NERVOUS SYSTEM Flashcards
Divisions of the Nervous System:
Central Nervous System
Peripheral Nervous System
Central Nervous System contains:
Brain and spinal cord
Peripheral Nervous System contains:
Nerves and Ganglia
Two Subdivisions of the PNS:
Sensory or Afferent Division
Motor of Efferent Division
a junction where the axon of one neuron interacts w/ another neuron or an effector organ such as a muscle or gland
π
Synapse -
end of the axon having synaptic vesicles filled w/ neurotransmitters such as: acetylcholine, norepinephrine, serotonine, dopamine, Ξ³- aminobutyric acid (GABA), glycine, endorphins
Presynaptic Terminal β
π membrane of dendrite
Postsynaptic Membrane β
an involuntary reaction in response to a stimulus applied to the periphery and transmitted to the CNS
Reflex β
β the neuronal pathway by which a reflex occurs; the basic functional unit of the nervous system because it is the smallest, simplest pathway capable of receiving a stimulus and yielding a response.
π Reflex Arc
extends from the foramen magnum at the base of the skull to the 2nd lumbar vertebra; 31 pairs of spinal nerves communicate bet. spinal cord & body
Spinal Cord β
β inferior end resembling horsetail
π Cauda Equina
π White Matter has 3 Columns:
dorsal, ventral, lateral
π White Matter has 3 Columns:
dorsal, ventral, lateral
simplest; muscles contract in response to a stretching force applied to them; example is the Knee-jerk Reflex/Patellar Reflex w/c determines if the higher CNS centers are functional
Stretch Reflex β
β functions to remove a limb or other body part from a painful stimulus
π Withdrawal Reflex/Flexor Reflex
β where nerves come together and separate
Plexuses
β C1-C4; w/ phrenic
nerve= innervates the diaphragm
π Cervical Plexus
β C5-T1; axillary nerve, radial nerve, musculocutaneous nerve, ulnar nerve, median nerve
π Brachial Plexus
β L1-S4; obturator nerve, femoral nerve, tibial nerve + common fibular nerve= sciatic nerve
π Lumbosacral Plexus
β connects the spinal cord to the remainder of the brain; contains several nuclei involved in control of heart rate, blood pressure, breathing; damage to its small areas can cause death
Brainstem
β most inferior portion & continues w/ the spinal cord
- functions for regulation of heart rate & blood vessel diameter, breathing,
Medulla Oblongata
β means βbridgeβ resembling an arched footbridge connecting the cerebrum to the cerbellum thus relaying info bet. them; immediately superior to medulla oblongata
-functions for breathing, swallowing, balance, chewing, salivation
Pons
β superior to pons; smallest in the brainstem
Midbrain
β scattered throughout the brainstem; major component of the reticular activating system
-functions in regulating cyclical motor functions such as respiration, chewing, walking, arousing & maintaining consciousness, regulating sleep-wake cycle
Reticular Formation