4. At the equilibrium potential of X channels,
(A) the membrane potential of the neuron is at 0 mV
(B) the membrane potential of the neuron is at -90 mV
(C) the neuron is at its resting membrane potential
(D) a flux of X ion into and out the neuron is equal.

30. (A)(B)(C)

1. A water-insoluble substance X has been shown to ameliorate the symptoms of Parkinson's disease in human, but its pharmacological mechanism has not yet clear. To investigate its mechanism in animals, the experimental group(s) should include animals that receive injection of (A) only substance X group (B) substance X and physiological saline groups (C) substance X and distilled water groups (D) substance X and the solvent that used for dissolve substance X groups.

2. The ion that is associated with exocytosis of synaptic vesicles after an action potential is (A) Na+ (B) Ca2+ (C) Cl- (D) K+

3. The synaptic potential (A) cannot be summated (B) is a long-distance transmission (C) occurs in the motor end plate (D) is also known as a pacemaker potential.

5. Which of following enzymes probably won't express in the noradrenergic neurons? (A) tyrosine hydroxylase (B) Dopa decarboxylase (C) dopamine beta-hydroxylase (D) phenyl ethanolamine N-methyltransferase.

6. The circulation of cerebrospinal fluid is between (A) pia mater and arachnoid mater (B) arachnoid mater and dura mater (C) pia mater and dura mater (D) pia mater and cerebrum.

7. Which of following receptor activations mediate skeletal muscle contraction? (A) adrenergic receptors (B) noradrenergic receptors (C) nicotinic acetylcholine receptors (D) muscarinic acetylcholine receptors.

8. Temporal summation of presynaptic signals summarizes potentials from (A) two different excitatory presynaptic neurons (B) two overlapping depolarization signals of the same synapse (C) two different inhibitory presynaptic neurons (D) two overlapping hyperpolarization signals of the same synapse.

9. Which of following respiratory status has the lowest intrapleural pressure (Pip)? (A) beginning of inspiration (B) middle of inspiration (C) end of inspiration and beginning of expiration (D) middle of expiration.

10. The percentage of oxygen-saturated hemoglobin in the systemic venous under resting state is about (A) 100 (B) 75 (C) 40 (D) 20.