Anatomy Test #2 The Muscular System

Front 1

Three types of muscle found in the body

Back 1

skeletal, cardiac, smooth

Front 2

prefixes that refer to muscles

Back 2

myo & mys

Front 3

what determines the concentration of muscles?

Back 3

the movement of microfilaments

Front 4

Skeletal muscle characteristics

Back 4

1. attached by tendons to bones
2. cells are multinucleated
3. Striated
4. voluntary

Front 5

What do muscle fibers look like?

Back 5

long cylinders

Front 6

Another name for muscle fibers

Back 6

muscle cells

Front 7

muscle cells are surrounded by what?

Back 7

connective tissue

Front 8

Endomysium

Back 8

encloses a single muscle fiber

Front 9

Perimysium

Back 9

Wraps around a fasicle of muscle fibers

Front 10

Epimysium

Back 10

covers the entire skeletal muscle

Front 11

Fascia

Back 11

On the outside of of the epimysium, continuous with hypodermis and epimysium

Front 12

Tendons

Back 12

cord-like structures composed of collagen fibers, often cross a joint due to toughness and small size

Front 13

Aponeuroses

Back 13

Sheet-like structures, attach muscles to other muscles or skin. Indirectly attach muscles to bones

Front 14

Aponeuroses is similar to what?

Back 14

A tendon but in sheet form

Front 15

Sites of muscle attatchment

Back 15

Bones, Cartilages, Connective tissue coverings

Front 16

Smooth muscle characteristics

Back 16

1. Lacks striations
2. Spindle-shaped cells
3. Single nucleus
4. Involuntary muscle control

Front 17

Cardiac muscle characteristics

Back 17

1. Striations
2. Single nucleus
3. Branching cells
4. Involuntary
5. Joined to other muscle cells at intercalated disks

Front 18

Skeletal muscle functions

Back 18

1. Produce movement
2. Maintain posture
3. Stabilize joints
4. Generate heat

Front 19

Do skeletal muscles push or pull to do work?

Back 19

They pull and shorten

Front 20

Microscopic anatomy: Sarcolemma

Back 20

specialized plasma membrane outside of muscle fiber

Front 21

Microscopic anatomy: Myofibrils

Back 21

Long organelles inside muscle cells, fill most of interior space of muscle fibers

Front 22

Microscopic anatomy: Sarcoplasmic reticulum

Back 22

specialized smooth endoplasmic reticulum

Front 23

Endoplasmic reticulum

Back 23

wrapped around myofibrils

Front 24

L band

Back 24

"Light band" contains only thin filaments

Front 25

A band

Back 25

"dark band" contain the entire length of the thick filaments

Front 26

Microscopic anatomy: Sarcomere

Back 26

contractile unit of a muscle fiber (functional unit of muscle fibers, repeating units like links on a chain)

Front 27

Myofilaments

Back 27

thin filament= actin filaments
thick filament= myosin filaments

Front 28

Myosin Filaments characteristics

Back 28

Thick filaments, composed of the protein myosin, has ATPase enzymes, myosin filaments have heads

Front 29

Actin Filaments characteristics

Back 29

Thin filaments, composed of the protein actin, anchored to the z-disc

Front 30

ATPase enzyme

Back 30

can break ATP to release energy to do work

Front 31

Z-disc

Back 31

Proteins that connect sarcomeres to other sarcomeres

Front 32

Sarcoplasmic reticulum

Back 32

stores and releases calcium, surrounds the myofibrils

Front 33

Excitability

Back 33

ability to receive and respond to a stimulus

Front 34

Contractility

Back 34

ability to shorten when an adequate stimulus is received

Front 35

Extensibility

Back 35

ability of muscle cells to be stretched

Front 36

Elasticity

Back 36

ability to recoil and resume resting length after stretching

Front 37

What stimulates a muscle to contract?

