Ch. 9 A&p Lecture Notes Cont'd

Front 1

The three types of muscle tissue is?

Back 1

Skeltal
Cardiac
Smooth

Front 2

____ and ____ muscle cells are elongated and are called muscle fibers.

Back 2

Skeletal and Smooth

Front 3

Muscle contraction depends on two kinds of myofilaments ____ and ____.

Back 3

Actin and Myosin

Front 4

muscle plasma membrane

Back 4

Sarcolemma

Front 5

cytoplasm of a muscle cell

Back 5

Sarcoplasm

Front 6

Myo, mys, and sarco all refer to ____

Back 6

muscle

Front 7

Packaged in ____ muscles that attach to and cover the bony skeleton

Back 7

Skeletal Muscle

Front 8

Has obvious stripes called striations

Back 8

Skeletal Muscle

Front 9

Is controlled voluntarily (by conscious control)

Back 9

Skeletal Muscle

Front 10

* Is responsible for overall body motility
* Is extremely adaptable and can exert forces ranging from a fractionof an ounce to over 70 pounds

Back 10

Skeletal Muscle

Front 11

* Occurs only in the heart
* Is striated like skeletal muscle but is not voluntary
* Contracts at a fairly steady rate set by the heart's pacemaker

Back 11

Cardiac Muscle

Front 12

allows the heart to respond to changes in bodily needs

Back 12

Neural Controls

Front 13

* Found in the walls of hollow visceral organs, such as the stomach, urinary bladder, and respiratory passages

Back 13

Smooth Muscle

Front 14

Forces food and other substances through internal body channels (peristalsis)

Back 14

Smooth Muscle

Front 15

It is not striated and is involuntary

Back 15

Smooth Muscle

Front 16

FUNCTIONAL CHARACTERISTICS OF MUSCLE TISSUE
_____, or _____ the ability to receive and respond to stimuli

Back 16

Excitability or irritability

Front 17

the ability to shorten forcibly

Back 17

Contractility

Front 18

The ability to be stretched or extended

Back 18

Extensibility

Front 19

the ability to recoil and resume the original resting length

Back 19

Elasticity

Front 20

____ muscles are responsible for all locomotion

Back 20

Skeletal

Front 21

____ muscle is responsible for coursing the blood through the body

Back 21

Cardiac

Front 22

____ muscle helps maintain blood pressure, and squeezes or propels substances (food,feces) through organs.

Back 22

Smooth

Front 23

___ also maintain posture, stabilize joints, and generate heat.

Back 23

muscles

Front 24

Each muscle is a discrete organ composed of muscle tissue, blood vessels, nerve fibers, and connective tissue

Back 24

Skeletal Muscle

Front 25

The three connective tissue sheaths are:

Back 25

Endomysium
Perimysium
Epimysium

Front 26

fine sheath of connective tissue composed of reticular fibers surrounding each muscle fiber

Back 26

Endomysium

Front 27

fibrous connective tissue that surrounds groups of muscle fibers called fascicles

Back 27

Perimysium

Front 28

an overcoat of dense regular connective tissue that surrounds the entire muscle

Back 28

Epimysium

Front 29

Each ___ is served by one nerve, an artery, and one or more veins

Back 29

Muscle

Front 30

Each ____ muscle fiber is supplied with a nerve ending that controls contraction

Back 30

Skeletal

Front 31

_____ fibers require continuous delivery of oxygen and nutrients via arteries

Back 31

Contracting

Front 32

Wastes must be moved via

Back 32

veins

Front 33

Most skeletal muscles span joints and are attached to ___ in at least two places

Back 33

bone

Front 34

When muscles ____ the movable bone, the muscle's insertion moves toward the immovable bone, the muscle's origin

Back 34

contract

Front 35

Muscles attach:
____- epimysium of the muscle is fused to the periosteum of a bone

Back 35

Directly

Front 36

Muscles attach:
_____- connective tissue wrappings extend beyond the muscle as a tendon or aponeurosis- similar to tendons but are membranes separating muscles from each other sinew

Back 36

Indirectly

Front 37

_____ are densely packed, rodlike contractile elements

Back 37

Myofibrils

Front 38

they make up most of the muscle volume

Back 38

Myofibrils

Front 39

The arrangement of ____ within a fiber is such that a perfectly aligned repeating series of dark A bands and light I bands

Back 39

Myofibrils

Front 40

The smallest contractile unit of a muscle

Back 40

Sarcomeres

Front 41

* The region of a myofibril between two successive Z discs
* Composed of myofilaments made up of contractile proteins
* Myofilaments are of two types- thick and thin

