Nervous System Flashcards
Nervous System
One of the smallest and yet the most complex of the 11 body systems.
Neurology
Study of normal functioning and disorders of the nervous system
Neurologist
A physician who diagnoses and treats disorders of the nervous system
Central Nervous System
Consists of the brain and spinal cord
Peripheral Nervous System
Consists of all nervous tissue outside the central nervous system
Nerve
Bundle of hundreds to thousands of axons plus associated connective tissue and blood vessels that lies outside the brain and spinal cord.
Cranial Nerves
12 pairs emerge from the brain and spinal cord
Spinal Nerves
31 pairs emerge from the spinal cord
Sensory Receptors
refers to a structure of the nervous system that monitors changes in the external or internal environment.
Sensory (Afferent) Division
Conveys input into the central nervous system from sensory receptors in the body.
Motor (Efferent) Division
Conveys output from the central nervous system to effectors (muscles and glands)
Somatic Nervous System
Conveys output from the central nervous system to skeletal muscles only.
Autonomic Nervous System
Conveys output from the CNS to smooth muscles, cardiac muscle, and glands. ANS is involuntary.
Autonomic Nervous System Two main branches
Sympathetic Nervous System- Increase heart rate
Parasympathetic Nervous System- Slows down the heart rate.
Enteric Nervous System
An extensive network of over 100 million neurons confined to the wall of the gastrointestinal tract. It can function independently. It communicates with and is regulated by the other branches of the ANS.
What are some functions of the CNS?
Thoughts, emotions, and memories.
Nervous tissue 2 types of cells?
Neurons- Most of the unique functions of the nervous system, such as sensing, thinking, remembering, controlling muscle activity, and regulating glandular secretions.
Neuroglia- are smaller cells, but they greatly outnumber neurons. Neuroglia support, nourish, and protect neurons, and maintain the interstitial fluid that bathes them. Neuroglia continues to divide throughout an individual’s lifetime.
Neurons
possess electrical excitability- the ability to respond to a stimulus and convert it into an action potential.
Stimulus
any change in the environment that is strong enough to initiate an action potential.
Action Potential
is an electrical signal that propagates along the surface of the membrane of a neuron.
