BI 112            Spring 2006 

Review terms for CH 48-49  Nervous systems and Sensory and Motor Mechanisms

What are the basic components of the Central Nervous System (CNS) and the Peripheral Nervous System (PNS)?  [match the following with the CNS or PNS:  brain, spinal cord, motor neurons, sensory neurons] 

How do motor neurons and sensory neurons differ w/respect to the direction of nerve impulse [i.e., towards or from the CNS] 

Motor neurons end at effectors (muscle or gland cells) and convey their chemical message to these body cells via neurotransmitters. In addition, neurotransmitters are the means by which neurons communicate with one another at chemical synapses. Neurotransmitters regulate ion channels in which of these, the pre- or postsynaptic membrane?  Which do neurotransmitters regulate:  voltage gated or chemically gated ion channels?  Can you explain the action of neurotransmitters in inhibitory synapses vs. excitatory synapses?  What is summation?

Distinguish between dendrite, axon, and cell body in the neuron.

What is the "Action Potential"

What role does K⁺ play in the neuron?

What role doe Na⁺ play in the neuron?

During an action potential, does Na+ move in or out of the neuron?

Is Cl^- found in greater concentration within or outside of the neuron's cytoplasm?

At rest, what is the net electrical charge (+ or -) inside the neuron's cytoplasm?  What ions contribute to that net charge? 

Other Key Terms

nerves

neurons

voltage-gated ion channels

chemically-gated ion channels

hyperpolarization

threshold potential

Schwann Cells

Nodes of Ranvier

myelin sheath

saltatory conduction

synapse

synaptic cleft

synaptic vesicles

pre- and postsynaptic membranes

neurotransmitters

acetylcholine

actin

myosin

nerve impulse

cephalization

hydrostatic skeleton

sensory receptors (examples of and their function, see your notes for details) 

sarcomere

actin

myosin