Nervous System Flashcards
there are varying levels of ___________ of nervous systems; higher __________ ability = more _______ behavior
there are varying levels of complexity of nervous systems: higher cognitive ability = more complex behavior
sensory neurons
transmit information from receptors that detect external (ie light, heat, sound) and internal (ie blood CO2 level, muscle tension) to the CNS
interneurons
integrate (analyze and interpret) sensory input in the CNS
motor neurons
transports motor output out of the CNS to effector cells (ie muscle and endocrine cells)
reflex
the body’s automatic response to stimuli that allow for a rapid response to stimuli- can be either spinal or cranial reflexes (ie knee-jerk, pupil dilation)
difference of reflexes from other information processing
decreases the number of neurons involved to increase speed of action potential to minimize bodily damage
-limited need for cognitive integration - involuntary
dendrites
receive signals from sensor cells
cell body
contains main organelles and nucleus
axon hillock
the region where the action potential is generated
axon
transmits the signal (action potential) to other cells
myelin sheath
insulating cells surrounding the axon
formed by: Oligodendrocytes in CNS and Schwann Cells in the PNS
synaptic (axon) terminal
the site where neurotransmitters are released into the synapse to communicate with other cells
synapse/synaptic cleft
gap between two neurons where communication through neurotransmitters occurs
types of supporting cells
astrocytes, glial cells, oligodendrocytes/Schwann cells
astrocytes
regulate the concentration of ions and neurotransmitters and forms the blood-brain barrier in the CNS
glial cells
lay the foundation for the development neural tube in fetuses and are responsible for structural support and the proper functioning of neurons in the CNS
Oligodendrocytes
form the myelin sheath in the CNS
Schwann Cells
form the myelin sheath in the PNS
resting potential
- 70mV
- results from differences in ionic concentration between the inside and outside of the cell
- higher concentration of Na+ on the outside
- higher concentration of K+ on the inside
how is resting potential maintained?
sodium-potassium pumps use active transport to pump 3 Na+ ions out for every 2 K+ ions pumped in and maintain negative potential inside and positive potential outside of the cell
action potential in role of membrane potential
Neurons have changes in membrane potential in response to stimuli that result
in either:
- hyperpolarization: inside of membrane becomes more negative
- depolarization: inside of membrane becomes more positive
graded potentials
change in membrane potential that varies depending on strength of the stimulus