Chapter 13 Textbook notes Flashcards
What are the two major divisions of the nervous system?
The central nervous system (CNS) which consists of the brain and spinal cord.
The peripheral nervous system (PNS), which consists of nerves
What are the 3 types of neurons
- Sensory
- Interneurons
- Motor
What do the sensory neurons do
Takes nerve signals from a sensory receptor to the CNS
What do the interneurons do
Lies entirely within the CNS. They receive input from sensory neurons and also from other interneurons in the CNS. They sum up all the information received from other neurons before they communicate with motor neurons
What do motor neurons do?
Takes nerve impulses away from the CNS to an effector
What do effectors do?
They carry out our responses to environmental changes, whether they are internal or external
The spinal cord controls what?
The flow of information to and from the brain
What liquid engulfs the spinal cord?
Cerebrospinal fluid, which guards the CNS against shocks caused by movement and helps supply nutrients and remove wastes
What does the somatic nervous system do?
This part of the PNS carries signals to and from skeletal muscles. Controls many voluntary responses to signals in the environment.
Examples are movements we make when walking or throwing a baseball
What are the two subdivisions of the PNS?
Somatic and Autonomic
What does the autonomic subdivision of the PNS do?
Controls the (mostly involuntary) internal processes in the body, such as heart beat and digestion.
What are the two divisions of autonomic?
The sympathetic nervous system and the parasympathetic nervous system
What does the sympathetic nervous system do?
Automatically stimulates the body when action is required. Responsible for fight-or-flight response. It quickens the heart rate to move blood through the blood vessels faster and releases sugar
What does the parasympathetic nervous system do?
Stimulates more routine functions, such as the secretion of digestive enzymes or saliva. Slows down the heart rate
Many axons are covered by a protective what
Myelin sheath
