A & P Exam 2

Front 1

MUSCLE TISSUE

Back 1

one of four primary tissue types. muscle tissues do one thing and one thing only- contract

Front 2

Functions of Muscle Tissue

Back 2

1. movement: moving the body through space.
2. Aids in maintaining body temperature.
3. maintains body posture
4. aids in moving things through the body
5. regulates blood flow i.e. shunting blood to places that need it. (from stomach to muscles in a quick get away
6. protects the body.
7. guards entrances and exits.

Front 3

Three Types of Muscle Tissue

Back 3

A) Skeletal muscle tissue; voluntary and striated. relatively fast contracting
B) Cardiac muscles; involuntary and striated; push blood through the body. also have intercalated discs (gap junction; little ports or holes from one cell membrane to another cell membrane)
C) Smooth Muscle; involuntary and not striated. still have actin and myosin, but have no striations. relatively slow contracting. involved in moving materials through the body

Front 4

Components of Skeletal Muscle Tissue:
superficial fascia

Back 4

loose connective tissue just below the skin that attaches the skin to the deeper tissues. (reticular fibers around the organs)

Front 5

Components of Skeletal Muscle Tissue: epimysium

Back 5

outer dense regular connective tissue surrounds the muscle belly. this level is largely comprised of collagen fibers. at the end of the muscles the epimysium becomes the tendon.

Front 6

Components of Skeletal Muscle Tissue: perimysium

Back 6

is a combination of collagen and elastic fibers surrounding muscle bundles (called fascicles) also lying in this layer are vessels and nerves.

Front 7

Components of Skeletal Muscle Tissue: endomysium

Back 7

collagen fiber layer that surrounds each muscle fiber.

Front 8

Components of Skeletal Muscle Tissue: muscle fiber/cell

Back 8

inside, we have hundreds of contractile units called myofibrils.

Front 9

Components of Skeletal Muscle Tissue: myofibril (contractile unit of muscle fiber)

Back 9

travel from one end to the other. functional unit of the cell

Front 10

Skeletal Muscle Microstructure

Back 10

myoblasts (immature muscle cell) : during embryologic development myoblasts fuse together to form one large multinucleated cell.

Front 11

Sarcomere

Back 11

functional contractile unit of the myofibril; it extends from one Z line to the next.

Front 12

Microfilament: Two Types

Back 12

1. Actin (thin filament)
2. Myosin (thick filament)

Front 13

M Line-

Back 13

backbone of myosin. attaches to myosin filaments

Front 14

Z Line-

Back 14

sarcomere goes from z line to z line. attaches to the actin filaments. backbone of the actin

Front 15

A Band-

Back 15

contains All of the myosin

Front 16

H Band-

Back 16

contains only myosin

Front 17

I Band-

Back 17

contains only actin

Front 18

Zone of Overlap-

Back 18

where the actin and myosin overlap

Front 19

Sarcoplastic Reticulum and It's Components
A) Sarcoplasmic Reticulum

Back 19

(sarco means muscle); membranous network of tubules running through the muscle fiber that surrounds each myofibril. also stores calcium while muscle is at rest.

Front 20

Sarcoplastic Reticulum and It's Components
B) Transverse Tubule

Back 20

't tubule'; tube that connects the sarcolemma (cell membrane of the muscle cell) indirectly with the sarcoplasmic reticulum

Front 21

Sarcoplastic Reticulum and It's Components
C) Terminal Cisternae

Back 21

enlarged ends of sarcoplasmic reticulum. larger reservoir adjacent to the "T" tubule.

Front 22

Sarcoplastic Reticulum and It's Components
D) Triad

Back 22

t tuble and two adjacent terminal cisternae

Front 23

Muscle Cell Contraction:
A) The Protein Filaments;

Back 23

contractile filaments inside the muscle (myosin and actin can bind with each other under the right circumstances)

Front 24

Muscle Cell Contraction:
The Protein Filaments

Back 24

1) Myosin; the thick filament. ATP binds to myosin head. myosin head splits ATP into ADP and P which cocks the head into open (ready) position
2) Actin; the thin filament. consists of two twisted protein strands with active sites located on these strands that allow it to bind with the myosin head.

Front 25

Muscle Cell Contraction:
B) Associated Molecules

Back 25

1. Tropomyosin; filamentous (long) strand of protein that covers the active site on the actin when muscle is at rest. prevents binding of actin/myosin
2. Troponin; globular protein that attaches to tropomyosin. When calcium binds to the troponin, the troponin will rotate tropomyosin off the active sites of the actin.

