Muscular System Pt.1

Question 1

What are the types of muscle?

Answer 1

1.Smooth Muscle
2.Cardiac Muscle
3. Skeletal Muscle

Question 2

Where is Smooth muscle found? What is it controlled by?

Answer 2

Lines digestive tract, arteries and is controlled by autonomic nervous system

Question 3

Where is Cardiac muscle found? What is it controlled by?

Answer 3

Found in the heart. Rate of contraction controlled by autonomic nervous system

Question 4

Where is Skeletal muscle found? What is it controlled by?

Answer 4

Found throughout body plan. Voluntary contraction controlled by somatic nervous system.

Question 5

Skeletal muscle cell=

Answer 5

Muscle fiber or myofiber

Question 6

Skeletal muscle membrane=

Answer 6

Sarcolemma

Question 7

Skeletal muscle cytoplasm=

Answer 7

Sarcoplasm

Question 8

Skeletal muscle endoplasmic reticulum=

Answer 8

Sarcoplasmic reticulum

Question 9

Sarco means “ “ and myo means “ “

Answer 9

Flesh and muscle

Question 10

One skeletal muscle fiber has “ “ and they are “ “ located

Answer 10

Many nuclei and peripherally located

Question 11

As a new muscle stem cell joins a muscle fiber, the nucleus begins in the center of the fiber before “ “

Answer 11

Traveling to the periphery

Question 12

Central nuclei indicates “ “

Answer 12

Muscle regeneration

Question 13

Myofibrils are found within muscle fibers they are?

Answer 13

Protein bundles within muscle fibers, made of actin and myosin divided into segments called sarcomeres

Question 14

Sarcoplasmic reticulum (SR) (specialized ER) are found within muscle fibers they?

Answer 14

Surround myofibrils and store and release calcium (Ca2+)

Question 15

T tubules are found within muscle fibers and they are?

Answer 15

Extensions of the sarcolemma deep into muscle fiber and allow the sarcolemma to contact the sarcoplasmic reticulum

Question 16

Each myofibril is made of many
“ “

Answer 16

End-to-end sarcomeres

Question 17

Why do muscles appear striated/striped ?

Answer 17

The repeated patterns of sarcomeres

Question 18

What are the 2 main components of the striation pattern of the sarcomere ?

Answer 18

1.I band
2.A band

Question 19

I band ?

Answer 19

Light band, composed of thin actin filaments

Question 20

A band ?

Answer 20

Dark band, composed of thick myosin filaments (with some overlap of actin filaments)

Question 21

What are the other components of the sarcomere?

Answer 21

1. H zone
2. Z line
3. M line

Question 22

H zone

Answer 22

Center of A band, composed of thick myosin filaments with (no actin)

Question 23

Z line

Answer 23

Anchors filaments in place, sarcomere boundary, and the center of I band

Question 24

M line

Answer 24

Anchors thick filaments and is the center of the A band

Question 25

Skeletal muscle fibers thick filaments are

Answer 25

Composed of myosin protein

Question 26

Skeletal muscle fibers thin filaments are

Answer 26

Mostly composed of actin protein, and contains two other regulatory proteins troponin and tropomyosin.

Question 27

Excitation-contraction coupling is the process...? What are the steps?

Answer 27

Leading to muscle contraction 1. Lower motor neuron action potential 2. Muscle action potential (excitation) 3. Muscle fiber contraction

Question 28

A neuromuscular junction is a

Answer 28

Specialized synapse between a motor neuron and muscle

Question 29

The neurotransmitter used is

Answer 29

Acetylcholine (ACh)

Question 30

The motor end plate is

Answer 30

The thickened area of sarcolemma (muscle membrane) that contains ACh receptors

Question 31

When does muscle contraction occur?

Answer 31

When the thin filaments (actin, troponin, tropomyosin) and thick filaments (myosin) overlap, shortening the sarcomere

Question 32

Muscle cells and neurons are excitable meaning

Answer 32

They can conduct electrical impulses

Question 33

Muscle cells also (3)

Answer 33

1. Have a resting membrane potential similar to a neuron (~-70mV) 2. Receives EPSPs due to binding of Ach to Ach receptors on motor end plate 3. Conducts action potential along membrane due to activation of voltage-gated sodium channels

Question 34

At the structure called triad

Answer 34

T-tubules interact with the sarcoplasmic reticulum (SR)

Question 35

T-tubules and Sr both contain " " that " "

Answer 35

"Receptors" that "interact with each other"

Question 36

Muscle action potential reaches " " on the T-tubules

Answer 36

"Dihydropyridine receptors (DHPRs)"

Question 37

What happens when DHPRS deform ryanodine receptors (RyRs) on the SR ?

Answer 37

Allows release of Ca2+ (calcium) into the cytoplasm

Question 38

Rigor mortis

Answer 38

The rigidity of the body after death.

Question 39

As sarcomeres shorten

Answer 39

1. Thin and thick filaments overlap more, but do not change length! 2. H zones and I bands narrow 3. Z lines move closer together