Lesson 2.1 The Nervous System Flashcards
What is the basic definition of homeostasis?
Homeostasis provides equilibrium in the body’s internal environment.
What is the nervous system responsible for?
The nervous system is responsible for our behaviours, perceptions, and memories.
What does CNS stand for?
The central nervous system.
How does information travel through the body?
Information from all over the body travels quickly to and from the central nervous system (CNS).
What is the CNS composed of?
The CNS consists of the brain and spinal cord.
How are the body’s messages sent?
The body’s messages are sent by impulses via neurons.
How fast do impulses travel?
Some of these impulses reach speeds between 44 and 429 kilometres per hour.
What does PNS stand for?
The peripheral nervous system (PNS) includes all nervous tissue outside the CNS.
What are the names of the two branches of the PNS system?
The PNS is divided into two branches: the somatic (voluntary) nervous system and the autonomic (involuntary) nervous system.
How does the somatic system gather information?
In the somatic nervous system, information is picked up from the five senses and from receptors that detect pain and temperature and transmitted to the CNS via sensory neurons.
What does the somatic system use to deliver signals through the body?
If necessary, signals are sent back from the brain, through the spinal cord and out through motor neurons to skeletal muscles where movement occurs.
Describe the basic nature of the reflex.
In the case of a reflex, the reaction is necessarily quicker, and the signals return from the spinal cord, bypassing the brain.
What is the main difference between the somatic and autonomic systems.
The autonomic nervous system is called involuntary because it is beyond conscious control.
What two systems support the autonomic system?
This system ensures a stable inner environment with the help of two additional systems called sympathetic and parasympathetic.
What is the sympathetic system responsible for?
The sympathetic nervous system is responsible for situations of stress, increasing heart rate and blood pressure, and increasing sensitivity and reaction to stimuli.
