Bio Lecture 7

Question 1

________ muscle - voluntary striated muscle that is usually attached to one or more bones

long, thin, cylindrical fibers

more than one nucleus per cell

overlapping microfilaments producing light and dark striations

Answer 1

skeletal

Question 2

_____ muscle - heart muscle, involuntarily controlled

striated, but involuntarily controlled

one nucleus per cell

Answer 2

Cardiac

Question 3

_____ muscle - involuntarily controlled

no striations
one nucleus per cell

Answer 3

smooth

Question 4

_____ - allows body to move from one place to place and movement of individual body parts

also moves body contents in course of respiration, circulation, digestion, urination, and childbirth

Answer 4

movement

Question 5

_____ - muscles maintain posture for resisting the pull of gravity

Answer 5

stability

Question 6

______ - muscles are used for facial expression, body language, writing and speech

Answer 6

communication

Question 7

____________ - sphincter muscles around eyelids, pupils, and mouth control admission of light, food, and drink into the body

others control movements out of the body

Answer 7

control of body openings and passages

Question 8

_______ _________ - the skeletal muscle produces 85% of body heat

Answer 8

heat production

Question 9

_____ - when stimulated, muscle cells respond with electrical changes across the plasma membrane

Answer 9

excitability

Question 10

_____ - when the muscle is stimulated, electrical excitation is conducted throughout the entire plasma membrane

Answer 10

conductivity

Question 11

_____ - muscle fibers shorten lengthwise when stimulated, which allows them to create movement

Answer 11

contractility

Question 12

_____ - muscle cells can be stretched cells can be stretched, and then the tension is released, it can recoil to its original resting length

Answer 12

elasticity

Question 13

____ - bundles of muscle fibers, visible to the naked eye as parallel strands

Answer 13

fascicles

Question 14

______ - connective tissue that surrounds fascicles

Answer 14

perimysium

Question 15

_____ - a fibrous sheath that separates muscles from one another (deep _____)

or that separates muscles from the overlying skin

Answer 15

fascia

Question 16

_____ muscles - muscles that are thick in the middle and tapered at the ends

moderately strong contractions

Answer 16

fusiform

Question 17

______ muscles - muscles that are uniform width and that have parallel fascicles

span long distances, weaker than fusiform

Answer 17

parallel

Question 18

_____ muscles - muscles that are fan shaped, with fibers meeting at a single point

strong bc of relatively small insertion

Answer 18

convergent

Question 19

______ muscles - feather shaped, with fascicles inserting obliquely on a tendon that runs the length of the muscle

(fibers meet at a line rather than a point)

strong muscles such as rectus femoris

Answer 19

pennate

Question 20

______ muscles (circular muscles) - form rings around body openings

Answer 20

sphincteral

Question 21

_____ - relatively stationary (and proximal) point of muscles attachment

Answer 21

origin

Question 22

______ more mobile (and distal) point of muscle attachment

Answer 22

insertion

Question 23

_____ - middle region between the origin and the insertion

Answer 23

Belly

Question 24

_____ ______ (agonist) - muscle that produces most of the force during a particular contraction

ex: biceps brachii for flexion of the elbow

Answer 24

prime mover

Question 25

______ - muscle that aids the prime mover to produce more power than a single muscle could ex: brachialis muscle assists the biceps brachii

Answer 25

synergist

Question 26

_____ - muscle that opposes the prime mover it relaxes to give the prime mover almost complete control over an action may maintain some tension on a joint ex: triceps brachii opposes the biceps brachii

Answer 26

antagonist

Question 27

_____ - muscle that prevents a bone from moving ex: fixator muscles of the scapula hold the scapula firmly in place during flexion of the elbow

Answer 27

fixator

Question 28

______ muscles are entirely contained within a particular region, having both its origin and insertion there

Answer 28

intrinsic

Question 29

______ muscles act on a particular region, but has its origin elsewhere some movements of the fingers are produced by ______ muscles in the forearm

Answer 29

extrinsic

Question 30

_____ - any elongated, rigid object that rotates around a fixed point

Answer 30

lever

Question 31

_____ - fixed point around which a lever rotates

Answer 31

fulcrum

Question 32

_____ force applied against inertia; something done through exertion

Answer 32

effort arm

Question 33

______ - part from fulcrum to point of resistance

Answer 33

resistance arm

Question 34

functions of lever (3)

Answer 34

exert more force against a resisting object than the force applied to the lever move the resisting object farther or faster than the effort arm there is a trade off between force and speed or distance

Question 35

_____ class lever - fulcrum is between the effort and the resistance

Answer 35

first

Question 36

_____ class lever - resistance is between the effort and the fulcrum

Answer 36

second

Question 37

_____ class lever - effort is between the fulcrum and the resistance

Answer 37

third

Question 38

_____ - plasma membrane of a muscle cell

Answer 38

sarcolemma

Question 39

______ ______ - tunnel-like infoldings of the sarcolemma that penetrate through the cell membrane and carry an electrical current from the surface of the cell to the interior when the cell is stimulated

