Chapter 10: Muscle Tissue

Question 1

Name the types of muscle tissue

Answer 1

skeletal, cardiac, and smooth

Question 2

Name all 5 functions of muscle tissue

Answer 2

1. Movement
2. Stability
3. Control of body openings and passages
4. Heat production (20-30% of BH at rest)
5. Glycemic Control (regulation of blood glucose)

Question 3

Name and describe all 5 characteristics of muscle tissue

Answer 3

1. Excitability: able to respond to a stimulus
2. Conductivity: signal for a muscle to contract is spread throughout the entire muscle
3. Contractability: the ability to forcefully shorten
4. Extensibility: to be stretched
5. Elasticity: ability to recoil to the original resting length when tension is released

Question 4

Characteristics of skeletal muscle fibers

Answer 4

multinucleated, striated, and voluntary

Question 5

What are connective tissue investments and what is their overall function

Answer 5

they are connective tissue sheaths that surround muscle tissue and organize muscle tissue, provide elasticity, and carry blood vessels and nerves to muscle fibers

Question 6

Epimysium

Answer 6

covers the surface of muscle, dense connective tissue, and continuous with fascia on outer surface. Extends into perimysium

Question 7

Fascia

Answer 7

connective tissue sheet that covers epimysium and separates muscles

Question 8

Perimysium

Answer 8

extension of epimysium into muscle; organizes collections of muscle fibers into fascicles; contains nerves and blood vessels

Question 9

Endomysium

Answer 9

extensions of the perimysium that surround individual muscle fibers; loose connective tissue; contains capillaries and nerves

Question 10

Fusiform

Answer 10

muscle shape that is thick in middle and tapers at ends; relatively strong; Ex: biceps brachii and gastrocnemius

Question 11

Pennate

Answer 11

feather shaped muscle; strongest muscle

Question 12

Aponeurosis

Answer 12

broad sheet of connective tissue that connects some muscles to bones in some cases of indirect attachment

Question 13

Mechanical advantage

Answer 13

the closer the load is to the fulcrum and the farther the effort is from the fulcrum, the less effort to move the load in short distances

Question 14

What is a muscle fiber and what is it made of

Answer 14

an individual skeletal muscle cell; sarcolemma: plasma membrane of cell; Sarcoplasm: cytoplasm of cell; contains myofibrils

Question 15

myofibrils

Answer 15

cylindrical bundles of protein microfilaments or myofilaments

Question 16

name types of myofilaments

Answer 16

thin, thick, or elastic

Question 17

Transverse tubules (T-tubules)

Answer 17

invaginations of the sarcolemma that incircle each myofibril

Question 18

Sarcoplasmic Reticulum (SR)

Answer 18

Endoplasmic reticulum that stores and releases calcium ions. Lies close to T-tubules

Question 19

Terminal Cisternae

Answer 19

dilated regions of the SR adjacent to T-tubules

Question 20

Triad

Answer 20

a T-tubule and two terminal cisternae

Question 21

Thick Filaments

Answer 21

Composed of contractile protein myosin

Question 22

Myosin molecules

Answer 22

golf club shaped; tail consisted of two twisted chains; double globular head with actin binding sites

Question 23

Myosin filament

Answer 23

composed of 200-500 myosin molecules

Question 24

Name all 3 Thin filaments and functions

Answer 24

1. Actin- contractile protein’ G-actin has active sites where myosin heads bind
2. Tropomyosin- regulatory protein; blocks active sites of actin in relaxed muscle fibers
3. troponin- 3 subunits one of which binds calcium

Question 25

Why do muscle striations occur?

Answer 25

due to arrangement of thick and thin filaments

Question 26

I Band

Answer 26

regions of thin filaments that do not overlap thick filaments; wide light bands

Question 27

A Band

Answer 27

Wide Dark Bands; region of overlapping thick and thin filamentts

Question 28

H Zone

Answer 28

Narrow light region in the center of A band; only thick filaments

Question 29

M Line

Answer 29

Dark line in center of H band; region where the two halves of myosin filaments are joined

Question 30

Z Disks

Answer 30

Dark line in center of I band; proteins anchoring thin filaments of adjacent sarcomeres

Question 31

sarcomeres

Answer 31

segment of a myofibril extending from one Z-disk to the next.

Question 32

Nodal tissues

Answer 32

specialized cardiac muscle fibers; spontaneously depolarizes; generates heartbeat

Question 33

characteristics of cardiac muscle tissue

Answer 33

involuntary, striated, and branched; no regeneration does not divide; intercalated disks which are special junctional complexes between cardiocytes

Question 34

characteristics of smooth muscle fibers

Answer 34

involuntary, no striations, no branching; spindle shaped; capable of dividing and regenerating; dense bodies that replace Z-disks