Brainscape's Knowledge GenomeTM

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


See full index

Bio168 > ch10 > Flashcards

ch10 Flashcards

muscle tissue

1
Q

Muscle Tissue is A primary tissue type divided into..?

A

Skeletal muscle
Smooth muscle
Cardiac muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • Are attached to the skeletal system

- Allow us to move

A

Skeletal Muscle

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

Includes only skeletal muscles

A

muscular system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  • Muscle tissue (muscle cells or fibers)
  • Connective tissues
  • Nerves
  • Blood vessels
A

Skeletal muscle structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. Produce skeletal movement
  2. Maintain body position
  3. Support soft tissues
  4. Guard body openings
  5. Maintain body temperature
A

Functions of skeletal muscles

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

Muscles have 3 layers of connective tissues …what are they?

A

o Epimysium
o Perimysium
o Endomysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  • Exterior collagen layer
  • Connected to deep fascia
  • Separates muscle from surrounding tissues
A

Epimysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  • Surrounds muscle fiber bundles (fascicles)

- Contains blood vessel and nerve supply to fascicles

A

Perimysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  • Surrounds individual muscle cells (muscle fibers)
  • Contains capillaries and nerve fibers containing muscle cells
  • Contains satellite cells (stem cells) that repair damage
A

Endomysium

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

o At ends of muscles
o To form connective tissue attachment to bone matrix
o i.e., tendon (bundle) or aponeurosis (sheet)

A

where/why endomysium, perimysium, and epimysium come together

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

Skeletal muscles are voluntary muscles, controlled by ____of the central nervous system

A

Nerves

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

(Blood vessels)

Muscles have extensive vascular systems that:

A

o Supply large amounts of oxygen
o Supply nutrients
o Carry away wastes

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

Skeletal muscle cells are called

A

fibers

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

 Are very long
 Develop through fusion of mesodermal cells (myoblasts)
 Become very large
 Contain hundreds of nuclei

A

Skeletal Muscle Fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  • The cell membrane of a muscle cell
  • Surrounds the sarcoplasm (cytoplasm of muscle fiber)
  • A change in transmembrane potential begins contractions
A

The Sarcolemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  • Transmit action potential though cell
  • Allow entire muscle fiber to contract simultaneously
  • Have same properties as sarcolemma
A

Transverse Tubules (T tubules)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
  • Lengthwise subdivisions within muscle fiber
  • Made up of bundles of protein filaments (myofilaments)
  • Myofilaments are responsible for muscle contraction
A

Myofibrils

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

2 Types of Myofilaments are?

A

thin filiments and thick filiments

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

Made of the protein actin

A

thin filiments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Made of the protein myosin

A

thick filiments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  • A membranous structure surrounding each myofibril
  • Helps transmit action potential to myofibril
  • Similar in structure to smooth endoplasmic reticulum
  • Forms chambers (terminal cisternae) attached to T tubules
A

Sarcoplasmic Reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Is formed by 1 T tubule and 2 terminal cisternae

A

A Triad

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  • Concentrate Ca2+ (via ion pumps)

- Release Ca2+ into sarcomeres to begin muscle contraction

A

Cisternae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  • The contractile units of muscle
  • Structural units of myofibrils
  • Form visible patterns within myofibrils
A

Sarcomeres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  • Are strands of protein
  • Reach from tips of thick filaments to the Z line
  • Stabilize the filaments
A

Titin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q
  • Transverse tubules encircle the sarcomere near zones of overlap
  • Ca2+ released by SR causes thin and thick filaments to interact
A

Sarcomere Function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q
  • Is caused by interactions of thick and thin filaments

- Structures of protein molecules determine interactions

A

Muscle Contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

a. Is 2 twisted rows of globular G actin

b. The active sites on G actin strands bind to myosin

A

F actin:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Holds F actin strands together

A

Nebulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

a. Is a double strand

b. Prevents actin-myosin interaction

A

Tropomyosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

a. A globular protein
b. Binds tropomyosin to G actin
c. Controlled by Ca2+

A

Troponin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q
  • Ca2+ binds to receptor on troponin molecules
  • Troponin-tropomyosin complex changes
  • Exposes active site of F actin
A