Front 26

Sliding Filament Theory:

Back 26

states that actin and myosin slide over each other during muscle contraction.

Front 27

The Contraction Cycle (5 Steps):
Step 1

Back 27

calcium ions bind to the troponin, rotating tropomyosin off the active site on the actin.

Front 28

The Contraction Cycle (5 Steps):
Step 2

Back 28

crossbridging occurs between the active site on the actin and the myosin head

Front 29

The Contraction Cycle (5 Steps): Step 3

Back 29

myosin head pivots or rachets toward the center of the sarcomere, pulling the z lines closer together causing contraction (ADP and P are released at this point)

Front 30

The Contraction Cycle (5 Steps):
Step 4

Back 30

crossbridging detachment- the bond remains intact until the myosin head binds with another ATP molecule. (rigor mortis; there is no more ATP production, so the muscle will remain contracted until the enzymes break it down)

Front 31

The Contraction Cycle (5 Steps)
Step 5

Back 31

myosin activation; the free myosin head splits the ATP into ADP and P which recocks the head again for the next cycle. The cycle stops when calcium levels return to low levels

Front 32

The Neuromuscular Junction
Nerve Impulse Perpetuation (6 Steps)

Back 32

causing muscle contraction

Front 33

The Neuromuscular Junction
Nerve Impulse Perpetuation (6 Steps)

Back 33

1. the nerve impulse travels down the axon causing an influx of calcium into the synaptic know which causes synaptic vessicles to fuse with nerve cell membrane.

Front 34

The Neuromuscular Junction
Nerve Impulse Perpetuation (6 Steps)

Back 34

2. vessicles dump neurotransmitters into the synaptic cleft

Front 35

The Neuromuscular Junction
Nerve Impulse Perpetuation (6 Steps)

Back 35

3. NT binds to receptor sites on sarcolemma (post-synaptic membrane)

Front 36

The Neuromuscular Junction
Nerve Impulse Perpetuation (6 Steps)

Back 36

4. NT binds to receptor sites opening ions channels in receptor protein allowing sodium in to the muscle changing membrane polarity causing depolarization of the sarcolemma

Front 37

The Neuromuscular Junction
Nerve Impulse Perpetuation (6 Steps)

Back 37

5. this wave of depolarization travels over the surface of the sarcolemma and down into the t tubules

Front 38

The Neuromuscular Junction
Nerve Impulse Perpetuation (6 Steps)

Back 38

6. this causes the release of calcium from the terminal cisternae which causes the actin active sites to be exposed

Front 39

Muscle Fatigue

Back 39

a muscle is fatigued when it can no longer contract despite continued neural stimulus

Front 40

Muscle Fatigue:
A) Aerobic Depletion

Back 40

during aerobic activity muscle fatigue is due to depletion of glucose, not oxygen

Front 41

Muscle Fatigue:
Anaerobic Depletion

Back 41

during intense, short bursts of exercise the oxygen usage exceeds oxygen availability.

Front 42

Muscle Fatigue:
Anaerobic Threshold

Back 42

boundary between aerobic energy usage (glucose and oxygen) and anaerobic energy usage (pyruvate).

Front 43

*Muscle restoration period

Back 43

can take up to one week.

Front 44

Muscle Mechanics
Muscle Contraction (3 Phases)
1. Latency Phase

Back 44

2 milliseconds between beginning of nerve stimulation and start of muscle contraction. (Action potential is sweeping over sarcolemma and calcium is being released)

Front 45

Muscle Mechanics
Muscle Contraction (3 Phases)
2. Contraction Phase

Back 45

20 msec-

Front 46

Muscle Mechanics
Muscle Contraction (3 Phases)

Back 46

20 msec-

Front 47

Motor Unit:

Back 47

one nerve fiber and all the fibers it innervates. inntervates is another word for control.

Front 48

All or None Principle:

Back 48

If you fire the motor neuron all of its muscle fibers will contract.

Front 49

Graded Contractions:

Back 49

muscle responses are actually graded contractions . muscle responses are graded units of motor responses in that muscle. the total force exerted or how quickly or slowly a muscle contracts is dependent on how many motor units are activated per given unit of time.

Front 50

Multiple Motor Unit Summation:

Back 50

aka recruitment. It is a smooth and steady increase in muscle tension from increasing the number of active motor units

Front 51

Wave Summation

Back 51

It is a second more powerful muscle stimulus arriving before the relaxation phase of the previous contraction has completely set in.

