Brainscape's Knowledge GenomeTM

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


See full index

BIO 122 > Muscles > Flashcards

Muscles Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Three types of muscles

A

Smooth
Skeletal
Cardiac

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

Striated Voluntary Muscle type

A

Skeletal Muscle

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

Striated involuntary muscle type

A

Cardiac Muscle

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

Unstriated involuntary muscle type

A

Smooth muscle

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

Connective tissue anchoring muscle at each end

A

Tendon

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

Each muscle consists of?

A

Muscle fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Each muscle fiber is composed of?

A

Myofibrils

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

Myofibrils consist of?

A

Myofilaments:
Thin (Actin) and Thick (Myosin)

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

What is the functional unit of a striated muscle?

A

Sarcomere

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

Boundaries of a sarcomere.

A

Z-Line

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

Term for the dark bands

A

A-bands

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

Term for the light bands that have the z-line in the middle. This is also considered the distance between thick filaments

A

I-band

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

Line visible in the middle of the a-band

A

M-line

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

Area that contains the M-line

A

H-Zone

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

Densest portion of the sarcomere

A

A-Band

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

Lighter portion of the a band

A

H-zone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Portion between a-bands

A

I-Band

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Middle of H-Zone

A

M-line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Projection outward of thick filament (myosin) that makes contact with the actin during contraction

A

Cross Bridges

20
Q

In a myofibril, each thin filament is surrounded by how many thick filaments?

A

3

21
Q

Two sites on the globular heads of myosin molecules that form the cross bridges

A

Actin-Binding site and Myosin ATPase site

22
Q

Main structural components of skeletal thin filaments

A

Actin molecules, Troponin (Globular) and Tropomyosin (thread-like)

23
Q

What is the function and mechanism of tropomyosin and troponin

A

Actin molecules have binding sites for myosin crossbridge. Troponin attached to tropomyosin wrap around the actin molecules to cover these binding sites.

24
Q

How does cross-bridge interaction between actin and myosin bring about muscle contraction? What is this called?

A

During contraction of striated muscle, thin filaments on each side of a sarcomere slide inward toward the A band’s center.
They pull closer together the Z discs to which they are attached, so the sarcomere shortens and the entire fiber becomes shorter.

Sliding Filament Theory

25
Q

What is the role of Calcium 2+ Ion in cross bridge activity

A

Calcium binds to troponin causing troponin to slide the tropomyosin away allowing for binding of actin and myosin at the now unblocked cross-bridge binding sites.

26
Q

This is triggered by the binding of actin and myosin

A

Power stroke

27
Q

T/F A-band gets shorter during muscle contraction

A

False, I-band and H-zone become shorter

28
Q

During muscle contraction, what happens to A band? Shorten,
lengthen?

A

It stays the same

29
Q

Bending of the crossbridge upon contact with actin

A

Power stroke

30
Q

This is needed to achieve desired extent of muscle shortening

A

Repeated power stroke

31
Q

4 steps of the crossbridge cycle

A

Binding
Power Stroke
Detachment
Repeat

32
Q

T/F All cross-bridge strokes are directed toward the center of the thin filament

A

F. All towards thick filament

33
Q

T/F Cross bridges are asynchronously cycling leading to some holding on while others are letting go causing the “ladder-like” climb

A

True

34
Q

extensions of the surface membrane that dip deep into the muscle fiber at the junctions between the A and I bands

A

Transverse (T) Tubules

35
Q

runs longitudinally and surrounds each myofibril, with separate segments encircling each A band and I band

A

Sarcoplasmic Reticulum

36
Q

saclike regions at the end of each sarcoplasmic reticulum segment

A

Lateral Sacs (Terminal Cisternae)

37
Q

T tubule membrane allows spread of _______ from surface membrane transmitting surface electric activity

A

Action Potential

38
Q

Action potential triggers what?

A

Release of Ca2+ from the lateral sacs

39
Q

What are the effects of Ca2+ movement to the musccle?

A

Release: Contraction
Re-uptake: Relaxation

40
Q

Type of voltage-gated calcium channel, meaning they open in response to changes in membrane potential.

These channels allow the influx of calcium ions (Ca2+) into cells

Long-lasting currents

A

L-type calcium channels or Ryanodine receptors

41
Q

Steps in excitation-contraction coupling and muscle relaxation (8)

A
  1. Action potential triggers acetylcholine release and muscle fiber action potential.
  2. T tubule action potential releases Ca2+ from sarcoplasmic reticulum.
  3. Ca2+ binds to troponin on thin filaments.
  4. Ca2+ on troponin alters tropomyosin shape, exposing actin binding sites.
  5. Myosin cross bridges attach to exposed actin binding sites.
  6. Cross bridge binding initiates power stroke, pulling thin filament.
  7. After power stroke, cross bridge detaches from actin.
  8. Action potential cessation leads to Ca2+ uptake, tropomyosin blocks actin binding sites.
42
Q

Tension in cardiac muscle depends on?

A

The amount of calcium ions in the myoplasm

43
Q

What is the difference in appearance of smooth muscle and skeletal muscle

A

Smooth muscle cells are nucleated

44
Q

T/F Contraction and relaxation occurs slowly in smooth muscle compared to skeletal muscle leading to more contractions

A

True

45
Q

T/F Calcium Binds to Troponin in smooth muscle cells to cause the myosin cross bridge

A

False, Calcium binds to calmodulin due to absence of troponin

46
Q

What are the steps in the calcium activation in smooth muscle cells

A

Ca2+ binds with calmodulin -> activates
Myosin Light Chain Kinase -> myosin light chain phosphorylation -> Phosphorylated myosin cross bridge can bind with actin

47
Q

Read the summary on the final 3 pages of the Muscle and movement pdf

A

Gl

BIO 122 (3 decks)

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