Question | Answer |
Muscle cells | Muscle fibers |
M line | A dark band that anchors the myosin in the center of the sarcomere |
H zone | Light area in the center of sarcomeres |
A band | Extends the length of the myosin |
I band | Consists of actin |
The arrangement of actin and myosin give a _______ appearance. | Banded |
Basic structural and functional unit of a muscle | Sarcomeres |
Sarcomeres | Joined end to end to form the myofibril |
Myosin myofilaments | Thick myofilaments |
Actin myofilaments | Thin myofilaments |
Myofilaments consist of two major kinds of protein fibers | Actin
Myosin |
Minute | Small |
Resting membrane potential | The charge difference across the membrane |
Action potential | The brief reversal back of the charge |
Motor neurons | Nerve cells that carry action potentials to skeletal muscle fibers |
Muscles are named according to their ___, ____, ____, ____, ____, ____, and _____ | Location
Size
Orientation of fibers
Shape
Origin
Insertion
Function |
Antagonists | Muscles that work in opposition to one another |
Synergists | Muscles that work together to accomplish specific movements |
Belly | The portion of the muscle between the origin and the insertion |
Prime mover | One muscle playsa major role in accomplishing he desired movement |
Occipitofromtalis | Raises the eyebrow |
Orbicularis oculi | Closes the eyelids and causes wrinkles |
Orbicularis oris | Pickers the lip |
Buccinator | Flattens the cheeks |
Zygomaticus | Smiling muscle |
Lavator labii superioris | Sneering |
Depressor anguli oris | Frowning |
Mastication | Chewing |
4 pairs of mastication muscles | Two pairs of ptertgoids
temporalis
Masseter |
Intrinsic tongue muscles | Change the shape of the tongue |
Extrinsic toungue muscles | Move the tongue |
Sternocleidomastoid | Lateral neck muscle and prime mover |
Neuromuscular junction | Each branch that connects to the muscle |
Insertion | The end of the muscle undergoing the greatest movement |
Origin | The most stationary end of the muscle |
The points of attachment of each muscle are it’s ____ and _____ | Origin
Insertion |
Slow twitch fibers | Contract more slowly and are more resistant to fatigue |
Fast twitch fibers | Contract quickly and fatigue quickly |
Muscle tone | Constant tension produced by the muscle is constant during contraction |
Isotonic | The amount of tension produced by the muscle is constant during contraction, but the length of the muscle changes |
Isometric | The length of the muscle doesn’t change, but the amount of tension increases during the contraction process |
2 types of muscle contractions | Isometric
Isotonic |
Muscle fatigue | Results when ATP is used during muscle contraction faster than it can be produced in the muscle cells |
Oxygen debt | The amount of oxygen needs in chemical reactions to convert lactic acid to glucose |
Aerobic respiration | With oxygen |
Anaerobic respiration | Without oxygen |
Creating phosphate | Another high energy molecule |
ATP | Short lived and unstable |
Recruitment | The increase in number of motor units being activated |
Tetany | The muscle remains contracted without relaxing |
Relaxation phase | The time during which the muscle relaxes |
Contraction phase | Time of contraction |
Lag phase | Time between application of stimulus to a motor neuron and the beginning of a contraction |
All or none response | When threshold is reached |
Threshold | The point where muscle fibers contract maximallly |
Muscle twitch | A contraction of an entire muscle in response to a stimulus |
Sliding filament mechanism | The sliding of actin past myosin during contraction |
Acetylcholinesterase | Enzymes that rapidly break down neuron and muscle cells |
Acetylcholine | A neurotransmitter |
Synaptic vesicles | Secretes neurotransmitter called acetylcholine |
Postsynaptic terminal | Muscle fiber |
Synaptic cleft | The presynaptic terminal and the muscle cell |
Prestnaptic terminal | Enlarged nerve terminal |
Motor unit | A single motor neuron |
Myofibrils | A threadlike structure that extends from one end of the fiber to the other |
Endonysium | Surround the muscle fiber |
Muscle fibers | Single muscle cell |
Fasciculi | Bundles of muscle |
Fascia | Surrounds and separate muscles |
Epimysuim | Connective tissue that surround entire muscle |
Epi | Upon |
Elasticity | Absolute to recoil |
Extensibility | The ability to be stretched |
Excitability | The capacity of skeletal muscle to respond to a stimulus |
Contractility | The ability of skeletal muscle to shorten with force |