SOLUTIONS GRADED A+
✔✔Which Glia types form Myelin? How are they different? - ✔✔Schwann cells and
oligodendroglia
-Oligodendroglia does the CNS and has one nucleus covering multiple axons.
Schwann cells does he PNS and has one nucleus covering one axon.
✔✔what is a neuron? How many are in the nervous system? - ✔✔also called nerve cell.
It is the information-processing and transmitting element in the nervous system
-100 to 1000 billion in nervous system
✔✔What are the three neuron types and definitions? - ✔✔Sensory (afferent) -a neuron
that detects changed in the environment
Motor (efferent)
-neuron that controls contraction of a muscle or secretion of gland
Interneurons
-neuron located entirely within the CNS
✔✔What are the two types of neuron signaling? - ✔✔electric and chemical.
✔✔What kind of process does neurons send messages? - ✔✔electrochemical process
✔✔what is an ion? - ✔✔chemicals in the body that contain an electrical charge
✔✔important ions in the nervous system and their charge? - ✔✔sodium (Na+)
Potassium (K+)
chloride (Cl-)
negative charges protein molecules
✔✔what kind of membrane surround nerve cells? what does that mean? - ✔✔semi-
permeable membrane that only allows some ions to pass into the cell
✔✔action potentials - ✔✔the fundamental units of neural communication
✔✔what are the membrane refractory periods? - ✔✔-Absolute
-relative
✔✔saltatory conduction - ✔✔the jumping of action potentials from node to node
✔✔what factors determine conduction velocity of APs - ✔✔-if there is myelin
-diameter of the axon
, ✔✔what causes conduction velocity to be the slowest to the fastest? - ✔✔fastest=large
diameter and myelinated
slowest= small diameter and unmyelinated
✔✔exocytosis - ✔✔process of releasing synaptic vesicles
✔✔what is the synaptic cleft and what is the width? - ✔✔it is the tiny gap between the
membrane of two neurons and is .02-.03 micrometers
✔✔what are the two post-synaptic receptor options? - ✔✔-Direct (ionotropic receptors)-
involve transmitter gated ion channels and is fast in transmission
-indirect (metabotropic receptors) involves postsynaptic receptors linked to G-proteins
and is slow transmission
✔✔what are post synaptic receptors - ✔✔open neurotransmitter dependent ion
channels in response to binding.
✔✔Acetylocholine - ✔✔-lower motor neuron
-fast excitatory
✔✔Dopamine - ✔✔-both excitatory and inhibitory
-involved in reward, attentiveness, motivation, learning, and memorization
✔✔norepinephrine - ✔✔-excitatory
-affects the heart
✔✔serotonin - ✔✔-inhibitory
-diverse connections, but critically involved in pain sensation
✔✔What mechanisms make PSP short or terminate it? - ✔✔-reuptake (recycles the
transmitter back into the pre-synaptic neuron)
-enzymatic deactivation (destroyed by enzymes)
✔✔sensory receptors? - ✔✔specialized cell housed by sensory receptor organs to
detect specific stimuli
✔✔interoceptors - ✔✔detect stimuli inside body like blood pressure, blood volume, and
blood pH
✔✔exteroceptors - ✔✔detect stimuli outside body like taste, smell, vision, hearing,
balance
✔✔what is the function of sensory receptors - ✔✔to encode some aspect of the external
or internal environment into graded electrical signal (receptor potential)