Introduction to the Nervous System and Nervous Tissue

These flashcards cover key concepts from the nervous system, including its divisions, functions, neuron types, and action potentials.

What are the main functions of the nervous system?

Controls perception, directs voluntary movement, regulates homeostasis, and is the seat of consciousness, personality, learning, and memory.

What are the two anatomical divisions of the nervous system?

Central nervous system (CNS) and peripheral nervous system (PNS).

What does the CNS consist of?

The brain and spinal cord.

What types of neurons are primarily found in the PNS?

Cranial and spinal nerves.

How is the nervous system functionally categorized?

Sensory, integrative, and motor functions.

What is the role of sensory neurons in the nervous system?

They gather information about internal and external environments.

What percentage of integrated sensory information is disregarded by the CNS?

99%.

What is the function of motor neurons?

They carry out motor functions to respond to integrated sensory information.

What type of neurotransmission do astrocytes facilitate?

They regulate the extracellular environment and anchor neurons and blood vessels.

What separates the presynaptic and postsynaptic neurons in chemical synapses?

Synaptic cleft.

What are the two types of ion channels in neurons?

Leak channels and gated channels.

What is the resting membrane potential of a typical neuron?

Approximately -70 mV.

When does hyperpolarization occur in a neuron?

When positive charges exit or negative charges enter the cytosol, making the membrane potential more negative.

What causes an action potential to be generated in a neuron?

When the local potential depolarizes the axon strong enough to reach the threshold.

What is the difference between saltatory and continuous conduction?

Saltatory conduction occurs in myelinated axons and is faster, while continuous conduction occurs in unmyelinated axons and is slower.