Initiating Contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q
  • Contain twisted myosin subunits

- Contain titin strands that recoil after stretching

A

Thick Filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The Myosin Molecule has

A

a tail and a head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

o Made of 2 globular protein subunits

o Reaches the nearest thin filament

A

the head (of the myosin molecule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

o Binds to other myosin molecules

A

the tail (of the myosin molecule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

(Myosin Action)

During Contraction, myosin heads:

A

o Interact with actin filaments, forming cross-bridges

o Pivot, producing motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

o Thin filaments of sarcomere slide toward M line
o Between thick filaments
o The width of A zone stays the same
o Z lines move closer together

A

Sliding filament theory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q
  • Is the location of neural stimulation
  • Action potential (electrical signal):
    o Travels along nerve axon
    o Ends at synaptic terminal
A

The Neuromuscular Junction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

o Releases neurotransmitter (acetylcholine or ACh)

o Into the synaptic cleft (gap between synaptic terminal and motor end plate)

A

(Skeletal Muscle Innervation)

Synaptic Terminal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

o Acetylcholine or Ach:

  • Travels across the synaptic cleft
  • Binds to membrane receptors on sarcolemma (motor end plate)
  • Causes sodium-ion rush into sarcoplasm
  • Is quickly broken down by enzyme (acetylcholinesterase or AChE)
A

The Neurotransmitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q
  • Generated by increase in sodium ions in sarcolemma
  • Travels along the T-tubules
  • Leads to excitation-contraction coupling
A

Action Potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q
  1. Exposure of active sites
  2. Formation of cross-bridges
  3. Pivoting of myosin heads
  4. Detachment of cross-bridges
  5. Reactivation of myosin
A

5 Steps of the Contraction Cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

As sarcomeres shorten, muscle pulls together, producing tension

A

Fiber Shortening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q
  • Depends on: duration of neural stimulus
  • Number of free calcium ions in sarcoplasm
  • Availability of ATP
A

Contraction Duration

46
Q
  • Ca2+ concentrations fall
  • Ca2+ detaches from troponin
  • Active sites are recovered by tropomyosin
  • Sarcomeres remain contracted until an outside force pulls muscle to original length
A

Relaxation

47
Q
  • A fixed muscular contraction after death
  • Caused when:
    o Ion pumps cease to function
    o Calcium builds up in the sarcoplasm
A

Rigor Mortis

48
Q
  • Skeletal muscle fibers shorten as thin filaments slide between thick filaments
  • Free Ca2+ in the sarcoplasm triggers contraction
  • SR releases Ca2+ when a motor neuron stimulates the muscle fiber
  • Contraction is an active process
  • Relaxation and return to resting length is passive
A

Key Concept

49
Q
  • Action potential reaches a triad
  • Releasing Ca2+
  • Triggering contraction
  • Requires myosin heads to be in “cocked” position
  • Loaded by ATP energy
A

Excitation–Contraction Coupling

50
Q

-As a whole, a muscle fiber is either contracted or relaxed
Depends on:
-The number of pivoting cross-bridges
-The fiber’s resting length at the time of stimulation
-The frequency of stimulation

A

Tension Production by Muscles Fibers

51
Q

Number of pivoting cross-bridges depends on:
Amount of overlap between thick and thin fibers
Optimum overlap produces greatest amount of tension

A

Length–Tension Relationships

52
Q

A single neural stimulation produces:

A

A single contraction or twitch

Which lasts about 7–100 msec.

