Unit 3 Anatomy

Front 1

What are the functions of muscles?

Back 1

Internal & External Movement, stabilize body positions, produce heat by contraction (thermoregulation), and regulate organ volumes by opening and closing sphincters

Front 2

How do muscle tissues differ from eachother?

Back 2

Have different microscopic anatomy & characteristics, different locations, and how they are controlled

Front 3

What are all of the ways muscles are controlled?

Back 3

By nerves, hormones, and being auto rhythmic

Front 4

What are the characteristics of skeletal muscle?

Back 4

Striated, voluntary, attach to moving bone, always controlled by nerve

Front 5

What are the characteristics of smooth muscle?

Back 5

Non striated and Involuntary. However if it’s Visceral Smooth muscle it makes up the walls of blood vessels and hollow organs and it can be controlled by any of the 3 ways. If it’s Multi unit smooth it makes up the iris and arrectorpili and is controlled by a nerve.

Front 6

What are the characteristics of cardiac muscle?

Back 6

Striated & branched, appears only in heart, involuntary, and is always auto rhythmic.

Front 7

Define intercalated discs.

Back 7

The thickening of the muscle cell membrane between cardiac muscle cells that house a gap junction

Front 8

Describe electrical current

Back 8

Charged particles that are moving

Front 9

Describe muscle cells in their resting state

Back 9

More positive on the outside and more negative on the inside

Front 10

What is membrane potential?

Back 10

The difference in charge across the membrane of a cell also called polar

Front 11

What type of ions are found outside of the cell?

Back 11

Sodium ions

Front 12

What are channels?

Back 12

Channels are 2 proteins that open the cell membrane and allow specific things to go through it. The muscle cell has sodium ion channels.

Front 13

What happens when a sodium ion channel opens?

Back 13

The difference in charge causes the positively charged ions to fly into the negatively charged muscle cell interior. When the sodium ions fly in it creates energy to open more ion channels eventually opening all the channels and depolarizing itself.

Front 14

Define action potential.

Back 14

The sequence of rolling open ion channels around the membrane of the cell caused by the first opening channel. It also is what tells the cells to physically contract.

Front 15

How and why does the muscle cell re-polarize itself?

Back 15

A Non-Polar muscle cell is useless so it uses ATP to pump out sodium ions in order to bring back the negative internal of the cell so it can be used again.

Front 16

What would happen if there’s no membrane potential?

Back 16

Sodium ions won’t move through the channel and this means no other channels will open. Membrane potential is needed for action potential.

Front 17

Define autorhythmic.

Back 17

Any muscle cell that can open its own first ion channel and start its own action potential.

Front 18

Define Contractility.

Back 18

The ability for a muscle to contract forcefully when it’s stimulated by an action potential.

Front 19

What happens during isotonic contractions?

Back 19

The muscle shorten and bulges as it contracts.

Front 20

What happens during a isometric contraction?

Back 20

Tension is developed by the contraction but it doesn’t shorten.

Front 21

Define extensibility.

Back 21

A muscle being able to stretch to a point and not be damaged by this stretch

Front 22

Define Elasticity.

Back 22

Being able to go back to original form after being stretched.

Front 23

What is the significance of the mesoderm in skeletal muscle?

Back 23

The mesoderm layer forms muscle and the mesoderm cells differentiate into myoblasts.

Front 24

How do myoblasts cells help the formation of muscle?

Back 24

A lot of myoblasts gather together and form a skeletal muscle cell

Front 25

What is the importance of CT wrappings in skeletal muscle?

Back 25

It keeps the cells of the muscle organized and from tangling.

Front 26

What tissue wraps around EACH MUSCLE CELL and what is it made of?

Back 26

It’s called endomysium and it is made of areolar CT

Front 27

What is the tissue called that wraps around BUNDLES OF MUSCLE and what is it made of?

Back 27

It’s called the Perimysium and it is made of Dense Irregular CT

Front 28

What is the tissue called that WRAPS AROUND THE ENTIRE MUSCLE and what is it made of?

Back 28

It’s called epimysium and it is made of Dense Irregular CT

Front 29

Define sarcolemma.

Back 29

The name for muscle cell membranes

Front 30

What are T-Tubles?

Back 30

Indentations in the muscle cell membrane.

Front 31

What is sarcoplasm?

Back 31

Sarcoplasm is the cytoplasm of the muscle cell and it carries the protein myoglobin.

Front 32

Define myoglobin.

