Exam 2 - Nervous System Flashcards
What are the thin projections of the neuron that recieve information?
Dendrites
What are the one or two processes extending from the soma that pass on information?
Axon
What is the part of the neuron where electrical signals are conducted away from the soma?
Initial segment/trigger zone/axon hillock
What are the branches of axons?
Collaterals
What is responsible for transmitting signals, usually chemical, from the neuron to the next cell?
Axon terminals
What cells found in the nervous system help support and nourish the neurons?
Glial cells/neuroglia
What covers some (but not all) axons, consists of a fatty material that serves as an insulator?
Myelin
What cell produces myelin?
Glial cells
What are the spaces between the myelin forming cells?
Nodes of Ranvier
What causes an electrical signal to be generated in the sensory neuron in response to a physical or chemical change in the internal or external environment?
Receptors
Where are receptors located?
Peripheral ends of afferent (sensory) neurons
What is the junction between excitable cells such as neurons where one cell can alter the activity of the other?
Synapse
What is a chemical messenger used at a synapse to transmit activity from one neuron to another?
Neurotransmitter
What type of neuron transmits information from sensory receptors into the central nervous system?
Afferent/Sensory neurons
What type of neuron transmits a signal from CNS out to the effecter cells?
Efferent/Motor neurons
What type of neuron lie in pathways between afferent and efferent neurons?
Interneurons
Where do interneurons lie?
CNS
What type of neuron conducts electrical signals towards a synapse?
Presynaptic neuron
What type of neuron conducts electrical signals away from a synapse?
Postsynaptic neuron
What is a cluster of neuronal cell bodies within the CNS?
Nucleus
What is a cluster of neuronal cell bodies outside the CNS?
Ganglion
What is a bundle of axons within the CNS?
Tract
What is a bundle of axons outside the CNS?
Nerve
How are the members of a given nucleus, ganglion, tract, or nerve similiar?
Function
What part of the spinal cord contains interneurons, cell bodies (with dendrites) of motor neurons, and the entering axons of sensory neurons?
Gray matter
What surrounds gray matter and consists largely of myelinated axons?
White matter
What carries informaiton up the spinal cord?
Ascending spinal tracts
What carries informaiton down the spinal cord?
Descending spinal tracts
What is the “bump” on the dorsal root that contains the cell bodies of the sensory neurons?
Dorsal root ganglion
What is a group of motor fibers leaving the spinal cord on the anterior side?
Ventral root
What is a group of sensory fibers entering the cord on its posterior side?
Dorsal root
What is formed by the union of a dorsal root and a ventral root?
Spinal nerve
What are the functions of the spinal cord?
Conduit for nerve cell fibers, contains neuronal circuits for walking and various reflexes
What serves as the pathway between the spinal cord and “higher brain centers”?
Brainstem
What does the brainstem give rise to?
Cranial nerves
What runs through te entire brainstem and integrates informaiton that controls swalling, vomiting, the cardiovascular and respiratory systems?
Reticular formation
What structure of the brain is involved with skeletal muscle function, helps to maintain balance and provide smooth, directed movements?
Cerebellum
What brain structure contains the right and left cerebral hemispheres?
Forebrain
What is made up of white matter and is the most important commissure?
Corpus callosum
What is the highly folded outer shell of the right and left cerebral hemispheres?
Cerebral cortex
What makes up the cerebral cortex?
Gray matter
What is the function of the cerebral cortex?
Brings together basic information into meaningful perceptual images and exerts ultimate control over movements
What serves as a relay station and is an important intergration center for sensory input on its way to the cortex?
Thalamus
What is the thalamus’ center a part of?
Reticular formation
In addition to serving as a relay station the thalams also helps control what?
Motor function
What group of mechanisms control the kinds of substances that leave the blood and enter the ECF of the brain?
Blood-brain barrier mechanisms
What fluid fills the cavities within the brain and surrounds the brains and spinal cord which provides a cushion against jolts?
