Lecture 5 Biological Basis of Behavior Flashcards
(35 cards)
Central nervous system
Brain, spinal cord, optic nerve, retina
Peripheral nervous system
Cranial nerves, spinal nerves, autonomic nervous system, somatic nervous system
Neuron (Nerve cells)
The basic cell of the nervous system; High demand for glucose and oxygen, no metabolic reserve
Neuron components
cell body, dendrite, axon
Glial cells (glia)
Non-neuronal brain cells that provide structural, nutritional support to the brain
Soma (cell body)
Contains dendrites and is connected to the axon via axon hillock. Performs macromolecule synthesis and integrate electrical signals
Dendrites
Tapered extensions of the cell body; collects information from other neurons’ axonal terminals
Axon
Cylindrical body, can be myelinated or unmyelinated; conducts information to other neurons
Axon terminals
Small swellings that are found at the terminal ends of axons; transmits information to other neurons
Myelin sheath
Glial cell; increases connection and transmission speed
Synaptic vesicle
spherical sac containing neurotransmitters
Neurotransmitter
the chemical released from the synaptic axon terminal that serves as the basis for communication between neurons
Synapse
An intercellular site where fast, highly localized transmission of chemical and electrical signals occur; includes: pre-synaptic and post-synaptic terminals and the synaptic cleft
Types of neurons
Unipolar, Bipolar, Multipolar
Resting potential
-70 millivolts across the neural membrane when not being stimulated
Depolarization
Reduction of a membrane’s potential so that it becomes less negative
Action potential
Electrical impulse that travels down the axon triggering the release of neurotransmitters
Threshold
-55 millivolts; When Na+ concentration is high enough to reach threshold voltage, depolarization occurs
Repolarization
Na+ channels close, K+ channels open K+ efflux down electro-chemical gradient
Hyperpolarization
“Overshoot” of repolarization
Refractory period
Time during which another action potential is impossible; limits the maximal firing rate of the neuron. Too much K+ is released
Post-synaptic potential (PSP)
A voltage change at a receptor site on a postsynaptic (-70mV –> -55mV)
Inhibitory PSP
A negative voltage shift that decreases the likelihood that the postsynaptic neuron will fire action potentials
Excitatory PSP
A negative voltage shift that increases the likelihood that the postsynaptic neuron will fire action potentials
