Upload
cory-knight
View
216
Download
0
Embed Size (px)
Citation preview
The Sliding Filament Theory
The thin filaments (actin) slide over the thick causing the sarcomere to shorten. This process requires ATP
Motor End PlateAxon of a motor neuron that attaches to the sarcolemma of the muscle fiber
Muscle
Neuron
Motor End Plate
Physiology of ContractionAn action potential causes the release of Ca+2 ions stimulating the myosin to move the actin filament
http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/muscles/muscles.html(labeling picture)
Muscle Contraction Summary
http://bcs.whfreeman.com/thelifewire/content/chp47/4702001.html
Narrated Summary with tabs
Anaerobic System1C6H12O6 2C3H6O3 + ATP
Glucose is broken down into Pyruvic AcidNeeds no oxygenNot a lot of ATP
Aerobic System1C3H6O3 + O2 CO2 + H2O + ATP
Starts with Pyruvic Acid from AnaerobicNeeds Oxygen to take placeMakes a lot of energyMany Steps - longest
What Happens When You ExerciseThe muscle cells burn off the ATP they have floating around in about 3 seconds. The phosphagen system kicks in and supplies energy for 8 to 10 seconds. This would be the major energy system used by the muscles of a 100-meter sprinter or weight lifter, where rapid acceleration, short-duration exercise occurs. If exercise continues longer, then the glycogen-lactic acid system kicks in. This would be true for short-distance exercises such as a 200- or 400-meter dash or 100-meter swim. Finally, if exercise continues, then aerobic respiration takes over. This would occur in endurance events such as an 800-meter dash, marathon run, rowing, cross-country skiing and distance skating.
All or None PrincipleWhen a muscle fiber is stimulates it either completely contracts or does not contract at all
Threshold Stimulus – the weakest stimulus that can cause a muscle to contractSub-Threshold Stimulus – a stimulus that is too weak to cause a contraction
Latent Period – time between the application of the stimulus and the muscle contractionContraction Period – time when filament are sliding over each other, causing a contractionRelaxation Period – Time during which filaments are sliding back into placeRefractory Period – Time following a contraction during which a muscle is unable to respond to a stimulus