The nervous system Flashcards
What does CNS stand for and what does it consist of?
Central nervous system-brain and spinal cord
What is the PNS?
Peripheral nervous system-nerves that carry messages to and from the CNS, muscles, organs and senses in the periphery of the body
What are the first subdivisions of the PNS?
Somatic and autonomic nervous systems
What is the somatic nervous system?
- associated with conscious and voluntary activities
- relay of sensory information to and from CNS
- consists of sensory and motor neurones
What is a sensory neurone?
- afferent
- carry information from sensory receptors to the CNS
What are motor neurons?
- efferent
- carry information from the CNS to the muscles
What is the autonomic nervous system?
- involuntary activities
- controls internal organs and glands
What are the subdivisions of the autonomic nervous system?
sympathetic and parasympathetic nervous systems
What is the sympathetic nervous system?
-involved in preparing the body for stress related activities
What is the parasympathetic nervous system?
-returns body to normal everyday function
What is homeostasis?
A state of equilibrium
-biological conditions are kept at optimum e.g. body temperature
Which nervous system is involved in the fight or flight response?
sympathetic nervous system
What does the sympathetic nervous system do to help in stress situations?
- causes body to release stored energy
- dilates blood vessels in muscles
- increasing heart rate and blood pressure
- linked to nearly every organ and gland to prepare the body for a rapid reaction when under threat
- dilating pupils
- hair stands on end
- slows digestion and urination
What is another name for the parasympathetic nervous system?
rest and digest system
What does the parasympathetic nervous system do?
relaxes the body after emergency has passed
- slows heart rate
- reduces blood pressure
- increases digestion and urination
