HHIS221: HUMAN HISTOLOGY
Lesson 5 | Nervous Tissue
Topic Outline:
● Nervous Tissue
● Divisions of the Nervous System
● Autonomic Nervous System (ANS)
● Cells in the Nervous System
● Development of Nerve Tissue
Nervous Tissue
● Nervous system - the most complex system in the body,
is formed by a network of many billion nerve cells
(neurons) - and glial cells (supporting cell)
● Functions:
➔ Responsible for the production and induction of
electrical impulses. Somatic Nervous System (SNS)
➔ It allows us to receive stimuli and process the ● Includes all neurons regardless of whether they are in the
information. CNS or the PNS that are associated with skeletal muscle,
Divisions of the Nervous System skin, and sense organs.
A. Anatomically ● Voluntary control
I. Central nervous system Autonomic Nervous System (ANS)
II. Peripheral nervous system ● Involuntary
B. Functionally ● Stimulates smooth and cardiac muscles, and glands
I. Afferent/ Sensory Division ● Two Pathways
● Somatic 1) Preganglionic Neuron - cell body in the CNS
● Visceral 2) Postganglionic Neuron - cell body in a ganglion
II. Efferent/ Motor Division ● Two DIvisions
● Somatic 1) Sympathetic
● Autonomic – Responds to impending danger or stress.
Anatomically – Responsible for increased heartbeat and blood
I. Central nervous system pressure, increased sweat production and dilation of
● Brain pupils.
● Spinal Cord – Sense of excitement and other physiological
II. Peripheral nervous system changes that occur in “fight or flight” situations
● cranial, spinal and peripheral nerves 2) Parasympathetic
● ganglia (aggregates of nerve cells) – ovoid structure – Called upon resting and relaxing situations.
containing neuronal cell bodies; relay station of – Responsible for conservation of energy, decreasing
nervous system; allows nerves to enter and leave heart rate, respiratory rate, decreasing pH of blood,
simultaneously constriction of pupils.
Functionally
I. Afferent/ Sensory Division – carries messages from Cells in the Nervous System
sense organs and internal organs to CNS I. Neurons or Nerve Cell
● Somatic – Perceived Consciously (sense organs) a. Soma
● Visceral – Not Perceived Consciously (internal b. Dendrites
organs, and cardiovascular structure) c. Axon
II. Efferent/ Motor Division – carries messages from CNS II. Neuroglial Cells / Glial Cells
to internal organs, glands, and muscles a. Neuroglia of the CNS
● Somatic – Conscious Control – Astrocytes
● Autonomic – Unconscious Control – Oligodendroglia
– Microglia
– Ependymal cells
b. Neuroglia of the PNS
– Schwann cells
– Satellite cells
1
Lesson 5 | Nervous Tissue
Topic Outline:
● Nervous Tissue
● Divisions of the Nervous System
● Autonomic Nervous System (ANS)
● Cells in the Nervous System
● Development of Nerve Tissue
Nervous Tissue
● Nervous system - the most complex system in the body,
is formed by a network of many billion nerve cells
(neurons) - and glial cells (supporting cell)
● Functions:
➔ Responsible for the production and induction of
electrical impulses. Somatic Nervous System (SNS)
➔ It allows us to receive stimuli and process the ● Includes all neurons regardless of whether they are in the
information. CNS or the PNS that are associated with skeletal muscle,
Divisions of the Nervous System skin, and sense organs.
A. Anatomically ● Voluntary control
I. Central nervous system Autonomic Nervous System (ANS)
II. Peripheral nervous system ● Involuntary
B. Functionally ● Stimulates smooth and cardiac muscles, and glands
I. Afferent/ Sensory Division ● Two Pathways
● Somatic 1) Preganglionic Neuron - cell body in the CNS
● Visceral 2) Postganglionic Neuron - cell body in a ganglion
II. Efferent/ Motor Division ● Two DIvisions
● Somatic 1) Sympathetic
● Autonomic – Responds to impending danger or stress.
Anatomically – Responsible for increased heartbeat and blood
I. Central nervous system pressure, increased sweat production and dilation of
● Brain pupils.
● Spinal Cord – Sense of excitement and other physiological
II. Peripheral nervous system changes that occur in “fight or flight” situations
● cranial, spinal and peripheral nerves 2) Parasympathetic
● ganglia (aggregates of nerve cells) – ovoid structure – Called upon resting and relaxing situations.
containing neuronal cell bodies; relay station of – Responsible for conservation of energy, decreasing
nervous system; allows nerves to enter and leave heart rate, respiratory rate, decreasing pH of blood,
simultaneously constriction of pupils.
Functionally
I. Afferent/ Sensory Division – carries messages from Cells in the Nervous System
sense organs and internal organs to CNS I. Neurons or Nerve Cell
● Somatic – Perceived Consciously (sense organs) a. Soma
● Visceral – Not Perceived Consciously (internal b. Dendrites
organs, and cardiovascular structure) c. Axon
II. Efferent/ Motor Division – carries messages from CNS II. Neuroglial Cells / Glial Cells
to internal organs, glands, and muscles a. Neuroglia of the CNS
● Somatic – Conscious Control – Astrocytes
● Autonomic – Unconscious Control – Oligodendroglia
– Microglia
– Ependymal cells
b. Neuroglia of the PNS
– Schwann cells
– Satellite cells
1