Cerebrospinal fluid
What is the most important control area for regulating the internal environment of the body?
Hypothalamus
What brain structure integrates homeostatic mechanisms and behavioral patterns that involves the correlation of neural and endocrine functions?
Hypothalamus
What is characterized by the interconnection of the cortex, thalamus, and the hypothalamus?
Limbic system
What group of structures is associated with learning, pleasure, and emotions?
Limbic system
What part of the nervous system is characterized by nerve cell fibers grouped into nerves that transmit informaiton to and from the CNS?
The peripheral nervous system
What is the term for the 12 pairs of nerves that connect with the brain in the PNS?
Cranial nerves
What is the term for the 31 pairs of nerves that connect with the spinal cord?
Spinal nerves
Most nerves (spinal or cranial) carry both sensory and efferent fibers. What nerves serve as an exception to this generality?
A few cranial nerves
What are the two divisions of the PNS
Afferent and efferent
What division of the PNS is made up of sensory neurons that carry info from receptors in the periphery to CNS?
Afferent division
What are the groups of cell bodies of sensory neurons in the afferent system called?
Ganglion
The cell bodies of the afferent system have two extensions. Where do they extend to?
One goes to the receptor another passes into the CNS
What structure within the afferent/sensory division of the PNS sense the external and internal environment?
Receptors
What part of the efferent division is made up of all axons of motor neurons going from the CNS to skeletal muscles?
Somatic nervous system
Where are the cell bodies of the somatic nervous system grouped?
Brainstem or spinal cord
How many neurons are there between the CNS and skeletal muscle cell in the somatic nervous system?
One
What neurtransmitter is always released onto the muscle cell in the somatic nervous system?
Acetylcholine
Fill in the blanks: Acetylcholine will always ___ the muscle and will never ___ the muscle cell.
Excite; inhibit
What part of the efferent division is made up of all the axons of neurons going fro,m the CNS to smooth muscle, cardiac muscle, and glands?
Autonomic nervous system
True/False: A cranial or spinal nerve may carry both a sympathetic and parasymathetic fiber.
False, can only carry either or
Choose the correct option: The autonomic nervous system can excite/inhibit/excite or inhbit the effector organ.
Excite or inhibit
How many neurons are chained togehter in the autonomic nervous system ?
Two
The first neuron of the two neuron chain of the autonomic system has its body where?
Brain stem or spinal cord
The second neuron of the two neuron chain of the autonomic system is located outside the CNS. What is the term for this cluster of cell bodies?
Autonomic ganglion
What is formed by the ganglia of the sypathetic fibers that lie close the spinal cord?
Sympathetic chains or trunks
What are the fibers called that run between the CNS and a ganglion in the autonomic nervous system?
Preganglionic fibers
What are the fibers called that run from the ganglion to the effector organ?
Postganglionic fibers
What is the term for fibers releasing acetylcholine as their neurotransmitter?
Cholinergic fibers
Sonatic nervous system fibers, most preganglionic fibers of both divisions of the ANS and most postganglionic fibers of the parasympathetic division of the ANS are all what?
Cholinergic fibers
What is the term for a fiber that releases norepinephrine as its neurotransmitter?
Adrenergic fibers
Most postganglionic fibers of the sympathetic division of the ANS are what?
Andrenergic fibers
There is a unique set of postganglionic cells in the sympathetic division that never develops axons. Where do the cells of this ganglion release their transmitter?
Directly into the blood stream
Which endocrine gland’s secretion is controlled by sympathetic preganglionic fibers?
Adrenal medulla
What is the epinphrine and norepinephrine referred to that is secreted by the adrenal medullae?
Hormones
How is the function of the hormone norepinphrine and epinphrine different than the neurotransmitter form?
Can effect other receptors far from the sympathetic postganglionic fibers
How does the parasympathetic and sympathetic nervous system effect heart rate?
