Unit 2 - Chapter 9 - Muscular System Flashcards
1
Q
muscular tissue enables the body to do what
A
move (movement)
2
Q
what is movement caused by
A
caused by ability of muscle cells called fibers to shorten or contract
3
Q
how to muscle cells shorten/contract in order to create movement
A
by converting chemical energy (obtained from food) into mechanical energy
4
Q
what are the 3 types of muscle tissue found in the body
A
skeletal, cardiac and smooth
5
Q
expand on skeletal muscle tissue
A
- 40 - 50% of body weight
- is the “red meat” attached to bones
- has crosswise stipes of striations under the microscope
- contractions can be voluntarily controlled
6
Q
expand on cardiac muscle tissue
A
- comprimised bulk of heart
- has many branches
- characterized by dark bands called “intercalated disks”
- interconnected nature of cardiac muscle cells allows heart to contract efficiently as a unit
7
Q
expand on smooth muscle tissue
A
- also called nonstriated, involuntary visceral muscle
- found in walls of hollow visceral structures (digestive tract, blood vessel, ureters)
- involuntary contractions
8
Q
expand on the major structures of the skeletal muscle
A
- each skeletal muscle is an organ composed mainly of skeletal muscle cells and connective tissue
- most skeletal muscles extend from one bone across a joint to another bone
9
Q
what are the 3 parts of a skeletal muscle
A
origin, insertion and body
10
Q
expand on the origin part of a skeletal muscle
A
attachement to the bone that remains relatively stationary or fixed when movement at the joint occurs
11
Q
expand on the insertion part of a skeletal muscle
A
point of attachement to the bone that moves when a muscle contracts
12
Q
expand on the body part of a skeletal muscle
A
its the main part of the muscle
13
Q
what do skeletal muscles attach to bones by?
A
tendons
14
Q
extand on tendons
A
- they are strong cords of fibrous connective tissue
- some tendons enclosed in synovial lined tubes called tendon sheaths
- lubricated by synovial fluid
15
Q
expand on bursae
A
- small synovial lines sacs containing a small amount of synovial fluid
- located between some tendons and underlying bones
16
Q
what microscopic structures do skeletal muscles contains
A
- contractile cells or muscle fibers
- sarcomere
17
Q
expand on contractile cells/muscle fibers found in skeletal muscle
A
- grouped into bundles and inricately arranged
- contain thick myofilaments (containing the protein myosin)
- contain thin myofilaments (composed of actin)
18
Q
expand on sarcomere (contractile unit) found in skeletal muscle
A
- seperated from one another by dark bands called Z lines
- contraction works as follows
thick and thin myofilaments slide past each other as a muscle contracts
contraction requires calcium and energy rich adenosine triphosphate (ATP) molecules
19
Q
there are different groups of muscles that produce a single movement. what are those 3 groups of muscles.
A
prime mover
synergist
antagonist
20
Q
expand on the prime mover when it comes to producing movement
A
muscle whose contraction if mainly responsible for producing a given movement
21
Q
expand on the synergist when it comes to producing a single movement
A
muscle whose contractions help the prome mover produce a given movement
22
Q
expand on the antagonist when it comes to producing a single movement
A
muscle whose actions oppose the action of a prime mover in any given movement
23
Q
expand on posture
A
- a type of muscle contraction called tonic contraction enables us to maintain body position
- only a few of a muscles fibers shorten at one time
- tonic contractions produce no movement of body parts
24
Q
expand on heat production
A
- survival depends on the bodys ability to maintain a constant body temperature
- contraction of muscle fibers produces most of the heat requires to maintain normal body temperature
25
expand on muscle fatigue
- reduced strength of muscle contraction
- caused by repeated muscle stimulation without adequate periods of rest
- repeated muscular contraction depletes cellular ATP stores and outstrips the ability of the blood supply to replenish oxygen and nutrients
- contraction in the absense of adequate oxygen produces lactic acid, which contributes to muscle burning
26
what is oxygen debt in terms of muscle fatigue
- metabolic effort required to burn excess lactic acid that may accumulate during prolonged periods of exercise
- labored breathing after strenuous exercise is required to pay the debt
- this increated metabolism helps restore energy and oxygen reserves to pre-exercise levels
27
what does mucle functioning depend on
depends on functioning of mnay other parts of the body
28
how do muscles cause movement
by pulling on bones across movable joints
29
what systems play an important role in producing normal movements
respiratory, circulatory, nervous, muscular and skeletal
30
what is a motor unit
the combo of a motor neuron and the muscle cell or cell it innervates
31
in terms of the motor unit - how do muscles move
stimulation of a muscle by a nerve (motor neuron) impulse is required before a muscle can shorten and produce movement
32
what is a motor neuron
nerve cell that transmits an impulse to a muscle, causing contraction
33
expand on the neuromuscular junction (NMJ)
it's the point of contact between a nerve ending and the muscle fiber it innervates
34
a muscle only contracts when.....
