A&P help

Not too sure how to answer this Hopefully these references will lead you to an answer.

Spatial summation

Spatial summation is a way of achieving an action potential in a neuron which involves input from multiple presynaptic cells. Spatial summation is the algebraic summation of potentials from different areas of input, usually on the dendrites. Summation of excitatory postsynaptic potentials allows the potential to reach the threshold to generate an action potential, whereas inhibitory postsynaptic potentials can prevent the cell from achieving an action potential.

Temporal summation

Temporal summation is another means of transmitting signals with increased frequency of impulse thus increasing the strength of signals in each fiber. The effect is generated by a single neuron as a way of achieving action potential. Summation occurs when the time constant is sufficiently long, a fraction of a second, and the frequency of rises in potential are high enough that a rise in potential begins before a previous one ends. The amplitude of the previous potential at the point where the second begins will algebraically summate, generating a potential that is overall larger than the individual potentials. This allows the potential to reach the threshold to generate an action potential.

Thankk you, I got the general idea. This was a question from PhysioEx 9.0 exercise 2 activity 4. I do not like this at all. Thank you for your help. If you have any additional information it would be greatly appreciated.

Not sure how to answer this question either but i hope this helps.



Skeletal muscle constitutes 40% of muscle mass. Derangement of muscle function can have profound systemic effects.

Physiological skeletal muscle contraction requires generation and spread of a membrane action potential, transduction of the electrical energy into an intracellular chemical signal that, in turn, triggers myofilament interaction.

Intracellular cytoskeletal proteins, cell membrane structures and the associated glycoprotein extracellular matrix are important for maintenance of cell architecture and force transmission.

Smooth and graded changes in force of contraction are achieved through summation of responses to successive stimuli and recruitment of motor units.

Sustained muscle contraction requires de novo synthesis of ATP, which is principally aerobic or anaerobic depending on muscle fibre type.