Term
| The basic neuronal unit containing specialized elements |
|
Definition
|
|
Term
| What 2 parts of a neuron receive information |
|
Definition
|
|
Term
| What part of a neuron transmits information |
|
Definition
|
|
Term
| What is it that separates the sections of myelin on axons? |
|
Definition
|
|
Term
| Can an axon be myelinated or non-myelinated? |
|
Definition
|
|
Term
| Maintains axon structure and function |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Helps regulate ECF composition, sustain neurons metabolically, form the blood brain barrier, and serve as guides for developing neurons |
|
Definition
|
|
Term
| Provides immune functions |
|
Definition
|
|
Term
| Regulates CSF production and flow |
|
Definition
| Ependymal Cells (non-glia) |
|
|
Term
| Neural growth and development primarily occurs where? |
|
Definition
|
|
Term
| __ __ molecules on neurons and glial cells along with soluble neurotrophic factors guide the growing axons to their appropriate targets |
|
Definition
|
|
Term
| Damaged __ axons may regenerate if the cell body is not also damaged |
|
Definition
|
|
Term
| Damaged __ nervous system neurons do not experience significant regeneration |
|
Definition
|
|
Term
| What are the concentrations of Na+ inside and outside of the cell. |
|
Definition
|
|
Term
| What are the concentrations of Cl- inside and outside of the cell? |
|
Definition
|
|
Term
| What are the concentrations of K+ inside and outside the cell? |
|
Definition
|
|
Term
| Resting membrane potential is based upon 2 principles. |
|
Definition
1. Membrane is permeable
2. Na/K pump |
|
|
Term
| Most of the body's K+ is located inside or outside the cell? |
|
Definition
|
|
Term
| The intracellular concentration of K+ is more than __ times that of extracellular K+ |
|
Definition
|
|
Term
| The asymmetrical distribution of K+ is maintained by what? |
|
Definition
|
|
Term
| Is the Na/K pump present in all membranes? |
|
Definition
|
|
Term
| What is the Na/K pump's energy source? |
|
Definition
|
|
Term
| This actively transports K+ from ECF to ICF against the electrochemical gradients - thus maintaining the high intracellular K+ concentration |
|
Definition
|
|
Term
|
Definition
|
|
Term
| What happens when you move a charged particle across a membrane? |
|
Definition
| it effects the electrochemical potential of that membrane |
|
|
Term
| At rest, nerve and skeletal muscle membranes have a high permeability to what? |
|
Definition
|
|
Term
| At rest, is the electrochemical gradient large or small? |
|
Definition
|
|
Term
| Is the Na+/K+ pump always pumping? |
|
Definition
|
|
Term
| K+ diffuses from ICF to ECF at rest, which generates an inside negative potential difference, this is the basis for what? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| What is the K+ equilibrium potential? |
|
Definition
|
|
Term
| Is there a greater net movement of K+ out or Na+ into the cell? |
|
Definition
|
|
Term
| The Na/K pump is always pumping 2 K in and 3 Na out. But K has leak channels which allow K to leak back out of the cell and make the cell more negative. This is why the net movement of K out is greater than Na in |
|
Definition
|
|
Term
| At steady negative RMP, ion fluxes through the channels and the pumps do what? |
|
Definition
|
|
Term
| When you __ a membrane, you are making it less negative |
|
Definition
|
|
Term
| To generate an action potential, you must depolarize to what value? |
|
Definition
|
|
Term
| Changes in serum K+ concentration alter the K+ equilibrium potential, and consequently what? |
|
Definition
|
|
Term
| The lower the serum K+, the __ the K+ concentration gradient across the membrane |
|
Definition
|
|
Term
| The lower the serum K+, the more or less negative the K+ equilibrium potential is? |
|
Definition
|
|
Term
| If the K+ equilibrium potential is more negative, this is said to be a ___ membrane |
|
Definition
|
|
Term
| The higher the serum K+, the ___ the K+ concentration gradient across the membrane |
