Nervous System

Flashcards for reviewing the nervous system, covering nervous tissue, central nervous system, limbic system, peripheral nervous system, and drug abuse.

What two structures compose the central nervous system?

The brain and spinal cord.

What are the three classes of neurons?

Sensory neurons, interneurons, and motor neurons.

What is an effector?

An organ, muscle fiber, or gland.

How do sensory neurons, interneurons, and motor neurons function in relation to the CNS?

Sensory neurons take messages to the CNS. Interneurons receive input from sensory neurons and other interneurons. Motor neurons take messages away from the CNS to an effector.

What is an action potential?

A rapid change in polarity across an axomembrane as the nerve impulse occurs.

What is the ion distribution on either side of the axomembrane during resting potential?

Sodium ions (Na+) is greater outside the axon than inside, and the concentration of potassium ions (K+) is greater inside the axon than outside.

What is voltage, and what is its unit of measurement?

Voltage, which is measured in millivolts (mV), is a measure of the electrical potential difference between two points.

How many neurons synapse at a ganglion?

Two

What are the protective membranes that wrap the brain and spinal cord called?

Meninges

What is integration in the context of synaptic transmission?

The summing up of inhibitory and excitatory signals received by a postsynaptic neuron.

How do neurotransmitters facilitate communication between two neurons?

They diffuse across the synaptic cleft from one neuron to the next.

Through what opening does the spinal cord extend from the base of the brain?

The foramen magnum.

What are the two primary functions of the spinal cord?

The spinal cord provides communication between the brain and peripheral nerves and is a center for reflex actions.

What are the four major parts of the brain?

The cerebrum, the diencephalon, the cerebellum, and the brain stem.

What are the general functions of the cerebrum, the cerebellum, the diencephalon, and the brain stem?

Cerebrum: Sensory input, integration, and voluntary motor responses. Cerebellum: Maintain posture and balance. Diencephalon: homeostasis. Brain stem: Relay station for tracts; Visual, auditory, and tactile responses.

In which side of the brain are Broca's and Wernicke's area located?

The left cerebral cortex.

What are the functions of Wernicke's area and Broca's area?

Wernicke's area for understanding the written and spoken word. Broca's area adds grammatical refinements and directs the primary motor area to stimulate the appropriate muscles for speaking.

What functions does the hypothalamus regulate to maintain homeostasis?

The hypothalamus regulates hunger, sleep, thirst, body temperature, and water balance.

What is the function of the limbic system?

The limbic system blends primitive emotions (rage, fear, joy, sadness) and higher mental functions (reason, memory) into a united whole.

What limbic system structures are involved in learning and long-term memory?

The hippocampus and the amygdala.

How does cocaine affect dopamine levels in the brain?

Cocaine potentiates the effects of dopamine by interfering with its uptake from synaptic clefts.

Of what is the peripheral nervous system composed?

Nerves and ganglia.

What are ganglia?

Ganglia are swellings associated with nerves that contain collections of cell bodies.

How many cranial and spinal nerves are there in the human body?

12 pairs of cranial nerves and 31 pairs of spinal nerves

What are reflexes?

Automatic responses to a stimulus.

What does the autonomic system regulate?

It regulates the activity of cardiac and smooth muscle and glands.

What are the two divisions of the autonomic nervous system?

The sympathetic and parasympathetic divisions.

In the sympathetic division, are preganglionic fibers short or long compared to postganglionic fibers?

Preganglionic fibers are short, and the postganglionic fibers are long.

What functions do reflex centers within the medulla oblongata control?

The medulla oblongata contains reflex centers for regulating heartbeat, breathing, and vasoconstriction.