Unit 3 Anatomy Chapters 14-16, 18, 19

Front

Nervous tissue is made of two types of cells.

Back

1. Neurons: Excitable nerve cells that transmit electrical signals and do not regenerate over time. 2. Supporting Cells: Non-excitable cells that support neurons.

Front

Characteristics of neurons.

Back

1. Extreme longevity, can live over 100 years. 2. Do not divide by mitosis and cannot be replaced if destroyed. 3. High metabolic rates, first to die if deprived of oxygen.

Front

Components of a neuron.

Back

1. Cell Body: A single nucleus surrounded by cytoplasm. 2. Processes: Dendrites and axons.

Front

Function of dendrites.

Back

Conduct electrical impulses toward the cell body and function as receptor sites to receive signals from other neurons.

Front

Function of axons.

Back

Conduct impulses away from the cell body.

Front

Definition of synapse.

Back

The junction that transfer information from the presynaptic neuron to the postsynaptic neuron, muscle, or a gland

Front

Types of synapses.

Back

1. Chemical Synapse: Uses neurotransmitters to send messages. 2. Electrical Synapse: Two cells form a gap junction for ion flow.

Front

Structure of a synapse.

Back

The plasma membranes of two neurons are separated by a narrow space called a synaptic cleft.

Front

The axon terminal of a presynaptic neuron contains synaptic vesicles filled with neurochemicals such as acetylcholine.

Back

Synaptic vesicles release neurotransmitters into the synaptic cleft, initiating a new impulse in the postsynaptic neuron.

Front

Supporting cells can divide by mitosis and make up 50% of the brain mass.

Back

They support and insulate neurons, preventing impulses from jumping between neurons.