controls the rapid activities of the body such as muscular contraction, secretions of some endocrine glands, heart rate, respiration rate, gastrointestinal motility, and rapid reflex actions. Dendrites ➢ These are branch-like structures that receive messages from other neurons and allow the transmission of messages to the cell body. Cell Body ➢ Each neuron has a cell body with a nucleus, Golgi body, endoplasmic reticulum, mitochondria, and other components. Axon ➢ An axon is a tube-like structure that carries electrical impulses from the cell body to the axon terminals that pass the impulse to another neuron. Synapse ➢ It is the chemical junction between the terminal of one neuron and the dendrites of another neuron. Afferent (sensory) neuron – transmits nerve impulses from effector organs to the spinal cord or brain. ▪ Efferent (motor) neuron - transmits nerve impulses from the spinal cord or brain to the effector organs. ▪ Interneuron – conduct impulses from an afferent to an efferent neuron within the CNS. CNS contains most of the nervous system, consisting of the brain (in vertebrates which have brains), and the spinal cord. PNS resides or extends outside the CNS, to serve the limbs and organs. It is not protected by bone, leaving it exposed to toxins and mechanical injuries

1. The Nervous System
Micah P. Arellado
Course Instructor

2. The Nervous
System
M. Arellado, 2023

3. The Nervous System
• controls the rapid activities of
the body such as muscular
contraction, secretions of some
endocrine glands, heart rate,
respiration rate, gastrointestinal
motility, and rapid reflex actions.
Composed of:
brain
spinal cord
nerves
M. Arellado, 2023

4. DENDRITES
NERVE CELL
BODY
NUCLEUS
MYELIN SHEATH
AXON TERMINALS
AXON
Dendrites
 These are branch-like structures that receive
messages from other neurons and allow the
transmission of messages to the cell body.
Cell Body
 Each neuron has a cell body with a nucleus,
Golgi body, endoplasmic
reticulum, mitochondria, and other components.
Axon
 An axon is a tube-like structure that carries
electrical impulses from the cell body to the
axon terminals that pass the impulse to another
neuron.
Synapse
 It is the chemical junction between the terminal
of one neuron and the dendrites of another
neuron.
M. Arellado, 2023

5.  Afferent (sensory) neuron – transmits nerve impulses
from effector organs to the spinal cord or brain.
 Efferent (motor) neuron - transmits nerve impulses
from the spinal cord or brain to the effector organs.
 Interneuron – conduct impulses from an afferent to an
efferent neuron within the CNS.
Direction of the Impulse
M. Arellado, 2023

6. Division of the Nervous System
Central Nervous System
(CNS)
• contains most of the
nervous system, consisting
of the brain (in vertebrates
which have brains), and the
spinal cord.
• resides or extends outside
the CNS, to serve the limbs
and organs. It is not
protected by bone, leaving it
exposed to toxins and
mechanical injuries.
Peripheral Nervous System
(PNS)
M. Arellado, 2023

7. Central nervous
system
VS
Peripheral nervous
system
M. Arellado, 2023

8. Divisions of the
Peripheral Nervous
System (PNS)
A. Somatic
• innervates striated or skeletal
muscles, and brings about
quick adjustments to changes
in environment (40 m/sec).
M. Arellado, 2023

9. Divisions of the
Peripheral Nervous
System (PNS)
B. Autonomic
• innervates glands
and visceral
musculature.
M. Arellado, 2023

10. Subdivision of Autonomic Nervous System
Para-sympathetic
• Controls normal body
functions
Example: Digestion
M. Arellado, 2023

11. Subdivision of Autonomic Nervous System
Sympathetic
• Controls “fight or flight
mechanism”
Example: during tress
M. Arellado, 2023

12. the END.
M. Arellado, 2023