Human Physiology Chapter 9: Muscle And Muscle Tissue Part 1

Front 1

What are the three main types of muscle tissue?

Back 1

Skeletal, cardiac, and smooth

Front 2

Where does skeletal muscle attach?

Back 2

Skeletal muscle attaches to the skeleton (bones, cartilage)

Front 3

What do skeletal muscle tissues look like?

Back 3

Skeletal muscle tissue are striated long cylinders or rods

Front 4

Are skeletal muscle tissues independent or dependent on each other?

Back 4

Independent

Front 5

Where is cardiac muscle located?

Back 5

Only in the heart

Front 6

What innervates skeletal muscle?

Back 6

Somatic motor neurons!

Front 7

What innervates cardiac muscle?

Back 7

Autonomic motor neurons

Front 8

What do cardiac muscle tissue cells look like?

Back 8

Cardiac muscle tissue cells are striated short branched cells that are highly interconnected

Front 9

What is the sympathetic effect on the cardiac muscles?

Back 9

Speed up contractions and beat harder

Front 10

What is the parasympathetic effect on the cardiac muscles?

Back 10

Slow down contractions

Front 11

Where is smooth muscle located?

Back 11

Walls of hollow organs

Front 12

What are some examples of smooth muscle in organs?

Back 12

Digestive tract, bladder, uterus, blood vessels, iris, bronchioles, etc.

Front 13

What innervates smooth muscle?

Back 13

Autonomic motor neurons

Front 14

What do smooth muscle tissue cells look like?

Back 14

Smooth and non-striated. Look vaguely like a pea in a pea pod

Front 15

What is the contraction speed like in smooth muscle?

Back 15

Usually slow and sustained

Front 16

What muscle type provides most of the bulk of muscles in the body?

Back 16

Skeletal

Front 17

Which muscle type maintains posture?

Back 17

Skeletal muscle, stretch reflexes

Front 18

Which muscle type stabilizes joints?

Back 18

Skeletal muscle in where muscle tone keeps joints stable

Front 19

Which muscle type generate heat?

Back 19

All muscle types!

Front 20

How is heat produced by the muscles?

Back 20

Heat is a by-product of ATP hydrolysis

Front 21

ATP breaks down into what three components?

Back 21

ADP + Phosphate + Energy

Front 22

When ATP breaks down, energy goes on to do what?

Back 22

Allow cells to do work and produce heat

Front 23

Muscle cells are what kind of cells?

Back 23

Excitable cells!

Front 24

What other cells are excitable besides muscle cells?

Back 24

Neurons!

Front 25

What does "excitable" mean?

Back 25

Cell can receive stimuli and propagate action potentials when stimulated

Front 26

What are the four functional characteristics of muscles?

Back 26

1. Excitability
2. Contractility
3. Extensibility
4. Elasticity

Front 27

What does contractility mean?

Back 27

The ability to shorten when stimulated

Front 28

Is contractility unique to muscle or can all cells do it?

Back 28

Unique to muscle

Front 29

What does extensibility mean?

Back 29

Relaxed muscles can be stretched

Front 30

What does elasticity mean?

Back 30

After contraction or stretch, muscles recoil back to resting length

Front 31

What word roots refer to muscle?

Back 31

myo, mys, and sarco

Front 32

Muscle cell is the same as what other term?

Back 32

Muscle fiber

Front 33

What is the plasma membrane called in all cells?

Back 33

Plasmalemma

Front 34

What is the plasma membrane called in muscle cells?

Back 34

Sarcolemma

Front 35

What type of neurons cause skeletal muscle to contract?

Back 35

Somatic motor neurons

Front 36

The point where axon terminal comes in close contact with muscle cell is called what?

Back 36

Neuromuscular junction (NMJ)

Front 37

At least one axon terminal must reach what for contraction to occur?

Back 37

One axon terminal must reach EACH muscle cell in a muscle to contract

Front 38

What is the receptive region called?

