Lesson 7: Muscular System Bio201 Objectives

Front 1

The four functions of the muscular system are:

Back 1

Movement
Posture
Protection
Heat Production

Front 2

Skeletal muscle tissue is connected to _____

Back 2

Bones

Front 3

Bones act as ________ and muscle provides the force to move bones

Back 3

Levers

Front 4

Muscles are constantly contracting to maintain your _____

Back 4

Posture

Front 5

The abdominal _______ are protected by the abdominal wall which is comprised in a large part by muscles

Back 5

Organs

Front 6

Muscle tissue is very _______ active and comprises a large mass of the body

Back 6

Metabolically

Front 7

Muscle tissue helps to maintain normal body ______

Back 7

Temperature

Front 8

What are the four major functional characteristics of muscle tissue

Back 8

Contractility
Excitability
Extensibility
Elasticity

Front 9

Which of the four major functional characteristics of muscle tissue does this describe: Muscle tissue has the ability to shorted forcefully

Back 9

Contractility

Front 10

Which of the four major functional characteristics of muscle tissue does this describe: Muscle tissue has the ability to respond to a stimulus

Back 10

Excitability

Front 11

Which of the four major functional characteristics of muscle tissue does this describe: Muscles can be stretched

Back 11

Extensibility

Front 12

Which of the four major functional characteristics of muscle tissue does this describe: After being stretched, muscles can recoil to their resting length

Back 12

Elasticity

Front 13

Skeletal muscle cells are also called muscle _____

Back 13

Fibers

Front 14

Skeletal Muscle cells are enlongated and _______

Back 14

Cylindrical

Front 15

Skeletal Muscle cells are _____ meaning they have many nuclei

Back 15

Multinucleated

Front 16

Skeletal Muscle cells are visibly _____ meaning they appear striped

Back 16

Striated

Front 17

Skeltal musscle cells are under ________ control

Back 17

Voluntary

Front 18

Muscle fibers can extend the entire length of the _____

Back 18

Muscle

Front 19

______ muscle cells are the muscle cells of the heart

Back 19

Cardiac

Front 20

_____ muscle cells are branching cells that connect to each other at intercalated disks

Back 20

Cardiac

Front 21

Cardiac muscle cells are visibly striped or ______

Back 21

Striated

Front 22

Cardiac muscle cells are under ______ control

Back 22

Involuntary

Front 23

______ muscle cells are found in the walls of internal organs

Back 23

Smooth

Front 24

______ muscle cells are spindle shaped cells with a single nucleus

Back 24

Smooth

Front 25

______ muscle cells are not striated.

Back 25

Smooth

Front 26

______ muscle cells are 1000x shorter than skeletal muscle fibers

Back 26

Smooth

Front 27

In smooth muscle cells all the phases of contraction are _____

Back 27

Slower

Front 28

In smooth muscle cells, actin and myosin myofilaments are present but not organized into _______

Back 28

Sacromeres

Front 29

Muscle ____ are muscle cells

Back 29

Fibers

Front 30

Are comprised of a group of muscle fibers

Back 30

Fasciculi

Front 31

Is comprised of a group of fasciculi

Back 31

Whole muscle

Front 32

______ tissue surround each structural level of a muscle

Back 32

Connective

Front 33

______ tissue binds the cells together giving strangth and support to the entire muscle

Back 33

Connective

Front 34

Is a type of connective tissue surrounding the muscle fibers

Back 34

Endomysium

Front 35

This type of connective tissue surrounds, separates, and electrically insultaes muscle cells

Back 35

Endomysium

Front 36

Connective tissue sheath that surround the fascicles

Back 36

Perimysium

Front 37

Connective tissue sheath around the whole muscle

Back 37

Epimysium

Front 38

A second connective tissue layer surrounds the whole muscle, superficial to the epimysium

Back 38

Fascia

Front 39

In muscle ______ the many nuclei of the cell lie just inside the plasma membrane

Back 39

Fibers

Front 40

The name for the plasma membrane of muscle fibers

Back 40

Sarcolemma

Front 41

Is the smooth endoplasmic reticulum of the muscle fiber. It forms a tubular network around each myofibril

Back 41

Sarcoplasmic reticulum

Front 42

The enlargement of the sarcoplasmic reticulum on either side of a trasverse tubule

Back 42

Terminal cisterna

Front 43

Calcium ____ are stored in the terminal cisternae

Back 43

Ions

Front 44

Is a transverse tubule and two adjacent terminal cisterna

Back 44

Triad

Front 45

Transverse tubules are tubes that extend at right angles from the sarcolemma into the interior of the cell

Back 45

T Tubules

Front 46

Electrical impulses can travel along these tubules to the interior

Back 46

T Tubules

Front 47

Mitochondria generate ____ which is stored in the energy currency molecule

Back 47

ATP

Front 48

Are the contractile structures that extend from one end of the myscle fiber to the other. They fill up most of the cell's cytoplasm

