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
β between the brainstem & cerebrum
Diencephalon
β largest part; shaped like yo-yo; influence mood; registers unlocalized, uncomfortable perception of pain
.Thalamus
β superior & posterior to thalamus; involved in emotional & visceral response to odors & pineal body that influence onset of puberty; control long-term cycle
Epithalamus
β βlittle brainβ; attached by cerebellar peduncles to brainstem
- involved in balance, maintenance of muscle tone, coordination of fine motor movement; comparator resulting in smooth & coordinated movements; learning motor skills like riding a bike or playing the piano
Cerebellum
β largest part of brain
longitudinal fissure β divides cerebrum into left & right hemisphere
Cerebrum
β numerous folds on the surface of each hemisphere, increase the surface area of cortex
gyri
β intervening grooves
sulci
β control voluntary motor functions, motivation, aggression, mood, olfactory reception
Frontal lobe
Mβ¦
Parietal lobe
β receives sensory input from & controls muscular activity in the left half of the body; involved in three dimensional or spatial perception & musical ability
Right Cerebral Hemisphere
β connection bet two hemispheres e.g. corpus callosum (largest)
π Commisures
receives input from & controls muscles in the right half of the body; more analytical w/ emphasis in math & speech
π Left Cerebral Hemisphere β
β major cortical areas involved in speech; damage result to aphasia-absent of defective speech or language comprehension
Sensory speech area (Wernickeβs area) in the parietal lobe & motor speech area (Brocaβs area) in inferior portion of frontal lobe
β series of neurons involved in long-term retention of a given piece of info, thought or idea; requires
rehearsal of info for transfer from β¦.
π Memory engrams or memory traces
β muscle tone, skilled
movements of hands
β muscle tone, movement of trunk muscle
β movement coordination
β posture adjustment during
movement
β posture, balance
π Lateral Corticospinal
π Anterior Corticospinal
π Rubrospinal
π Reticulospinal
π Vestibulospinal
β pathways that transmit action potentials from periphery to various brain parts
β for pain, temp, light
touch, pressure, tickle, itch sensation
β proprioception, touch,
deep pressure, vibration
β body position
(proprioception) to cerebellum
Ascending Tracts
π Spinothalamic Tract
π Dorsal Column
π Spinocerebellar
β group of functionally related nuclei; important in planning, organizing, coordinating motor movements & posture
- example are the corpus striatum &
substantia nigra
- basal nuclei disorders feature βresting tremorβ or slight shaking of hands when a person is not performing a task; Parkinsonβs disease; cerebral palsy; difficulty in rising from a sitting position and initiating a walk
Basal Nuclei
connective tissue membranes surrounding and protecting the brain & spinal cord
Meninges β
β bet the dura mater & periosteum of the vertebrae
epidural space
β βtough motherβ
subdural space β between dura mater & arachnoid w/ serous fluid
Dura mater
βfight-or-flightβ division; prepares the body for physical activity; prepares the person to face a threat or leave as quickly as possible
π Increases heart rate and blood pressure, dilates respiratory passageways, stimulates perspiration
Sympathetic division
π βrest or reposeβ division
π Stimulates vegetative activities such as
digestion, defecation, urination
π Slows down the heart rate and respiration
π Causes the pupils of the eye to constrict
and lens to thicken
Parasympathetic Division
π Capable of monitoring & controlling the digestive tract independently of the CNS.
π Enteric Nervous System