Back 38

Motor end plate

Front 39

Where is the receptive region located?

Back 39

At the neuromuscular junction

Front 40

What type of gated ion channels are located on the receptive region?

Back 40

Chemically-gated channels

Front 41

What type of signals occur at the receptive region?

Back 41

Graded potentials

Front 42

Where is the conducting region on a muscle cell located?

Back 42

Located in the sarcolemma in all directions away from the NMJ

Front 43

What type of gated ion channels are located in the conducting region?

Back 43

Voltage-gated Na+ and K+ channels

Front 44

What type of signals occur in the conducting region?

Back 44

Action potentials!

Front 45

Do muscle cells have a secretory region?

Back 45

NO!

Front 46

What are end plate potentials?

Back 46

EPPs are graded potentials that occur in the receptive region of a muscle cell at the motor end plate

Front 47

What do EPPs do?

Back 47

EPPs excite muscle cell to set off muscle APs

Front 48

Acetylcholine binds to what receptor?

Back 48

Cholinergic receptors

Front 49

What occurs when ACh binds to their receptors?

Back 49

Opens Na+ and K+ channels where Na+ entry predominates

Front 50

What does Na+ entry cause?

Back 50

Causes depolarization

Front 51

Somatic motor neurons ALWAYS secrete what?

Back 51

ACh

Front 52

ACh ALWAYS excites what and sets off what?

Back 52

Skeletal muscle which sets off EPPs

Front 53

EPPs set off what?

Back 53

Muscle action potentials

Front 54

Muscle APs set off what?

Back 54

Muscle contraction

Front 55

Muscle APs have what periods just like neurons?

Back 55

Absolute and relative refractory periods!

Front 56

What is the sarcolemma at the NMJ called?

Back 56

Motor end plate!

Front 57

What is the major difference between neuron APs and muscle APs?

Back 57

In neuron APs, one EPSP won't set off neuron AP while one WILL fire a muscle AP.

Front 58

In a muscle cell, a single EPP will do what? What is this considered?

Back 58

Depolarize to threshold and fire AP. It is considered muscles "safety factor"

Front 59

If a motor neuron fires, what will always occur?

Back 59

Muscle cell will contract

Front 60

How do we keep a skeletal muscle cell from contracting?

Back 60

Inhibit its motor neuron

Front 61

Each skeletal muscle is a discrete what?

Back 61

Discrete organ

Front 62

Each skeletal muscle has its own what?

Back 62

Nerve and blood supply

Front 63

Each muscle fiber is what?

Back 63

Innervated

Front 64

Each skeletal muscle is a discrete what?

Back 64

Discrete organ

Front 65

One motor neuron can innervate how many muscle fibers?

Back 65

Lots!

Front 66

Each skeletal muscle has its own what?

Back 66

Nerve and blood supply

Front 67

What are fascicles?

Back 67

Fascicles are bundles of muscle fibers

Front 68

Each muscle fiber is what?

Back 68

Innervated

Front 69

One motor neuron can innervate how many muscle fibers?

Back 69

Lots!

Front 70

Muscle fibers are filled with what?

Back 70

Myofibrils

Front 71

What are fascicles?

Back 71

Fascicles are bundles of muscle fibers

Front 72

What are myofibrils?

Back 72

Myofibrils are rodlike elements of cytoskeleton that run the length of the muscle fiber

Front 73

Muscle fibers are filled with what?

Back 73

Myofibrils

Front 74

What are myofibrils composed of?

Back 74

Myofilaments

Front 75

What are myofibrils?

Back 75

Myofibrils are rodlike elements of cytoskeleton that run the length of the muscle fiber

Front 76

Mitochondrion are located where in the muscle?

Back 76

In the muscle fiber next to the myofibrils

Front 77

What are myofibrils composed of?

Back 77

Myofilaments

Front 78

Mitochondrion are located where in the muscle?

Back 78

In the muscle fiber next to the myofibrils

Front 79

What causes muscle contraction in the muscle?

