Week 8 - Basics of Muscle Tissues

Question 1

What are the four special characteristics of muscle tissues?

Answer 1

Excitability
Contractility
Extensibility
Elasticity

Question 2

What are the four basic muscle functions?

Answer 2

Movement of bones or fluids
Maintaining posture & body positioning
Stabilizing joints
Heat generation

Question 3

Excitability

Answer 3

Ability to receive and respond to stimuli

Question 4

Contractility

Answer 4

ability to shorten when stimulated

Question 5

Extensibility

Answer 5

ability to be stretched

Question 6

Elasticity

Answer 6

ability to recoil to resting length

Question 7

Three types of Muscle Tissue

Answer 7

Skeletal
Cardiac
Smooth

Question 8

Skeletal Muscle

Answer 8

Attaches to bone and skin
Striated
Voluntary
Long and multi nucleated

Question 9

Cardiac Muscle

Answer 9

Walls of the heart
Striated
involuntary
Branching, intercalated discs

Question 10

Smooth Muscle

Answer 10

Walls of hollow organs
Not striated
involuntary
Short, spindle, football shaped

Question 11

Epimysium

Answer 11

surrounds entire muscle

Question 12

Perimysium

Answer 12

surrounds fascicles
(groups of muscle fibers)

Question 13

Endomysium

Answer 13

surrounds each muscle fiber (cell)

Question 14

Muscles attach Directly -

Answer 14

epimysium fused to periosteum or perichondrium

Question 15

Muscles attach Indirectly -

Answer 15

connective tissue extend beyond muscle as tendon or aponeurosis

Question 16

Fascia
Skeletal muscle surrounded by fascia -

Answer 16

thin fibrous C.T. sheath for reinforcement, passage for nerves, blood vessels & attachment

Question 17

Muscle - structure and organization

Answer 17

100s-1000s of cells wrapped in C.T. with blood and nerves.
Epimysium surrounds muscle

Question 18

Fascicle - structure and organization

Answer 18

portion of the muscle
bundle of cells wrapped in C.T. sheath
Perimysium surrounds fascicle

Question 19

Muscle Fiber Cell - structure and organization

Answer 19

Long, multinucleate with mitochondria
Striated appearance
Endomysium surrounds each cell
Sarcolemma - cell membrane
Sarcoplasmic Reticulum - stores Calcium

Question 20

Muscle cell (muscle fiber) contains

Answer 20

many myofibrils, mitochondrion, wrapped in sarcolemma (membrane)

Question 21

Myofibril

Answer 21

striations are evident

Question 22

Sarcomere is a

Answer 22

muscle segment

Question 23

Sarcomere components

Answer 23

Smallest contractile (functional) unit
Composed of myofilaments (actin and myosin)
Bands have names (A, H, I)
Z-Discs - edge of sarcomere

Question 24

Z-Discs

Answer 24

Edges of sarcomere

Question 25

How is the muscle organized from largest to smallest

Answer 25

Epimysium Muscle Perimysium Fascicle Endomysium Sarcolemma Muscle Fiber Myofibril Sarcomere Filaments

Question 26

Thick filament

Answer 26

Myosin

Question 27

Thin filament

Answer 27

Actin

Question 28

Thick filament has ..

Answer 28

Myosin protein Myosin heads form Cross Bridges Contain binding sites for Actin & ATP ATPase Enzyme

Question 29

ATPase enzyme

Answer 29

an enzyme that breaks down the third phosphate group off the ATP. Breaking that bond releases the energy that myosin uses to make the muscle contraction work

Question 30

Thin filament has

Answer 30

F (fibrous) actin protein consisting of G (globular) actin subunits G-actin bears active sites for myosin head binding Tropomyosin and troponin are regulatory proteins

Question 31

What does troponin do

Answer 31

holds the tropomyosin in place (long strand of protein winding around actin)

Question 32

What does tropomyosin do

Answer 32

Normally blocks the active site on the actin subunits

Question 33

Membrane Potential is/has

Answer 33

Created by separation of charge has Na+/K+ pumps & Gradients has potential energy measured in volts (mV)

Question 34

With Action Potential, which way does each ion want to move if a channel opens

Answer 34

Sodium moves in to the cell causing depolarization Potassium moves out of cell causing repolarization

Question 35

Motor Command

Answer 35

Cerebullum

Question 36

Action Potential

Answer 36

a neural impulse; a brief electrical charge that travels down an axon

Question 37

Origin of muscles

Answer 37

Is the more stationary point of attachment

Question 38

Insertion point of muscles

Answer 38

Is the more mobile point of attachment

Question 39

Belly of the muscle

Answer 39

Is the central portion of the muscle

Question 40

Synapses

Answer 40

A gap between nerve cells

Question 41

Neurotransmitter

Answer 41

a chemical used to carry a signal from an axon to a receptor cell to pass along a message

Question 42

ATPase enzyme

Answer 42

enzyme that breaks 3rd phosphate off to change conformation of myosin head, and thus allows the myosin head to create cross-bridges within actin active subunits

Question 43

Globular Actin subunits

Answer 43

the blueberry components of actin that bind together to form the F (fibrous) actin

Question 44

Troponin

Answer 44

the site where calcium ions bind allowing troponin to change its grip on tropomyosin which moves tropomyosin to uncover the actin active sites

Question 45

Actin

Answer 45

thin filament Consists of two strands of actin subunits twisted into a helix has two regulatory proteins - troponin tropomyosin

Question 46

Smooth ER

Answer 46

surrounds each myofibril modified form of smooth ER called the sarcoplasmic reticulum

Question 47

Terminal Cisternae

Answer 47

part of the sarcoplasmic reticulum (wider region) Used for calcium storage

Question 48

Sarcolemma

Answer 48

the plasma membrane of muscle fibers

Question 49

triads

Answer 49

pair of terminal cisternae T-Tubule when an action potential travels down the sarcolemma of a muscle cell Causes the the releases of calcium from the Sarcoplasmic reticulum

Question 50

Excitement-Contraction (E-C) Coupling

Answer 50

AP transmission along sarcolemma leading to sliding of the myofilament then muscle contraction Steps of the contraction cycle & relates to rigor mortis and muscle cramping

Question 51

Rigor Mortis

Answer 51

Stiffness of death