Biology

Exam 2 Review

Ch 12 Fundamentals of the nervous system

-List the main functions of the nervous system.

-Explain the structural and functional divisions of the nervous system

-Define neuron, describe its structural components, and relate each structure to its functional role

* A neuron is the cell of the nervous system specialized to generate and transmit electrical signals; a nerve cell.

* It consists of an axon, dendrites, and a cell body

* Cell body-

* Chromatophilic bodies- Clusters of rough ER and free ribosomes that function to renew membranes of the neuron

* Axons-

* Neuron has only one

* Impulse generator and conductor

* Transmits impulses away from the cell body

* Dendrites-

* Extensively branching from the cell body

* Transmit electrical signals toward the cell body

* Function as receptive sites for receiving signals from other neurons

-List the types of neuroglia in nervous tissue, and distinguish them by location and function.

* Astrocytes are the most abundant glial cell type

* Abundant, star-shaped cells

* Brace neurons

* Form barrier between capillaries and neurons

* Control the chemical environment of the brain (CNS)

* Microglia

* Spider-like phagocytes

* Dispose of debris

* Ependymal cells

* Line the central cavity of the spinal cord and brain

* Bear cilia—help circulate the cerebrospinal fluid

* Oligodendrocytes—have few branches

* Wrap their cell processes around axons in CNS

* Produce myelin sheaths in the CNS

-Define reflex, and list the basic components of a reflex arc. Distinguish monosynaptic reflexes from polysynaptic reflexes

* Reflex- Rapid, autonomic motor responses

* Receptor—site where stimulus acts

* Sensory neuron—transmits afferent impulses to the CNS

* Integration center—consists of one or more synapses in the CNS

* Motor neuron—conducts efferent...