Answer 39

transverse tubules

Question 40

_____ - cell membrane of a cell

Answer 40

sarcoplam

Question 41

_____ long protein bundles about 1 micrometer un diameter

Answer 41

myofibrils

Question 42

_____ provides stored energy for the muscle during exercise

Answer 42

glycogen

Question 43

_____ binds oxygen until it is needed for muscular activity

Answer 43

myoglobin

Question 44

______ ______ - reservoir for calcium ions which are needed to activate the muscle contraction process

Answer 44

sarcoplasmic reticulum

Question 45

______ - parallel protein microfilaments that make up myofibrils

Answer 45

myofilaments

Question 46

two kinds of myofilaments

Answer 46

myosin myofilaments - thick actin myofilaments - thin

Question 47

_____ myofilaments run parallel to each other and are anchored one end to a Z line

Answer 47

actin

Question 48

_____ myofilaments run parallel to each other and fit in between actin myofilaments

Answer 48

myosin

Question 49

a _____ is the term for the segment that spans from one Z line to the next Z line

Answer 49

sarcomere there are dark areas and light areas

Question 50

I bands are _____ and contain only thin filaments

Answer 50

light

Question 51

A bands are _____ and contain thick filaments

Answer 51

dark

Question 52

H bands are found ______ they are found where the actin and myosin filaments do not overlap

Answer 52

in the middle of the A band

Question 53

The ______ shortens during muscle contractions, but the filaments do not

Answer 53

sarcomere

Question 54

as the __ lines get closer together, actin and myosin filaments overlap more and more

Answer 54

Z

Question 55

Because the ___ bands are the areas consisting of areas where thick filaments are not overlapped by thin filaments, the ___bands shorten during muscle contraction

Answer 55

H

Question 56

Because the ___ bands extend from one end of the thick filaments to the other end (overlapping with thin, or not), and because the filaments themselves do not shorten, ___ bands remain the same length

Answer 56

A

Question 57

_____ are nerve cells that lead from the central nervous system to muscles (or glands)

Answer 57

Motor neurons

Question 58

Each motor nerve fiber branches about ___ times at its distal end, leading to different muscle fibers

Answer 58

200

Question 59

Each muscle fiber is innervated by only ___ motor neuron

Answer 59

one

Question 60

_____ a junction at the end of an axon where it stimulates another cell

Answer 60

Synapse

Question 61

________ ______ - a synapse between a nerve fiber and a muscle cell

Answer 61

Neuromuscular junction

Question 62

________ ____ - The swollen tip at the distal end of an axon; the site of synaptic vesicles and neurotransmitter release

Answer 62

synaptic knob

Question 63

______ _____ - A spheroid organelle in a synaptic knob; contains neurotransmitter

Answer 63

Synaptic vesicles

Question 64

______ - A chemical released at the distal end of an axon that stimulates an adjacent cell

Answer 64

Neurotransmitter

Question 65

_____ ___ _____ - A depression in a muscle fiber where it has synaptic contact with a nerve fiber and has a high density of neurotransmitter receptors

Answer 65

Motor end plate

Question 66

______ ____ – a narrow space between the synaptic knob of an axon and the adjacent cell a neurotransmitter has to diffuse across this space

Answer 66

Synaptic cleft

Question 67

_____ ____ - a motor neuron and all the skeletal muscles innervated by it

Answer 67

Motor unit

Question 68

_____ _____ _____ - where fine control is needed very few muscle fibers per nerve fiber provide fine degree of control needed for subtle movements small neurons that are easily stimulated

Answer 68

small motor units

Question 69

_____ _____ _____ : many muscle fibers per nerve fiber much stronger, but lacking fine control large neurons that are harder to stimulate

Answer 69

Large motor units

Question 70

_____ - Exercise stimulates muscle fibers to produce more protein myofilaments - Myofibrils grow thicker - a large myofibril splits longitudinally, so a well- conditioned muscle cell has more myofibrils - Some scientists think that entire muscle cell may split, leading to increased numbers of muscle cells (not just myofibrils)

Answer 70

Growth

Question 71

_______ – muscle shrinks if it is not used

Answer 71

atrophy

Question 72

_____ atrophy – typically seen when a limb is kept in a cast for weeks

Answer 72

Disuse

Question 73

_______ atrophy – seen in cases where the spinal cord or nerve connections to a muscle are damaged

Answer 73

Denervation

Question 74

______ atrophy – occurs due to aging, regardless of exercise

Answer 74

Senescence

Question 75

_______ Muscle - Makes up most of the heart - Striated like skeletal muscle - Short, stumpy, slightly branched cells - Have intercalated discs where the cells meet - Each cell has one centrally-placed nucleus

Answer 75

Cardiac

Question 76

______ Muscle - Found in blood vessels, air passages, the iris of the eye, and digestive, respiratory, urinary and reproductive tracts - Fusiform in shape - Each cell has a single nucleus

Answer 76

Smooth