Chapter 5 HW Flashcards
Jumping jacks use which muscle actions?
Abduction: Movement of a part of the body away from the midline
Adduction: movement of a part of the body toward the midline
Synaptic knob
Releases the chemical (neurotransmitter) Acetylcholine (protein) at the nerve end.
Electromyography (EMG)
A procedure that assesses the health of the muscles by testing how a muscle responds to electric stimuli
Inversion
Position in which the soles of the feet are together, facing each other
Eversion
Position in which the soles of the feet point away from each other
Dorsiflexion
Position of standing on the heels with the toes pointing up off the floor
Plantar flexion
Position of standing on tiptoes with the heels off the floor
Supination
Rotation that turns the palms up. You could hold soup in the palm of your hand when your palm is supinated.
Pronation
Rotation that turns the palms down. You would pour soup from your hand during pronation
Myofibril
Compose the functional units of a muscle cell
Sarcolemma
The muscle cell membrane
Fixator
A muscle that holds an origin stable for another muscle
Lever
Rigid object that can be used to lift something
Motor unit
A single nerve cell and all the muscle cells it stimulates
Power stroke
Myosin pulls on actin, which draws the Z lines toward the center, shortening the sacromere
Prime mover
The main muscle of the synergist to perform the action
Synergist
Muscles that have the same action
Antagonist
A muscle that has an opposing action
Epimysium
The connective tissue that surrounds the entire muscle
Perimysium
Connective tissue surrounding a fascicle (muscle fibers)
Third class lever system
Most common lever system used in the body
Depression
The act of opening the jaw or lowering the shoulders
Circumduction
The act of making a circle with part of the body
Rotation
The act of spinning on an axis
Tetany
Sustained muscle contractions
Sliding filament theory
Muscle contraction involves thick myofilaments grabbing thin myofilaments and pulling them toward the center of the sarcomere
Anaerobic respiration
Skeletal muscle tissue performs anaerobic respiration, Involves fewer steps than aerobic respiration, does not require oxygen, and produces enough energy to form just two ATP molecules, produces lactic acid
Muscular dystrophy
Group of genetic disorders that result in progressive weakening and degeneration of muscle tissue and its replacement with fibrous scar tissue
Myasthenia gravis
Antibodies attack the acetylcholine receptors in the neuromuscular junctions. Muscle weakness results because the muscle cannot fully respond to the nerve impulses
Cramp
Painful muscle spasm as a result of heavy exercise, dehydration, electrolyte imbalance, extreme cold, low blood glucose levels, or lack of blood flow
Origin
The attachment of a muscle to a bone or structure that does not move when the muscle contracts
Insertion
The attachment of a muscle to a bone or structure that does move when the muscle contracts
Refractory phase
The calcium is actively transported back to the sarcoplasmic reticulum and the muscle produces acetylcholinesterase to remove the acetylcholine from the receptors
Muscle fatigue
Labels of lactic acid build up, muscle cells become less and less able to respond to the nerve stimuli, eventually the muscle may weaken to the point of not being able to respond at all
Sprain
A tear in a ligament
Strain
A tear in a muscle or a tendon
Aerobic respiration
Smooth, skeletal, and cardiac muscle tissue all perform aerobic respiration. Multistep process, requires oxygen, results in carbon dioxide, produces enough energy to form 36 ATP molecules
Isotonic contraction
Tension in the muscles remain constant, and motion was the result
Isometric contraction
Muscles bulge with increased tension, but movement would not have resulted
Muscle atrophy
Decrease in muscle size due to a decrease in muscle tissue
Flexion
Action that bends a part of the body anteriorly, such as flexing the elbow
Extension
Action that bends a part of the body posteriorly, such as straightening the arm at the elbow
Adduction
Movement of a part of the body toward the midline
Abduction
Movement of a part of the body away from the midline
Muscle elasticity
If a muscle cell is stretched, it will return to its original shape
Contractility
A muscle cell can shorter with force. Muscles can only pull, they cannot push
Motor unit recruitment
Involvement of multiple muscles for one movement
Cardiac muscle tissue
Autorhythmic (self stimulating), no nerve stimulus needed for cardiac muscle cells to contract. Aerobic respiration.
Skeletal muscle tissue
Voluntary, under conscious control, aerobic and anaerobic respiration
Smooth muscle tissue
Involuntary, not under conscious control. Aerobic respiration.
Fascia
Connective tissues that surrounds several muscles of an area forming muscle compartments
Z-lines
Form the ends of a sacromere, which is composed of thick and thin filaments
Which minerals are required for muscle cell function?
Calcium and potassium
Muscle responses to nerve stimulation
Based on the threshold amount of acetylcholine fitting into receptors, all or nothing, ultimately responsible for conductivity and contractility
