Peripheral nervous system Flashcards
what are the two functional divisions of the PNS?
autonomic
somatic
What does the autonomic nervous system regulate?
regulates certain body processes, such as blood pressure and the rate of breathing. This system works automatically (autonomously), without a person’s conscious effort.
What does sympathetic nervous system do in the autonomic nervous system?
the part of your nervous system that carries signals related to your “fight-or-flight” response
What does parasympathetic nervous system do in the autonomic nervous system?
balances your sympathetic nervous system. your parasympathetic nervous system helps to control your body’s response during times of rest.
What does the somatic nervous system do? (2)
allows you to move and control muscles throughout your body. It also feeds information from four of your senses — smell, sound, taste and touch — into your brain.
What are the two types of nerves that sit within the somatic nervous system? how many of each?
spinal nerves (31 pairs)
Cranial nerves (12 pairs)
Where do the cranial nerves come from?
directly from the brain
In the somatic system, which nerves arise from the cerebrum?
optic nerves
olfactory nerves
where do the other 10 nerves from the brainstem extend into?
the periphery and therefore the group are classed within the PNS
How many spinal nerves are there?
31pairs
are all spinal nerves part of the somatic nervous system?
yes
How are the cervical spinal nerves named?
by the vertebrae below
How are all nerves except the cervical spinal nerves named?
by the number of the single vertebrae above
Where in the spinal cord are the sensory fibres located?
in the posterior root
Where in the spinal cord are the motor fibres located?
in the anterior root
what does the posterior root and anterior root join to form?
the peripheral nerves: mixed in fibres
Spinal nerves leave the __________ column through the ___________ __________ located between two successive, adjacent vertebrae
vertebral
intervertebral foramina
What are the two branches of the peripheral nerves once they leave the spinal cord?
the Dorsal ramus (rami)
the ventral ramus (rami)
What information does does the dorsal ramus carry?
the information that supplies the muscles and sensation to the back
what information does the ventral ramus carry?
the information that supplies the skin and muscles of the limbs and anterior trunk
the ventral rami converge with each other to form networks of nerves called what?
plexuses
what is a plexus?
a network of neutrons from several segments of the spinal cord that combine to form nerves to specific parts of the body
what is the benefit of a plexus?
regions receive a nerve supply from more than one spinal nerve, so damage to one nerve does not cause loss of function of that region
what are the 4 major plexuses?
cervical
brachial
lumbar
sarcal
where is the cervical plexus?
the neck
what does the cervical plexus supply?
the skin
muscles of the head, neck and upper region of shoulders
where is the brachial plexus located?
at the top of the shoulder
what does the brachial plexus supply?
the skin
muscles of the arm, shoulder and upper chest
Where is the lumbar plexus located?
between the waist and hip
What does the lumbar plexus supply?
the front and sides of the abdominal wall and some of the thigh
where is the sacral plexus located?
at the base of the abdomen
What does the sacral plexus supply?
the skin
the muscles and organs of the pelvis
the autonomic nervous system controls the ____________ body activities of _________ and ________ muscle and the activities of the _______.
automatic
smooth
cardiac
glands
What are the two divisions of the autonomic nervous system?
sympathetic
parasympathetic
What kind of neurones make up the autonomic nervous system?
visceral motor neurones
in what kind of situations is the sympathetic nervous system dominant?
stress situations
What does the sympathetic nervous system prepare the body for?
expending energy and dealing with emergency situations
Where do the neurones (cell bodies) of the sympathetic nervous system originate?
in the thoracic segments and some lumbar segments of the spinal cord
what does the activation of the sympathetic nervous system do to our eyes?
causes the pupils to dilate allowing more light to enter
what does the activation of the sympathetic nervous system do to our heart?
pumps faster so we can take in more oxygen
What does the sympathetic nervous system do to our blood vessels in the body?
Shunts blood to more vital organs such as the heart, muscles and brain
What does the sympathetic nervous activation do to the lungs?
bronchodilation and decreased pulmonary secretions occur to allow more airflow through the lungs.
What does the parasympathetic nervous system balance?
the action of the sympathetic nervous system
The parasympathetic nervous system works to conserve _______ and create the conditions needed for ______ and _______. it ______ down the body processes.
energy
rest
sleep
slows
Where do the neurones originate in the parasympathetic nervous system?
in the brain stem and sacral segments of the spinal cord
What are the 6 parasympathetic responses?
- decrease heart rate
- decrease respiratory rate/constricts bronchioles
- constricts skeletal blood vessels
- increases gastointestinal activity
- contracts bladder
- constricts pupils
The sympathetic stimulation of the autonomic nervous system is increased by the release of which hormone?
adrenaline
where is adrenaline produced?
the medulla of the adrenal glands on the kidney
The adrenal medullar is classes as part of which nervous system?
the autonomic nervous system
