Chapter 13 Part 1 Flashcards
name the components of the central nervous system and the peripheral nervous system
central nervous system = brain and spinal cord
peripheral nervous system = cranial nerves and spinal nerves
define spinal reflex
a rapid, automatic response triggered by specific stimuli. spinal reflexes are controlled in the spinal cord
do spinal reflexes function with or without input from the brain?
may or may not have input from the brain. not required
does the human body have more sensory, motor, or interneurons?
rank them
most – interneurons (20 billion)
next - sensory neurons (10 million)
least - motor neurons (half a million)
what are “neuronal pools”?
functional groups of interneurons
do neuronal pools have excitatory or inhibitory neurons?
may contain both
name the 5 classifications by organization of neuronal pools
divergence
convergence
serial processing
parallel processing
reverberation
“divergence” is a mechanism for doing what?
spreading stimulation to multiple neurons or neuronal pools in the CNS
are interneurons only in the CNS?
YES
Convergence is a mechanism for…
providing input to a SINGLE neuron from multiple sources
serial processing is a mechanism in which….
neurons or neuronal pools work SEQUENTIALLY
straight line
parallel processing is a mechanism in which…
neurons/neuronal pools process the SAME information AT THE SAME TIME (simultaneously)
reverberation is…
a positive feedback mechanism
once a reverberating circuit has been activated, it will continue until synaptic fatigue or an inhibitory stimulus breaks the cycle
highly complicated examples of reverberation among neuronal pools in the brain may help with what?
maintaining consciousness, muscle coordination, and normal breathing
when sensory neurons bring information to the CNS, what organization of neuronal pools is involved?
DIVERGENCE. the CNS spans over a wide area – the brain and the spinal cord
before parallel processing can take place, __________ must occur
divergence
classify reflexes based on DEVELOPMENT
innate reflexes – connections that form between neurons during development. withdrawal from pain, chewing, suckling, tacking objects with the eyes
r
acquired reflexes – more complex and learned. ie: driver stepping on break
can reflexes be modified over time, or suppressed through conscious effort?
YES
if youre walking a tightrope, you can suppress the feeling of the bee sting on your hand, where under other circumstances your reflexes may cause you to do otherwise
classify reflexes based on RESPONSE
somatic reflexes – skeletal muscle contraction. superficial and stretch reflexes
visceral (automatic) reflexes – smooth and cardiac muscles, glands, and adipose tissue
somatic reflexes provide a mechanism for the ______ control of the muscular system (voluntary or involuntary?)
INVOLUNTARY
differentiate between superficial reflexes and stretch reflexes
superficial reflexes are triggered by stimuli at the SKIN or MUCOUS MEMBRANES
stretch reflexes are triggered by the sudden elongation of a tendon, and thus of the muscle to which it attaches