Back 79

Muscle myofilaments sliding past each other

Front 80

What causes muscle contraction in the muscle?

Back 80

Muscle myofilaments sliding past each other

Front 81

Each myofibril is surrounded by what?

Back 81

The sarcoplasmic reticulum

Front 82

What do mitochondrion do?

Back 82

Cellular respiration and ATP production

Front 83

What is the SR?

Back 83

The SR is a network of tubules that store Ca+ needed for contraction

Front 84

What are myofilaments?

Back 84

Myofilaments are protein filaments that overlap to form a repeating pattern

Front 85

What is another name for myofilaments?

Back 85

sarcomere

Front 86

What two things are part of the Triad?

Back 86

T Tubule and the 2 Terminal cisternae of the SR

Front 87

What happens when AP passes the triads?

Back 87

Ca2+ is released and floods the cytoplasm

Front 88

What do T tubules do?

Back 88

T tubules carry muscle AP from the sarcolemma to interior of each fiber

Front 89

Thin filaments attach to what?

Back 89

Thin filaments attach to a Z disc

Front 90

Thick filaments are anchored to what?

Back 90

Thick filaments are anchored at the M line

Front 91

Myofilaments are what filaments that overlap?

Back 91

Thick and thin filaments that overlap

Front 92

Z discs and M lines are what?

Back 92

Proteins!

Front 93

What are sarcomeres?

Back 93

Sarcomeres are the basic contractile unit of a muscle fiber

Front 94

When muscle fiber is stimulated, sarcomeres do what?

Back 94

They shorten according to the sliding filament model

Front 95

What is the sliding filament model?

Back 95

Thin filaments over thick filaments

Front 96

The length of each myofilament does what?

Back 96

The length of each myofilament does not change

Front 97

Thick filaments are composed of what type of protein?

Back 97

Myosin protein

Front 98

Thin filaments are composed of what type of protein?

Back 98

Actin protein

Front 99

Tropomyosin and Troponin are what kind of filament?

Back 99

Thin filament

Front 100

What kind of proteins are Tropomyosin and Troponin?

Back 100

Regulatory proteins

Front 101

The myosin head on thick filaments is also called what?

Back 101

Cross bridge

Front 102

Myosin heads attach to what protein?

Back 102

Actin on thin filaments

Front 103

What is it called when myosin binds to actin?

Back 103

Cross bridges are attached

Front 104

What must be attached in order for the muscle to contract?

Back 104

Myosin heads attached to the actin

Front 105

What does Tropomyosin do?

Back 105

Tropomyosin covers the binding sites on actin subunits to prevent binding

Front 106

In order to expose the binding cites on actin subunits, what must occur?

Back 106

Troponin must move the tropomyosin out of the way

Front 107

What is the consequence of tropomyosin covering the binding sites on the actin subunits?

Back 107

Muscle stays relaxed

Front 108

What is the consequence of troponin moving the tropomyosin covering the binding sites?

Back 108

Allows muscle to contract

Front 109

When the muscle is relaxed, the myosin head is in its low or high energy "cocked" position?

Back 109

High-energy cocked position

Front 110

When the muscle is relaxed, are the myosin binding sites covered or uncovered?

Back 110

Covered!

Front 111

When the muscle is stimulated, troponin does what?

Back 111

Troponin moves tropomyosin out of the way

Front 112

When the muscle is stimulated, what is the 4 step process of contraction? How long does it continue?

Back 112

1. Troponin moves tropomyosin out of the way
2. cross bridges attach
3. Myosin heads tilt forward and thin filaments slide
4. Myosin heads detach and bind again
It continues as long as muscle is stimulated

Front 113

When muscle stimulation stops, what do the cross bridges do?

Back 113

They detach!

Front 114

When muscle stimulation stops, tropomyosin does what?

Back 114

Covers the myosin binding sites

Front 115

When muscle stimulation stops, the thin filaments do what?

Back 115

Thin filaments slide back to resting position due to elasticity of muscle