Brainscape's Knowledge GenomeTM

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


See full index

Cells to systems > Lecture 18 > Flashcards

Lecture 18 Flashcards

1
Q

Where is acetylcholine released in the neuromuscular junction

A

motor end plate

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

What is another name for neuromuscular junction

A

• Also known as NMJ or

myoneural junction

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

where is the NMJ located

A

Site where an axon and

muscle fiber meet

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

What are the parts at NMJ

A
  • Motor neuron
  • Motor end plate
  • Synapse
  • Synaptic cleft
  • Synaptic vesicles
  • Neurotransmitters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the use of motor unit

A 
• All muscle fibers controlled
by motor neuron
•As few as four fibers
• As many as 1000’s of
muscle fibers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How is the muscle stimulated to contract

A 
• Acetylcholine (ACh)
• Nerve impulse causes release of
ACh from synaptic vesicles
• ACh binds to ACh receptors on
motor end plate
• Generates a muscle impulse
• Muscle impulse eventually
reaches the SR and the cisternae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the muscle coverings

A
  • Muscle coverings:
  • Epimysium
  • Perimysium
  • Endomysium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Names of the muscles from the most surface layer to the smallest part of the muscle

A

Muscle > Fascicles > muscle fibers (cells) > myofibrills > thick and thin filaments

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

What are the thick and thin myofilaments made of

A
  • Actin and myosin proteins

* Titin is an elastic myofilament

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

What is the triad in muscle fibers

A

Triad
• Cisternae of SR
• T tubule

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

What is sarcomere

A 
the combination of myofilaments 
• I band (thin)
• A band (thick and
thin)
• H zone (thick)
• Z line (or disc)
• M line
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is wrapping around the actin molecule like a DNA

A

tropomyosin

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

What is the bulb attached to the tropomyosin

A

troponin

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

What is the protruding part of the myosin

A

cross-bridges

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

What is the cross–bridges made of

A

the head of the myosin molecule with actin-binding site and myosin ATPase site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is connecting the myosin head to the tail

A

hindges

17
Q

What does troponin have

A

Ca2+ binding site

18
Q

How does muscle impulses have an impact on calcium ions

A

• Muscle impulses cause SR to
release calcium ions into cytosol
• Calcium binds to troponin to
change its shape

19
Q

What happens when calcium binds to tropinin

A 
• Calcium binds to troponin to
change its shape
• The position of tropomyosin is
altered
• Binding sites on actin are now
exposed
• Actin and myosin molecules bind
via myosin cross-bridges
20
Q

how does muscle contract

A

Exposed binding sites on actin molecules allow the muscle contraction cycle to occur.
2. cross bridges bind actin to myosin
3. cross-bridges pull thin filament (power stroke), ADP and P released from myosin
4. New ATP binds to myosin, releasing linkages
5 ATP splits, which provides power to cock the myosin cross-bridge

21
Q

Where does the Ca2+ comes from

A

sacroplasmic reticulum, a lateral sac

22
Q

What can Ca2+ do

A

Ca2+ binding to troponin removes blocking action of tropomyosin

23
Q

What are the Cross Bridge Cycling steps

A 
• Myosin cross-bridge attaches
to actin binding site
• Myosin cross-bridge pulls
thin filament
• ADP and phosphate
released from myosin
• New ATP binds to
myosin
• Linkage between actin
and myosin cross-bridge
break
• ATP splits
• Myosin cross-bridge goes back
to original position
24
Q

What happens during relaxation of the muscle

A

• Acetylcholinesterase – rapidly decomposes Ach remaining in
the synapse
• Muscle impulse stops
• Stimulus to sarcolemma and muscle fiber membrane ceases
• Calcium moves back into sarcoplasmic reticulum (SR)
• Myosin and actin binding prevented
• Muscle fiber relaxes

25
Q

How can muscle contraction be observed

A

Muscle contraction can be observed by removing a
single skeletal muscle fiber and connecting it to a device
that senses and records changes in the overall length of
the muscle fiber.

26
Q

What is the use of acetylcholinesterase

A

to break down acetylcholine to acetic acid and choline. To help to terminate the ligand binding channels. so muscle will be able to relax

27
Q

What is the epimysium for

A

wrap around all of the muscle together

28
Q

What is perimysium

A

wraps around the bundle fasicles

29
Q

What is the endomysium for

A

placed inbetween all the muscle fibers and wraps individual muscle fiber

30
Q

Sarcolemma

A

muscle membrane

31
Q

What is the energy stored in the myosin from the ATP

A

the myosin head

32
Q

what is the three role of calcium in muscle contraction

A
  • used in the neuron presynapse to release vesicles of acetylcholine
  • used in unblocking myosin binding site in actin for contraction by attaching to troponin
  • used in muscle relaxation by removing from actin back to sarcolemma
33
Q

What are the 3 things that ATP is used in muscle contraction

A
  • movement of the myosin for contraction
  • attaching to the myosin head which then relax the muscle, breaking the bond of ATP to ADP
  • using to move the calcium back into SR, using calcium ATPase pump
34
Q

When Recording a Muscle Contraction what is a twitch

A
  • Latent period
  • Period of contraction
  • Period of relaxation

Cells to systems (25 decks)

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