Chapter 10 - Muscular System

Front 1

Muscles can only ____ since they ____ when they ____ to create a force. In general they cannot ___ and create a force.

Back 1

pull, shorten, contract, push

Front 2

Muscles constitute % of total body weight of adults?

Back 2

40-50%

Front 3

Myology

Back 3

The scientific study of muscles.

Front 4

Three types of muscle tissue

Back 4

1. Skeletal muscle

2. Cardiac muscle

3. Smooth muscle

Front 5

Skeletal Muscle functions

Back 5

a) move the bones of the skeleton or

b) skin

Front 6

Body contains __ Skeletal muscles

Back 6

about 700

Front 7

Skeletal Muscle basic form

Back 7

striated - cells are long, cylindrical and multinucleated. There are visible alternating light and dark bands.

Front 8

Skeletal muscle has ____ control of contraction and relaxation

Back 8

voluntary

Front 9

Cardiac muscles (4)

Back 9

form most of heart wall

striated

involuntary control

Authorhythmic

Front 10

Cardiac muscle are authorhythmic because of

Back 10

pacemaker cells

Front 11

Smooth Muscle (3)

Back 11

located in walls of hollow structures (e.g. blood vessels, airways, digestive tract, skin) where there is some sort of movement

nonstriated or smooth

involuntary control

Front 12

The prime function of muscle tissue is to:

Back 12

change chemical energy into motion (movement) energy to generate force and produce movement

Front 13

Muscle tissue has seven specific functions:

Back 13

1. Produce skeleton movement

2. Maintain posture and body position

3. support soft tissue

4. guard body entrances and exits

5. maintain body temperature

6. store nutrients

7. assists in bulk transport of body fluids

Front 14

Produce skeleton movement

Back 14

skeletal muscle contractions pull on tendons and move the bones of the skeleton

- muscles produce large and critical movements such as walking, running and breathing, and fine movements like writing

Front 15

Maintain Posture and Body Position

Back 15

tension in our skeletal muscles stabilize joints and maintains body posture

Front 16

Support soft tissues

Back 16

the abdominal wall and the floor of the pelvic cavity consist of layers of skeletal muscle

- muscles support the weight of the abdominal organs and protect them from injury

Front 17

Guard Body Entrances and Exits

Back 17

the openings of the digestive and urinary tracts are encircled by skeletal muscles.

- These muscles (sphincters) provide voluntary control over swallowing, defecation and urination

Front 18

Maintain Body Temperature

Back 18

skeletal muscles generate heat (thermogenesis) (shivering)

- the heat released by working muscles keeps/helps maintain normal body temp. (e.g. shivering to produce some extra heat to warm body)

Front 19

Store Nutrients

Back 19

The contractile proteins in skeletal muscles can be broken down to release amino acids into circulation

- these amino acids can be used by the body to provide energy when the diet does not contain adequate proteins or calories

Front 20

Assists in bulk transport of body fluids

Back 20

Skeletal muscle contractions assist with the return of blood and lymph from the peripheral tissues to the cardiovascular system (CVS)

- the skeletal muscle pump is a well-recognized mechanism that is instrucmental in the return of venous blood from the peripheral tissues (Movement of blood)

-Skeletal muscle contractions also result in passive contraction of lymphatic capillaries and vessels which in turn trans[port lymph from the periphery to the cardiovascular system lymphatic ducts and ultimately in the right atrium of the heart. (movement of lymph-ECF->lymphatic capillaries->vessels->ducts->CVS)

Front 21

Skeletal muscle is a _____ composed of ______ called ______. What other three things are found in muscles?

Back 21

separate organ, thousands of elongated muscle cells, muscle fibers (myofibers).

Connective tissue, blood vessels, nerves.

Front 22

Organization of Skeletal Muscle (3 collagen-rich layers of connective tissue)

Back 22

Epimysium

Perimysium

Endomysium

Front 23

Epimysium

Back 23

superficial layer that encircles the whole muscle.

- seperates the muscle from surrounding tissues and organs

Front 24

Perimysium

Back 24

surrounds groups of 10-100 individual muscle fibers, and separates them into bundles called a fascicle.

- contains blood vessels and nerves that serve the muscle fibers within the fascicles.

