Nervous System and Neuron Basics (Biology 30)

Flashcards covering neuron structure, CNS vs PNS, glial cells, myelin sheath, nodes of Ranvier, neurolemma, synapses, reflexes, learning-related dendrite growth, and homeostasis.

What is the functional unit of the nervous system?

Neuron.

the two main components of the nervous system

Central nervous system (brain and spinal cord) and peripheral nervous system (nerves outside the CNS).

What are the two directions neurons are classified by in terms of information flow?

Sensory (afferent) neurons carry information into the CNS and motor (efferent) neurons carry information out to muscles or effectors.

What is the term for a bundle of neurons in the peripheral nervous system?

Nerve.

Which part of a neuron receives impulses from other neurons?

Dendrite.

What is the cell body of a neuron called and what does it contain?

The soma (cell body); it contains the nucleus.

What is the long projection that transmits impulses away from the cell body?

axon

What are the end branches of an axon that connect to the next neuron or an effector called?

Axon terminals or synaptic/terminal branches.

What is the junction where one neuron communicates with the next neuron or an effector?

Synapse (involving synaptic knobs at the end of the axon).

What non-neuronal cells provide support and maintenance for neurons?

Glial cells.

What does the term glial mean and what is their general role?

Glial means glue; they provide structural support, metabolism, and healing for neurons.

What fatty covering speeds up nerve impulses along an axon?

Myelin sheath.

Which cells form the myelin sheath in the peripheral nervous system?

Schwann cells.

What are the gaps in the myelin sheath called?

Nodes of Ranvier.

What is the outer layer produced by Schwann cells that aids in healing after nerve damage?

Neurolemma.

Which cells provide myelin in the central nervous system?

Oligodendrocytes.

What is the term for the white appearance of myelinated axons?

White matter.

What is the role of dendrites in learning and forming connections?

Dendrites receive impulses and form connections with other neurons, increasing dendritic branching as you learn.

What are the three common types of neurons mentioned, and what do they do?

Sensory (afferent) neurons carry information to the CNS, motor (efferent) neurons carry information to muscles, and interneurons connect neurons within the CNS.

What is a reflex, and how does it relate to the nervous system?

A reflex is an involuntary, automatic response to a stimulus; it involves a reflex arc.

What is homeostasis in the context of the nervous and endocrine systems?

Maintaining a stable internal environment (e.g., temperature, water/salt balance, glucose) often via negative feedback.

What is negative feedback used for in the body?

To return a system to its set point and maintain homeostasis.