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Flashcards in Chapter 10 Deck (66)
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1
Q

Type of muscle tissues

A
  • Skeletal muscle tissue
  • Cardiac muscle tissue
  • Smooth muscle tissue
2
Q

Type of muscle that are attached to the skeletal system and allow us to move; they are voluntary muscles,
controlled by nerves of the central nervous system

A

Skeletal Muscles

3
Q

Six Functions of Skeletal Muscle Tissue

A
  1. Produce skeletal movement
  2. Maintain posture and body position
  3. Support soft tissues
  4. Guard entrances and exits
  5. Maintain body temperature
  6. Store nutrient reserves
4
Q

three layers of connective tissues of muscles

A
  1. Epimysium (Exterior collagen tissue)
  2. Perimysium (Surrounds muscle fiber bundle)
  3. Endomysium (Surrounds muscle cells
5
Q

cells that are very long and develop through fusion of mesodermal cells
(myoblasts)

A

Skeletal Muscle Cells

6
Q

The cell membrane of a muscle fiber (cell)

A

sarcolemma

7
Q

Structure that Transmit action potential through cell and allow entire muscle fiber to contract simultaneously

A

Transverse tubules (T tubules)

8
Q

Lengthwise subdivisions within muscle fiber

A

Myofibrils

9
Q

Types of myofilaments

A

Thin and thick filaments

10
Q

Filament made of the protein actin

A

Thin filaments

11
Q

Filament made of the protein myosin

A

Thick filaments

12
Q

A membranous structure surrounding each myofibril that helps transmit action potential to myofibril

A

Sarcoplasmic Reticulum (SR)

13
Q

formed by one T tubule and two terminal

cisternae and is found in the SR

A

Triad

14
Q

Chambers found in SR that concentrate Ca2+ (via ion pumps) and release Ca2+ into sarcomeres to begin muscle
contraction

A

Cisternae

15
Q

The basic contractile units of muscle

A

Sarcomeres

16
Q

The center of the A band and is at midline of sarcomere

A

M line

17
Q

The area around the M line that has thick filaments but no thin filaments

A

H Band

18
Q

The densest, darkest area on a light micrograph where thick and thin filaments overlap

A

Zone of overlap

19
Q

The centers of the I bands found at two ends of sarcomere

A

Z lines

20
Q

strands of protein that reach from tips of thick filaments to the Z line and functions to stabilize the filaments

A

Titin

21
Q

two twisted rows of globular G-actin

A

F-actin (filamentous actin)

22
Q

The active sites on G-actin strands bind to?

A

myosin

23
Q

Holds F-actin strands together

A

Nebulin

24
Q

double strand that prevents actin–myosin interaction

A

Tropomyosin

25
Q

globular protein that binds tropomyosin to G-actin and is controlled by Ca2+

A

Troponin

26
Q

Filaments that Contain about 300 twisted myosin subunits and titin strands that recoil after stretching

A

Thick Filaments

27
Q

What does the myosin heads do during contraction?

A
  • Interact with actin filaments, forming crossbridges

* Pivot, producing motion

28
Q

Theory stating that thin filaments of sarcomere slide toward M line,
alongside thick filaments; The width of A zone stays the same and Z lines move closer together

A

Sliding filament theory

29
Q

Special intercellular connection between the

nervous system and skeletal muscle fiber that controls calcium ion release into the sarcoplasm

A

neuromuscular junction (NMJ)

30
Q

What happens during excitation-contraction coupling?

A
  • Action potential reaches a triad
  • Releasing Ca2+
  • Triggering contraction
  • Requires myosin heads to be in “cocked” position
  • Loaded by ATP energy
31
Q

6 steps of the Contraction Cycle

A
  1. Contraction Cycle Begins
  2. Active-Site Exposure
  3. Cross-Bridge Formation
  4. Myosin Head Pivoting
  5. Cross-Bridge Detachment
  6. Myosin Reactivation
32
Q

What happens during muscle relaxation?

A
  • Ca2+ concentrations fall
  • Ca2+ detaches from troponin
  • Active sites are re-covered by tropomyosin
33
Q

A fixed muscular contraction after death caused when:
• Ion pumps cease to function; ran out of ATP
• Calcium builds up in the sarcoplasm

A

Rigor Mortis

34
Q

A single contraction or twitch lasts about?