an applied stimulus reached a certain minimal level of inensity (called a threshold stimulus)
35
what happens once the muscle is stimulated by the threshold stimulus
the muscle fiber wil contract completely ( a response called all or none)
36
are all muscle fibers controlled by the same motor unit
no, they all have different motor units that have different threshold-stimulus levels
37
expand on twitch contractions
quick, jerky responsed to a stimulus
38
expand on tetanic contractions
sustained and steady muscular contractions caused by a series of stimuli bombarding a muscle in rapid succession
39
what is a isotonic contraction
contraction of a muscle that produces movement at a jount
40
what happens during isotonic contractions
the muscle changes length, causing the insertion end of the muscle to move relative to the point of origin
41
what do concentric contractions do
shorten muscles
42
what do eccentric contractions fo
allow muscles to increase in length
43
what type of contraction cause most body moevements
isotonic contractions
44
what are isometric contractions
muscle contractions that do not produce movement; the muscle as a whole does not shorten
45
what happens during isometric contractiongs
- no movement occurs
- thension withtin the muscle increases
46
what happens to muscles during prolonged inactivity
causes disuse atrophy
47
what happens to muscles during regular exercise
increases muscle size, called hypertrophy
48
what is strength trainjing
contraction of mucles against heavy resistance
49
what happens to muscles during strength training
- increased the number of myofilaments in each muscle fiber, and as a result, the total mass of the muscle increases
- DOES NOT INCREASE NUMBER OF MUSCLE FIBERS
50
what does endurance training do to muscles
- allows more efficient delivery of oxygen and nutrients to a muscle via increased blood flow
- DOES NOT USUALLY RESULT IN MUSCULAR HYPERTROPHY
51
what is a flexion and give an example
movement that decreased the angle between two bones at their joint (bending)
52
what is an extension and provide an example
- movement that increases the angle between two bones at their joint (straightening)
53
what is abduction
movement of a part away from the midline of the body
54
what is adduction
movement of a part toward the midline of the body
55
what is rotation/circumduction
movement around a longitudial axis
56
what is supination
supination results in a hand position with the palm turned to the anterior position; (facing upward)
57
what is pronation
hand position that occurs when the palm faces posterior (facing to the floor)
58
what is dorsiflexion
foot movement that results in elevation of the dorsum or top of the foot
59
what is plantar flexion
the bottom of the foot is directed downward
60
what are muscles of the head and neck
orbicularis oculi
orbicularis oris
zygomaticus
61
what are the muscles of mastication
masseter and temporal
62
what does the sternocleidomastoid do
flexes head
63
what does the trapezius do
elevates shoulders and extends head
64
what are the muscles of the upper extremities
pectoralis major
latissimus dorsi
deltoid
biceps brachii
triceps brachii
65
what does the pectoralis major do
flexes upper arm
66
what does the latissimus dorsi do
extends upper arm
67
what does the deltoid do
abducts upper arm
68
what does the biceps brachii do
flexes forearm
69
what does the triceps brachii do
extends forearm
70
what are the abdominal muscles
rectus abdominis
external oblique
internal oblique
- transversus abdominis
71
what are respiratory mucles
intercostal muscles
diaphragm
72
what are the muscles of the lower extremeities
illiopsoas
glueus maximus
adductor mucles
hamstring muscles
73
what does the gluteus maximus do
extends thigh
74
what does the adductor muscle do
adduct thighs
75
what does the hamstring muscle do
flex leg
76
what does the quadriceps femoris group do
extend leg
77
what does the tibialis anterior do
dorsilflexes foot
78
what does the gastrocnemius do
plantar flexes foot
79
what does the fibularis group do
flexes foot
80
what are myopathies
muscle disorders which can range from milk to life-threatening
81
what causes a muscle strain (injury)
overexertion or trauma
- involves stretching or tearing of muscle fibers
82
what are muscle cramps
painful muscle spasms (involuntary twitches)
83
what do crush injuries result from
severe muscle trauma and may release cell contents that ultimately cause kidney failure
84
stress-induced muscle tension can cause what
headaches and back pain
85
expand on muscle infections and provide an example
- several bacteria, viruses and parasites can infect muscles
- poliomyelitits is a viral infection of motor nerves that ranges from mild to life threatening
86
what is muscular dystrophy
a group of genetic disorders characterized by muscle atrophy
87
what is the most common type of muscular dystrophy and expand on it
- duchenne muscular dystrophy
- characterized by rapid progression of weakness and atrophy
- x linked inherited disease, affecting mostly boys
88
what is myasthenia gravis
autoimmune muscle disease characterized by weakness and chronic fatigue
