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Flashcards in Chapter 10 Deck (66):
1

Type of muscle tissues

• Skeletal muscle tissue
• Cardiac muscle tissue
• Smooth muscle tissue

2

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

Skeletal Muscles

3

Six Functions of Skeletal Muscle Tissue

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

three layers of connective tissues of muscles

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

5

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

Skeletal Muscle Cells

6

The cell membrane of a muscle fiber (cell)

sarcolemma

7

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

Transverse tubules (T tubules)

8

Lengthwise subdivisions within muscle fiber

Myofibrils

9

Types of myofilaments

Thin and thick filaments

10

Filament made of the protein actin

Thin filaments

11

Filament made of the protein myosin

Thick filaments

12

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

Sarcoplasmic Reticulum (SR)

13

formed by one T tubule and two terminal
cisternae and is found in the SR

Triad

14

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

Cisternae

15

The basic contractile units of muscle

Sarcomeres

16

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

M line

17

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

H Band

18

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

Zone of overlap

19

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

Z lines

20

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

Titin

21

two twisted rows of globular G-actin

F-actin (filamentous actin)

22

The active sites on G-actin strands bind to?

myosin

23

Holds F-actin strands together

Nebulin

24

double strand that prevents actin–myosin interaction

Tropomyosin

25

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

Troponin

26

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

Thick Filaments

27

What does the myosin heads do during contraction?

• Interact with actin filaments, forming crossbridges
• Pivot, producing motion

28

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

Sliding filament theory

29

Special intercellular connection between the
nervous system and skeletal muscle fiber that controls calcium ion release into the sarcoplasm

neuromuscular junction (NMJ)

30

What happens during excitation-contraction coupling?

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

31

6 steps of the Contraction Cycle

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

32

What happens during muscle relaxation?

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

33

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

Rigor Mortis

34

A single contraction or twitch lasts about?

7–100 msec

35

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

Latent period

36

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

Contraction phase

37

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

Relaxation phase

38

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

Treppe

39

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

Wave summation

40

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

Incomplete tetanus

41

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

Complete tetanus

42

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

Motor units in a skeletal muscle

43

2 Patterns of tension production

• Isotonic contraction
• Isometric contraction

44

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

Isotonic Contraction

45

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

concentric contraction

46

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

eccentric contraction

47

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

Isometric Contraction

48

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

Aerobic Metabolism

49

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

Glycolysis

50

Results of muscle Fatigue

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

51

Term used when muscles can no longer perform a required activity

fatigued

52

The time required after exertion for muscles to
return to normal

Recovery Period

53

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

Cori Cycle

54

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

Oxygen Debt/excess postexercise oxygen
consumption (EPOC)

55

Three Major Types of Skeletal Muscle Fibers

1. Fast fibers
2. Slow fibers
3. Intermediate fibers

56

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

Fast Fibers

57

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)

Slow Fibers

58

Fibers that are mid-sized, have low myoglobin
and more capillaries than fast fibers, and are slower to fatigue

Intermediate Fibers

59

Muscle growth from heavy training

Muscle Hypertrophy

60

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

Muscle Atrophy

61

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

cardiac muscle cells
(cardiocytes)

62

Are specialized contact points between
cardiocytes

Intercalated Discs

63

Functions of intercalated discs

• Maintain structure
• Enhance molecular and electrical connections
• Conduct action potentials

64

Contraction without neural stimulation that are controlled by pacemaker cells

Automaticity

65

Characteristics of Smooth Muscle Cells

• 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

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

calmodulin