Nerves! Flashcards
3 basic functions of nervous system
Sensory
Integrative- analyzing sensory info and makes decisions on behavior
Response- to stimuli by muscle movement or gland secretions
2 divisions of nervous system
Central & Peripheral
Afferent Neuron
aka sensory neurons- conduct impulses from various parts of the body to the CNS (are part of the PNS)
Unipolar neurons
Efferent Neurons
aka motor neurons- out put component, which is the movement/action originating from the CNS to the muscle or glands
Effect= bring about a response
multi polar
PNS divides into 2 systems
Somatic- voluntary movements– senses
Autonomic- involuntary in viscera (aka involuntary nervous system)
ANS divides into 2 more systems
Sympathetic- fight or flight= simulator
Parasympathetic- prepares for F or F = inhibitor
Neuroglia
support nurture and protect neurons. 2 types in PNS- Schwann cells which make myelin sheath; Satellite cells which support ganglia neurons. Smaller cells. 4 types in CSN (astrocytes, microglial, ependymal, oligodendrocytes)
“Nerve glue”
aka Glial cells
Functional contact btwn 2 neaurons
synapes
Classifications of neurons
Unipolar- 1 process that is fusion of dendtrite and axon. divides like at off cell body
Bipolar- 1 dend + 1 axon that extend from either side of cell body
Multipolar- several dend + 1 axon. most common. Major type in CNS. Looks like what I think of when I think neuron
Association nerves
carry impluses from one neuron to another and make up 90% of body
White matter
myelinated- all CNS most PNS. Only axons can be myelinated. Dentrites are NEVER myelinated.
Grey matter
non- myelinated
Polarized
membrane potential in a cell
continuous conduction
in unmyelinated axons which is a step by step depolarization of adjacent areas on plasma membrane
Nodes of Ranvier
the spot in a myelinated sheath that is a gap to allow for impulse pass. There are groups of voltage gated Na+ channels here
Saltatory Conduction
the jumping on impulse from one node of ranvier to the next
synapes
area between 2 neurons or neuron + effector, filled with extracellular fluid
sender of the signal neuron
Presynaptic
receiver of the implus
Post synaptic
how many types of synapes
- Electrical and chemical. Electrical send through gap junctions( minute fluid filled tunnels between plasma membrane of each neuron) Electrical are way faster. they are 2 way. and can synchronize activity of group of neurons and effectors
Neuronal Pool
buttloads of neurons organized into complecated patterns in CSN. These get arragned into circucits. 4 types of circutes
What are the 4 types of neuronal pool circuits in the CNS?
Divergence- 1 presynaptic that synapes with many postsynaptic
Convergeence- many presynaptic synaping to 1 post synaptic neuron
Reverberating- presynaptic cell stimulated causes post syn cell to transmit series of impulses done a chain. Ex- breathing. & short term memory
Parallel after discharge- 1 pre stimulates a group with a common post cell. Causes varying synaptic delts so last neuron exhibits multiple impules. Believed to be used for presise thinknig like math problems
4 parts of the brain
Stem- stalk of mushroom)
Diencephalon- above stem
Cerebrum- cap of mushroom
Cerebellum- behind stem
What makes up the stem?
Medulla- joins with spinal cord making inferior part of stem