Parasympathetic decreases HR, sympathetic increases HR
How does the parasympathetic and sympathetic nervous system effect churning movements of the stomach?
Parasympathetic increases, sympathetic decreases
Which division of the ANS generally mobilizes the body during activity or stress?
Sympathetic division
What division of the ANS generally promotes maintenance functions and conserves body energy?
Parasympathetic division
What division of the ANS originates in the thoracic and lumbar regions of the spinal cord?
Sympathetic
What division of the ANS originates in the brain stem and sacral region?
Parasympathetic
What are the most notable inorganic ions as it pertains to membrane potentials in the human body?
Na+, K+, and Cl-
When oppositely charged particles come together what can the force of attraction be used for?
To perform work
When do seperated electrical charges have the potential to do work?
When they are seperated
What is defined by the potential of electrical charges to do work?
Electrical potential/potential difference
What unit it electrical potential measured in?
Volts
What is defined as the movement of electric charge?
Current
What is the hindrance to the movement of charge through a material?
Resistance
What are materials with high resistance to current flow?
Insulators
What are materials with low resistance to current flow?
Conductors
What is Ohm’s law?
Current = Voltage / Resistance
Why is pure water a poor conductor?
It contains few ions
Why does the addition of sodium and chloride ions to water allow water to act as a conductor?
Provies charges that can carry current
Since lipids are highly resistant to current what important role does it play?
Membranes can seperate opposite charges
What is the potential difference found in a cell at rest?
Resting membrane potential
What cells have a membrane potential that can change rapidly in response to stimulation?
Muscle and nerve cells
Why would a membrane potential occur?
More negative charges inside the cell than positive cells and vice versa for outside the cell and the charges inside and outside the cell are attracted to each other,
True/False: The total number of positive and negative charges that have to be separated across the membrane to account for RMP is insignificant relative to the total number of charges actually within the cell.
True, because the bulk of the ICF and ECF is neutral
What determines the magnitude of a resting membrane potential?
Differences in the number of ions between ICF and ECF and permeability of plasma membrane
Sodium and chloride are mainly found inside or outside a neuron?
Outside
Potassium is mainly found inside or outside a neuron?
Inside
What is responsible for the difference in sodium and potassium relative to a neuron?
Sodium-potassium pump
What is the charge of the inside of a cell at RMP?
Negative
What can be used to determine the equilibrium potential?
Nernst equation
What is the RMP of a normal neuron?
-90 mV
In a normal neuron which way is the concentration gradient pushing sodium? Which way is the attraction of opposite charges pushing sodium?
Inside; inside
Why does the concentration of sodium inside the cell progressively increase and that of potassium decrease?
Sodium-potassium pump
What is the term for the sodium-potassium pump since it is electrically charged?
Electrogenic pump
What is a change in which the membrane potential becomes less negative (i.e. closer to 0 or even positive)?
Depolarization
What is a change in which the membrane potential becomes more negative than the RMP?
Hyperpolarization
What occurs when a membrane potential that has been depolarized or hyperpolarized returns towards RMP?
Repolarization
What are local changes in membrane potential in either a depolaring or a hyperpolarizing direction?
Graded potentials
What is meant by graded in a graded potential?
The size of the potential change is variable and related to the magnitude of event that procedes it
What type of graded potential is produced at the peripheral end of a sensory neuron in response to an external stimulus?
Receptor potential
What type of graded potential is produced in a postsynaptic cell in response to neurotransmitter by a presynaptic axon terminal?
Postsynaptic potential
What type of graded potential is produced spontaneously (by ion leakage)?
Pacemaker potential
What structures make up the forebrain?
Cerebrum and diencephalon
What structures make up the cerebrum?
Cerebral cortex and basal ganglia
What structures make up the diencephalon?
Thalamus and hypothalamus
What structures make up the brain stem?
Mid brain, pons, medulla oblongata, and cerebellum
What structures make up the hindbrain?
Pons, medulla, and cerebellum