53
Q

Require many repeated stimuli

A

Sustained muscular contractions

54
Q

There are 3 twitches:

A

Latent period
Contraction phase
Relaxation phase

55
Q
  • The action potential moves through sarcolemma

- Causing Ca2+ release

A

Latent period

56
Q
  • Calcium ions bind

- Tension builds to peak

A

Contraction phase

57
Q
  • Ca2+ levels fall

- Active sites are covered and tension falls to resting levels

A

Relaxation phase

58
Q

-A stair-step increase in twitch tension
-Repeated stimulations immediately after relaxation phase
Stimulus frequency <50/second
-Causes a series of contractions with increasing tension

A

Treppe

59
Q

-Increasing tension or summation of twitches
-Repeated stimulations before the end of relaxation phase
Stimulus frequency >50/second
-Causes increasing tension or summation of twitches

A

Wave summation

60
Q
  • Twitches reach maximum tension

- If rapid stimulation continues and muscle is not allowed to relax, twitches reach maximum level of tension

A

Incomplete tetanus

61
Q

If stimulation frequency is high enough, muscle never begins to relax, and is in continuous contraction

A

Complete tetanus

62
Q

Depends on:

  • Internal tension produced by muscle fibers
  • External tension exerted by muscle fibers on elastic extracellular fibers
  • Total number of muscle fibers stimulated
A

Tension Production by Skeletal Muscles

63
Q
  • Contain hundreds of muscle fibers
  • That contract at the same time
  • Controlled by a single motor neuron
A

Motor units in a skeletal muscle

64
Q

In a whole muscle or group of muscles, smooth motion and increasing tension are produced by slowly increasing the size or number of motor units stimulated

A

Recruitment (multiple motor unit summation)

65
Q
  • Achieved when all motor units reach tetanus

- Can be sustained only a very short time

A

Maximum tension

66
Q
  • Less than maximum tension

- Allows motor units rest in rotation

A

Sustained tension

67
Q
  • The normal tension and firmness of a muscle at rest
  • Muscle units actively maintain body position, without motion
  • Increasing muscle tone increases metabolic energy used, even at rest
A

Muscle tone

68
Q

Skeletal muscle develops tension, but is prevented from changing length
(same measure)

A

Isometric Contraction

69
Q

The active energy molecule

A

Adenosine triphosphate (ATP)

70
Q

The storage molecule for excess ATP energy in resting muscle

A

creatine phosphate (CP)

71
Q
  • Using the enzyme creatine kinase (CK)

- When CP is used up, other mechanisms generate ATP

A

Energy recharges ADP to ATP

72
Q
  • Is the primary energy source of resting muscles
  • Breaks down fatty acids
  • Produces 34 ATP molecules per glucose molecule
A

Aerobic Metabolism

73
Q
  • Is the primary energy source for peak muscular activity
  • Produces two ATP molecules per molecule of glucose
  • Breaks down glucose from glycogen stored in skeletal muscles
A

Glycolysis

74
Q

When muscles can no longer perform a required activity

A

Muscle Fatigue

75
Q
  • Depletion of metabolic reserves
  • Damage to sarcolemma and sarcoplasmic reticulum
  • Low pH (lactic acid)
  • Muscle exhaustion and pain
A

Results of Muscle Fatigue

76
Q
  • The time required after exertion for muscles to return to normal
  • Oxygen becomes available
  • Mitochondrial activity resumes
A

The Recovery Period

77
Q
  • The removal and recycling of lactic acid by the liver
  • Liver converts lactate to pyruvate
  • Glucose is released to recharge muscle glycogen reserves
A

The Cori Cycle

78
Q

After exercise or other exertion:

  • The body needs more oxygen than usual to normalize metabolic activities
  • Resulting in heavy breathing
  • Also called excess postexercise oxygen consumption (EPOC)
A

Oxygen Debt

79
Q
  • Active muscles produce heat

- Up to 70% of muscle energy can be lost as heat, raising body temperature

A

Heat Production and Loss

80
Q
  • Growth hormone
  • Testosterone
  • Thyroid hormones
  • Epinephrine
A

Hormones and Muscle Metabolism

81
Q

The maximum amount of tension produced

A

force

82
Q

The amount of time an activity can be sustained

A

Endurance

83
Q

Force and endurance depend on…

A
  • The types of muscle fibers

- Physical conditioning

84
Q
  1. Fast fibers
  2. Slow fibers
  3. Intermediate fibers
A

Three Major Types of Skeletal Muscle Fibers

85
Q

-Contract very quickly
-Have large diameter, large glycogen reserves, few mitochondria
-Have strong contractions, fatigue quickly
~ weight lifting/muscle building