Back 41

Sarcomeres

Front 42

____ filaments are chiefly composed of the protein actin

Back 42

Thin

Front 43

* Each actin molecule is a helical polymer of globular subunits called G actin
* The subunits contain the active sites to which myosin heads attach during contraction
* Tropomyosin and troponin are reulatory subunits bound to actin

Back 43

Ultrastructure of Myofilaments: thin filaments

Front 44

____ ____ is an elaborate, smooth endoplasmic reticulum that mostly runs longitudinally and surrounds each myofibril
* Paired terminal cisternae form perpendicular cross channels
* Functions in the regulation of intracellular calcium levels

Back 44

Sarcoplasmic Reticulum

Front 45

____ filaments slide past the thick ones so that the actin and myosin filaments overlap to a greater degree

Back 45

Thin

Front 46

In the _____ state, thin and thick filaments overlap only slightly

Back 46

relaxed

Front 47

Upon stimulation, ____ heads bind to actin and sliding begins

Back 47

Myosin

Front 48

Ach (acetylcholine) bound to ACh receptors is quickly destroyed by the enzyme ______ this destruction prevents continued muscle fiber contraction in the absence of additional stimuli

Back 48

acetylcholinesterase

Front 49

A transient depolarization event that includes polarity reversal of a sarcolemma (or nerve cell membrane) and the propagation of an action potential along the membrane- it passes along the membrane

Back 49

Action potential

Front 50

Calcium diffuses into the end bulb when it is stimulated and activates enzymes that cause the synaptic vescles to move toward the synaptic cleft. Some vesicles fuse with the membrane and release thier neurotransmitter (a good example of exocytosis). The acetylcholine molecules diffuse across the cleft and fit into receptor opening the gates so depolarization can occur

Back 50

Role of Acetylocholine

Front 51

* All metabolic processes have come to a halt in a dead body, no ATP is being produced. Therefore, because of a lack of ATP [ ATP is required to reuptake calcium into the sarcomere's sarcoplamic reticulum], the myosin head cannot be released from the actin filament, and the sarcomere cannot relax. Because this happens in muscles all over the body, they become "stiff" and "locked" into place.
* begins to manifest after about 3-4 hours after death, and lasts about 24 hours

Back 51

Rigor Mortis

Front 52

____ of muscle fibers (cells) and muscles (organs) is similar- "all or nothing" - stimulus is any strength above threshold, the nerve or muscle fiber will either give a complete or no response at all.

Back 52

Contraction

Front 53

Name the two types of muscle contraction

Back 53

Isometric and Isotonic

Front 54

increasing muscle tension (muscle does not shorten during contraction)

Back 54

Isometric

Front 55

decreasing muscle length (muscle shortens during contraction)

Back 55

Isotonic

Front 56

A ___ ___ is a motor neuron and all the muscle fibers it supplies

Back 56

Motor Unit

Front 57

The number of muscle fibers per ___ ___ can vary form four to several hundred

Back 57

Motor Unit

Front 58

Muscles that control fine movements (fingers, eyes) have ____ motor units.

Back 58

small

Front 59

Large weight-bearing muscles (thighs, hips) have ____ motor units

Back 59

Large

Front 60

Muscle fibers from a ___ ___ are spread throughout the muscle; therefore, contraction of a single motor unit causes weak contraction of the entire muscle

Back 60

Motor unit: the nerve-muscle functional unit

Front 61

A muscle ___ is the response of a muscle to a single, brief threshold stimulus

Back 61

Muscle Twitch

Front 62

Name the 3 phases to a muscle twitch

Back 62

Latent period
Period of contraction
Period of relaxation

Front 63

first few msec after stimulus; EC coupling takeing place

Back 63

Latent period

Front 64

cross bridges form; muscle shortens

Back 64

Period of contraction

Front 65

Ca2+ reabsorbed; muscle tension goes to zero

Back 65

Period of relaxation

Front 66

* variations in the degree of muscle contraction
* required for proper control of skeletal movement

Back 66

Graded muscle responses

Front 67

Responses are graded by *changing the frequency of stimulation
* Changing the strength of the stimulus

Back 67

Graded muscle responses

Front 68

* a single stimulus results in a single contractile response- a muscle twitch

Back 68

Muscle Response to varying stimuli

Front 69

* Frequently delivered stimuli (muscle does not have time to completely relax) increases contractile force

