Anatomy and Physiology Answer Key

Muscle physiology and performance page 65 1 a c any

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Unformatted text preview: ically. Increased capacity of the muscle to oxidize fats, which allows glycogen to be used at a slower rate. Increased myoglobin content in the muscle, which stores oxygen and aids oxygen delivery to mitochondria. An increase in the number of capillaries surrounding muscle fibers increases oxygen delivery and removal of wastes. An increase in the size and density of mitochondria in the muscle. An increase in the concentration and activity of Krebs cycle enzymes improves capacity for aerobic respiration. An increase in fiber size which can accommodate an increase in mitochondria, myoglobin, and glycogen storage. 1. (a) Sensory: Reception of internal and external stimuli. (b) Integrative: Interpretation of sensory messages. (c) Motor: Initiation and coordination of an appropriate response to the sensory input. 2. (a) CNS: Brain and spinal cord. The brain has ultimate control of almost all body activities (except simple spinal reflexes). The spinal cord interprets simple reflexes and relays impulses to and from the brain. (b) PNS: All nerves and sensory receptors outside the CNS. Divided into sensory and motor divisions. The motor division controls both voluntary (somatic) and involuntary (autonomic) responses. Regulates sensory reception, relays impulses to the CNS, brings about the motor response. 3. Separation of the motor division of the PNS into somatic and autonomic divisions allows essential functions to occur without conscious involvement. In this way, the conscious part of the brain is not overwhelmed by having to coordinate every motor response. This improves efficiency of motor function. The Autonomic Nervous System (page 72) 1. (a) Sympathetic NS: Fibers originate from the spinal cord in thoracic and lumbar regions. Preganglionic fibers are short and release acetylcholine. Postganglionic fibers are long and usually liberate norepinephrine. The sympathetic NS is more active when the body is preparing for action ('fight or flight'). (b) Parasympathetic NS: Fibers originate from the brainstem and the sacral region of the spinal cord. Preg...
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This document was uploaded on 01/28/2014.

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