1What are the 3 types of Muscles
Smooth
Cardiac
Skeletal
2Where are Smooth muscles located
On the walls of organs
3What kind of control do we have over Smooth Muscles
Involuntary Control
4Where are Cardiac Muscles located
They form the walls of the heart
5What kind of control do we have over Cardiac Muscles
Involuntary Control
6Where are Skeletal Muscles located
Along the skeleton
7How do skeletal muscles appear
They appear striated, with alternating dark and light bands
8What kind of control do we have over skeletal muscles
Voluntary control
9What is the structure of Skeletal Muscle in order of size
Bone -> Tendon -> Fascia -> Muscle -> Fascicles -> Muscle Fibers -> Myofibrils -> Sarcomere -> Myofilaments
10What are Fascia
The thin sheets of connective tissue that holds muscle in place
11What is the Epimysium
The outer layer that surrounds muscle fibers
12What is the Sarcomere
The smallest functional unit of muscle that is the basis for contraction
13What are Myofilaments
Actin and Myosin, proteins that are found in sarcomeres
14What is found in Sarcomeres
Actin, Myosin, and Z-Discs
15What is Myosin
Thick Filaments that contain connective "heads"
16What is Actin
Thin Filaments that are made up of Troponin and Tropomyosin
17What does Troponin do
Binds to calcium
18What does Tropomyosin do
Reveals binding sites
19What are Z-Discs
Borders between sarcomeres
20What is ATP
A molecule that serves as the primary energy carrier in cells
21What CANNOT occur without ATP
Human Movement and Muscle Contraction
22What does ATP attach to
Myosin
23What does ATP attaching to Myosin do
Dettaches actin from myosin, which allows for cross-bridging
24What is cross-bridging
The connection formed between actin and myosin during muscle contraction
25What does the Nervous System do
Provides the link between thoughts and actions by relaying messages that travel so fast you don't notice them
26What are the cells of nerves called
Neurons
27What do Motor Neurons do
Carry messages from the brain via the spinal cord to the muscles
28What is a Neuromuscular junction
The area where each motor neuron ending sits together, close to a muscle fiber
29What chemical do motor neurons release
Acetylcholine (ACh)
30What does Acetylcholine do
It's released into the neuromuscular junction and tells the muscle to contract
31What does Sodium and Potassium do for the muscle
An Action Potential, which sends an electrical impulse to travel down the axon of the nerve
32What is the 1st step of Excitation-Contraction Coupling
An electrical signal leaves the brain and travels down the axon
33What is the 2nd step of Excitation-Contraction Coupling
Neurotransmitter Acetylcholine attaches to receptors on adjacent cell membrane
34What is the 3rd step of Excitation-Contraction Coupling
Muscle becomes "excited" and releases calcium
35What is the 4th step of Excitation-Contraction Coupling
Calcium binds to troponin
36What is the 5th step of Excitation-Contraction Coupling
Tropomyosin moves out of the way and reveals "binding sites"
37What happens when tropomyosin moves out of the way
It allows they myosin head to attach to actin to form a cross-bridge
38What is the 6th step of Excitation-Contraction Coupling
ATP attaches to the myosin head, and the head pulls back from the actin
39What is the 7th step of Excitation-Contraction Coupling
Myosin will re-attach to actin as long as calcium is present
40What is the 8th step of Excitation-Contraction Coupling
Nervous excitement will stop once there is no longer a need for contraction, causing calcium to stop being released
41What is the 9th step of Excitation-Contraction Coupling
Calcium leaves and detaches from troponin
42What is the 10th and final step of Excitation-Contraction Coupling
Sarcomere returns to resting length
43What are the 3 types of muscle contraction
Eccentric
Concentric
Isometric
44What is Eccentric Contraction
Where resistance exceeds force production
45What happens to the sarcomere during Eccentric Contraction
It lengthens as myosin heads still hold on to actin
46What is Concentric Contraction
Force production exceeds resistance
47What happens to the sarcomere during Concentric Contraction
The sarcomere shortens
48What is Isometric Contraction
Force produced matches resistance
49What happens to the sarcomere during Isometric Contraction
No visible change in sarcomere length
50What causes more damage to the muscle, Concentric or Eccentric
Eccentric because the sarcomere lengthens while simultaneously contracting
51What has the highest force production capacity
Resting length
52What is the Force-Velocity Relationship during muscle contraction
Velocity increases at the expense of decreased force production and vice versa
53What is Force
How much weight you can move
54What is Strength
The amount of force you can produce
55What is Velocity
How fast you can move said weight
56What is Power
The ability to exert force FAST
57What are Fusiform Muscles
Muscles that have PARALLEL fibers to the muscle's axis
58What are characteristics of Fusiform Muscles
Larger range of motion and lower force production/capability
59What are Pennate Muscles
Muscles that have fibers that are DIAGONAL to a tendon that runs the entire length of the muscle
60What are characteristics of Pennate Muscles
Large Physiological cross-sectional area (PCSA), which means more force, and smaller ROM
61What is a Motor Unit
A motor neuron and all the muscle fibers it innervates
62What is a Motor Pool
The collective of motor neurons that innervate an entire muscle
63What are the major types of Motor Units
Type 1 (Slow Twitch)
Type 2b (Fast Twitch)
64What do Type 1 (Slow Twitch) Muscles do
Low force production, high fatigue resistance
65What do Type 2b (Fast Twitch) Muscles do
High Force production, quick to fatigue, and has a larger girth
66How will a Motor Unit be recruited
Based on the intensity of the activity
67What is the Size Principle
Explains the order in which muscle fibers are recruited
68What's an example of Size Principle
The faster a light load is moved, the more fast-twitch fibers are recruited
69What are Acute Responses
Decreased ATP, Increased HR, Sweating, Breathlessness, and Fatigue, which occurs after a bout of exercise
70What is Adaptation
Long-lasting changes that include Increased Size (Hypertrophy), Endurance, Strength, Power, and neuromuscular efficiency
71What is Proprioception
Knowing where the body is in space
72Where are Muscle Spindles located
They lie parallel to fibers deep in the belly of the mucsle
73What do Muscle Spindles sense
Change in length and Rate of length change
74What are Muscle Spindles responsible for
They initiate the stretch reflex and the patellar tendon reflex
75What is Reciprocal Inhibition
Contraction of an agonist muscle results in the relaxation of the antagonist muscle
76Where is the Golgi Tendon Organ (GTO) located
At the Musculotendinous Junction
77What does the GTO sense
It senses strain
78What is Autogenic Inhibition
Sustained contraction of a muscle is immediately followed by a relaxation/inhibition of the same muscle
79What is a Reflex
An involuntary motor response occuring outside of the central nervous system