|
Definition
|
|
Term
| The higher the serum K+, the more or less negative the K+ equilibrium potential and RMP |
|
Definition
|
|
Term
| If the K+ equilibrium potential is less negative (more positive), then this is said to be a __ membrane |
|
Definition
|
|
Term
| Name the 6 main factors that can cause K+ to shift into cells (from ECF to ICF) |
|
Definition
1. Presence of insulin
2. Beta-adrenergic agonists (epi/norepi)
3. Alkalemia
4. Diuretics
5. GI excretions
6. Sweating/Vomiting |
|
|
Term
|
Definition
|
|
Term
| ___ mechanisms usually work to correct the increased ECF K+ concentration by various means |
|
Definition
|
|
Term
| Prolonged K+ shifting into the cells can lead to ___ serum K+ concentration |
|
Definition
|
|
Term
| A decreased serum K+ concentration |
|
Definition
|
|
Term
| Name 6 symptoms of Hypokalemia |
|
Definition
1. Abnormal heart rhythms
2. Breakdown of muscle fibers
3. Constipation
4. Fatigue
5. Muscle weakness or spasms
6. Paralysis (can include lungs) |
|
|
Term
| Breakdown of muscle fibers |
|
Definition
|
|
Term
|
Definition
|
|
Term
| What are 3 common treatments for hypokalemia? |
|
Definition
1. K+ supplements
2. IV therapy
3. Diets rich in K+ (bananas) |
|
|
Term
| Name 7 major factors that can cause K+ to shift out of cells (from ICF to ECF) |
|
Definition
1. Lack of insulin
2. Beta-adrenergic antagonists
3. Extreme exercise
4. Hyperosmolarity
5. Cell lysis (burns, sx, tumors)
6. Lack of aldosterone
7. Acidemia |
|
|
Term
|
Definition
|
|
Term
| What is the primary function of aldosterone? |
|
Definition
|
|
Term
| ___ mechanisms usually work to correct the increased ECF K+ concentration by various means |
|
Definition
|
|
Term
| Excess K+ can be excreted by the kidneys in the ___ |
|
Definition
|
|
Term
| Some metabolic disorders or renal problems can lead to prolonged __ serum K+ |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Nam 3 symptoms of hyperkalemia |
|
Definition
1. Irregular heartbeat
2. Nausea
3. Slow, weak, or absent pulse |
|
|
Term
| At rest, is intracellular Na+ low or high? |
|
Definition
|
|
Term
| At rest is the conductance of Na+ low or high? |
|
Definition
|
|
Term
| At rest, the RMP for Na+ is close or far from equilibrium potential? |
|
Definition
|
|
Term
| Local potentials whose magnitude vary and die out within a few mm of the site of origin |
|
Definition
|
|
Term
| The depolarization or hyperpolarization of a membrane. Usually occurs in a very local area within a membrane region. Does not propogate or produce an action potential. It is an oscillation of membrane potential. |
|
Definition
|
|
Term
| Rapid changes in the membrane potential in which the membrane depolarizes then repolarizes |
|
Definition
|
|
Term
| How does myelin effect the propogation of action potentials? |
|
Definition
|
|
Term
| A very rapid event (1 msec) that is composed of a depolarization (upstroke) and repolarization |
|
Definition
|
|
Term
| Initiated when an inward current (positive charge entering muscle cell) depolarizes the muscle cell membrane. This inward current is usually the result of a current spread from action potentials at neighboring sites. |
|
Definition
|
|
Term
| If there is a sufficient inward current to depolarize the muscle membrane to the threshold potential of __mV, then activation gates and voltage-gated __ channels rapidly open. |
|
Definition
|
|
Term
| Once threshold is reached and Na+ channels open, Na+ conductance increases and becomes even higher than K+ conductance. The rapid increase in Na+ produces and inward Na+ current that further depolarizes the membrane potential toward the Na+ equilibrium potential. This constitutes the ___ of the action potential. |
|
Definition
|
|
Term
| The __ is followed by a repolarization to the RMP. |
|
Definition
|
|
Term
| Repolarization is caused by 2 slower events: |
|
Definition
