The peripheral nervous system (PNS) consists of sensory neurons that pick up information from inside and outside the body and send it to the central nervous system (CNS), and motor neurons that transmit signals from the CNS to organs and tissues. The PNS has two major divisions - the somatic nervous system which controls voluntary functions like movement, and the autonomic nervous system which regulates involuntary functions like digestion. The autonomic nervous system has three divisions - the sympathetic nervous system which triggers the fight or flight response, the parasympathetic nervous system which allows relaxation, and the enteric nervous system which controls digestion.
2. Peripheral Nervous System
The peripheral nervous system (PNS) consists of a network
of nerve extensions clusters of nerve cells in the autonomic
nervous and ganglia (sing. ganglion) connected to different
visceral organs and tissues system and sensory nerves -
within the body.
3. Sensory neurons in the PNS pick up information from outside
and inside the body and send electrical signals through the
peripheral nerves towards the central nervous system. The CNS
processes this information and instructs motor neurons to transmit
signals to the nerves in a target organ or tissue. Once the organ or
tissue receives the signals, the body reacts or responds
appropriately.
4. The PNS has two major divisions:
the somatic nervous system and the
autonomic nervous system.
5. The somatic nervous system is also known as the motor
system. It is composed of effector nerves that control motor
neurons for voluntary functions. The somatic nervous system
permits actions that are consciously controlled by an individual,
such as movements of the head, arms, and legs.
6. On the other hand, the autonomic nervous system consists of peripheral
nerves that function involuntarily. One major autonomic function occurs
when sensory neurons within the body carry impulses from internal organs
to the central nervous system. In turn, the motor neurons in the CNS
transmit electrical signals to the target organs; nerves to make it function.
The autonomic nervous system controls the beating of the heart, the
digestion of food, and the secretion of hormones.
7. The autonomic nervous system has three
divisions of its own, namely, sympathetic nervous
system, parasympathetic nervous system, and
enteric nervous system.
8. The sympathetic nervous system is responsible for the “fight or
flight” response of the body. It controls the body’s ability to
respond accordingly to stressful or dangerous situations protecting
an individual from possible threats or injury. In the sympathetic
system, the motor neurons of the central nervous system
specifically target the heart and the muscles, accelerating the
heartbeat and causing muscle tensions in times of physical, mental
or emotional pressure.
9. The parasympathetic nervous system opposes the function
of the sympathetic nervous system. In other words, it allows a
person to relax This occurs when the motor neurons from the
central nervous system send signals that regulate the
heartbeat and loosen tight muscles in the body.
10. A third division called the enteric nervous system
includes particularly the autonomic functions in the
digestive system. The enteric nervous system is made
up of nerves that control the churning of food, the
secretion of gastric juices, and the movement of
digestive organs during the process of digestion.
12. Quiz no. ______
1. Consists of a network of nerve
extensions clusters of nerve cells in
the autonomic nervous and ganglia
connected to different visceral organs
and tissues system and sensory
nerves - within the body.
13. 2.It is composed of effector
nerves that control motor
neurons for voluntary
functions. Also known as
motor system.
14. 3. Controls the beating of the heart,
the digestion of food, and the
secretion of hormones.
16. 5. Opposes the function of the
sympathetic nervous system. In other
words, it allows a person to relax
17. 6. Made up of nerves that control the
churning of food, the secretion of
gastric juices, and the movement of
digestive organs during the process of
digestion.
18. 7-8. Two major divisions of PNS
9-11.Three divisions of autonomic
nervous system.
19.
20.
21.
22.
23. The autonomic nervous system is a control system that acts
largely unconsciously and regulates bodily functions, such as the
heart rate, digestion, respiratory rate, pupillary response, urination,
and sexual arousal. This system is the primary mechanism in
control of the fight-or-flight response .
24. GANGLIA - Collection of neuron cell bodies located in the peripheral nervous
system (PNS).
25. A visceral organ is an internal organ of the body, especially one
in the chest or abdomen, such as the heart, lungs, liver, or
intestines. Visceral organs are soft, hollow, and multilayered. They
are part of the digestive, respiratory, urogenital, endocrine, or
circulatory systems
26. A motor neuron (or motoneuron or efferent neuron ) is a neuron
whose cell body is located in the motor cortex, brainstem or the spinal
cord, and whose axon (fiber) projects to the spinal cord or outside of the
spinal cord to directly or indirectly control effector organs, mainly
muscles and glands.
