Quiz 7 - Neural Tissue/Brain & Cranial Nerves Flashcards
Wave of depolarization that is propagated across and entire cell membrane
Action Potential
The properties of the nation potential are independent of the relative strength of the depolarizing stimulus as long as that stimulus exceeds the threshold potential.
All-or-None Principle
Generation of action potential
- Depolarize membrane to threshold potential
- Activate sodium channels/Sodium ions enter cell and membrane is depolarized
- Sodium channels close/potassium channels reopen. Membrane polarizes again
- Resting potential is re-established and normal ion permeability is restored.
Junction between a neuron and another cell
Synapse
Transmission of neural impulse from one cell to another.
Synaptic Transmission
Signal jumping between myelin.
Saltation
Signals travel faster with myelin.
Space between the two cells
Synaptic cleft
Synaptic Transmission: _______ _______ of the synaptic terminal releases neurotransmitter into the synaptic cleft.
Presynaptic Membrane
Synaptic Transmission: ____________ diffuses across the synaptic cleft and reacts with the _________ membrane
Neurotransmitter
Postsynaptic
Postsynaptic membrane may be ________, GENERATING propagation of an action potential in the postsynaptic membrane.
Depolarized
Postsynaptic membrane may become __________, INHIBITING propagation of an action potential in the postsynaptic membrane.
Hyperpolarized
The effect of a neurotransmitter on the postsynaptic membrane depends on the properties of the _______, not on the nature of the _________.
Receptor
Neurotransmitter
End formation by which the axon of a motor neuron establishes synaptic contact with a skeletal muscle fiber
Motor End Plate
The ________ is modified around the motor end plate.
Sarcolemma
A single motor neuron, plus those muscle fibers controlled by it.
The motor unit
Autoimmune disease causing muscle weakness.
Myasthenia Gravis
Antibodies bind to the receptors and both the neurotransmitters.
More common and earlier onset in _________ (men/women).
Myasthenia Gravis
Women
Symptom: Trouble blinkning, swallowing, tracking with eyes.
Myasthenia Gravis
Neurotoxin prevents muscle contraction by preventing release of neurotransmitter from motor neuron.
Botulism
Mis-canned food is a prime source for ______.
Botulism
Neurotoxin causes excessive stimulation of target muscle, which results in severe muscle spasms and sustained muscle contractions.
Tetanus
Open wounds are susceptible to ______.
Tetanus
Potential at which sodium-channels open, allowing sodium ions to readily enter the cell; depolarization to -60 to -55mV (small kids opening fire door… once that threshold is reached, it doesn’t matter if it is barely reached or 10x what’s necessary)
Threshold Potential
Local changes in membrane potential can be additive if they occur close together in time or space (multiple signals close together in time or space)
Summation
Amount of change is directly proportional to the size of the stimulus.
Graded Potential
Resting potential becomes more negative vs. resting potential becomes less negative
Hyperpolarizing vs. Depolarizing
Myelinate axons of the PNS
Schwann Cells
A cluster of neuron cell bodies
Ganglion
Surround and provide support for neuron cell bodies within a ganglion
Satellite Cells
The multi-layered membranous wrapping formed by the oligodendrocyte; increases the speed of action potential propagation along the axon.
Myelin
Process wrap around axons of the CNS, INSULATING them
Oligodendrocyte
The “immune system” cells of the CNS
Microglia
Support cell for neurons in the CNS; a component of the “blood-brain barrier” (gate-keepers for what comes out of blood vessels)
Astrocyte
Epithelial cells, lining the ventricles of the brain and the central canal of the spinal cord; some specialized ependymal cells secrete cerebrospinal fluid.
Ependymal Cell
Support cells of the nervous system
Neuroglia
Cells of the afferent division of the PNS (internal & external senses)
Sensory neurons
Cells of the efferent division of the PNS
Motor Neurons
May act as connectors between sensory and motor neurons; located entirely within the CNS
Interneurons
Small, with a short axon not easily distinguished from the dendrites; primarily found in the brain and in special sense organs
Anaxonic
Has one long axon and many dendrites; most common type of neuron in the CNS
Multipolar
Appears to have one process which bifurcates into an axon and a single dendrite; most sensory neurons are _________.
Unipolar
Has one long axon and only one dendrite, positioned at opposite ends of the soma; occurs in special sense organs
Bipolar
Junction between a neuron and another cell
Synapse
End of an axon which interacts with another cell and the synapse.
Synaptic Terminal
Long cytoplasmic process which carries nervous impulses away from the soma
Axon
Highly branched processes which carry nervous impulses toward the soma.
Dendrites
Cells that transmit nervous impulses
Neurons
SNS & function
Somatic Nervous System - Motor controls going to skeletal muscles.
