MNB.10_The_nervous_system_at_cellular_level_HMA

What are the principal features of nervous systems in vertebrates?

Distinctive features include the differentiation between the Central Nervous System (CNS) and Peripheral Nervous System (PNS).

What is the structure of a nerve cell composed of?

A nerve cell (neuron) consists of dendrites, soma (cell body), axon, and synaptic terminal.

List the three types of neurons.

The three types of neurons are multipolar, pseudounipolar, and bipolar.

What are ganglia?

Ganglia are masses of nerve cell bodies located outside the Central Nervous System.

What is the difference between white matter and grey matter?

White matter is formed exclusively of axons, while grey matter contains cell bodies, dendrites, and some axons.

What are glial cells?

Glial cells are non-nervous cells that support and protect neurons.

Differentiate between myelinated and non-myelinated nerve fibers.

Myelinated fibers have a myelin sheath for insulation, non-myelinated fibers do not and are embedded in Schwann cell cytoplasm.

What is the role of the Central Nervous System (CNS)?

The CNS processes information and coordinates activity in the body, composed of the brain and spinal cord.

What does the Peripheral Nervous System (PNS) include?

The PNS includes all nerves and neurons that do not lie within the CNS.

What is neurogenesis?

Neurogenesis is the process of generating neurons from neural stem cells and progenitor cells.

What is anencephaly?

Anencephaly is a neural tube defect where the neural tube fails to close, affecting brain development.

How does maternal folic acid supplement help prevent neural tube defects?

Maternal folic acid supplementation can reduce neural tube closure defects by about 70% when taken periconceptionally.

Which system is responsible for voluntary muscle movements?

The Somatic Nervous System is responsible for voluntary muscle control.

What is the role of receptors in the nervous system?

Receptors are cells that receive sensations and stimuli from the environment.

How long can axons be in the nervous system?

Axons can be up to 1 meter in length, such as the sciatic nerve.

What are the three types of macroglial cells in the CNS?

Astrocytes, oligodendrocytes, and ependymal cells are the three types of macroglial cells.

What is the function of oligodendrocytes?

Oligodendrocytes are responsible for myelination of axons in the CNS.

What is sciatica?

Sciatica is pain caused by damage to the sciatic nerve.

What is the function of astrocytes?

Astrocytes support neurons, maintain the blood-brain barrier, and provide structural support.

What condition results from the autoimmune attack on oligodendrocytes?

Multiple sclerosis results from the autoimmune damage to oligodendrocytes and the myelin they produce.

What does a pseudounipolar neuron connect?

A pseudounipolar neuron connects sensory organs to the spinal cord.

What is the function of microglia?

Microglia act as the immune defense in the CNS, transforming into phagocytic cells.

What distinguishes bipolar neurons?

Bipolar neurons have one dendrite and one axon and are involved in specialized sensory pathways.

What is found within the perikaryon of a neuron?

The perikaryon contains Nissl bodies, which are sites of protein synthesis.

What is a ganglion?

A ganglion is a collection of nerve cell bodies located outside the CNS.

How do neurons communicate at synapses?

Neurons communicate by releasing neurotransmitters at the synaptic terminal into the synaptic cleft.

What is the primary function of the autonomic nervous system?

The autonomic nervous system regulates involuntary bodily functions, including heart rate and digestion.

Define the term ‘neural tube disorders’.

Neural tube disorders are malformations resulting from the failure of the neural tube closure during embryonic development.

Which vitamin is critical for DNA base synthesis and neural tube closure?

Vitamin B9 (folic acid) is critical for DNA base synthesis and helps prevent neural tube defects.

What characterizes the nodes of Ranvier in myelinated fibers?

Nodes of Ranvier are gaps between Schwann cells where the axon is exposed and not covered by myelin.

What is the structural organization of peripheral nerves?

Peripheral nerves are organized into fascicles, surrounded by endoneurium, perineurium, and epineurium.

How many neuroglial cells are estimated to exist compared to neurons?

There are six to ten times more neuroglial cells than neurons in the CNS.

What occurs during neurulation?

Neurulation is the process of neural system development from the ectoderm, forming the neural plate.

What does the term ‘myelination’ refer to?

Myelination refers to the process of forming a myelin sheath around axons to insulate them.

How does the CNS primarily support neurons?

The CNS primarily supports neurons through glial cells that provide insulation and structural support.