A

7–100 msec

35
Q

Period during twitches where the action potential moves through sarcolemma ,causing Ca2+ release

A

Latent period

36
Q

Phase during twitches where calcium ions bind and tension builds to peak

A

Contraction phase

37
Q

Phase during twitches where Ca2+ levels fall, active sites are covered and tension falls to
resting levels

A

Relaxation phase

38
Q

A stair-step increase in twitch tension in which repeated stimulations occur immediately after relaxation
phase; it causes a series of contractions with increasing
tension

A

Treppe

39
Q

Increasing tension or summation of twitches in which repeated stimulations occur before the end of relaxation
phase; it causes increasing tension or summation of
twitches

A

Wave summation

40
Q

Condition where twitches reach maximum tensios and if rapid stimulation continues and muscle is not
allowed to relax, twitches reach maximum level of
tension

A

Incomplete tetanus

41
Q

Condition that occurs when stimulation frequency is high enough, causing muscle
never begins to relax, and is in continuous
contraction

A

Complete tetanus

42
Q

Contain hundreds of muscle fibers that contract at the same time and are controlled by a single motor neuron

A

Motor units in a skeletal muscle

43
Q

2 Patterns of tension production

A
  • Isotonic contraction

* Isometric contraction

44
Q

Type of contraction where skeletal muscle changes length resulting in motion;

A

Isotonic Contraction

45
Q

type of contraction where muscle shortens if muscle tension > load (resistance)

A

concentric contraction

46
Q

type of contraction where muscle lengthens if muscle tension < load (resistance)

A

eccentric contraction

47
Q

type of contraction where skeletal muscle develops tension, but is
prevented from changing length

A

Isometric Contraction

48
Q

Is the primary energy source of resting muscles:
• Breaks down fatty acids
• Produces 34 ATP molecules per glucose molecule

A

Aerobic Metabolism

49
Q

Is the primary energy source for peak muscular activity; it produces two ATP molecules per molecule of glucose and breaks down glucose from glycogen stored in skeletal
muscles

A

Glycolysis

50
Q

Results of muscle Fatigue

A
• Depletion of metabolic reserves
• Damage to sarcolemma and sarcoplasmic
reticulum
• Low pH (lactic acid)
• Muscle exhaustion and pain
51
Q

Term used when muscles can no longer perform a required activity

A

fatigued

52
Q

The time required after exertion for muscles to

return to normal

A

Recovery Period

53
Q

The removal and recycling of lactic acid by the liver where the liver converts lactate to pyruvate and glucose is released to recharge muscle glycogen
reserves

A

Cori Cycle

54
Q

Occurs after exercise or other exertion which results to the body needing more oxygen than usual to normalize metabolic activities, which then causes heavy breathing

A

Oxygen Debt/excess postexercise oxygen

consumption (EPOC)

55
Q

Three Major Types of Skeletal Muscle Fibers

A
  1. Fast fibers
  2. Slow fibers
  3. Intermediate fibers
56
Q

Fibers that contract very quickly and have large diameter, large glycogen reserves, and few mitochondria; they have strong contractions, but fatigue quickly

A

Fast Fibers

57
Q

Fibers that slow to contract, slow to fatigue have small diameter, more mitochondria and have high oxygen supply due to myoglobin (red pigment, binds oxygen)

A

Slow Fibers

58
Q

Fibers that are mid-sized, have low myoglobin

and more capillaries than fast fibers, and are slower to fatigue

A

Intermediate Fibers

59
Q

Muscle growth from heavy training

A

Muscle Hypertrophy

60
Q

Term used for lack of muscle activity leading to reduces muscle size, tone, and power

A

Muscle Atrophy

61
Q
cells that 
• Are small
• Have a single nucleus
• Have short, wide T tubules
• Have no triads
• Have SR with no terminal cisternae
• Are aerobic (high in myoglobin, mitochondria)
• Have intercalated discs
A

cardiac muscle cells

cardiocytes

62
Q

Are specialized contact points between

cardiocytes

A

Intercalated Discs

63
Q

Functions of intercalated discs

A
  • Maintain structure
  • Enhance molecular and electrical connections
  • Conduct action potentials
64
Q

Contraction without neural stimulation that are controlled by pacemaker cells

A

Automaticity

65
Q

Characteristics of Smooth Muscle Cells

A

• Long, slender, and spindle shaped
• Have a single, central nucleus
• Have no T tubules, myofibrils, or sarcomeres
• Have no tendons or aponeuroses
• Have scattered myosin fibers
• Myosin fibers have more heads per thick filament
• Have thin filaments attached to dense bodies
• Dense bodies transmit contractions from cell to
cell

66
Q

Where Ca2+ binds with in the smooth muscle tissue, which results to activation of myosin light–chain kinase

A

calmodulin