Chapter 10 Muscle Tissue

Front 1

What are the four basic functions of the muscular system?

Back 1

motion, movement of subtances with the body, stabilizing body position and regulating organ volume, thermogenesis

Front 2

shivering

Back 2

involuntary contractions of the skeletal muscle

Front 3

List 5 characteristics of muscle tissue.

Back 3

excitability, conductivity, contractility, extensibility, elasticity

Front 4

excitability

Back 4

ability to respond to certain stimuli by producing electrical signals called action potentials.

Front 5

conductivity

Back 5

the ability to conduct action potentials along the plasma membrane

Front 6

contractibility

Back 6

the ability of muscle tissue to shorten and to thicken, thus generatig force to do work.

Front 7

extensibility

Back 7

capacity in muscle to be extended without damaging tissue

Front 8

elasticity

Back 8

muscle’s capacity to return to its original shape after contraction or extension--recoil

Front 9

fascia

Back 9

a sheet or broad band of fibrous connective tissue deep to the skin or around muscles and other organs of the body.

Front 10

superficial fascia (subcutaneous layer)

Back 10

- is immediately deep to the skin
- composed of aereolar connective tissue and adipose tissue

Front 11

What are 4 functions of superficial fascia?

Back 11

- stores water and fat.
- reduces the rate of heat loss
- provides mechanical protection against traumatic blows.
- provides a framework for nerves and blood vessels to enter and to exit muscles.

Front 12

deep fascia

Back 12

is composed of dense irregular CT and lines the body wall and limbs
also holds muscles together, separating them into functional groups

Front 13

Whate are the functions of deep fascia?

Back 13

- allows free movement of muscles
- supports nerves, blood vessels and lymphatic vessels
- fills spaces between the muscles

Front 14

Explain motion as a function of muscle tissue

Back 14

movements such as walking or running

Front 15

Movement of substances within the body

Back 15

All three types of muscle tissue help moves substances such as blood, flood, sperm, ova, and urine.

Front 16

Stabilizing body positions and regulating organ volume.

Back 16

Skeletal muscle contractions maintain stable body positions and posture. Sustained and contractions of smooth muscles nlock exit of food from the stomach and urine from the urinary bladder for temporary storage.

Front 17

Thermogenesis

Back 17

Skeletal muscle contractions may generate 85% of all body heat to help maintain normal body temperature.

Front 18

epimysium

Back 18

is the outermost layer of dense irregular connective tissue that encircles the whole muscle

Front 19

perimysium

Back 19

surrounds bundles of 10-100 muscle fibers called fascicles

Front 20

fascicles

Back 20

small bundles or clusters of muscle cells/fibers

Front 21

endomysium

Back 21

penetrates into the interior of each fascile separating individual muscle fibers from one another

Front 22

tendon

Back 22

When all three levels of connective tissue mentioned above, the epimyseum, the perimyseum, and the endomyseum extend beyond the muscle fibers and form a dense cord of connective tissue that enables the attachment of muscle to the periosteum of the bone. Ex: calcaneal tendon of the calf muscle.

Front 23

aponeurosis

Back 23

when the connective tissue elements forming a tendon, extend as a broad flat layer ex: aponeurotica on top of the skull

Front 24

Starting with the connective tissue that surrounds individual muscle fiber, list the connective tissue layers in order.

Back 24

endomysium, perimysium, epimysium, deep fascia, superfical fascia

Front 25

motor unit

Back 25

a motor neuron plus all the skeletal muscle fibers it stimulates

Front 26

neuromuscular junction

Back 26

the type of synapse formed between a motor neuron and a skeletal muscle fiber

Front 27

Describe the process by which a motor neuron communicates with a muscle cell.

Back 27

The interface between a motoneuron and muscle fiber is a specialized synapse called the neuromuscular junction. Upon adequate stimulation, the motoneuron releases a flood of neurotransmitters that bind to postsynaptic receptors and triggers a response in the muscle fiber. In invertebrates, depending on the neurotransmitter released and the type of receptor it binds, the response in the muscle fiber could either be excitatory or inhibitory.

Front 28

What neurotransmitter is released at the neuromuscular junction?

Back 28

acetylcholene (AcH)

Front 29

motor end plate

Back 29

the region of the muscle fiber plasma membrane that is adjacent to the axon terminals.

Front 30

List the structural organization of a skeletal muscle from superficial to deep.

Back 30

skeletal muscle, fascicle, muscle fiber, myofibril, thin and thick filaments

Front 31

Describe the components of a muscle fiber/myofibril.

Back 31

sarcolemma: the plasma membrane of a muscle fiber
sarcoplasm: the muscle fiber's cytoplasm
sarcoplasmic reticulum: a fluid-filled system of cisterns which encircles each myofibril

Front 32

Myofibrils are composed of what?

Back 32

thin, thick and elastic filaments

Front 33

thin filaments

Back 33

protein composition: actin, troponin and tropomyosin
functions: contains myosin head binding sites; slides along thick filament during contraction

Front 34

thick filaments

Back 34

protein composition: myosin
functions: myosin heads (cross brideges) move thin filaments toward the center of sarcomere during contraction.

Front 35

elastic filaments

Back 35

protein: titin/connectin
functions: anchors thick filaments to Z discs and stabilizes them during contraction and relaxation.

Front 36

What is the function of the sarcoplasmic reticulum?

Back 36

During relaxation: stores Calcium ions
During contraction: releases calcium ions throuch Calcium ion release channels.

Front 37

Explain the role of Calcium and regulator proteins in muscle contraction.

Back 37

An increase in calcium concentration in the sacoplasm starts filament sliding, while a decrease turns off the sliding process.