PSYCH 3313 Lecture Notes - Lecture 15: Muscle Atrophy, Substantia Nigra, Reciprocal Inhibition
10 Oct 2016
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Document Summary
Lecture: october 10: types of muscles, smooth muscles, digestive tract, arteries, reproductive system, striated muscles, skeletal muscles, cardiac muscles of the heart. Muscle changes over time: use anaerobic metabolism, exercise builds muscle; more actin and myosin filaments produced, lack of activity reverses process, peak muscle mass about age 25; muscle mass diminishes 50% by age 80. Muscles interact at joints: muscles can do one thing: contract, antagonistic pairs, flexor contracts and extensor relaxes to bend a joint, extensor contracts and flexor relaxes to straighten a joint, additional muscles allow joints to rotate. Control of alpha motor neurons: alpha motor neurons receive input from , muscle spindles (sense of stretch, golgi tendon organs (sense of muscle tension, brainstem and motor cortex neurons (efferent signals, spinal interneurons. Muscular feedback: muscle spindle = feedback loop from muscle fiber to spinal cord, golgi tendon organs = feedback about degree to muscle contraction, or force, the ib sensory fiber carries information about muscle contraction from.
