LESSON 4: NERVOUS TISSUES LBBBIO7
FIRST TRIMESTER | 2025-2026
○ Saltatory conduction: sodium ions jump from
SYNCHRONOUS MEETING NOTES one node to another, speeding conduction until
reaching the axon terminal, causing release of
neurotransmitters.
4th group - The Nervous Tissues
○ Neurons with variable numbers of dendrites are
called multipolar neurons.
● Highly specialized tissue with high function. ○ Most common type of synapse: axodendritic,
● Conducts impulses through the formation of action but axo-somatic and axo-axonal
potentials.
General Features
● Neuroglia (Supporting Cells)
○ Found outside neurons.
○ Schwann cells: originate from neural crest cells.
● Structures and Functions
○ Astroglia: for nutrition and osmotic pressure
○ Dendrite: receives signals and transmits them
regulation.
toward the cell body; shorter than axons;
○ Oligodendroglia: secrete myelin.
receives input from other cells or another nerve
○ Microglia: phagocytic cells that remove bacteria
which goes to the cell body (perikaryon).
or antigens.
○ Synapse: connection or junction between two
○ Ependymal cells: line the cavities of ventricles
nerves.
and produce cerebrospinal fluid (CSF).
○ Axon: very long; connects to another nerve
through the synapse; releases
Study Guide Answers
neurotransmitters.
○ Most common neurotransmitter: acetylcholine.
○ Supporting cells / satellite cells: function similar First Study Guide
to astrocytes, nourishing the main body of the
nerve and regulating osmotic pressure and 1. Describe/know how neurons receive, propagate, and transmit
certain ions. nerve impulses. Know the role of the parts (soma, axon, dendrites)
○ Nucleus: found at the center; contains the of a nerve cell.
nucleolus.
● The nervous system contains complex intercommunicating
○ Nucleolus: site of ribosomal RNA.
networks of nerve cells that receive and conduct impulses
○ Dots within the cell body: aggregations of Golgi
along their neural pathways or axons to the CNS for
bodies and ribosomes.
analysis, integration, interpretation, and response.
○ Soma / Perikaryon: the cell body.
● The appropriate response to a stimulus from the neurons
● Myelination
of the CNS is the activation of muscle (skeletal, smooth, or
○ Axons are myelinated.
cardiac) functions or glandular secretions (endocrine or
○ Myelin is a type of sphingomyelin or
exocrine).
phospholipid that protects axons from external
● The structural and functional cells of the nervous tissue
chemicals.
are the neurons. Although neurons vary in size and shape,
○ Schwann cells: produce myelin in the PNS.
they share common features. Each neuron consists of:
○ Oligodendrocytes: produce myelin in the CNS.
○ Soma (cell body): contains the nucleus,
○ Nodes of Ranvier: gaps between myelin
nucleolus, numerous different organelles, and
segments; responsible for saltatory conduction.
the surrounding cytoplasm or perikaryon.
LBBBIO7: Histology Laboratory LESSON 4 1
FIRST TRIMESTER | 2025-2026
○ Saltatory conduction: sodium ions jump from
SYNCHRONOUS MEETING NOTES one node to another, speeding conduction until
reaching the axon terminal, causing release of
neurotransmitters.
4th group - The Nervous Tissues
○ Neurons with variable numbers of dendrites are
called multipolar neurons.
● Highly specialized tissue with high function. ○ Most common type of synapse: axodendritic,
● Conducts impulses through the formation of action but axo-somatic and axo-axonal
potentials.
General Features
● Neuroglia (Supporting Cells)
○ Found outside neurons.
○ Schwann cells: originate from neural crest cells.
● Structures and Functions
○ Astroglia: for nutrition and osmotic pressure
○ Dendrite: receives signals and transmits them
regulation.
toward the cell body; shorter than axons;
○ Oligodendroglia: secrete myelin.
receives input from other cells or another nerve
○ Microglia: phagocytic cells that remove bacteria
which goes to the cell body (perikaryon).
or antigens.
○ Synapse: connection or junction between two
○ Ependymal cells: line the cavities of ventricles
nerves.
and produce cerebrospinal fluid (CSF).
○ Axon: very long; connects to another nerve
through the synapse; releases
Study Guide Answers
neurotransmitters.
○ Most common neurotransmitter: acetylcholine.
○ Supporting cells / satellite cells: function similar First Study Guide
to astrocytes, nourishing the main body of the
nerve and regulating osmotic pressure and 1. Describe/know how neurons receive, propagate, and transmit
certain ions. nerve impulses. Know the role of the parts (soma, axon, dendrites)
○ Nucleus: found at the center; contains the of a nerve cell.
nucleolus.
● The nervous system contains complex intercommunicating
○ Nucleolus: site of ribosomal RNA.
networks of nerve cells that receive and conduct impulses
○ Dots within the cell body: aggregations of Golgi
along their neural pathways or axons to the CNS for
bodies and ribosomes.
analysis, integration, interpretation, and response.
○ Soma / Perikaryon: the cell body.
● The appropriate response to a stimulus from the neurons
● Myelination
of the CNS is the activation of muscle (skeletal, smooth, or
○ Axons are myelinated.
cardiac) functions or glandular secretions (endocrine or
○ Myelin is a type of sphingomyelin or
exocrine).
phospholipid that protects axons from external
● The structural and functional cells of the nervous tissue
chemicals.
are the neurons. Although neurons vary in size and shape,
○ Schwann cells: produce myelin in the PNS.
they share common features. Each neuron consists of:
○ Oligodendrocytes: produce myelin in the CNS.
○ Soma (cell body): contains the nucleus,
○ Nodes of Ranvier: gaps between myelin
nucleolus, numerous different organelles, and
segments; responsible for saltatory conduction.
the surrounding cytoplasm or perikaryon.
LBBBIO7: Histology Laboratory LESSON 4 1
