Chapter 16 and 17 Test Review Flashcards
What are the rotator cuff muscles?
Teres Minor, Infraspinatus, Supraspinatus, and subscapularis
What are the functions of muscles?
Movement of the body as a whole or movement of its parts (heat production and posture)
What is excitability or irritability?
Ability to be stimulated
What is sarcolemma?
Plasma membrane of muscle fibers
When are satellite cells active?
During exercise and injuries
What do T tubules do?
Allow electrical impulses to travel along the sarcolemma to move deeper into the cell
What are myofibrils?
Numerous fine fibers packed close together in sarcoplasm and run lengthwise along muscle fibers
What is a sarcomere?
Smallest contractile unit of muscle fibers
What is another name for skeletal muscle?
Striated
What is a triad?
Triplet of tubules that allows an electrical impulse to stimulate the membranes of adjacent sacs (T tubule sandwiched between 2 sacs of SR)
What is Myosin?
Molecules shaped like twisted golf clubs that are chemically attracted to actin molecules
What is actin?
globular protein that forms two fibrous strands twisted around each other to form the bulk of the thin filament
What is tropomyosin?
Protein that blocks the active sites on actin molecules
What is troponin?
Protein that holds tropomyosin molecules in place
What muscles are involved with the shoulder girdle?
Trapezius, levator scapulae, rhomboids, and 7th cervical vertebrae
What muscles move the thigh?
Muscles crossing the front of the hip, 3 gluteal muscles, tensor fasciae latae, and thigh adductors
What muscles move the upper arm?
Brachiallis and Biceps Brachii
What are the actions of teres minor?
Helps hold head of humerus in glenoid cavity, stabilizes shoulder joint, and rotates humerus laterally
What are the actions of teres major?
Posteromedially extends, medially rotates, and adducts arm synergist of latissimus dorsi
What muscle extends the forearm?
Triceps brachii
What are the muscles of quadriceps?
Rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius
What are the hamstring muscles?
Semitendinosus, biceps femoris, and semimembranosus
What body systems are responsible for maintaining body posture?
Nervous, muscular, skeletal, respiratory, digestive, excretory, and endocrine
What is a treppe?
Steplike increase in strength of contraction seen in series of twitch contractions that occur 1 second apart
What is acetylcholine?
neurotransmitter released into synaptic cleft, can be inhibitory or excitatory based on receptors
What is responsible for cross-bridging?
Calcium
What are the 3 twitch contractions?
Latent, Contraction, and Relaxation
What are the different muscle tissues?
Cardiac, Smooth and Skeletal
What are the characteristics of cardiac muscle?
Involuntary, syncytium, paarallel myofibrils
What are the characteristics of smooth muscle?
Single nucleus, no striations
What is isotonic contraction?
Contraction in which the tone or tension in a muscle remains the same as the length of the muscle changes
What is isometric contraction?
Contraction in which the muscle length remains the same while muscle tension increases
What does isotonic mean?
Same tension
True or False: Most body movements occur as a result of both types of contractions
True
What is another name for treppe?
The staircase phenomenon
What happens during the latent phase of twitch contraction?
Nerve impulses travel to the sarcoplasmic reticulum to trigger the release of calcium
What happens in the contraction phase?
The binding of calcium to troponin and the sliding of filaments
What happens in the relaxation phase?
Sliding stops
What influences strength of muscle contraction?
An electrical stimulus
What might cause physiological muscle fatigue?
Lack of ATP
What is the first event that occurs in muscle relaxation?
Calcium ions are released
What is the powerstroke of myosin?
Myosin heads bend with great force after forming cross bridges, pulling the thin filaments past them
What extends and adducts the arm?
Teres major and latissimus dorsi
What muscle flexes the semipronated and semisupinated forearm?
Brachioradialis
What muscles move the upper arm? Originate?
Latissimus Dorsi: vertebra to illium
lumbodorsal fascia
When lifting your hands above your head, muscles involved?
Rotator cuffs, deltoid, trapezius, serratus anterior
Muscles involved in rotating the arm outward?
Teres minor and infraspinatus
Action of biceps brachii
flexes supinated forearm, forearm and hand
Action of triceps
extends lower arm
Action of brachiallis
flexes forearm
What muscles move the feet?
Gastrocnemius, plantan, flexor halliscus, flexor digitorum longus, tibialis posterior, fibularis brevis, fibularis longus
Function of creatine phosphate
Extra energy
What are myofilaments?
Finer fibers of myofibrils (myosin-thick, actin-thin)
What is an A Band
The segment that runs the entire length of the thick filaments/myosin
What are white fibers?
Fast and with little myoglobin
Aerobic respiration
occurs with adequate oxygen
Anaerobic
Lack of oxygen
Graded Strength Principle
Greater number of fibers contracting, stronger the contraction; based on the fact that skeletal muscles contract with varying degrees of strength at different times
Cramps
Muscle spasms that are fatigued or mildly inflamed
Convulsions
Abnormal, uncoordinated tetanic contracitons of groups of muscles, brain disturbance
