A&p Chapter 10 Muscular Tissue

Front 1

Types of muscular tissue:

Back 1

-Skeletal
-Cardiac
-Smooth

Front 2

Most skeletal muscles move___________.

Back 2

Bones

Front 3

Alternating light & dark bands, as seen when examined w/a microscope

Back 3

Striated

Front 4

Skeletal muscle tissue works mainly in a ________ manner.

Back 4

voluntary

Front 5

most skeletal muscles also are controlled____________ to some extent

Back 5

subconsciously

Front 6

without conscious control

Back 6

subsconsciously

Front 7

found only in the walls of the heart

Back 7

cardiac muscle tissue

Front 8

striated like skeletal muscle
action is involuntary (contraction &relaxation of the heart)

Back 8

cardiac muscle tissue

Front 9

-located in the walls of hollow internal structures (blood vessels, airways, & many organs)
-lacks the striations of skeletal & cardiac muscle tissue
-usually involuntary

Back 9

smooth muscle tissue

Front 10

What are the functions of muscular tissue?

Back 10

-Producing body movements
-stabilizing body positions
-moving substances w/in the body
-generating heat

Front 11

Properties that enable muscle to function and contribute to homeostasis: Properties of Muscular Tissue

Back 11

-Electrical Excitability(ability to respond to stimuli)
-Contractility(Ability to contract forcefully when stimulated)
-Extensibility(ability to stretch w/out being damaged0
-Elasticity)ability to return to an original length

Front 12

connective tissue components

Back 12

-fascia
-epimysium
-perimysium
-endomysium
-tendon
-aponeurosis

Front 13

Dense sheet or broad band of irregular connective tissue that surrounds muscles.

Back 13

fascia

Front 14

the outermost layer of muscle tissue
that separates 10-100 muscle fibers into bundles called fascicies

Back 14

epimysium

Front 15

surrounds numerous bundles of fascicies

Back 15

perimysium

Front 16

separates individual muscle fibers from one another

Back 16

endomysium

Front 17

cord that attaches a muscle to a bone

Back 17

tendon

Front 18

broad, flattened tendon

Back 18

aponeurosis

Front 19

the plasma membrane of a muscle cell

Back 19

sarcolemma

Front 20

-connect the plasma membrane to the interior of the cell
-muscle action potentials travel through them
-ensures that action potential excites all parts of the muscle fiber at the same time

Back 20

transverse (T) tubules

Front 21

The cytoplasm of a muscle fiber

Back 21

Sarcoplasm

Front 22

-includes glycogen used for synthesis of ATP and a red-colored proten called myoglobin, which binds oxygen molecules
-myoglobin releases oxygen when it is needed for ATP production

Back 22

Sarcoplasm

Front 23

Neurons that stimulate skeletal muscle to contract are_______________.

Back 23

Somatic motor neurons

Front 24

An enlargement of existing muscle fibers

Back 24

Hypertrophy
(how muscle growth occurs)

Front 25

testosterone and human growth hormone

Back 25

stimulates hypertrophy

Front 26

These retain the capacity to regenerate damaged muscle fibers

Back 26

Satellite cells

Front 27

Thread-like structures which have a contractile function

Back 27

Myobibrils

Front 28

-Membranous sacs which encircles each myofibril
-stores calcium ions
-release of calcium ions triggers muscle contraction

Back 28

Sarcoplasmic reticulum (SR)

Front 29

Function in the contractile process

Back 29

Filaments

Front 30

basic functional unit of a myofibril

Back 30

Sarcomeres (compartments of arranged filaments)

Front 31

Z discs

Back 31

-Separate one sarcomere from the next
-thick and thin filaments overlap one another

Front 32

A Band

Back 32

-darker middle part of the sarcomere
-thick and thin filaments overlap

Front 33

I Band

Back 33

-lighter, contains thin filaments (no thick filaments)
-Z discs pass through the center of each

Front 34

H Zone

Back 34

Center of each A band which contains thick but no thin filaments

Front 35

M Line

Back 35

supporting proteins that hold the thick filaments together in the H zone

Front 36

The Sliding Filament Mechanism

Back 36

-Myosin heads attach to and "walk" along the thin filaments at both ends of a sarcomere
-Progressively pulls the thin filaments toward the center of the sarcomere
-Z discs come closer together and the sarcomere shortens
-Leads to shortening of the entire muscle

Front 37

Synapse

Back 37

Where communication occurs between a somatic motor neuron and a muscle fiber

Front 38

synaptic cleft

Back 38

gap that separates the two cells

Front 39

neurotransmitter

Back 39

chemical released by the initial cell communicating with the second cell

Front 40

Describe the way nerve impulses elicit a muscle action potential.

Back 40

1.) RElease of acetylcholine-nerve impulse arriving at the synaptic end bulbs causes many synaptic vesicles to release ACh into the synaptic cleft
2.)Activation of ACh receptors-binding of ACh to the receptor on the motor end plate/opens ion channel & allows flow of Na to the inside of the muscle cell
3.)Production of muscle action potential-inflow of Na makes the inside of the muscle fiber more positively charged, triggering a muscle action potential
4.)Termination of ACh activity-ACh effects last only briefly because it is rapidly broken down by acetylcholinesterase`

Front 41

4 steps of the contraction cycle

Back 41

1.) ATP hydrolysis-reorients and energizes the myosin head
2.)Formation of cross-bridges-myosin head attaches to the myhosin-binding site on actin
3.) Power stroke-during the power stroke the crossbridge rotates, sliding the filaments
4.) Detachment of myosin from actin
-as next ATP binds to the myosin head, the myosin head detaches from actin
-contraction cycle repeats as long as ATP is available
-Continuing cycles apply the force that shortens the sarcomere

Front 42

3 ways muscle fibers produce ATP

Back 42

-creatinephosphate
-anaerobic cellular respiration
-aerobic cellular respiration

Front 43

Inability of muscle to maintain force of contraction after prolonged activity

Back 43

muscle fatigue

Front 44

Factors contributing to muscle fatigue

Back 44

-inadequate release of calcium ions from the SR
-depletion of creatine phosphate
-insufficient oxygen
-depletion of glycogen and other nutrients
-buildup of lactic acid and ADP
-failure of the motor neuron to release enough acetylcholine

Front 45

Oxygen Debt

Back 45

the added oxygen that is taken into the body after exercise

Front 46

3 ways oxygen debt is used to restore muscle cells to the resting level

Back 46

-converts lactic acid into glycogen
-synthesizes creatine phosphate and ATP
-replaces the oxygen rem9oved from myoglobin

Front 47

consists of a motor neuron and the muscle fibers it stimulates

Back 47

motor units