Ex Phys Chapter 1

Question 1

sometimes called involuntary muscle is not under direct conscious control

Answer 1

smooth muscle

Question 2

muscle found only in the heart, composing the vast majority of the heart’s structure

Answer 2

Cardiac muscle

Question 3

These muscles are under conscious control and are so named because most attach to and move the skeleton

Answer 3

Skeletal muscles

Question 4

Skeletal muscles and bones make up the _____ system

Answer 4

Musculo-skeletal system

Question 5

the body contains more than ______ skeletal muscles

Answer 5

600

Question 6

out connective tissue covering of the muscle

Answer 6

epimysium

Question 7

small bundles of fibers wrapped in a connective tissue sheath of the muscle

Answer 7

fascicles

Question 8

the connective tissues sheath surrounding each fascicle

Answer 8

perimysium

Question 9

inside the perimysium, these muscle cells take the form of

Answer 9

muscle fibers

Question 10

unlike most cells, these cells are multinucleate

Answer 10

muscle cells

Question 11

this sheath of connective tissue also covers each muscle fiber

Answer 11

endomysium

Question 12

the basic unit of a myofibril

Answer 12

sarcomere

Question 13

surrounding each individual muscle fiber is the plasma membrane AKA the ____

Answer 13

plasmalemma

Question 14

the plasmalemma is part of a larger unit known as the ____

Answer 14

sarcolemma

Question 15

the sarcolemma is composed of _____ &________

Answer 15

The plasmalemma and basement membrane

Question 16

These cells are located between the plasmalemma and the basement membrane. They’re involved in growth, and dev. of muscle

Answer 16

Satellite Cells

Question 17

A gelatin-like substance filling the spaces of the myofibrils. (the cytoplasm of the muscle fiber) it contains a high amount of myglobin and glycogen

Answer 17

Sarcoplasm

Question 18

The sarcoplasm houses an extensive network of ___. (extensions of the plasmalemma that pass laterally through the muscle fiber)

Answer 18

Transverse tubules. (T tubules)

Question 19

A longitudinal network of tubules known as_____ are also found within the fiber. It runs parallel to the myofibrils and loop around them. It’s a storage site for calcium.

Answer 19

Sarcoplasmic reticulum

Question 20

Each muscle fiber contains several hundred to several thousand _____. They’re made up of the basic contractile elements of skeletal muscle-the sarcomeres.

Answer 20

myofibrils

Question 21

the dark regions of myofibrils

Answer 21

A band

Question 22

The light regions of myofibrils

Answer 22

I band

Question 23

The lighter band within the A band.

Answer 23

H zone

Question 24

The dark line in the H zone

Answer 24

m-line

Question 25

The light I band has a dark stripe known as the

Answer 25

z disk or z line

Question 26

The basic functional unit of a myofibril, and the basic contractile uint of muscle

Answer 26

sarcomere

Question 27

Thinner filaments are composed mostly of _____ (lighter parts of sarcomere)

Answer 27

actin

Question 28

Thicker Filaments are mostly composed of ___ (darker parts of sarcomere)

Answer 28

Myosin

Question 29

Although each filament is referred to as an actin filament is actually composed of actin, _______ & _______. each end has one end inserted into a z disk, with opposite end extending toward the center of the sarcomere.

Answer 29

Actin, tropomyosin and troponin.

Question 30

______ an anchoring protein for actin, co-extends with actin and appears to be playing a regulatory role in mediating actin and myosin interactions.

