11.3 The Peripheral Nervous System Flashcards
What is the Peripheral Nervous system made of?
Nerves that link the brain and the spinal cord to the rest of the body
What do sensory neurons do?
Carry information from all parts of the body to the central nervous system
What do motor neurons do?
Carry information from the central nervous system to the effectors
What are the two main divisions of the Peripheral nervous system?
The Somatic System and the Autonomic System
What kind of control is the Somatic system under?
Voluntary control
What do the Neurons of the Somatic system service?
The head, trunk (torso), and limbs
What do the Sensory Neurons of the Somatic system do?
Carry information about the external environment inward, from receptors in the skin, tendons, and muscles
What do the Motor Neurons of the Somatic system do?
Carry information to the skeletal muscles
How many nerves does the Somatic system contain?
12 pairs of Cranial Nerves
31 pairs of Spinal Nerves
(all myelinated)
What are the Cranial nerves associated with?
Functions of the head, neck, and face
What does the Vagus nerve do?
Connects mant internal organs
What kind of control is the autonomic system under?
Involuntary control
How does the Autonomic nervous system maintain homeostasis?
By adjusting the body to variations in internal and external environments
What parts of the brain control the Autonomic nervous system?
The Hypothalamus an the Medulla Oblongata
What are the divisions of the Autonomic nervous system?
The sympathetic and parasympathetic nervous system
When is the sympathetic nervous system activated?
In stressful situations
What neurotransmitter does the Sympathetic nervous system release?
Norepinephrine, which has excitatory effects on the muscles
What happens when the sympathetic nerves are triggered?
They trigger the adrenal glands to release epinephrine and norepinephrine. It also inhibits some parts of the body
What do epinephrine and norepinephrine do?
Act as hormones that activates the stress response
When is the Parasympathetic nervous system activated?
When the body is calm and at rest
What does the parasympathetic nervous system do?
Acts to restore and conserve energy in the body
How does the parasympathetic nervous system work on the body?
It slows the heart rate, reduces blood pressure, promotes the digestion of food, and stimulates the reproductive organs
What neurotransmitter does the parasympathetic nervous system use?
Acetylcholine
How does caffeine affect the nervous system?
It is a stimulant that causes sympathetic nervous system to increase the heart rate and blood pressure
