Chapter 3: Neurons, DNA, and Glial Cells: Structure and Function in the Nervous System

What is the function of the soma in a neuron?

The soma contains the organelles necessary for the cell's life processes, including the nucleus.

What are dendrites and their role in neurons?

Dendrites are branched extensions of a neuron's cell body that receive signals from other neurons.

What is the purpose of the axon in a neuron?

The axon carries electrical impulses within the neuron to propagate signals to neighboring neurons.

What is the axon terminal?

The axon terminal is the end of the axon where signals are transmitted to other neurons.

What is the structure of DNA?

DNA consists of two linked strands forming a double helix, with a backbone of alternating sugar and phosphate groups and four bases: Adenine (A), Cytosine (C), Guanine (G), and Thymine (T).

What are the two main steps of protein synthesis?

The two main steps are transcription (copying DNA into RNA) and translation (using RNA to synthesize proteins).

What is messenger RNA (mRNA) and its function?

mRNA is a single-stranded RNA molecule that copies genetic codes from DNA and corresponds to the genetic sequence of a gene.

What is the role of ribosomes in protein synthesis?

Ribosomes, often attached to the endoplasmic reticulum, synthesize proteins based on the information carried by mRNA.

What is the function of the rough endoplasmic reticulum?

The rough ER, containing ribosomes, synthesizes proteins that are transported out of the cell.

What are glial cells and their primary functions?

Glial cells support neurons by providing insulation, nutrients, and aiding in repair and waste elimination.

What are the five types of glial cells?

The five types are astrocytes, oligodendrocytes, microglia, ependymal cells, and Schwann cells.

What is the role of astrocytes in the nervous system?

Astrocytes provide support and nutrients for neurons, form part of the blood-brain barrier, and promote healing of damaged brain tissue.

What is myelin and which cells produce it in the CNS?

Myelin is a fatty substance that insulates axons, produced by oligodendrocytes in the CNS.

How do Schwann cells differ from oligodendrocytes?

Schwann cells provide myelin for only one axon in the PNS and guide axons during development and regrowth, while oligodendrocytes can serve multiple axons.

What is the function of microglia?

Microglia act as the immune system of the brain, monitoring health, identifying foreign tissue, and aiding in repair.

What are ependymal cells and their role?

Ependymal cells are specialized glial cells that produce cerebrospinal fluid (CSF) and help circulate it.

What is the blood-brain barrier?

The blood-brain barrier is a protective layer that lines the inner surfaces of blood vessels in the brain, maintaining homeostasis.

How do astrocytes contribute to the blood-brain barrier?

Astrocytes provide physical and chemical support to the blood-brain barrier, influencing the function and development of brain endothelial cells.

What is cerebrospinal fluid (CSF) and how much is produced daily?

Cerebrospinal fluid is produced by ependymal cells, with a total of approximately 500 mL produced daily.