ANS & function
Autonomic Nervous System - Cardiac and smooth muscles - involuntary.
Carrying nerve impulses from the CNS to muscles, visceral organs and glands.
Efferent Division
Carrying nerve impulses from sensory receptors to the CNS.
Afferent Division
S.A.M.E.
Sensory - Afferent
Motor - Efferent
CNS/make-up
Central Nervous System - brain and spinal cord
PNS/make-up
Peripheral Nervous System - Neural tissue outside of the CNS
Center of conscious thought
Cerebrum
Located int he frontal lobe, just in front of the central sulcus. Processes motor neuron info
Motor Cortex
Located in the parietal lobe, just behind the central sulcus. Processes sensory neuron info
Sensory Cortex
Located throughout the cerebral cortex
Association and Integration areas
Composed primarily of myelinated axons
Central White Matter
Cluster of gray matter embedded within the central white matter
Cerebral Nuclei
Containing the thalamus and hypothalamus
Diencephalon
Located on either side of the third ventricle.
Relays and filters sensory information ascending from the spinal cord to the cerebral nuclei and cortex
Thalamus
Lying below the thalamus and making up the lower walls and floor of the third ventricle.
Boss of pituitary gland.
Hypothalamus
The ‘primitive’ or ‘emotional’ brain
Limbic System
Joins lower parts of the brain stem and spinal cord to the diencephalon and cerebrum.
Mesencephalon
Coordinates automatic adjustment of skeletal muscles to maintain posture.
Cerebellum
Links the cerebellum to the mesencephalon, cerebrum and s spinal cord.
Pons
Contains nuclei for cranial nerves V through VIII
Pons
Contains nuclei dealing with control of respiration
Pons
An enlarged continuation of the spinal cord, extending from the foramen magnum to the pons
Medulla Oblongata
Relay for all sensory and motor nerve tracts.
Contains nuclei for cranial nerves VIII through XII.
Medulla Oblongata
Oh, Oh, Oh To Touch And Feel Vaginas Gives Vinny A Hard-on
Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, Hypoglossal
Nerver Roots: (Efferent fibers), (Afferent fibers), (housing sensory neuron cell bodies)
Ventral Root, Dorsal Root, Dorsal Root Ganglion
Coverings of the spinal cord.
Meninges
Meaning that continues onto nerves stemming off spinal cord.
Dura Mater
Space outside of the dura mater
Epidural Space
Inside the dura mater.
Arachnoid Mater
Deepest meninge; Fused to the outside surface of the spinal cord
Pia Mater
Spinal nerve coverings:
Surrounds each individual fiber of the PNS.
smallest/deepest
Endoneurium
Spinal nerve coverings:
Surrounds a fascicle (bundle of nerve fibers)
Middle (size/location)
Perineurium
Spinal nerve coverings:
Surrounds a peripheral nerve.
largest/most superficial
Epineurium
Sensory and motor innervation to skin and muscles near the spinal column
Dorsal primary ramus
Sensory and motor innervation to the rest of the body
Ventral primary ramus
White ramus (myelinated) and gray ramus
Rami Communicantes
In general, prepares the body for fight or flight.
Sympathetic division of ANS
_______ neurons originate in the thoracolumbar region.
Preganglionic
In general, prepares the body for ‘rest and repose’
Parasympathetic
________ speeds the heart up and ________ slows it down.
Sympathetic/Parasympathetic
Area monitored by a single receptor cell.
Receptive Field
Process by which the brain causes a sensation to be perceived as originating at the point of stimulation.
Projection
Adjustment to a sensory stimulus over time
Sensory Adaptation
Send info about outside environment.
Exteroceptors
Send info about internal environment
Interoceptors
Respond to mechanical deformation of the nerve receptor
Mechanoreceptor
Respond to damage
Pain receptor
Respond to temp.
Thermoreceptor
Respond to chemical
Chemoreceptor
Respond to light.
Photoreceptor
The general senses: touch, pressure, vibration
Tactile receptors
Pressure receptors in organ walls sending stretch signals.
Baroreceptors
Send signals to the cerebellum about where we are in space.
Proprioceptors
Signal oxygen deprivation, damage or close to damaging.
Pain receptors
Free nerve endings with a large receptive field.
Do NOT adapt.
Stimulus travels to the thalamus, and then to the cerebral cortex.
Pain Receptors
The sense of taste
gustation
Vision anatomy: composed of the sclera and the cornea.
Fibrous tunic
Vision anatomy: composed of the choroid layer, iris, pupil and ciliary body.
Vascular tunic
Vision anatomy: composed of the pigmented layer and the neural layer.
Neural tunic
For visual acuity in dim light, distributed in a broad band on the periphery of the retina.
Rods
For color vision, distributed along the posterior retinal surface, concentrated in the fovea centralis of the macula lutea.
Cones