Nervous System 1: Organization, Brain Structures, Glia & Pathways Study Guide

What is the primary function of the nervous system?

To sense and react to the environment, increasing survival and reproduction.

What are the two main divisions of the nervous system?

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

What type of nervous system do cnidarians have?

A nerve net with interconnected neurons and no central control organ.

What is the structure of the nervous system in echinoderms?

A nerve ring that serves as a central control structure with radial nerves.

What is a ladder-type nervous system?

A system found in Platyhelminthes with two longitudinal nerve cords and transverse nerves.

What are ganglia?

Segmentally arranged clusters of neurons found in more complex organisms like annelids and arthropods.

What is the role of astrocytes in the nervous system?

To maintain the blood-brain barrier and regulate extracellular fluids.

What cells are involved in myelination in the CNS?

Oligodendrocytes.

What is the function of Schwann cells?

To myelinate axons in the Peripheral Nervous System (PNS).

What is the embryonic origin of the central nervous system?

It develops from the neural tube.

What are the main parts of the brain?

Cerebrum, cerebellum, thalamus, hypothalamus, and brainstem.

What is the function of the cerebellum?

To coordinate movement, balance, and motor coordination.

What does the thalamus do?

It serves as the main input center for sensory information to the cerebrum.

What are the functions of the brainstem?

To route sensory information and regulate basic life functions like respiration and heartbeat.

What is the structure of the spinal cord?

White matter outside and gray matter inside, with a central canal filled with cerebrospinal fluid.

What is a reflex action?

A rapid, involuntary response to a stimulus.

What are the two functional components of the Peripheral Nervous System?

Afferent (sensory) and efferent (motor) systems.

What is the difference between visceral and somatic senses?

Visceral senses are not consciously perceived (e.g., blood pressure), while somatic senses are (e.g., vision).

What does the autonomic system control?

Involuntary functions like heart rate and digestion.

What are the three divisions of the autonomic nervous system?

Enteric, parasympathetic, and sympathetic systems.

What is the pathway of a signal in the nervous system?

Stimulus → sensory receptor → afferent neuron → CNS → efferent neuron → effector.

What is a neuron?

A nerve cell that transmits signals in the nervous system.