11.4 The Peripheral Nervous System Flashcards
What is the peripheral nervous system
all parts of the nervous system, excluding the brain and spinal cord, relays information between the CNS and other parts of the body
What are the two main parts of the peripheral nervous system?
Somatic and Autonomic
The somatic system is
largely under voluntary control, and its neurons service the head, trunk, and limbs
What do sensory neurons do in the somatic system?
they carry information about the external environment inward, from the receptors in the skin, tendons, and skeletal muscles.
What do motor neurons do in the somatic system
carry information to skeletal muscles
What is included in motor neurons?
12 pairs of cranial nerves and 31 pairs of spinal nerves all of which are myelinated.
Cranial nerves are largely associated with
function in the head neck and face with the exception of the vagus nerve
Spinal nerves that emerge from each side of the spinal cord contain both
sensory and motor neurons that control the area where they are found.
What is the autonomic system?
it is under autonomic or involuntary control and its nerves either stimulate or inhibit the glands or smooth muscle.
How does the autonomic system maintain homeostasis?
It adjusts the body to variations in the external and internal environments without an individual having to think about it and control it consciously.
Which parts of the brain control the autonomic system?
the hypothalamus and medulla oblongata
What are the two divisions of the autonomic system?
Sympathetic (fight or flight) and parasympathetic (rest and digest)
Which neurotransmitters do sympathetic neurons release?
norepinephrine and epinephrine which have excitatory effects on its target muscles and trigger the adrenal glands. These are the hormones that activate the stress response
How does the sympathetic system inhibit?
it slows digestion and the sphincter controlling bladder constricts. At the same time, it gives the skeletal muscles a boost of energy which increases blood pressure and the heart beats faster.
What happens to your body in a sympathetic resonse
It gives the skeletal muscles a boost of energy which increases blood pressure and the heart beats faster.
The purpose of the parasympathetic is to
restore and conserve energy
The parasympathetic response is to
slow the heart rate, reduce blood pressure, promote digestion and stimulate reproductive organs
Which neurotransmitter does the parasympathetic system use to control organ responses?
acetylcholine
Caffeine is a commonly used stimulant that causes the sympathetic nervous system to
increase heart rate and blood pressure
Eyes (para and sym)
para: constrict pupil
sym: dialate
Salivary Glands (para and sym)
para: stimulates
sym:inhibits
Heart (para and sym)
para: slows
sym: accelerates
Lungs (para and sym)
para: constricts bronchi
sym: dilate bronchi
Stomach (para and sym)
para: stimulates digestion
sym: inhibits digestion
Liver (para and sym)
para: stimulates bile release
sym: stimulates glucose release
Intestines (para and sym)
para: stimulates peristalsis and secretion
sym: inhibits peristalsis and secretion
Bladder (para and sym)
para: constrics
sym: relaxes
Pain is an interpretation of the brain ____________ received by specialized cells known as the _______________
sensory input, substantia gelatinosa
The SG forms a band in the ___________ of the __________ in the spinal cord
dorsal horn, grey matter
SG gets its name because it is
gelatinous and unmyelinated
Pain is perceived by the brain when
the SG cells are stimulated by an afferent nerve of the of the peripheral NS
SG produces a
neurotransmitter that communicates with the injured part and relays it to the brain
In response to pain, our brain releases
endorphins and enkephalins
Enkephalins are
natural pain killers of the class opioids
The neurotransmitters released when the brain senses pain are produced by
the pituitary gland and the hypothalamus during pain, excitement, sex, and when eating spicy foods
Endorphins and Enkephalins attach to the SG cells _________ and prevents _________ with the injured organ or tissue
receptor sites, communication
Explain what happens during a runners high
During exercise, endorphins and enkephalins are released and they attach to SG receptor sites. What the runner is experiencing is a reduction of pain
Do sympathetic and natural painkillers use the same mechanisms?
Yes
What do opioids do? What are some examples? Why do people get addicted?
They prevent the pain transmitters from being made. Examples are heroin, codiene and morphine. People get addicted because since they also stop the production of natural pain killers meaning they have to be taken continuously to experience a constant affect.
How is opium made?
scraping and air drying the mily sap of the unripe seedpod of the opium poppy
