Nervous System - 11.3 Flashcards
What are the two main divisions of the Peripheral Nervous System?
Somatic and Autonomic System
Explain the somatic system.
Under voluntary control - neurons service head, trunk, and limbs
What type of neurons does the somatic system have?
Myelinated neurons
What are the nerves in the somatic system?
Cranial Nerves and spinal nerves
How many cranial nerves are there in the somatic system, and what do they do?
There are 12 pairs cranial nerves - associated with the functions in the head, neck, and face
What is the exception in the cranial nerves?
Vagus nerve - connects to many internal organs (heart, bronchi, liver, pancreas, etc)
How many spinal nerves, and what do they do?
31 pairs - each spinal nerve contains both sensory and motor neurons (service area where they are found)
Which nerve control rib cage?
Thoracic nerve
What does the autonomic system do?
It controls internal reactions to a situation and is under voluntary control.
Nerves stimulate or inhibit glands - or the functioning of smooth or cardiac muscles
Maintains homeostasis - but adjusting to variations in the external and internal environments
What control the autonomic system and where are they bundled?
The medulla oblagata and the hypothalamus
They are bundled together with somatic system neurons in the cranial and spinal nerves
What do the parasympathetic and sympathetic nervous system do?
Carry information to the effectors.
What is the sympathetic system - what does it do?
activated in stressful situation - “flight or flight.”
What do sympathetic neurons release?
A neurotransmitter- norepinephrine
What do sympathetic nerves trigger adrenal glands to release?
Epinephrine and norepinephrine (both activate the stress response)
What are some places the sympathetic nervous system trigger in stress situations?
Tears constrict, blood pressure increases, heart rate increases, digestion closes, urination constricts
