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Chapter 6 muscles
Question | Answer |
---|---|
The ability of skeletal muscle to shorten with force | Contractility |
The capacity of skeletal muscle to respond to a stimulus | Excitability |
Extensibility | The ability to be stretched |
Ability to recoil to their original resting length after they have been stretched | Elasticity |
Each skeletal muscle is surrounded by a connective tissue sheath called | The epimysium |
______ is another connective tissue located outside the epimysium | Fascia |
The fasciculi are composed of single muscle cells called ______ | Fibers |
Each fiber is surrounded by a connective tissue sheath called the | Perimysium |
A threadlike structure that extends from one end of the fiber to the other | Myofibrils |
Thin myofilaments | Actin myofilaments |
Thick myofilaments | Myosin myofilaments |
Actin and myosin myofilaments form highly ordered units called | Sarcomeres |
What band extends the length of the myosin | The A band |
On each side of the Z line is a light area called | I band |
The change difference across the membrane is called the | Resting membrane potential |
The brief reversal back of the charge is called | Action potential |
Nerve cells that carry action potentials to skeletal muscle fibers | Motor neurons |
Each branch that connects to the muscle forms | Neuromuscular junction |
A single motor neuron and all the skeletal muscle fibers it innervates are called | A motor unit |
The enlarged merger terminal | Presynaptic terminal |
Space between the presynaptic terminal and the muscle cell is the | Synaptic cleft |
Each presynaptic terminal contains | Synaptic vesicles |
A contraction of the entire in response to a stimulus that causes the action potential in on of more muscle | Muscle twitch |
The time between application of a stimulus to a motor neuron and the beginning of a contraction is the | Lag phase |
The time of contraction is the | Contraction phase |
The time during which the muscle relaxes is the | Relaxation phase |
Where the muscle remains contracted without relaxing | Tetany |
The increase in number of motor units being activated is called | Recruitment |
ATP | Adenosine Triphosphate |
ATP | is needed for energy for muscle contraction |
ATP | Is produced in the mitochondria |
ATP | Is short lived and unstable |
Muscles that work together to accomplish specific movements are | Synergists |
Muscles that work in opposition to one another are called | Antagonists |
Most stationary end of the muscle | Origin (head) |
The end of the muscle undergoing the greatest movement | Insertion |
Portion of the muscle between the origin and the insertion is the | Belly |
Some muscles have multiple | Origins or heads |
2 types of muscle contractions | Isometric & isotonic |
Anaerobic respiration | Without oxygen |
Aerobic respiration | With oxygen (more efficient) |
If one muscle plays the major role in accomplishing the desired movement, it is the | Prime mover |
Mastication | Chewing |
4 pairs of mastication muscles | 2 pairs of pterygoids, temporalis, and masseter |
Intrinsic tongue muscles | Change the shape of the tongue |
Extrinsic tongue muscles | Move the tongue |
Sternocleidomastoid | Lateral neck muscle and prime mover |
Platysma | Sheetlike muscle that covers the anterolateral neck |
Occipitofrontalis | Raises the eyebrows |
Orbicularis oculi | Closes the eyelids (causes crows feet) |
Orbicularis oris | Puckers the lips |
Buccinator | Flattens the cheeks |
Zygomaticus | Smiling muscle |
Levator labii superioris | Sneering |
Depressor Anguli oris | Frowning |
Group of muscles on each side of the back | Erector spinae |
External intercostals | Elevate the ribs during inspiration |
Internal intercostals | Contract during forced expiration |
Ok each side of the linea alba is the ______ ________ muscle | Rectus abdominis |
Scapular movements: | Trapezius & serratus anterior |
Trapezius | Rotates scapula |
Serratus anterior | Pulls scapula anteriorly |
Pectoralis major | Adducts and flexes the arm |
Latissimus dorsi | Medially rotates, adducts, & powerfully extends the arm "swimmer muscles" |
Deltoid | Attaches the humerus to the scapula and clavicle |
Triceps brachii | Extends the forearm |
Biceps brachii | Flexes the forearm |
Brachialis | Flexes forearm |
Brachioradialis | Flexes and supinates the forearm |
Flexor carpi | Flexes the wrist |
Extensor carpi | Extends the wrist |
Flexor digitorum | Flexes the fingers |
Extensor digitorum | Extends the fingers |
19 hand muscles | Intrinsic hand muscles |
Gluteus maximus | Buttocks |
Quadriceps femoris | Extends the leg |