A

Fast Fibers

86
Q

-Are slow to contract, slow to fatigue
-Have small diameter, more mitochondria
-Have high oxygen supply
-Contain myoglobin (red pigment, binds oxygen)
~ endurance/distance

A

Slow Fibers

87
Q
  • Are mid-sized
  • Have low myoglobin
  • Have more capillaries than fast fibers, slower to fatigue
A

Intermediate Fibers

88
Q
  • Mostly fast fibers

- Pale (e.g., chicken breast)

A

White muscles

89
Q
  • Mostly slow fibers

- Dark (e.g., chicken legs)

A

Red muscles

90
Q
  • Mixed fibers

- Pink

A

Most human muscles

91
Q
  • Muscle growth from heavy training
  • Increases diameter of muscle fibers
  • Increases number of myofibrils
  • Increases mitochondria, glycogen reserves
A

Muscle Hypertrophy

92
Q
  • Lack of muscle activity

- Reduces muscle size, tone, and power

A

Muscle Atrophy

93
Q

Improves both power and endurance

A

Physical Conditioning

94
Q

-Use fast fibers
-Fatigue quickly with strenuous activity
Improved by:
-Frequent, brief, intensive workouts
-Causes hypertrophy

A

Anaerobic activities (e.g., 50-meter dash, weightlifting)

95
Q

-Supported by mitochondria
-Require oxygen and nutrients
Improves:
-Endurance by training fast fibers to be more like intermediate fibers
-Cardiovascular performance

A

Aerobic activities (prolonged activity)

96
Q
  • Cardiac muscle cells are striated and found only in the heart
  • Striations are similar to that of skeletal muscle because the internal arrangement of myofilaments is similar
A

Cardiac Muscle Tissue

97
Q
  • 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

Unlike skeletal muscle, cardiac muscle cells (cardiocytes):

98
Q
  • Are specialized contact points between cardiocytes

- Join cell membranes of adjacent cardiocytes (gap junctions, desmosomes)

A

Intercalated Discs

99
Q

-Coordination of cardiocytes
Because intercalated discs link heart cells mechanically, chemically, and electrically, the heart functions like a single, fused mass of cells

A

Intercalated Discs

100
Q

Functions of :
Maintain structure
Enhance molecular and electrical connections
Conduct action potentials

A

Intercalated Discs

101
Q
  • Contraction without neural stimulation

- Controlled by pacemaker cells

A

Automaticity

102
Q

reproductive and glandular systems

A

Produces movements

103
Q
  • Forms sphincters

- Produces contractions

A

digestive and urinary systems

104
Q
  • Non striated tissue
  • Different internal organization of actin and myosin
  • Different functional characteristics
A

Structural Characteristics of Smooth Muscle Tissue

105
Q

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

A

Characteristics of Smooth Muscle Cells

106
Q
  • Excitation–contraction coupling
  • Length–tension relationships
  • Control of contractions
  • Smooth muscle tone
A

Functional Characteristics of Smooth Muscle Tissue

107
Q

-Free Ca2+ in cytoplasm triggers contraction
-Ca2+ binds with calmodulin
In the sarcoplasm
-Activates myosin light–chain kinase
-Enzyme breaks down ATP, initiates contraction

A

Excitation–Contraction Coupling

108
Q
  • Thick and thin filaments are scattered
  • Resting length not related to tension development
  • Functions over a wide range of lengths (plasticity)
A

Length–Tension Relationships

109
Q

Connected to motor neurons

A

Multiunit smooth muscle cells

110
Q
  • Not connected to motor neurons

- Rhythmic cycles of activity controlled by pacesetter cells

A

Visceral smooth muscle cells

111
Q
  • Maintains normal levels of activity

- Modified by neural, hormonal, or chemical factors

A

Smooth Muscle Tone

Bio168 (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions