Groups of myofibrils form muscle fiber (myofiber)
  3. Groups of myofiber form the fascicle
  4. Groups of fascicles form the Muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Myosin are thick filaments, what makes up myosin and what holds it in place?

A

They have 2 heavy chains with globular heads, which bind to actin with ATPase domains
2 light chains
Myosin is held in place by Titin proteins connected to Z-disk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Actin or thin filaments are made of filamentous actin (f-actin) monomers, which bind to form double stranded chains. The length of the actin filament are determined by nebulin. Where are tropomyosin and troponin located in the Actin?

A

Tropomyosin strands wrap between the actin strands and troponin sits on tropomyosin strands and covers myosin bindin sites on actin filament so the myosin does not randomly contract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the M-line of the sarcomere (myosin and actin together)?

A

attachment site for myosin (in the middle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are z-disk in sarcomeres?

A

they separate sarcomeres, and is the site of attachment for actin and titin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the H-band in sarcomeres?

A

space on either side of M-line where there is no actin (Hband/zone will shorter with contraction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the A-band in sarcomeres?

A

distance from the end of one myosin head to the head of the opposite myosin, where actin and myosin overlap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the I-band in sarcomeres?

A

space on either side of the Z-disk where there is no myosin, (I-band will shorten with contraction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

For contraction to occur, myosin must bind to actin, however, troponin blocks the myosin binding sites on the actin filaments, how contraction activated?

A

Calcium is released from the sarcoplasmic reticulum and binds to troponin

This causes a conformational change which pulls tropomyosin away, exposing the myosin binding sites so myosin and actin can bind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

For sliding filament mechanism of muscle contraction, what are key things to remember? (4)

A
  1. thin filaments slide past thick filaments
  2. Z-disks are closer together, H and I bands are smaller
  3. All myofibrils contract at the same time
  4. **Actin and myosin do not change in length, they just overlap
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are typical of type I skeletal muscle fibers?

A

Slow, less powerful contraction

Many mitochondria

Slow fatigability

17
Q

What are typical of type IIA skeletal muscle fibers?

A

Intermediate, powerful contraction

Some mitochondria

Intermediate fatigability

18
Q

What are typical of type IIB skeletal muscle fibers?

A

Fast, powerful contraction

Few mitocondria

Rapid fatigability (anaerobic respiration)

19
Q

What is a sarcolemma?

A

membrane around each muscle cell

20
Q

What do transverse (T) tubules do?

A

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

21
Q

What are the sarcoplasm and sarcoplasm reticulum (SR)?

A

Sarcoplasm is cyotplasm of muscle cell

SR: tubular system acting like smooth ER, which are the terminal cisternae (flattened sac of SR on either side of T tubule) releases Ca to get contraction

22
Q

What is a triad for electrical impulse transmission?

A

the T tubule and 2 terminal cisternae

23
Q

What are the End feet?

A

connect T tubles with SR to allow Calcium release

24
Q

How is skeletal muscle innervation and how many nerves per muscle fiber?

A

they are innervated by peripheral alpha motor neurons from the anterior horn

1 nerve per muscle fiber, >1 muscle fiber per nerve

25
Q

How do the nerve axons transmit the signal to the muscle?

A

Release acetocholine into the synaptic cleft, causes end feet to release Ca+ and causing the contraction

26
Q

What soes the neruromuscular spindle apparatus do?

A

it has a relfexive response to prevent over stretching of a muscle

27
Q

What do extrafusal and intrfusal muscle fibers do in neuromuscular spindle apparatus?

A

Extrafusal contract the muscle

Intrafusal (deep) sense length and rate of chang of the muscle, cause the response

28
Q

What do type Ia sensory nerve fibers do?

A

they are the afferent innervation of intrafusal fibers that send signals to the spinal cord

29
Q

what do alpha motor and gamma motor nerve fibers do?

A

they are the efferent innervation of extrafusal (alpha) and intrafusal (gamma) muscle fibers

30
Q

How do the type Ia fibers and alpha and gamma fibers talk to eachother?

A

Afferent Ia fibers sense stretch in intrafusal fibers and send signal to A and G efferent fibers, causing extra/intrafusal fibers to contract and shorten, relieving the stretch

31
Q

What makes up a neuron and what do they do?

A

Soma/body: contains organelles of neurons

Dendrite: receives signals from other neurons

Axon Hillock: connection between some and axon, summates all signals to make action potention

Axon: conveys electrical impulse to synapse

Synapse: transfers impulse from neuron to target tissue

32
Q

What makes up a nerve?

A

Axons-> groups of axons = Fasicle -> Nerve =groups of fascicles

33
Q

What fascia covers each axon, each fascicle and each nerve?

A

axon: endoneurium
fascicle: perineurium
Nerve: epineurium

34
Q

What are multipolar neurons?

A

multiple dendrites and one axon

35
Q

What are bipolar neurons?

A

one single dendrite with multiple extensions and one axon with the cell body in the middle

36
Q

What are pseudounipolar neurons?

A

one cell process with a single dendrite branch (receives signal) and axon branch (sends signal to muscle), with the cell body connected by a short single process

37
Q

What is a schwann cell (in PNS)?

A

surround axon and create myelin sheath in PNS, wrap around one part of one axon

38
Q

What is an oligodendrocyte?

A

surround axon and create myelin sheath in CNS, wrap around a part of many axons

39
Q

What is a myelin sheath?

A

circumferential layers of myelin allowing for faster signal conduction velocity

045. MSK Test 2 (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions