physiology of training terms (ch5) Flashcards
a group of specialized myocardial cells, located in the wall of the right atrium that controls the hearts rate of contraction
the pacemaker of the heart
sinoatrial node (SA node)
the specialized mass of conducting cells in the heart located at the atrioventricular junction
atrioventricular node (AV node)
to decrease the electrical potential across a membrane, as when the inside of a neuron becomes less negative to the outside
depolarize
to restore the difference in charge between the inside and outside of the plasma membrane of a muscle fiber or cell following depolarization
repolarize
local control of blood distribution (through vasodilation) in response to a tissues changing metabolic needs
autoregulation
fat cells
adipocytes
the mechanism by which an increased amount of blood in the ventricle places a stretch on the cardiac muscle fibers, thereby causing a stronger ventricular contraction to increase the amount of blood ejected
Frank-Starling mechanism
the pressure in the aorta and pulmonary trunk, that the left and right ventricles of the heart must overcome to eject blood
afterload
the pumping up of muscle that happens during a single exercise bout, resulting mainly from fluid accumulation in the interstitial and intracellular spaces of the muscle
transient hypertrophy
swelling resulting from an excessive accumulation of fluid in the tissues of the body
edema
a measure of the amount of air that passes through the lungs in one minute; calculated as the tidal volume multiplied by the ventilatory rate
minute ventilation
the sensory organ within a muscle that is sensitive to stretch and thus protects the muscle against too much stress
muscle spindles
a sensory organ with a tendon that, when stimulated, causes an inhibition of the entire muscle group to protect against too much force
Golgi tendon organs (GTO)
point of transition between predominately aerobic energy production to anaerobic energy production; involves recruitment of fast-twitch muscle fibers and identified via gas exchange during exercise testing
ventilatory threshold
a branch of the autonomic nervous system responsible for mobilizing the body’s energy and resources during times of stress and arousal
opposes the physiological effects of the parasympathetic nervous system
sympathetic nervous system
a subdivision of the autonomic nervous system that is involved in regulating the routine functions of the body
opposes the physiological effects of the sympathetic nervous system
parasympathetic nervous system
the production of glucose from non-sugar substrates such as pyruvate, lactate, glycerol, and glucogenic amino acids
gluconeogenesis
the release of triglycerides from fat cells
lipolysis
three fatty acids joined to a glycerol (carbon and hydrogen structure) backbone; how fat is stored in the body
triglycerides
soreness that occurs 24 to 48 hours after strenuous exercise, the exact cause of which is unknown
delayed onset muscle soreness (DOMS)
an abnormal increase of ketone bodies in the body; usually the result of a low-carbohydrate diet, fasting, or starvation
ketosis
polypeptide structurally similar to insulin that is secreted either during fetal development or during childhood and that mediates growth hormone activity
insulin-like growth factor 1 (IGF-1)
type of stretching that involves taking the joints through their ranges of motion while continuously moving
often beneficial in warming up for a particular sport or activity that involves the same joint movements
dynamic stretching
a series of chemical reactions that act to break pyruvate down to carbon dioxide, water, and many hydrogen-powered molecules known as NADH and FADH2
Kreb’s cycle
a deficiency of glucose in the blood commonly caused by too much insulin, too little glucose, or too much exercise
most commonly found in the insulin-dependent diabetic and characterized by symptoms such as fatigue, dizziness, confusion, headache, nausea, or anxiety
hypoglycemia
an internal state of physiological balance
homeostasis
a metabolic by-product of anaerobic glycolysis
when accumulates it increases blood pH, which slows down enzyme activity and ultimately causes fatigue
lactic acid
the narrowing of blood vessels resulting from contraction of the muscular wall of the vessels, particularly in the periphery of the body (limbs)
peripheral vasoconstriction
the process by which the body generates heat from energy production
thermogenesis
a cluster of factors associated with increased risk for coronary heart disease and diabetes
metabolic syndrome (MetS)
the amount of resistance that can be moved though the range of motion one time before the muscle is temporarily fatigued
one-repetition maximum (1 RM)
the frequency of impulses sent to a muscle
increased force can be generated through an increase in either the number of muscle fibers recruited or the rate at which the impulses are sent
rate coding
the tension generating response following the application of a single stimulus to muscle
twitch
the repeated stimulation of a muscle that leads to an increase in tension compared to single twitch
summation
the highest tension developed by a muscle in response to high frequency of stimulation
tetanus
a chemical substance such as acetylcholine or dopamine that transmits nerve impulses across synapses
neurotransmitter
the form of endoplasmic reticulum where calcium is stored to be used for muscle activation; located in striated muscle fibers
sarcoplasmic reticulum
the principle that a physiological system subjected to above-normal stress will respond by increasing in strength or function accordingly
overload
the systematic process of applying overload
progression
the principle of exercise training that suggests that any improvement in physical fitness due to physical activity is entirely reversible with the discontinuation of the training program
reversibility
holding a nonmoving (static) position to immobilize a joint in a position that places the desired muscles and connective tissues passively at their greatest possible length
static stretching
the reflex inhibition of the motor neurons of antagonists when the agonists are contracted
reciprocal inhibition
an involuntary motor response that, when stimulated, causes a suddenly stretched muscle to respond with a corresponding contraction
stretch reflex
the basic functional unit of the myofibril containing the contractile proteins that generate skeletal muscle movements
sarcomere