Back 69

Muscle Response to varying stimuli
* wave summation

Front 70

MUSCLE RESPONSE TO VARYING STIMULI
* more rapidly delivered stimuli result in ____ ____

Back 70

incomplete tetanus

Front 71

MUSCLE RESPONSE TO VARYING STIMULI
* If stimuli are given quickly enough, complete tetanus results-

Back 71

a uniform contraction

Front 72

The stimulus strength at which the first observable muscle contraction occurs- all or none law

Back 72

Threshold stimulus

Front 73

muscle contracts more vigorously as stimulus strength is increased

Back 73

Beyond threshold

Front 74

* Force of contraction is precisley controlled by ____ motor unit summation
* This phenomenon, called recruitment, brings more and more muscle fibers into play.

Back 74

multiple

Front 75

increased contraction in response to multiple stimuli of the same strength

Back 75

Treppe: The staircase Effect

Front 76

* Contactions increase because:
* There is increasing availability of Ca2+ in the sarcoplasm
* Muscle enzyme systems become more efficient because heat is increased as muscle contracts

Back 76

Treppe: The Staircase Effect

Front 77

* Low serum levels of calcium can produce a condition called tetany. In this case, the skeletal muscle fibers are persistently contracted because they are persistently depolarized, and this is occurring because the serum calcium is very low without replacement!

Back 77

Tetany- Continuous Contraction

Front 78

______ is the rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart

Back 78

Fibrillation

Front 79

* ____ are when a person's body shakes rapidly and uncontrollably. During convulsions, the person's muscles contract and relax repeatedly. It is not known what causes the abnormal impulses from the brain. ____ may occur in such conditions as epilepsy, poisoning, high fever, disturbances of calcium or phosphorus metabolism, alkalosis, diabetes, oxygen insufficiency, and a low bollod-sugar content.

Back 79

Convulsions

Front 80

* Is the constant, slightly contracted state of all muscles, which does not produce active movements
* Keeps the muscles firm, healthy, and ready to respond to stimulus

Back 80

Muscle Tone

Front 81

Spinal reflexes account for ___ ___ by:
* Activating one motor unit and then another
* Responding to activation of stretch receptors in muscles and tendons

Back 81

Muscle Tone

Front 82

the muscle changes in length (decreasing the angle of the joint) and moves the load

Back 82

Isotonic Contractions

Front 83

Name the two types of isotonic contractions:

Back 83

Concentric
Eccentric

Front 84

the muscle shortens and does work (picking up a book, kicking a ball).

Back 84

Concentric contractions

Front 85

the muscle contracts as it lengthens (walking up a hill, calf muscles).

Back 85

Eccentric Contractions

Front 86

* Tension increases to the muscle's capacity, but the muscle neither shortens nor lengthens
* Occurs if the load is greater than the tension the muscle is able to develop (pushing against a wall nothing happens)

Back 86

Isometric Contractions

Front 87

____ is the only source used directly for contractile activity

Back 87

ATP

Front 88

As soon as available stores of ATP are hydrolyzed (4-6 seconds), they are regenerated by:

Back 88

The interaction of ADP with cratine phosphate

Front 89

MUSCLE METABOLISM: ____ ____
* When muscle contractile activity reaches 70% of maximum:
* Bulging muscles compress blood vessels
* Oxygen delivery is impaired
* Pyruvic Acid is converted to lactic acid

Back 89

Anaerobic Gycolysis

Front 90

___ ____:
* diffuses into th bloodstream
* Is picked up and used as fuel by the liver, kidnys, and heart
* Is converted back into pyruvic acid by the liver

Back 90

Lactic Acid

Front 91

the muscle is in a state of physiological inability to contract

Back 91

Muscle Fatigue

Front 92

___ ___ occurs when:
* ATP production fails to keep pace with ATP use
* There is a relative deficit of ATP, causing contractions
* Lactic acid accumulates in the muscle
* Ionic imbalaces are present

Back 92

Muscle Fatigue

Front 93

* Intese exercise produces rapid muscle fatigue (with rapid recovery)
* Na+-K+ pumps cannot restore ionic balances quickly enough
* low-intensity exercise produces slow-developing fatigue
* SR is damaged and Ca2+ regulation is disrupted

Back 93

Muscle Fatigue

Front 94

* Vigorous exercise causes dramatic changes in muscle chemistry

Back 94

Oxygen Debt

Front 95

For a muscle to return to a ____ state:
* Oxygen reserves must be replenished
* Lactic acid must be converted to pyruvic acid
* Glycogen stores must be replaced
* ATP and CP reserves must be resynthesized