Front 52

Incomplete Tetanus

Back 52

a series of muscle contractions producing a peak tension during rapid cycles of contraction and relaxation

Front 53

Complete Tetanus

Back 53

a series of muscle contractions where the rate of stimulation is such that the relaxation phase has been eliminated.

Front 54

Treppe

Back 54

a series of muscle contractions where the muscle is stimulated a second time immediately after the relaxation phase has ended. The following contraction will have a slightly higher tension due to calcium remaining outside the terminal cisternae

Front 55

Muscle Tone

Back 55

the resting tension within a muscle without able to produce movement there are always a small number of motor units firing providing that tone.

Front 56

Isotonic Contractions:

Back 56

tension in the muscle increases enough to overcome resistance allowing the muscle belly to shorten. (lifting the table with success)

Front 57

Isometric Contractions:

Back 57

tension in the muscle increases but there is no change in the overall muscle belly length. (trying to lift a truck with one hand)

Front 58

The Three Types of Skeletal Muscle Fibers
Fast;

Back 58

; 'white'
-majority of the muscle fibers (skeletal)
-contract 3x faster than the slow fibers, .01 sec
-they are large in diameter
-densely packed with myofbrils (more actin more myosin)
-large glycogen reserve
-fewer mitochondria

Front 59

The Three Types of Skeletal Muscle Fibers
Slow "red fiber type"

Back 59

-half the diameter of the fast and fire 3x slower
-can fire for longer periods of time.
-have more mitochondria
-have a greater capillary bed supply
-have a large amount of myoglobin (able to hold on to more O2) wont burn out as quickly
-glycogen reserves are smaller

Front 60

The Three Types of Skeletal Muscle Fibers
Intermediate

Back 60

- have properties of both fast and slow
-look like fast fibers, but resist fatigue better

Front 61

Muscle Fiber Contraction

Back 61

; all muscle fibers have an optimum length for producing maximum contraction
1) stretch too far- not enough zone of overlap for a forceful contraction.
2) near or at full contraction- full zone of overlap. very little room for further sliding of the filaments.

Front 62

Maximal Tension

Back 62

(this concept applies to the entire muscle)- all muscles have a small range of motion where maximal tension is reached.
Ex. Elbow

Front 63

A) Full Extension

Back 63

1. Very little zone of overlap, not efficient
2. The fire of muscle contraction causes the joint compression, not efficient

Front 64

B) Flexion (90%) optimum angle, is efficient

Back 64

1. Optimum zone of overlap to generate the most amount of force
2. Allow ?? To be generated

Front 65

C) Full Flexion, not efficient

Back 65

1. Full zone of overlap prevents further contraction
2. It continues to cause separation of radius & ulna w/ joint

Front 66

Muscle Power Arcs

Back 66

(the range of motion or degrees where the muscle exerts most of its force); muscles overcome the narrow ranges of motion where the muscle is most efficient by evolving different muscle shapes.

Front 67

Muscle Shapes (5 General Types)
1. parallel :

Back 67

all muscle fibers run in the same direction. ex : bicep bracii

Front 68

Muscle Shapes (5 General Types)
2. convergent :

Back 68

fibers of the muscle converge to a tendon. ex: pectoralis major

Front 69

Muscle Shapes (5 General Types)
3. unipennate :

Back 69

different motor units fire at different degrees or times. ex:extensor digitorum

Front 70

Muscle Shapes (5 General Types)
4. bipennate:

Back 70

two muscle bellies come together to a common tendon ex: gastrocnemius

Front 71

Muscle Shapes (5 General Types)
circular :

Back 71

sphincters ex: mouth, eyes

Front 72

The Three Classes of Biomechanical Levers

Back 72

A) First Class- teeter tawter or see-saw
B) Second Class- allows us to carry large amounts of weight with small amounts of effort. ex: wheel barrow
C) Third Class- has the effort between the resistance and fulcrum. not powerful but fast levers.

Front 73

The Three Parts of a Muscle

Back 73

A) origin- beginning of muscle base, typically the most proximal portion, the immovable end of the attachment. closest to the axial skeleton.
B) belly- the body or bulk of the muscle fibers
C) insertion- the attachment site of a muscle that is typically at the distal end. Also the movable end of the attachment site away from the axial skeleton.

