Question | Answer |
Classifications for fibers | Fast or slow Glycolytic or oxidative |
Fast fibers | Contain myosin with high ATPase activity |
Fibers with numerous mitochondria have a high capacity for ______________. | Oxidative Phosphoralation |
Oxidative fibers | Red muscle fibers contain large amounts of myoglobin |
Myoglobin | Oxygen bindgin protein that increase the rate of oxygen diffusion and provides a small store oxygen |
Gycolytic Fibers | Few mitochondria Many glycolytic enzymes Surrounded by less blood vessels white muscle fibers |
Slow oxidative fibers | Low myosin ATPase activity and high oxidative capacity Produces less tension but sustainable |
Fast oxidative-glycoltyic fibers | High myosin ATPase activity and high oxidative capacity and intermediate glycolytic capacity Produces intermediate tension but drops off over time |
Fast glycolytic fibers | High myosin ATPase activity and high glycolytic capacity Produces greatest amount of tension but doesn't last long |
more oxidative fibers are more ______. more glycolytic fibers are more ______. | Red white |
Things that affect fiber type/number | genetics use/disease presence of oxygen (aerobic or anaerobic) |
Motor commands originate in the _______ | motor cortex. |
Skeletal muscles are only ________ so they must _______. | Stimulated work in pairs |
flexor | muscle that decreases joint angle |
Propriation system--sensory system: Info | load and body position |
Propriation system--sensory system: Receptors | Stretch receptors (mechanoceptors) |
muscle spindle | Detect changes in length of muscle |
golgi tendon organ | Detects changes in muscle tension |
Afferent signal from muscles is sent to | Brain Local reflex circuts |
Local Circuts | Afferents to interneurons to motorneurons |
Spinal Reflex | Involuntary Contraction |
Knee jerk response | -Stretch patellar ligament -Stretch receptor input to spinal cord -positive input to CNS -positive input to entensors -negative input to flexor (inhibits motorneuron) |
Withdrawl response | Pain in foot--registered by spinal cord Interneurons in cord: Inhibit extensor, stimulates flexor inhibits contralateral flexors Send input to the brain |
Smooth Muscle: locations | Lines the: digestive track blood vessels urogential ducts glands |
Smooth muscle: characteristics | Not striated; layered autonomic (can stimulate or inhibit) |
Smooth muscle: myofilaments | myosin and actin thick and thin thick lie between thin thin attatch to dense bodies (not z line) cells often linked by gap junctions synchronise contractions |
Smooth Muscle: Contraction Overview | Need to increase intracellular calcium. |
Smooth Muscle: Contraction method of action steps 1-3 | Opening of Ca+ channels is triggered by automnomic, endocrines chemicals stretch or pacemaker cells ca+ activates callmodulin activated calmodin activates myosin light chain kinase |
Smooth Muscle: Contraction method of action steps 4-6 | Myosin light chain kinase phophoralates myosin cross bridge is formed cross bridge cycling occurs |
Smooth Muscle: Relaxation Overview | Need decrease in cytosolic caclcium |
Smooth Muscle: Relaxation Method of Action | Increase myosin light chain phosphate no cross bridging occurs |
Aerobic Conditions cause | Increase # of mitochondria in fibers Increase # of capillaries around myofibers Increased vascularization Increase in endurance=less fatigue |
Anaerobic conditions cause | greater myofiber diameter increase in glycolytic enzymes |
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