Answer 30

nebulin

Question 31

a tube shaped protein that twists are the actin strands

Answer 31

tropomyosin

Question 32

a nerve cell that connects with and innervates many muscle fibers

Answer 32

A motor neuron

Question 33

a single motor neuron and all the muscle fibers it signals collectively termed as a

Answer 33

motor unit

Question 34

The synapse of gap between the motor neuron and muscle fiber are known as the ___

Answer 34

the neuromuscular junction

Question 35

The complex sequence of events that triggers a muscle fiber to contract is termed as _______

Answer 35

excitation-contraction coupling

Question 36

a nerve impulse is also known as

Answer 36

action potential

Question 37

the action potential arrives at the motor neuron's

Answer 37

dendrites

Question 38

axon terminals leave a signaling molecule or neurotransmitter called

Answer 38

Acetylcholine

Question 39

___ binds to troponin on thin filament

Answer 39

Calcium

Question 40

_____ binds to actin when tropomyosin is gone

Answer 40

myosin

Question 41

the explanation for how muscle fibers shorten

Answer 41

the sliding filament theory

Question 42

The tilting of the myosin head is called the

Answer 42

power stroke

Question 43

after the power stroke ends

Answer 43

- myosin heads detach - myosin head rotates back to original position - myosin attaches to another active site further down

Question 44

In addition to the binding site for actin, a myosin head contains a binding site for the molecule _____

Answer 44

Adenine triphosphate

Question 45

energy from _____ breakdown is used to power the tilting of the myosin head

Answer 45

(ATP) Adenine triphosphate

Question 46

This enzyme is located in myosin head and splits the atp to yield adenosine diphospahate (ADP) and inorganic phosphate, and energy. The breakdown of this energy is used to tilt the myosin head.

Answer 46

adenine tripohosphatase

Question 47

After Action potential (AP) ends

Answer 47

- electrical stimulation of SR ends - calcium is pumped back into SR - Stored until next AP arrives - Requires ATP

Question 48

without calcium present:

Answer 48

tropomyosin and troponin return to resting conformation. - covers myosin-binding site - prevents actin-myosin bridging

Question 49

Fast myosin ATPase

Answer 49

fast contraction cycling

Question 50

Slower myosin ATPase

Answer 50

slower contraction cycling

Question 51

- Type II fibers have a more highly developed ____ | - & 5times faster release of ______

Answer 51

Sarcoplasmic reticulum | Ca2

Question 52

Type ___ motor units are smaller neurons with less than 300 fibers

Answer 52

1

Question 53

Type ___ motor units have larger neurons and contain more than 300 fibers

Answer 53

2

Question 54

-fibers per motor neuron:

Answer 54

type I

Question 55

- fibers per motor neuron: >300 - motor neuron size: larger - conduction velocity : faster - contraction speed (ms): 50 - Type of myosin ATPase: fast - Sarcoplasmic reticulum: high

Answer 55

Type IIa and type IIx

Question 56

Can maintain exercise for a prolonged period, requires oxygen for atp production, low-intensity aerobic exercise, daily activities.

Answer 56

Type 1

Question 57

- poor aerobic endurance, fatigue quickly, | - produce atp anaerobically

Answer 57

Type II fibers

Question 58

- More force, faster fatigue than type 1 | - short, high intensity endurance events (1,600 m run)

Answer 58

Type IIa

Question 59

- Seldom used for everyday activities | - short explosive sprints (100m)

Answer 59

type IIx

Question 60

training can induce a ___% change in fiber type

Answer 60

10%

Question 61

the motor unties decrease as individual ages

Answer 61

type II

Question 62

- Muscle shortens while producing force - Most familiar type of contraction - Sarcomere shortens, filaments slide toward center

Answer 62

Concentric contraction

Question 63

- Muscle lengthens while producing force - Cross-bridges form but sarcomere lengthens - Example: lowering heavy weight

Answer 63

Eccentric contraction

Question 64

- Muscle produces force but does not change length - Joint angle does not change - Myosin cross-bridges form and recycle, no sliding

Answer 64

Static (isometric) contraction

Question 65

- Muscle produces force and changes length | - Joint movement produced

Answer 65

Dynamic contraction

Question 66

- Optimal sarcomere length = optimal overlap | - Too short or too stretched = little or no force develops

Answer 66

Length-tension relationship

Question 67

- Concentric: maximal force development decreases at higher speeds - Eccentric: maximal force development increases at higher speeds

Answer 67

Speed-force relationship