Front 74

Muscle Actions

Back 74

A) agonist 'prime mover'- a muscle whose contraction is cheifly responsible for a particular movement. (biceps-forearm flexion)
B) synergist- assists the prime mover. stabilizes during motion.
C) antagonist- also prime movers, but their action opposes the agonist being considered. (forearm flexion-triceps)

Front 75

Rectus-

Back 75

straight

Front 76

Medius-

Back 76

medial

Front 77

Obliqus-

Back 77

fibers run at an oblique angle

Front 78

Transversus-

Back 78

fibers run transverse

Front 79

Superficialis-

Back 79

more superficial

Front 80

Profundus-

Back 80

more deep

Front 81

Superioris-

Back 81

closer toward head

Front 82

Minimus-

Back 82

smaller

Front 83

Maximus, Majorus-

Back 83

larger

Front 84

Internus-

Back 84

inside

Front 85

Brevis-

Back 85

short

Front 86

Flexion-

Back 86

reduces the angle between articular elements

Front 87

Extension-

Back 87

increases the angle between articular elements

Front 88

Hyperextension-

Back 88

extension which continues past the anatomical position

Front 89

Abduction-

Back 89

refers to moving the distal end of an extremity or body part away from the body or midline in a coronal plane

Front 90

Adduction-

Back 90

refers to moving the distal end of an extremity or body part toward the body or midline in a coronal plane

Front 91

Rotation-

Back 91

movement of a body part about its long axis

Front 92

Supination-

Back 92

refers to the forearm, internal rotation of the palm, or rotation of the forearm about it's long axis to the posterior palm position

Front 93

Circumduction-

Back 93

active or passive circular movement of the limbs or eyes

Front 94

Elevation-

Back 94

general term, to raise up a body part superiorly

Front 95

Depression-

Back 95

general term, to lower a body part inferiorly

Front 96

Protraction-

Back 96

moving a body part forward in a horizontal plane

Front 97

Retraction-

Back 97

moving a body part backward in the horizontal plane

Front 98

Inversion-

Back 98

refers to the ankle, turning the sole of the foot inward in a coronal plane

Front 99

Eversion-

Back 99

refers to the ankle, turning the sole of the foot outward in a coronal plane

Front 100

Plantar Flexion-

Back 100

refers to the foot and ankle, flexing the foot in a plantar direction

Front 101

Dorsiflexion-

Back 101

refers to the foot and ankle, flexing the foot superiorly toward the head-not called extension

Front 102

Muscles of Mastication
Masseter

Back 102

O= zygomatic arch
I= ramus of mandible
A= elevates mandible

Front 103

Muscles that Move the Head
Sternocleidomastoid

Back 103

O= sternum and clavicle
I= mastoid process of the temporal bone
A= if both sides contract, it flexes the neck; if one side contracts, it rotates the head toward the opposite side

Front 104

Muscles that Move the Shoulder
Trapezius

Back 104

O= occipital bone, ligamentum nuchae, spines of C7-T12
I= clavicle, acromion, scapula
A= Elevates (upper portion) or depresses (lower portion) scapula; adducts scapula, extends head

Front 105

Muscles that Move the Arm
Pectoralis major

Back 105

O= clavicle, sternum, costal cartilages of ribs 2-6
I= lateral lip of the bicipital groove
A= flexes, adducts and medially rotates the arm

Front 106

Muscles that Move the Arm
Latissimus dorsi

Back 106

O= spinous processes of T7 through all lumbar through sacrum, posterior iliac crest, lumbodorsal fascia
I= medial lip of the bicipital groove
A= extends, adducts and medially rotates arm

Front 107

Muscles that Move the Arm
Deltoid

Back 107

O= clavicle, acromion and spine of scapula
I= deltoid tuberosity of humerus
A= abducts arm, forward flexion, extension of shoulder

Front 108

Muscles that Move the Arm
Supraspinatus

Back 108

O= supraspinous fossa
I= greater tubercle of humerus
A= abducts arm

Front 109

Muscles that Move the Arm
Infraspinatus

Back 109

O= infraspinous fossa
I= greater tubercle of humerus
A= rotates arm laterally

Front 110

Muscles that Move the Arm
Subscapularis

Back 110

O= subscapular fossa
I= lesser tubercle of humerus
A= rotates arm medially

Front 111

Muscles that Move the Arm
Teres major (lat’s little helper)

Back 111

O= inferior angle of scapula
I= intertubercular groove of humerus (medial lip of bicipital groove)
A= medially rotates and adducts the arm

Front 112

Muscles that Move the Arm
Teres minor

Back 112

O= lateral (axillary) border of scapula
I= greater tubercle of humerus
A= rotates arm laterally

Front 113

Muscles that Move the Forearm
Biceps Brachii

Back 113

O= above the glenoid fossa (long head) ; coracoid process of scapula (short head)
I= radial tuberosity
A= flexes forearm (elbow) and supinates forearm

Front 114

Muscles that Move the Forearm
Triceps Brachii : 3 heads, long, medial lateral.

