Chapter 10

Question 0

1. Movement
2. Maintain posture
3. Support soft tissue
4. Guard entrances and exits
5. Maintain body temperature
6. Store nutrient reserves

Answer 0

6 functions of skeletal muscle

Question 1

Skeletal
Cardiac
Smooth

Answer 1

3 tissue types

Question 2

Epimysium
Perimysium
Endomysium

Answer 2

3 muscle layers

Question 3

Exterior collagen fibers
Connected to deep fascia
Separates muscle from surrounding tissues

Answer 3

Epimysium

Question 4

Surrounds muscle fiber bundles (fascicles)

Contains blood vessel and nerve supply to fascicles

Answer 4

Perimysium

Question 5

Surrounds individual muscle cells
Contains capillaries and nerve fibers
Contacting muscle cells
Contains myosatelite cells (stem cells)

Answer 5

Endomysium

Question 6

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

Answer 6

Skeletal muscle cells

Question 7

The cell membrane of muscle fibers
Surrounds the sarcoplasm
A change in transmembrane potential begins contractions( causes contractions)

Answer 7

The sarcolemma

Question 8

Transmit action potential through cell
Allow entire muscle fiber to contract simultaneously
Have same properties as sarcolemma

Answer 8

The transverse tubules

Question 9

Lengthwise subdivisions within muscle fibers.
Made up of bundles of protein filaments.
Myofilaments are responsible for muscle contractions.

Answer 9

Myofibrils

Question 10

Thin filaments (made of actin)
Thick filaments (made of myosin)

Answer 10

Type of myofilaments

Question 11

A membranous structure surrounding each myofibril.
Helps transmit action potential to myofibril.
Similar structure to smooth endoplasmic reticulum.
Forma chambers (terminal cisternae)
Attached to t tubules

Answer 11

Sarcoplasmic reticulum

Question 12

Concentrate Ca2

Release Ca2 into sarcomeres to begin muscle contraction

Answer 12

Cisternae

Question 13

The contractile units of muscle
Structural units of myofibrils
Form visible patterns within myofibrils
A striped or striated pattern within myofibrils

Answer 13

Sarcomeres

Question 14

Strands of protein
Reach from tips of thick filaments to the z line
Stabilize the filaments

Answer 14

Titin

Question 15

Two twisted rows of globular g actin

The active sites of g actin strands bind to myosin

Answer 15

F actin

Question 16

Calcium binds to receptor on troponin molecule.
Troponin-tropomyosin complex changes.
Exposes active site of f actin.

Answer 16

Initiating contraction

Question 17

Thin filaments of sarcomere slide toward m line, alongside thick filaments.
The width of a zone stays the same.
Z lines move closer together.

Answer 17

Sliding filament theory

Question 18

Special intercellular connection between the nervous system and skeletal muscle fibers.
Controls calcium ion release into the sarcoplasm

Answer 18

Neuromuscular junction

Question 19

A fixed muscular contraction after death.

Answer 19

Rigor Mortis

Question 20

The action potential moves through sarcolemma

Causing calcium release

Answer 20

Latent period

Question 21

Calcium ions bond

Tension builds to peak

Answer 21

Contraction phase

Question 22

Calcium levels fall

Active sites are covered and tension falls to resting levels

Answer 22

Relaxation phase

Question 23

A stair step increase in twitch tension
Repeated stimulations immediately after relaxation phase
Stimulates frequency <50 seconds

Answer 23

Treppe

Question 24

Increasing tension or summation of twitches Repeated stimulations before the end of relaxation phase Stimulus frequency >50 seconds

Answer 24

Wave summation

Question 25

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

Answer 25

Incomplete tetanus

Question 26

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

Answer 26

Complete tetanus

Question 27

The normal tension and firmness of a muscle at rest | Muscle units actively maintain body position, without motion

Answer 27

Muscle tone

Question 28

If muscle tension > load, the muscle shortens (concentric) | If muscle tension < load, the muscle lengthens (eccentric)

Answer 28

Isotonic contraction

Question 29

Skeletal muscle develops tension, but is prevented from changing length Iso= same metric= measure

Answer 29

Isometric contraction

Question 30

The pull of elastic elements (tendons and ligaments) | Expands the sarcomeres to resting length

Answer 30

Elastic forces

Question 31

Reverse the direction of the original motion | Are the work of opposing skeletal muscle pairs

Answer 31

Opposing muscle contractions

Question 32

Can take the place of opposing muscle contraction to return a muscle to its resting state

Answer 32

Gravity

Question 33

The active energy model

Answer 33

ATP

Question 34

The storage molecule for excess ATP energy in resting muscle

Answer 34

CP

Question 35

Cells produce ATP in two ways 1. Aerobic metabolism of fatty acids in the mitochondria 2. Anaerobic glycolysis in the cytoplasm

Answer 35

ATP generation

Question 36

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

Answer 36

Aerobic metabolism

Question 37

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

Answer 37

Glycolysis

Question 38

When muscles can no longer perform a required activity, they are fatigued

Answer 38

Muscle fatigue

Question 39

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

Answer 39

The Cori cycle

Question 40

After exercise or other exertion The body needs more oxygen than usual to normalize metabolic activities Resulting in heavy breathing Also called excess post exercise oxygen consumption

Answer 40

Oxygen debt

Question 41

Fast Slow Intermediate

Answer 41

Types of skeletal muscle fibers

Question 42

Contract very quickly

Answer 42

Fast fibers

Question 43

Are slow to contract, slow to fatigue

Answer 43

Slow fibers

Question 44

Are mid sized | Have low myoglobin

Answer 44

Intermediate fibers

Question 45

Mostly fast fibers | Pale

Answer 45

White muscle

Question 46

Mostly slow fibers | Dark

Answer 46

Red muscles

Question 47

Mixed fibers | Pink

Answer 47

Most human muscles

Question 48

Muscle growth from heavy trained | Toned muscles

Answer 48

Muscle hypertrophy

Question 49

Lack of muscle activity | Reduces muscle size, tone, and power

Answer 49

Muscle atrophy

Question 50

``` Striated Are small Have a single nucleus Have short, wide T tubules Have intercalated discs ```

Answer 50

Cardiac muscle tissue

Question 51

Contraction without neural stimulation | Controlled by pacemaker cells

Answer 51

Automaticity

Question 52

Forms around other tissues Arrector pili muscles cause goose bumps In blood vessels and airways Regulates blood pressure and airflow

Answer 52

Smooth muscle

Question 53

Nonstriated tissue | Different internal organization of actin and myosin

Answer 53

Smooth muscle

Question 54

Long slender and spindle shaped Single nucleus No T tubules, myofibrils, or sarcomeres Myosin fibers have more heads per thick filaments Have thin filaments attached to dense bodies which transmit contractions from cell to cell

Answer 54

Smooth muscle characteristics

Question 55

Maintains normal level of activity | Modified by neural, hormonal, or chemical factors

Answer 55

Smooth muscle tone