25.A a. Axon b. Dendrites c. Cell body d. synapse. 26. The is a small space across which an impulse travels to move from one neuron to another. 27.The a. central b. peripheral 28.A nervous system is made up of the brain and spinal cord. a. central b. peripheral a. Glial cell b. nervous system is made up of all the nerves outside the brain and spinal cord. is made up of a cell body, dendrite, and axon. Meninges e Neuron d. Cerebrospinal fluid

What is the function of the presynaptic “autoreceptors" in axon terminals? a. To release substances into the blood O b. To detect transmitter concentrations in the cleft O. To release neurotransmitters into extracellular fluid d. To release the neurotransmitter acetylcholine

1. Transmitter substances   a. may be inhibitory or stimulatory.   b. change the permeability of postsynaptic cells.   c. elicit graded potentials near the synapse.   d. all of these 2. The major divisions of the peripheral nervous system are   a. peripheral and central systems.   b. afferent and autonomic systems.   c. somatic and autonomic systems.   d. sympathetic and parasympathetic systems. 3. At rest, a nerve cell has a high concentration of __________ inside and a high concentration of __________ outside.   a. potassium; sodium   b. acetylcholine; chlorine   c. sodium; potassium   d. phosphorus; calcium 4.  Which of the following would NOT be defined as a part of the central nervous system?   a. brain   b. cerebellum   c. spinal nerves   d. neuroglia cells 5.  The basic unit of the nervous system is   a. a nerve impulse.   b. the brain.   c. neuroglia.   d. the neuron.

The reflex arc is the fastest way the body has to move a body part from danger or away from the source of pain. Have you ever noticed your own reflex response? Did you notice that you felt the pain after you yanked your hand away from the source of pain? Which is the sequence of structures involved in a reflex response? a. motor neurons → effectors → brain → sensory neurons → interneurons b. effectors → sensory neurons → brain → motor neurons c. sensory neurons → interneurons → motor neurons → effectors d. sensory neurons → motor neurons → interneurons → effectors