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Muscular System
Chapter 8
Question | Answer |
---|---|
Muscles make up what percent of body weight? | About 40% |
When under conscious control muscles do what? | Contract to moves the bones. |
Excitability | Ability to receive and respond to stimulus. |
Contractility | Ability to shorten or contract. |
Extensibility | A muscle can be stretched or extended. |
Elasticity | The capacity to recoil or return to the original shape and length after contraction or extension. |
About what percent or heat is produced in the body in a result of muscle contractions? | Nearly 85% |
Epimysium | A connective tissue sheath that surrounds each muscle. The outer protective layer of muscles. |
Sarcolemma | The cell membrane of a muscle cell. |
Rigor Mortis | "Stiffness of death" |
Intramuscular Injection | Gluteus medius, not gluteus maximus to avoid damaging the sciatic nerve. |
Indirect Attachments | Tendon and aponeuroses form this, its an attachment from muscles to the periosteum of bones or connective tissue of other muscles. |
Insertion | More movable attachments of the muscle. |
Motor neurons | Stimulate the skeletal muscles. |
Motor unit | A single motor neuron and all the muscle fibers it stimulates. |
Neuromuscular junction | The region where an axon terminal meets a muscle fiber. |
Acetylcholine | A neurotransmitter |
Aerobic respiration | Oxygen's available. |
Anaerobic respiration | Oxygen is not available. |
Lactic acid | Causes a burning sensation in the muscles when it builds up. |
ATP | Immediate or initial source of energy for muscle contractions. |
Oxygen dept | Additional oxygen that's required after physical activity to restore resting condition. |
Oxygen dept is paid back by? | Labored breathing that continues after activity. |
Antagonist | Muscles that oppose or reverse a particular movement. |
Orbicularis Oculi | Muscle around the eyes. Action of winking, blinking,and squinting. |
Masseter | A muscle for chewing. |
Orbicularis Oris | Encircles mouth, used to close mouth, to form words, and to pucker up for kissing. |
Flexion | To bend EX; bending elbow or knee. |
Abduction | To take away EX; outward movement of the legs in "jumping jacks". |
Sternocleidomastoid | Moves the head side to side or bends head towards the chest. |
External Intercostal Muscles | Contracts to elevate the ribs during the inspiration phase of breathing. Located In spaces between the ribs. |
Diaphragm | Dome-shaped muscle responsible for the major movement in the thoracic cavity during quiet, relaxed breathing. |
Pectoralis major | To adduct and rotate the arm medially across the chest. |
Latissimus dorsi | Adducts and rotates the arm medially and lowers the shoulder. |
Deltoid | Abducts the arm to a horizontal position. Also a site for intramuscular injections. |
Gluteus medius | Superior and deep to the gluteus maximus. Also a common sight for intramuscular injection. |
Quadriceps Femoris | Primary ex-tensors of the leg along with four other muscles that are on anterior and lateral sides of thigh. |
Peroneus | Lateral compartment of leg; It everts the foot and also helps plantar flexion. |
Gastrocnemius and Soleus | Major muscles in the posterior compartment of leg form the fleshy mass in the calf. |
Calcaneal Tendon | Achilles tendon . Strong planter flexors of the foot. |