Back 114

O= below glenoid fossa (long head), lateral and posterior shaft of humerus proximally (lateral head), posterior surface of humerus distally (medial head)
I= olecranon process of ulna
A= extends forearm (elbow), some shoulder extension as well

Front 115

Muscles that Move the Wrist and Fingers
Flexor carpi radialis Index finger

Back 115

O= medial epicondyle of humerus
I= ventral surface of metacarpals II, III
A= flexes and abducts palm

Front 116

Muscles that Move the Wrist and Fingers
Extensor digitorum

Back 116

O= lateral epicondyle of humerus
I= dorsal surface of phalanges
A= extends phalanges and palm

Front 117

Muscles that Move the Thigh
Gluteus maximus

Back 117

O= iliac crest, sacrum, coccyx
I= gluteal tuberosity of femur
A= extends thigh (hip joint) and laterally rotates thigh

Front 118

Muscles that Move the Thigh
Adductor longus: pulls legs to the midline.

Back 118

O= pubis
I= linea aspera of femur
A= adducts thigh

Front 119

Muscles that Act on the leg
Quadriceps femoris
*Rectus femoris

Back 119

O= anterior inferior iliac spine
I= tibial tuberosity via patellar ligament
A= extends leg (knee), flexes thigh (hip)

Front 120

Muscles that Act on the leg
Quadriceps femoris
Vastus lateralis

Back 120

O= greater trochanter and lateral to linea aspera of femur
I= tibial tuberosity via patellar ligament
A= extends leg, knee extension

Front 121

Muscles that Act on the leg
Quadriceps femoris
Vastus medialus (lower portion of vmo)

Back 121

O= medial to linea aspera of femur
I= tibial tuberosity via patellar ligament
A= extends leg

Front 122

Hamstrings
*Biceps femoris

Back 122

O= ischial tuberosity and linea aspera
I= lateral condyle of tibia and head of fibula
A= flexes leg and extends thigh

Front 123

Hamstrings
Biceps femoris

Back 123

O= ischial tuberosity and linea aspera
I= lateral condyle of tibia and head of fibula
A= flexes leg and extends thigh

Front 124

Hamstrings
Semitendinosus (more superficial)

Back 124

O= ischial tuberosity
I= medial surface of proximal tibia
A= flexes leg and extends thigh

Front 125

Hamstrings
Semimembranous (more deep)

Back 125

O= ischial tuberosity
I= medial condyle of tibia
A= flexes leg and extends thigh

Front 126

Muscles that Move the Foot and Toes
Gastrocnemius (2 heads) crosses two joints. Fast twitch muscle.

Back 126

O= above lateral and medial condyles of femur
I= calcaneus by way of Achilles tendon
A= plantar flexes foot and flexes leg at knee

Front 127

Muscles that Move the Foot and Toes
Soleus deep to the gastrocnemius Slow twitch muscle.

Back 127

O= posteromedial tibia; head of fibula
I= calcaneus by way of Achilles tendon
A= plantar flexes foot

Front 128

Muscles of the Abdominal Wall
External abdominal oblique

Back 128

O= lower 8 ribs
I= linea alba and iliac crest
A= compresses abdomen; flexes or bends spine; depresses ribs

Front 129

Muscles of the Abdominal Wall
Rectus abdominus

Back 129

O= xiphoid process and costal cartilages of ribs 5-7
I= symphysis pubis
A= compresses abdomen, flexes vertebral column, and depresses ribs

Front 130

Muscles Used in Breathing
External intercostals, faces same direction as the external obliques

Back 130

O= one rib above
I= next rib below
A= breathing (elevates ribs) causes inhalation & pulls the ribs closer together upward

Front 131

Muscles Used in Breathing
Internal intercostals, deep to the externals & run the same direction as the internal obliques.

Back 131

O= one rib
I= next rib
A= breathing (depresses ribs) causes exhalation and ribs to pull closer together moving downward.