Ch 9 & 10

Question 1

Agonist

Answer 1

Prime mover

Question 2

Antagonist

Answer 2

Opposes and slows the action of agonist making movement graceful

Question 3

Synergists

Answer 3

Work with agonists to help minimize unwanted deviations from a movement

Question 4

Fixators

Answer 4

Hold a bone in place

Makes movement more efficient and reduces risk of injury

Question 5

Origin

Answer 5

Less moveable anchoring point

Question 6

Insertion

Answer 6

Attaches to the structure or bone that will be moved

Question 7

Fulcrum (central)

Answer 7

Joint at which movement occurs in a lever

Question 8

Second class lever

Answer 8

Resistance is in the middle and applied force is farthest away from fulcrom

Question 9

Third class lever

Answer 9

Applied force is in the middle and resistance is furthest away from fulcrum

Question 10

Myofibrils

Answer 10

Bundles of specialized proteins ( cylindrical organelles) located within the sacroplasm
Make up 50-80% of of a muscle cell’s volume

Question 11

Myocytes

Answer 11

Muscle cells

Question 12

Sarcomere

Answer 12

Functional unit of contraction

Section of myofibril that extends from one Z-disc to the next Z-disc

Question 13

Sacroplasm

Answer 13

“Cytoplasm” of muscle cells

Question 14

Fascicles

Answer 14

Multiple skeletal muscle fibers together with the surrounding endomysium

Question 15

Endomysium

Answer 15

Extracellular matrix of myocytes

Holds muscle cells together

Question 16

Muscle tension

Answer 16

Basic function of all muscle types

Creates movement, maintains posture, stabilizes joints, generates heat regulates flow of materials through hollow organs

Question 17

First class lever

Answer 17

Folcrum is in the middle

Question 18

Contractility

Answer 18

Ability of proteins within muscle cell to draw together.

Question 19

Excitability

Answer 19

Electrical Changes across the plasma membrane caused by a stimuli

Question 20

Conductivity

Answer 20

Movement of electrical changes across the entire length of the plasma membrane

Question 20

Extensibility

Answer 20

Stretch

The ability of a muscle cell to stretch up to 3 times their resting length wothout damage

Question 22

Elasticity

Answer 22

Ability of muscle cell to return to original shape after being stretched

Question 23

Sarcolemma

Answer 23

“Plasma membrane” of a muscle cell

Composed of phospholipid bilayer with multiple specialized proteins

Question 24

Sacroplasmic reticulum (SR)

Answer 24

Modified smooth endoplasmic reticulum that forms a weblike network surrounding each myofibril

Stores and releases calcium ions
Activities vital to muscle contraction and relaxation

Question 25

Transverse tubules

Answer 25

Inward extensions of the sarcolemma into the the muscle fiber Form a tunnel like network within the muscle fiber that is filled with extracellular fluid

Question 26

Terminal cisternae

Answer 26

Flank each side of the T- tubules | These are enlarged portions of the SR

Question 27

Triad

Answer 27

Combination of the T-tubule and two terminal cisternae

Question 28

Myofilaments

Answer 28

The hundreds to thousands of protein bundles that compose a myofibril 3 Types Contractile proteins- produce tension Regulatory proteins- control when muscle fiber can contract Structural proteins- hold myofilaments in their proper place & ensure structural stability of myofibril and muscle fiber

Question 29

Three types of myofilaments

Answer 29

Thick filaments- composed of many molecules of myosin Thin filaments- composed of contractile and regulatory proteins Elastic filaments- thinnest type, composed of single massive structural protein called titin

Question 30

Myosin

Answer 30

Contractile protein found in myofilaments

Question 31

Actin

Answer 31

Can bind to a myosin head at the “active site”

Question 32

Tropomyosin

Answer 32

Long ropelike regulatory protein that spirals around the two actin strands to cover the “active sites” Helps to switch off and on the process of muscle contraction

Question 33

Troponin

Answer 33

Smaller globular regulatory protein holds tropomyosin in place Helps to switch off and on the process of muscle contraction

Question 34

Type 1 fibers

Answer 34

Slow twitch Small in diameter Less forceful Maintain extended periods of contraction

Question 35

Type II fibers

Answer 35

Fast twitch fibers Larger in diameter, contract more rapidly Quickly fatigued 3 types: IIa (FOG)- Fast Oxidative glycolytic IIx (FO) - Fast Oxidative IIb (FG) - fast glycolytic

Question 36

Excitation-contraction coupling

Answer 36

The link between the depolarization of action potential to Ca++ to release from sarcoplasmic reticulum

Question 37

Muscle twitch

Answer 37

Response of a muscle fiber to a single action potential in a motor neuron

Question 38

Latent period

Answer 38

Time it takes for action potential to spread through sarcolemma

Question 39

Contraction period

Answer 39

Rapid increase in tension as crossbridge cycles occur repeatedly

Question 40

Relaxation period

Answer 40

Tension increases due to decreasing calcium ions. Tropomyosin once against n blocks the active sites of myosin

Question 41

6 types of neuroglia cells

Answer 41

1. Ciliated ependymal cells-move cerebrous spinal fluid around 2. Astrocytes- form the blood brain barrier 3. Microglia- fight infection through phagocytosis 4. Oligodendrocytes- bind the CNS neurons together and insulate axons of CNS 5. Non ciliated ependymal cells- secrete cerebro spinal fluid Schann cells- make up the myelin sheaths of the PNS