KIN 362 1st Edition Exam 2 Study Guide Neural physiology review Neuron a specialized cell transmitting nerve impulses a nerve cell Spinal nerves any of the paired nerves which leave the spinal cord of a craniate vertebrate supply muscles of the trunk and limbs and connect with the nerves of the sympathetic nervous system which arise by a short motor ventral root and short sensory dorsal root and of which there are 31 pairs in humans Spinal reflexes a reflex arc involving the spinal cord Reflex arc the nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between Neurotransmitters a chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and by diffusing across the synapse or junction causes the transfer of the impulse to another nerve fiber Reciprocal inhibition describes the process of muscles on one side of a joint relaxing to accommodate contraction on the other side of that joint Joints are controlled by two opposing sets of muscles extensors and flexors which must work in synchrony for smooth movement Crossed extensor reflex a withdrawal reflex When the reflex occurs the flexors in the withdrawing limb contract and the extensors relax while in the other limb the opposite occurs Proprioception is a sense of how our bodies are positioned stretch reflex is a muscle contraction in response to stretching within the muscles It is a monosynaptic reflex which provides automatic regulation of skeletal muscles length golgi tendon organ senses changes in muscle tension It is a proprioceptive sensory receptive organ that is at the origins and insertion of skeletal muscle fibers into the tendons of skeletal muscle Static stretching a stretch that is held in a challenging but comfortable position for a period of time usually somewhere between 10 to 30 seconds These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute dynamic stretching a form of stretching beneficial in sports utilizing momentm from form static0 active stretching strength and the momentum from static active stretching strength in an effort to propel the muscle into an extended range of motion not exceeding one s static passive stretching ability postural sway the phenomenon of constant displacement and correction of the position of the center of gravity within the base of support Balance training balance training refers to a type of training that focuses on the ability to maintain proper posture over the body s base of support low back stretching critical for everyone Flexibility of the low back and hip along with strong lumbar muscles hamstrings and hip flexors will prevent low back pain PNF Stretching stretching that entails contract relax technique There is a max isometric contraction of the muscle that calls on the GTO That is followed by a passive stretch reflex contraction of antagonist This requires a partner Plyometrics exercise involving repeated rapid stretching and contracting of muscles as by jumping and rebounding to increase muscle power Learned skills mastered skills go through area 6 pre motor sports skill area extrapyramidal tract cerebellum and motor neurons Muscle physiology review Muscle fiber a myocyte also known as a muscle cell or muscle fiber is the type of cell found in muscle tissue Myocytes are long tubular cells that develop from myoblasts to form muscles in a process known as myogenesis motor unit a motor unit consists of one somatic efferent motor neuron and all of the muscle fibers cells that it innervates In the figure to the right two motor units are illustrated diagrammatically graded contractions variations in the degree of muscle contraction and are required for proper control of skeletal muscle movement They are graded by changing the frequency and strength of the stimulus size principle motor units are recruited from smallest to largest This means that slow twitch low force fatigue resistant muscle fibers are activated before fast twitch high force less fatigue resistant muscle fibers Removing motor unit inhibition Yelling is a technique that overrides the inhibition of motor units Asynchronous firing of motor units Allows movements to be executed smoothly maximal contractions the peak force produced by a muscle as it contracts while pulling against an immovable object Muscle spasm an involuntary contraction of a muscle that can cause a great deal of pain muscle fiber types characteristics Slow Oxidative slow twitch muscle fibers that rely primarily on oxidative metabolism to produce energy Fast oxidative Glycolytic fast twitch muscle fibers that can work under oxidative and glycolytic conditions Fast Glycolytic Fast twitch muscle fibers that perform primarily under glycolytic conditions Muscle Fatigue Plausible causes decrease blood supply depletion of phosphagen stores and oxygen and myoglobin glycogen depletion lactic acid production fatigue at neuromuscular junction dehydration and increased body core temperature Muscle Strength v Muscle endurance Strength maximal force that can be exerted against a resistance related to muscle size Endurance ability to repeatedly contract against a resistance or to sustain a contraction related to blood supply Hypertrophy the enlargement of an organ or tissue from the increase in size of its cells Hyperplasia the enlargement of an organ or tissue caused by an increase in the reproduction rate of its cells neuromuscular facilitation Capillary density a physiological measure that takes a cross section of muscle and counts the number of capillaries Bodybuilding v power lifting Bodybuilding the practice of strengthening and enlarging the muscles of the body through exercise Powerlifting consists of three attempts at a maximal weight Precautions in weight training Warm up before lifting less viscosity in warm muscle increase contraction speed Maintain correct posture protect intervertebral disks Breathe Exhale on lift Wear weight lifting belt when necessary valsalva maneuver holding your breath when weight lifting This increases the intrathoracic pressure causing an increase in blood pressure Types of muscle contraction Isotonic Resistance is held constant concentric occurs when the muscle shortens eccentric occurs when the muscle lengthens Isometric Joint angle is held constant Isokinetic Speed is held constant Weight training programs principles