Front 25

Fasicles

Back 25

Bundles of muscle fibers.

large enough to be seen with naked eye. What you see when you tear a piece of meat.

Front 26

Endomysium

Back 26

thin stretch of connective tissue that surrounds individual muscle fibers. This layer contains:

- capillary networks that supply the muscle fibers

- myosatellite cells can repair damaged muscle tissue

-nerve fibers that control the muscle

Front 27

Satellite Cells

Back 27

stems cells in muscle that can repair damaged muscle tissue (unfused myoblasts)

Front 28

Which layers are visible to naked eye? not?

Back 28

Epimysium

Perimysium

Not

Endomysium

Front 29

Aponeurosis

Back 29

(tendon)

collagen fibers of the epimysium, perimysium and endomysium come together to form it at the end of a muscle.

e.g. the calcaneal (achilles) tendon of the gastrocnemius (calf) muscle attaches the muscle to the calcaneus.

Front 30

Muscle Fibers are actually the ____ and are also called ____ but NOT ____, they are something different.

Back 30

muscle cells, myofibers, myfibrils

Front 31

Each muscle fibers has these characteristics: (2)

Back 31

- arises from the fusion of hundreds of myoblasts during fetasl development

. multinucleated - each cell has a hundred or so nuclei

.large cells - typically 10-30cm long (!) by 0.01-0.1mm in diameter

- Muscle fibers do not divide after they are formed, by they can increase in size

. the # of muscle cells is set before birth and most of them alst a lifetime

. satellite cells remain in mature muscle and are still able to fuse with each other or with damaged muscle fibers to repair them

Front 32

Atrophy

Back 32

is the shrinking of muscles which occurs in a person who is bedridden and has not been using muscles. Also occurs with aging.

Front 33

Hypertrophy

Back 33

the muscle growth that occurs mainly by enlargement of existing fibers

Front 34

Muscle Fibers are composed of these components. (8)

Back 34

1. Sarcolemma

2. T-Tubule

3. Sarcoplasma

4. Myofibrils

5. Sarcomere

6. Sacroplasmic Reticulum

7. Triad

8. Terminal Cisternae

Front 35

Sarcolemma

Back 35

- plasma membrane of a muscle cell

. multiple nuclei are locatewd just beneath the sacrolemma

. sarcolemma has an electrochemical potential across its membrane, like all living cells

Front 36

T-Tubules (transverse tubules)

Back 36

narrow tubes that are continuous with the sarcolemma and extend inside the cell like little tunnels

- T-tubules are open to the outside and are full of extracellular fluid

- T-tubules are extensions of sacrolemma + surround myofibrils, which are organelles within the muscle fiber

Front 37

Sarcoplasm

Back 37

cytoplasm of a musle fiber

Front 38

Myofibrils

Back 38

cellular organelles that are contractile elements of the muscle fiber

- under a microscopem, each muscle fiber appears filled with tiny parallel threads that extend the entire length of a muscle fibers

- they are encircled by T-Tubules

-Myofibrils are made up of thin filament and thick filaments, which are arranged in sarcomeres which are the basic functional units of a myofibrils

Front 39

Sarcoplasmic Reticulum

Back 39

a system of fluid-dilled sacs that encircle each myofibril

- on either side of a T Tubule, the SR forms extended chambers called terminal cisternae. The combination of a pair of terminal cisternae plus a T tubule is known as a triad

Front 40

terminal cisternae

Back 40

on either side of a T Tubule, the SR forms extended chambers called terminal cisternae

Front 41

triad

Back 41

The combination of a pair of terminal cisternae plus a T tubule is known as a triad

Front 42

In a relaxed muscle fiber the SR stores ___

Back 42

calcium

Front 43

The release of ___ from the SR triggers muscle contraction

Back 43

calcium

Front 44

T-Tubules are _____ of _____ and surround _____ which are ____ within the muscle fiber

Back 44

extentions, sarcolemma, myofibrils

Front 45

Z-Line

Back 45

mark boundary between adjacent sarcomeres

Front 46

Actinin

Back 46

interconnects thin filaments of adjacent sarcomere

Front 47

Titin

Back 47

attaches thick-filaments to Z-line

Front 48

I-Band

Back 48

thin filaments only

Front 49

A-Band

Back 49

thick filaments in center of sacromere + part of thin filament