Back 48

Myofibrils

Front 49

Myofibrils are composed of two types of _______

Back 49

myofilaments

Front 50

The myofilaments are the contractile _____

Back 50

Proteins

Front 51

A thin myofilament is called

Back 51

Actin

Front 52

A thick myofilament is called

Back 52

Myosin

Front 53

The myofilaments are arranged in such a manner to form visible alternating light and dark _____

Back 53

Bands

Front 54

Myofilaments are organized into repeating fuctional units called

Back 54

Sarcomeres

Front 55

Dark band formed by the thich myofilaments

Back 55

A band

Front 56

Light band between A bands. Contains only thin myofilaments

Back 56

I band

Front 57

Is where the actin myofilaments are held into place

Back 57

Z line

Front 58

A sacromere extends from _ line to _ line (1)

Back 58

Z

Front 59

Region between ends of actin myofilaments. Contains only myosin

Back 59

H Zone

Front 60

This line is in the middle of the H zone

Back 60

M Line

Front 61

Each myosin molecule is shaped like a ______ club

Back 61

Golf

Front 62

In thick myofilament the ____ portion lies parallel to the myofilament

Back 62

Rod

Front 63

In thick myofilamentthe double ____ portion extend laterally from the rods

Back 63

Head

Front 64

In thick myofilament The head of the myosin can bind to an actin subunit forming a ______

Back 64

Crossbridge

Front 65

In thick myofilament the head also has the ability to move _______

Back 65

back and fourth

Front 66

______ myofilament is comprised of actin, tropomyosin and troponin

Back 66

Thin

Front 67

Two strands of subunits form a double helix. Each subunit has a binding site for mosin. This is true of _____

Back 67

Actin

Front 68

Elongated protein that wraps around the actin

Back 68

Tropomyosin

Front 69

Protein that covers the binding site on the actin subunits

Back 69

Tropomyosin

Front 70

This protein prevents the myosin head from attaching

Back 70

Tropomyosin

Front 71

Binds to actin, tropomyosin and calcium

Back 71

Troponin

Front 72

When ____ binds to troponin, tropomyosin moves uncovering the binding sites on the actin subunits making it possible for myosin to bind to the actin

Back 72

Ca++

Front 73

In multiple corssbridge _____ all crossbridges are neither bound or disconnected at the same time.

Back 73

Cycles

Front 74

A muscle fiber contracts as thin and thich myofilaments silde ____ one another

Back 74

Past

Front 75

The sarcomeres _____ but the length of each myofilament does not change in SF theory

Back 75

Shorten

Front 76

In sliding filament theory I bands and H zones change _____

Back 76

Length

Front 77

In sliding filament theory A bands remain a constant

Back 77

Length

Front 78

Is where a motor neuron and a muscle fiber meet

Back 78

Neuromscular Junction

Front 79

The neuromuscle junction is also called a _____

Back 79

Synapse

Front 80

Nerve cells that conduct nerve inmpulses from the brain or spinal cord to skeletal muscle fibers

Back 80

Motor neurons

Front 81

Nerve impulses are also called

Back 81

Action Potentials

Front 82

For a muscle fiber to contract it must be stimulated by an action potential from the process of a ______

Back 82

Neuron

Front 83

Motor neurons extend to muscles of the way of axons. The axoms branch out to connect with several muscle ______

Back 83

Fibers

Front 84

The end of the axon is called an axon

Back 84

Terminal

Front 85

The receiving area of the sarcolemma

Back 85

Motor endplate

Front 86

The space between the axon terminal and the motor endplate

Back 86

Synaptic cleft

Front 87

Sacs in the axon terminal contain acetylcholine

Back 87

Synaptic Vesicles

Front 88

An enzyme in the synaptic cleft that brakes down acetylcholine into acetic acid and choline

Back 88

Acetylcholinesterase

Front 89

keeps acetylcholine from accumulating in the synaptic cleft where it would be a constant stiumuls

Back 89

Acetylcholinesterase

Front 90

Is reabsorbed and recycled ito more acetylcholine

Back 90

Choline

Front 91

Can be used by the cell in the glucose catabolism pathway

Back 91

Acetic acid

Front 92

A motor neuron and all of the seletal muscle fibers that it innervates

Back 92

Motor unit

Front 93

Few muscle fibers per motor unit means ____ control. Small motor units are used for precise small movements like eye and hand movement

Back 93

Better

Front 94

The number of ____ ____ activated in a muscle is dependant on how much muscle tension is required to perform the task

Back 94

Motor Units

Front 95

Stimulation of additional motor units for increased strength of contraction

Back 95

Recruitment

Front 96

Constant ongoing tension of muscles

Back 96

Muscle tone

Front 97

Name the three stages of the All-Or-None law of skeletal muscle contraction

Back 97

Each action potential stimulates a muscle fiber