Back 95

Oxygen Debt

Front 96

the extra amount of O2 needed for the above restorative processes

Back 96

Oxygen Debt

Front 97

* Only 40% of the energy released in muscle activity is useful as work
* The remaining 60% is given off as heat
* Dangerous heat levels are prevented by radiation of heat from the skin and sweating

Back 97

Heat Production During Muscle Activity

Front 98

The force of _____ contraction is affected by:
* the number of muscle fibers contracting- the more motor fibers in a muscle, the stronger the contraction
* The relative size of the muscle - the bulkier the muscle, the greater its strength
* Degree of muscle stretch - muscles contract strongest when muscle fibrs are 80-120% of their normal resting length.

Back 98

Muscular

Front 99

____ of contraction- determined by speed in which ATPases split ATP

Back 99

Speed

Front 100

ATP- forming pathways
- use aerobic pathways

Back 100

Oxidative fibers

Front 101

ATP-forming pathways
- use anaerobic glycolysis

Back 101

Glycolytic fibers

Front 102

These two criteria define thre categories--slow oxidative fibers, fast oxidative fibers, and fast glycolytic fibers

Back 102

Oxidative and Glycolytic fibers

Front 103

____ oxidative fibers contract slowly, ahve slow acting myosin ATPases, and are fatigue resistant (marathon runners)

Back 103

SLOW

Front 104

____ oxidative fibers contract quickly, have fast myosin ATPases, and have moderate resistance to fatigue

Back 104

Fast

Front 105

Fast ____ fibers contract quickly, have fast myosin ATPases and are easily fatigued (sprinter)

Back 105

glycolytic

Front 106

Isometrics Training and Fast Twitch Muscle fibers
Isometric Exercises using the Resistance Band- The little known 'secret formula' for speeding past your competition.

Back 106

A Commercial Use

Front 107

____ exercise results in an increase of:
* Muscle capillaries
* Number of mitochondria (ATP)
* Myoglobin sythesis- the primary oxygen-carrying pigment of muscle tissues

Back 107

Aerobic

Front 108

the primary oxygen-carrying pigment of muscle tissues.

Back 108

Myoglobin synthesis

Front 109

(typically anaerobic) results in:
* Muscle hypertrophy
* Increased mitochondria, myofilaments, and glycogen stores

Back 109

Resistance exercise

Front 110

* Forcing a muscle to work promoteds increased muscualr strength
* Muscles adapt to increased demands
* Muscles must be overloaded to produce further gains

Back 110

The Overload Principle

Front 111

* found in walls of hollow organs (except the heart)
* Have essentially the same contractile mechanisms as skeletal muscle

Back 111

Smooth Muscle

Front 112

* When the longitudinal layer contracts, the organ dilates and contracts
* When the ciruclar layer contracts, the organ elongates

Back 112

Peristalsis

Front 113

Alternating contractions and relaxations of smooth muscles that mix and squeeze substances through the lumen of hollow organs

Back 113

Peristalsis

Front 114

* Smooth muscle lacks neuromuscular juctions
* Innervating nerves have bulbous swellings called varicosities

Back 114

Innervation of Smooth Muscle

Front 115

_____ release neurotransmitters into wide synaptic clefts called diffuse junctions

Back 115

Varicosities

Front 116

* Whole sheets of smooth muscle exhibits slow, synchronized contraction
* They contract in unison, reflecting their electrical coupling with gap junctions
* Action potentials are transmitted from cell to cell

Back 116

Contraction of Smooth Muscle

Front 117

* Some smooth muscle cells:
* Act as pacemakers and set the contactile pace for whole sheets of muscle
* Are self-excitatory and depolarize without external stimuli

Back 117

Contraction of Smooth Muscle

Front 118

Unique characteristics of smooth muscle include:
* Smooth muscle tone
* Slow, prolonged contractile activity
* low energy requirements
* Response to stretch

Back 118

Special features of Smooth Muscle Contraction

Front 119

* Smooth muscle exhibits a phenomenon called stress-relaxation response in which:
* Smooth muscle responds to stretch only briefly, and then adapts to its new length
* Teh new length, however, retains its ability to contract
* This enables organs such as the stomach and bladder to temporarily store contents

Back 119

Response to stretch

Front 120

* Certain smooth muscles can divide and increase their numbers by undergoing ____

Back 120

Hyperplasia

Front 121

* this is shown by estrogens effect on the uterus
* At puberty, estrogen stimulates the synthesis of more smooth muscle, causing the uterus to grow to adult size
* During pregnancy, estrogen stimulates uterine to accommodate the increasing size of the growing fetus.