Back 32

Myoglobin is an oxygen storing capable protein in the sarcoplasm

Front 33

What is the purpose of myoglobin?

Back 33

Muscle cells require a lot of ATP and in order to produce ATP you need oxygen. Myoglobin helps store extra oxygen to keep up with the muscle’s work load.

Front 34

Why do your muscles get bigger from exercise?

Back 34

The more active you are the more oxygen you need so muscles fill with myoglobin to keep up with the increased activity

Front 35

Define myofibrils.

Back 35

Myofibrils are thread like structure that are the contractile unit of skeletal muscle cells and cause contraction.

Front 36

What is SR?

Back 36

SR is Sarcoplasmic Reticulum which is the muscles version of Endoplasmic Reticulum and is full to the brim with calcium ion ls and it wraps around myofibrils

Front 37

Define Z-Discs.

Back 37

Squiggly lines that make up myofibril seen when magnified

Front 38

Define sarcomere.

Back 38

The area between z discs are sarcomeres.

Front 39

What are a string of sarcomeres?

Back 39

A string of sarcomeres make up a myofibril

Front 40

How many protein groups make up a sarcomere?

Back 40

3 protein groups make up a sarcomere

Front 41

What does the first protein group, contractile proteins, do and what are the proteins in them?

Back 41

Contractile proteins contract the muscle and they’re made up of actin and myosin.

Front 42

What is actin and what does it do?

Back 42

Actin is a contractile protein and it makes up the structure call thin filaments in a sarcomere.

Front 43

What is myosin and what does it do?

Back 43

Myosin is a contractile protein and it makes up the structure called thick filaments in sarcomeres.

Front 44

What are pockets or grooves on thin filaments called?

Back 44

These pockets or grooves are called myosin head binding sites

Front 45

What does the protein myomesin do?

Back 45

Myomesin forms a line that goes down the center of the sarcomere called the M-Line.

Front 46

What does the protein titin do?

Back 46

The protein titin attaches to the edge of the thick filaments and then attached to the z-discs.

Front 47

What does the 3rd and final protein group, Regulatory proteins, do and what are the proteins in this group?

Back 47

It allows us to control when we do and don’t contract our muscles. The proteins Troponin and Tropomyosin make up this group.

Front 48

What does Tropomyosin do?

Back 48

This protein is what wraps around the thin filaments and allows the myosin head binding sites to close.

Front 49

What does Troponin do?

Back 49

This protein is what holds the Tropomyosin on the thin filaments like a clothes pin.

Front 50

How does the sarcomere help contract muscle ?

Back 50

When the muscle cell needs to contract Calcium ions from the SR take the Troponin off of the Tropomyosin. This allows the Tropomyosin to roll out of the way causing the myosin heads to go into the myosin head binding sites.

Front 51

Define H-Zone

Back 51

The H-Zone is the center of a relaxed sarcomere that only contains the THICK FILAMENT

Front 52

Define I-Bands.

Back 52

The area near z-discs on a relaxed sarcomere that only contains thin filaments

Front 53

Define A-bands.

Back 53

The A-Bands is a large central area of the sarcomere that contains all of the thick filaments and SOME of the thin filaments.

Front 54

In a contracted sarcomere what bands/zones are present?

Back 54

The H-Zone and I-bands are lost leaving only the A-Band in a contracted sarcomere.

Front 55

Define Neurons.

Back 55

Neurons are the master cells in a nervous system.

Front 56

What type of Neurons control muscles?

Back 56

Motor Neurons control muscles

Front 57

What are Dendrites?

Back 57

Dendrites are the spikey part at the top of a motor neuron and it receives information.

Front 58

What is the “Cell Body” of a neuron and what does it do?

Back 58

The cell body is the top part of a motor neuron that the dendrites come off of and it is the brain of the Neuron. It holds the nucleus and processes the information dendrites receive.

Front 59

What is the job of Neurons and what is this job called?

Back 59

The job of neurons is to communicate a message to another cell. This communication is called a SYNAPSE.

Front 60

What is the synaptic end bulb?

Back 60

The synaptic end bulb is the part of the neuron that sends messages to another cell

Front 61

What are synaptic vesicles?

Back 61

Synaptic vesicles are circular structure in a synaptic end bulb.

Front 62

Define Neuromuscular Junction.

Back 62

This is the name for the synapse between a motor neuron and a muscle cell.

Front 63

Define Neurotransmitters.

Back 63

Neurotransmitters are the general name given to any chemical in synaptic vesicles.

Front 64

What neurotransmitter is used when stimulating a muscle cell?

