Nervous System Flashcards
functions of the nervous system (3)
- sensory function: sense changes in intern an external environments
- integrative function: analyzes/stores information; makes decisions based upon info
- motor function: responds to stimuli
nervous system cell types
- NEURON
1. unable to undergo mitosis
2. generate/conduct impulses - NEUROGLIA
1. support/nurture/protect neurons
2. capable of mitosis
parts of central nervous system (2)
- brain
- spinal cord
parts/function of peripheral nervous system (4)
- cranial(12)/spinal nerves(31)
- serves as the “wires” for CNS
- sensory and motor function
- subdivided somatic & autonomic nervous system
somatic nervous system (2)
- “voluntary nervous system”
- carries sensory information to CNS
autonomic nervous sytem
- “involuntary nervous system”
- carries impulses from CNS to visceral smooth muscle
- subdivided into sympathetic/parasympathetic division
sympathetic division ANS
- prepares body for energy expending activity
- flight or fight response
parasympathetic division of ANS
- pacifies body
- allows for rest conservation of energy
Parts of a neuron (3)
- cell body
- dendrite
- axon
part of neuron: cell body (2)
- neurofibrils form cytoskeleton
- chromatophilic nissil bodies make roughER for protein synthasis
part of neuron: dendrites (2)
- input processes for neuron
- tree like branches extend from cell body
part of neuron: axon (3)
- joins cell body at cone shaped “axon hillock”
- propagate impulses away from cell body
- end in synaptic bulbs (knobs); carrying synaptic vesicles ; storing neurotransmitters
schwann cells (2)
- neurolemmocytes
- produce myelin sheaths (protein rich lipid sheath)
- most neurons of PNS
- nodes of ranvier
- increase speed of impulse delivery
- myelin is made in CNS by?
- myelin is made in PNS by?
- oligodendrocytes
- neurolemmocytes
structural classification of neuron: MULTIPOLAR (3)
- several dendrites
- 1 long prominent axon
- most neurons within brain/spinal cord
structural classification of neuron: BIPOLAR (2)
- 1 dendrite/ 1 axon
- retina/inner ear
structural classification of neuron: UNIPOLAR (4)
- one process that branches
- aggregate in special masses of nervous tissue
- ganglion
- located just outside the CNS
functional classification of neuron: SENSORY (afferent)
-transmit impulses from sensory receptors to CNS
functional classification of neuron: INTERNEURONS (2)
- found entirely in CNS
- convey impulses within CNS
functional classification of neuron: MOTOR (efferent) (2)
- multipolar neurons
- convey Impulses out of CNS
how many classifications of neuroglia in CNS/PNS?
- CNS: 4
- PNS: 2
CNS neuroglia: astrocytes
- star shaped cells
- form blood-brain barrier
- regulate entry of substances to the CNS
CNS neuroglia: oligodendrocytes (3)
- produce myelin of CNS
- most numerous glial cell of CNS
- do not produce neurilemmae
CNS neuroglia: ependymal cells
- regulate cerebral spinal fluid
- work blood barrier keeping substances out of brain
- one cell layer thick, porous membrane
CNS neuroglia: microglial cells (2)
- 4th of CNS glial cells
- provide structure support/ immune protection
what are the PNS neuroglia?
- satellite cells
2. schwann cells
what is a synapse?
the functional (not physical connection) between axon of neuron and dendrite or cell body of other neuron
function of synapse (2)
- allow one way communication between neurons/cells
- allow information to be integrated and filtered
structure of synapse: PRESYNAPTIC NEURON
-carries nerve impulse towards synapse
structure of synapse: SYNAPTIC CLEFT
-physical gap separating interaction neurons at chemical synapse
structure of synapse: POSTSYNAPTIC NEURON
-receives signal at synapse from axon
what is cell membrane potential? (3)
- difference in electrical charge between fluid just inside and just outside the cell membrane
- outside SODIUM
- inside POTASSIUM
what is a cell exhibiting cell membrane potential said to be?
polarized
cell membrane potential: RESTING MEMBRANE POTENTIAL
- resting membrane potential of a neuron is NEGATIVE -70
- inside cell
cell membrane potential: GRADED POTENTIAL (2)
- deviation from resting membrane potential by stimulus
- degree of change proportional to intensity and duration of stimulus from graded potential
- activation potential is -55
all or none response (2)
- nerve impulse conducted whenever stimulus threshold potential or greater is reached in the trigger zone
- all impulses same strength
what is continuous conduction?
-step by step depolarization of go each adjacent portion of axolemma
-only un-myelinated axons
pain sensation vs motor sensation
what type of propagation do myelinated cells exhibit?
saltatory (leaping) conduction
what triggers release of neurotransmitters from synaptic vesicles in synaptic cleft?
increase in intracellular calcium triggers exocytosis
excitatory post-synaptic potential (4)
- EPSP
- back to ZERO
- causes depolarization
- brings closer to threshold/impulse
inhibitory post-synaptic potential
- IPSP
- away from ZERO
- causes hyperpolarization
- further from threshold/impulse
neurotransmitters (3)
- biochemical messengers released from synaptic vesicles
- relay nerve impulses across chemical synapse
- excitatory or inhibitory
neurotranmitter: ACETYLCHOLINE
-excitatory neurotransmitter in motor division of somatic nervous system
steps for inactivation of neurotransmitters 1-3
- presence of enzymes in synaptic cleft rapidly decompose
- neurotrans reabsorbed by presynaptic/nearby neuron
- astrocytes via endocytosis (reuptake)
Choroid plexuses
Responsible for formation of cerebral spinal fluid
gray matter
- unmyelinated axons
- receives and integrates outgoing information (reflex arcs)
white matter
- myelinated
- 2 way highway for nerve impulses
choroid plexuses are responsible for…
the formation of cerebral spinal fluid
order of reflex arc
really sick idiots means er
- receptor
- sensory neuron
- integrating center
- motor neuron
- effector
how many nerves / vertebrae
33vertebrae/31 nerves
what is the caudina equine?
- anchors cord to coccyx
- roots angle inferiorly/travel vertically
dorsal root
sensory nerve fibers
dorsal root ganglion
periphery unipolar sensory neurons
ventral root
motor neurons
cerebrum contains what matter on the outside and in/
- white matter outside
- grey matter inside
- largest part of the brain
what does limbic system govern
- emotional aspects
- rings of structures
3 parts of the Diencephalon
- thalmus
- hypothalmus
- pineal gland
cerebellum
coordinates and smoothes skeletal muscle movement
cervical plexus/phenic nerve
diaphragm
brachial plexus
innervates shoulders/arms
median nerve
in brachial plexus
- forearm
- skin
- hands
lumbosacral plexus /sciatic nerve
supplies buttox, perineum, lower limbs