Back 37

motor neuron (nerve cell)

Front 38

Motor unit

Back 38

one motor neuron and all the skeletal muscle cells stimulated by that neuron

Front 39

Relationship between motor units and motor neurons

Back 39

Motor neurons are branching to a motor unit

Front 40

Neuromuscular junction

Back 40

Association site of axon terminal of the motor neuron and muscle, location where an axon terminal of a neuron interacts with the sarcolemma of a muscle fiber

Front 41

Axons

Back 41

long extensions that carry signals

Front 42

Action Potential

Back 42

special kind of electrical signal (can be carried by neurons and muscle cells)

Front 43

Axon terminals

Back 43

Ends of axons

Front 44

Synaptic Gap

Back 44

Gap between nerve and muscle (THEY DO NOT MAKE CONTACT) The area between is filled with interstitial fluid

Front 45

How many fibers are stimulated during a muscle contraction?

Back 45

It depends based on how much force is put into the contraction

Front 46

Graded response

Back 46

different degrees of muscle shortening

Front 47

How are graded responses produced?

Back 47

By changing:
1.The frequency of muscle stimulation
2. The number of muscle cells being stimulated at one time

Front 48

Use one or fewer motor units

Back 48

Very small, very fine, precise movements (only in muscles of eyes)

Front 49

Use many motor units and larger motor units

Back 49

Large, powerful, less precise movements (ie hamstrings)

Front 50

Types of graded responses

Back 50

Twitch, Tetanus, Unfused tetanus, Fused tetanus

Front 51

Twitch

Back 51

Single, brief contraction, not a normal muscle function

Front 52

Tetanus

Back 52

One contraction is immediately followed by another, the muscle does not completely return to a resting state

Front 53

Fused (complete) Tetanus

Back 53

Sustained, continuous contraction

Front 54

First source of energy to muscles

Back 54

Stored ATP, only 4-6 seconds of energy provided, ATP bonds are broken to release energy

Front 55

Unfused (incomplete) Tetanus

Back 55

Some relaxation occurs between contractions

Front 56

Second source of energy to muscles

Back 56

Direct phosphorylation of ADP by creatine phosphate

Front 57

Third source of energy to muscles

Back 57

Aerobic respiration or Anaerobic glycolysis

Front 58

How does Aerobic respiration give the muscles energy?

Back 58

Glucose is broken down to carbon dioxide and water, releasing ATP

Front 59

Characteristics of aerobic respiration

Back 59

Requires Oxygen, Very efficient with high ATP output

Front 60

How does anaerobic glycolysis provide muscles with energy?

Back 60

Glucose is broken down to pyruvic acid to produce some ATP

Front 61

Anaerobic glycolysis characteristics

Back 61

Does not require oxygen, does require large amounts of glucose. Not efficient but is fast

Front 62

What type of exercise requires anaerobic glycolysis?

Back 62

powerful explosive exercise, does not last long so it is reserved for intense short exercise

Front 63

What type of exercise requires aerobic respiration?

Back 63

Endurance exercise, ie running and cycling

Front 64

What happens when a muscle is fatigued?

Back 64

It can no longer contract even with stimulus

Front 65

Cause of fatigue

Back 65

Oxygen deficit

Front 66

How is muscle fatigue cured?

Back 66

oxygen must be repaid to get rid of accumulated lactic acid

Front 67

Types of muscle contractions

Back 67

Isotonic, Isometric, Eccentric

Front 68

Isotonic Contractions

Back 68

The muscle shortens and movement occurs (visible movement), myofilaments are able to slide past each other during contractions

Front 69

Isometric contraction

Back 69

Tension in the muscle increases, the muscle is unable to shorten or produce movement, movement will not occur

Front 70

Eccentric Contraction

Back 70

Muscle breaking, stopping the muscle from going as fast as it usually would

Front 71

Muscle tone

Back 71

Some fibers are always contracted, different muscle fibers at different times, involutary

Front 72

Sarcoplasmic Reticulum

Back 72

Looks like a crocheted sweater surrounding myofibrils, they store calcium

Front 73

Acetylcholine

Back 73

neurotransmitter in neuromuscular junctions, stimulate muscle cells