Back 64

Acetylcholine is the neurotransmitter used when stimulating a muscle cell

Front 65

Define Synaptic Cleft.

Back 65

The synaptic cleft is the gap left between the cell the message is being sent to and the neuron

Front 66

Define Motor End Plate.

Back 66

The motor end plate is the section of muscle on the other end of the synaptic cleft.

Front 67

How does skeletal muscle contract?

Back 67

Skeletal muscle contracts when action potential travels down a neuron and caused the synaptic vesicles to release Acetylcholine. Acetylcholine is released into the cleft and goes across it to open the first sodium ion channel. Sodium ion channels roll open to create action potential. The action potential releases calcium ions from the SR and the calcium ions pull off Troponin to allow tropomyosin to roll back. The ATP on the myosin head is broken down causing it to pop up into the myosin head binding sites and roll toward the M-Line therefore shortening the sarcomere.

Front 68

How do you stop a muscle contraction?

Back 68

You stop a muscle contraction by by removing the calcium ions from the sarcomere and pumping it into the SR using ATP.

Front 69

What is Calsequestrin?

Back 69

Calsequestrin is a protein that keeps the calcium organized in the SR helping the released calcium get back in.

Front 70

What are the uses of ATP in muscle cells?

Back 70

They re-polarize cells,engage myosin heads, pump calcium ions back into the SR, and for fight or flight.

Front 71

How does fight or flight work?

Back 71

The protein Creatine Kinase collects the extra phosphate when ATP->ADP+P and attaches it to the protein Creatine. When fight or flight happens Creatine Kinase takes back the phosphate and adds it back to ADP to instantly make ATP.

Front 72

How long does energy from fight or flight last?

Back 72

Roughly 30 seconds.

Front 73

What is the “All or None” principle?

Back 73

It is a principle that states if a muscle contracts, it either contracts completely or not at all.

Front 74

What is the first way we control the strength of muscle contractions?

Back 74

One way we control the strength of contractions are by the size and number of motor neurons moved or recruited. So if there is a 2 neurons and Neuron A is connected to three muscle cells and Neuron B is connected to 7 muscle cells. A would be for minimal strength B would be for medium strength and A+B would be for Maximum strength.

Front 75

What is the second way we control strength?

Back 75

Another way we control strength is by the frequency of stimulation. Or how quickly the neuron fires to the muscle per second. Slower=weaker, Faster=Stronger.

Front 76

What is a Myogram?

Back 76

The recording of an electrical current through a muscle cell.

Front 77

Define twitch contraction.

Back 77

Twitch contractions are when a muscle cell is stimulated once then stops.

Front 78

What does a twitch contraction of a muscle cell look like on a myogram?

Back 78

It looks like an upside down parabola

Front 79

What is the latent period of a myogram?

Back 79

The latent period is the beginning portion of the upside down parabola. It is flat and the reason for this is because the calcium hasn’t taken off the Troponin yet.

Front 80

What is the contraction period of a myogram?

Back 80

The contraction period of a myogram is the uphill portion of the parabola. This is when the sodium is flying in and depolarizing the cell.

Front 81

What is the refraction period of a myogram?

Back 81

The refraction period is the very peak of the parabola on a myogram.

Front 82

What is the relaxation period of the myogram?

Back 82

The relaxation period is the downhill portion of a parabola and it this is the period when the ATP is pumping out the calcium and re-polarizing the cell.

Front 83

What happens to the relaxation period as the neuron fires faster?

Back 83

The relaxation period gets shorter the faster the neuron fires.

Front 84

Define Dense Bodies

Back 84

Dense bodies are structures that intermediate filaments attach to in smooth muscle cells.

Front 85

What is the SA Node?

Back 85

The SA node is like the natural pacemaker in the heart.

Front 86

How does the heart create action potential?

Back 86

The heart is auto rhythmic and makes its own action potential

Front 87

What is special about the heart and the way it contracts?

Back 87

The heart contracts as a unit and all the cells contract in unison.

Front 88

What happens during a heart attack?

Back 88

The blood vessel supplying the heart muscle itself gets blocked and the muscles cells that aren’t getting the nutrients from the blood end up dying.

Front 89

What happens when the muscle cells die during a heart attack?

Back 89

They break apart and everything in them is released including Troponin. The blood cleans up Troponin and filters it through the kidney and you urinate it out

Front 90

What are the blood Troponin levels like during a heart attack? Why?

Back 90

They’re high because they’re released into blood when the muscle cells die .