Back 121

Hyperplasia

Front 122

* The cells of single-unit smooth muscle, commonly called visceral muscle:
* Contract rhythmically as a unit
* Are electrically coupled to one another via gap junctions
* Often exhibit spontaneous action potentials
* Are arranged in opposing sheets and exhibit stress relaxation response

Back 122

Types of Smooth Muscle: SIngle unit

Front 123

____ smooth muscles are found:
* In large airways to the lungs
* In large arteries
* In arrecor pili muscles
* Attached to hair follicles
* In the internal eye muscles

Back 123

Multiunit

Front 124

* Their characteristics include
* Rare gap junctions
* Infrequent spontaneous depolarization
* Structurally independent muscle fibers
* A rich nerve supply, which, with a number of muscle fibers, forms motor units
* Graded contractiopns in response to neural stimuli

Back 124

Multiunit

Front 125

group of inheritied muscle destroying diseases where muscles enlarge due to fat and connective tissue deposits, but muscle fibers atrophy

Back 125

Muscualar Dystrophy

Front 126

* _____ ___ _____
* Inheritied, sex-linked disease carried by females and expressed in males (1/3500)
* Diagnosed between the ages of 2-10
* Victims become clumsy and fall frequently as their muscles fail

Back 126

Muscular Dystrophy: Duchenne muscular dystrophy

Front 127

* pregresses form the extrmities upward, and victims die of respiratory failure in their 20's
* Caused by a lack of the cytoplasmic protein dystrophin-vital part of a protein complex that connects the cytoskeleton of a muscle fiber
* There is no cure, but myoblast transfer therapy shows promise

Back 127

Muscular Dystrophy

Front 128

____ ____ interferes with messages your nerves send to your muscles. ____ ____ often affects muscles in your head. Common symptoms are trouble with eye and eyelid movement, facial expression and swallowing. If you have ___ ___, it is important to follow your treatment plan. If you do, you can expect your life to be normal or close to it.

Back 128

Myasthenia Gravis

Front 129

____ ____ is caused by a problem in the transmission of nerve signals to your muscles. Normally, nerve endings release a substance that attches to receptors on your muscles. That tells your muscles to contract. If you have ___ ____ your body's own immune system makes antibodies to block that signal.

Back 129

Myasthenia Gravis

Front 130

____ ____ is a nervous system disease that affects your brain and spinal cord. It damges the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down or blocks messages between your brain and your body, leading to the symptoms of __. they include:
* Visual disturbances
* Muscle weakness
* Trouble with coordiantion and balance
* Sensations such as numbness, prickling, or "pins and needles"
* Thinking and memory problems

Back 130

Multiple Sclerosis

Front 131

Muscle tissue develops from embryonic ____ called myoblasts

Back 131

mesoderm

Front 132

Multinucleated skeletal muscles form by fusion of ___

Back 132

Myoblasts

Front 133

Cardiac and skeletal muscle become ____ but can lengthen and thicken

Back 133

Amitotic

Front 134

Myoblastlike ____ cells show very limited regenerative ability

Back 134

Satellite

Front 135

___ cells lack satellite cells

Back 135

Cardiac

Front 136

___ muscle has good regenerative ability

Back 136

Smooth

Front 137

* Muscular development reflects neuromuscular coordination
* Development occurs head-to-toe and proximal to distal
* Peak natural neural control of muscles is achieved by midaldolescence
* Athletics and training can improve neuromuscular control

Back 137

Developmental Aspects: After Birth

Front 138

* There is a biological basis for greater strength in men than women
* Women's skeletal muscle makes up 36% of their body mass
* Mens skeletal muscle makes up 42% of their body mass.

Back 138

Developmental Aspects: Male and Female

Front 139

* These differences are due primarily to the male sex hormone testosterone
* With more muscle mass, men are generally stronger than women
* Body strength per unit muscle mass, however, is the same in both sexes

Back 139

Developmental Aspects: Male and Female

Front 140

* With ag, connective tissue increases and muscle fibers decrease
* Muscles become stringier and more sinewy
* By age 80, 50% of muscle mass is lost (sarcopenia)

Back 140

Developmental Aspects: Age Related

Front 141

* Regular exercise reverses sarcopenia
* Aging of the cardivascular system affects every organ in the body
* Atherosclerosis may block distal arteries, leading to intermittent claudication and causing severe pain in leg muscles.

Back 141

Developmental Aspects: Age Related