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Correctly arrange the sequence of events in excitation-contraction coupling in cardiac muscle.

What happens to the proportion of energy derived from muscle glycogen as the duration of exercise is prolonged?

Classify each of the following statements according to whether they are characteristics of skeletal muscle, smooth muscle, or both.

Determine whether each of the following statements about smooth muscle structure is TRUE or FALSE.

Classify the following characteristics by matching them to the skeletal muscle fiber type category they best represent.  

When cross-bridges cycle, the relative positions of the thick and thin filaments change. Match the following sarcomere characteristics as becoming greater, less, or staying the same as a result of sarcomere shortening.  

As a graduate teaching assistant for your physiology class, you are required to provide grade for the following examples of student work regarding receptors and provide a justification for the assigned grade. No two answers can have the same grade assigned.   1. Postynaptic membranes receive both excitatory impulses (which increase the likelihood of threshold), and inhibitory impulses (which decrease the likelihood of threshold). Excitatory temporal summation results from multiple action potentials in a presynaptic neuron causing sustained neurotransmitter release that results in ligand-gated Na+Na channels opening in the postsynaptic membrane [q1].  Justification of the grade [q4]   2. Synaptic integration refers to the fact that a multitude of graded synaptic impulses are necessary to eventually summate and produce action potentials. The combination of excitatory (temporal) and inhibitory (spatial) influences acting at any time will influence the likelihood of the axon hillock reaching threshold, voltage-gated Na+ Na+ channels being opened and action potential generation. [q2] Justification of the grade [q5]   3. Net postsynaptic neuronal influence determines whether or not a presynpatic neuron reaches threshold and generates an action potential. Membrane potential movement towards greater negatives are excitatory. For example, stimuli resulting in negative ion efflux or positive ions influx moves membrane potential away from threshold and can be referred to as temporal summation [q3] Justification of the grade [q6]

Compartments A and B are separated by a membrane that is permeable to K+K+ but not to Na+Na+ or Cl−Cl-. At time zero, a solution of KCl is poured into compartment A and an equally concentrated solution of NaCl is poured into compartment B. Which would be true once equilibrium is reached?

Which of the following is TRUE about the concentration gradient of Na+ in a neuron at rest?

Classify each of the following statements as being descriptive of graded potentials or action potentials.