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Chapter 6 Muscles
Brandi Gibson
Question | Answer |
---|---|
Muscle Cells | Muscle fibers |
The ability to to be stretched | Extensibility |
What surrounds each skeletal muscle? | epimysium |
What is fascia? | Another connective tissue located outside the epimysium. |
What are Motor neurons? | nerve cells that carry action potentials to skeletal muscle fibers. |
Each branch that connects to the muscle forms what? | Neuromusclular junction |
What does each preynaptic terminal contain? | synaptic vesicles |
Muscle twitch | a contraction of an entire muscle in response to a stimulus that causes the action potential in one or more muscle fibers |
A muscle fiber will not respond to stimulus until that stimulus reaches a level called? | Threshold |
Contractility | the ability of skeletal muscles to shorten with force |
What occurs in the absence of oxygen? | Anaerobic Respiration |
What kind of Muscle fibers fatigue quickly? | Fast twitch fibers |
Slow Twitch fibers are? | Muscle fibers that are resistant to fatigue |
What are muscles that work against each other called? | Antagonists |
Synergists are what? | Muscles that work together |
Two types of tongue muscles | Intringic and Extrinsic |
What does the levator superioris enable us to do? | Sneer |
Occipitofrontals allow us to what? | Rise the eyebrows |
Buccinator does what? | Flattens the cheeks |
Mastication does what? | Allows us to chew |
Zygomaticus lets us? | Smile |
the whole muscle is surrounded by 2 layers of tissue called what? | Fascia and epimysium |
What is the condition in which the muscle remains contracted without relaxing is called? | Tetany |
What is a muscle twitch? | A contraction of an entire muscle in response to stimulus |
Aerobic respiration occurs when? | In the presence of oxygen |
Which tongue muscle changes the shape of the tongue? | Intrinsic |
What muscle closes the eyelid? | Orbiculoris oculi |
Triceps brachii | extends the forearm |
Where is the latissimus dorsi? | the back muscles |
What does the rotator cuff do? | Attaches the humerus to the scapula |
Flexor carpi | flexes wrist |
Extensor carpi | extends wrist |
Rentinaculum (bracelet) | covers flexors and extensors and holds them in place |
How many hand muscles are there between the metacarpals? | 19 |
Pectoralis major | chest muscle, adducts and flexes the arm |
Linea alba | extends from the sternum to the navel to the pubis |
What does the Gluteus maximus control? | Buttocks/It rotates the thigh |
What is a common injection site? | The Gluteus meduis |
Sternocleioidmastoid? | Prime mover lateral neck muscle-rotates and abductes the head |
External Intercostals | elevates ribs during inspiration |
Internal Intercostals | Contracts during forced expiration |
Diaphram | Is used during quiet breathing |
Orbicularis oris | puckers the lips |
Depresser anguli oris | frowning |
What is the beginning of a contraction called? | Lag phase |
The increase in number of motor units being activated is called? | Recruitment |
A single motor neuron and all the skeletal muscle fibers it innervates are called? | Motor unit |
Excitability | the capacity of skeletal muscle to respond to a stimulus |
Elasticity | ability to recoil to their original resting length after they have been stretched |
Each muscle fiber is a single cylindrical cell containing several what? | Nuclei |
myofibrils? | threadlike structure that extends from one end of the fiber to the other |
Why does muscles produce heat? | its essential for maintenance of normal body temperature |
Myofibrils consists of what 2 kinds of proteins? | actin myofilameants and myosin myofilaments |
Actin and myosin myofilaments form highly ordered units called what? | sarcomeres |
Flexor digitorum | flexes fingers |
extensor digitorum | extends fingers |
How many muscles are in the foot? | 20 and they are called intransit |