1. Closure of activation gates on the Na+ channels (leading to closure of the voltage gated Na+ channels and decreased Na+ conductance)
2. Increased K+ conductance, which drives the membrane potential back toward the K+ equilibrium potential |
|
|
Term
| Decreased serum K+ concentration will __ the negativity of both the K+ equilibirum potential and the RMP |
|
Definition
|
|
Term
| When K+ serum is decreased, what does this do to RMP in relation to threshold? |
|
Definition
| Moves it further from threshold and more difficult to get an action potential |
|
|
Term
| __ serum K+ concentration requires more inward current to depolarize the membrane to threshold and initiate the upstroke of the action potential |
|
Definition
|
|
Term
| Increased serum K+ concentration will __ the negativity of the K+ equilibrium and RMP |
|
Definition
|
|
Term
| When K+ serum is increased what does this do to RMP in relation to threshold? |
|
Definition
| Moves it closer to threshold and easier to generate an action potential |
|
|
Term
| Less inward current is required to initiate the upstroke of an action potential when K+ serum is ___ |
|
Definition
|
|
Term
| ___ serum K+ levels initially results in very quick, easily generated action potentials |
|
Definition
|
|
Term
| During periods of ____, there is prolonged depolarization which causes inactivation gates to close and remain closed, and Na+ channels are closed regardless of the position of the activation gates. |
|
Definition
|
|
Term
| Does activation and inactivation gates both have to be open to generate an action potential? |
|
Definition
|
|
Term
| These type of gates keep action potentials from firing no matter what when they are closed. |
|
Definition
|
|
Term
| Occurs by the spread of local currents from the active depolarized regions to adjacent inactive regions. These local depolarizing currents are caused by the inward Na+ current of the upstroke of the action potential. |
|
Definition
| Propogation of action potential |
|
|
Term
| Some drugs can prevent the upstrok of AP or block the propogation of APs along the nerve fibers by binding specific ion channels. Name 2. |
|
Definition
1. Lidocaine
2. Tetrodotoxin |
|
|
Term
| A voltage-gated Na+ antagonist |
|
Definition
|
|
Term
| Binds voltage gated Na+ channels. Found in the ovaries of puffer fish. |
|
Definition
|
|
Term
| Name the 2 types of synapses |
|
Definition
|
|
Term
| A junction between 2 neurons |
|
Definition
|
|
Term
| Depolarization to threshold in a neuron due to a graded potential generated by synaptic input to a neuron |
|
Definition
|
|
Term
| In electrical synapses, pre and post synaptic cells are connected by what? |
|
Definition
|
|
Term
| This type of synapse allows a local current to flow in the presynaptic cell to flow directly across the junction into the postsynaptic cell. |
|
Definition
|
|
Term
| Are electrical synapses fast or slow? |
|
Definition
|
|
Term
| Thought to play a role in the synchronization of electrical activity within neuronal networks |
|
Definition
|
|
Term
| In this type of synapse, the synaptic cleft prevents direct propogation of an electrical current from the pre to post synaptic cell |
|
Definition
|
|
Term
| In a chemical synapse, the __synaptic membrane releases a chemical messenger (neurotransmitter) from their axon terminals into the synaptic cleft |
|
Definition
|
|
Term
| In a chemical synapse, the neurotransmitter bidns to the receptors on the __synaptic neurons |
|
Definition
|
|
Term
| In a chemical synapse, what steps must be taken for the neurotransmitter to be released? |
|
Definition
| Action potential voltage gated Ca++ opens in the presynaptic terminal. Ca++ influx initiate membrane vesicle fusion and neurotransmitter release |
|
|
Term
| In a chemical synapse, how is the postsynaptic cell activated? |
|
Definition
| A portion of the released neurotransmitter binds either ionotropic or metabotropic ligand gated receptors |
|
|
Term
| In a chemical synapse, an unbound transmitter is removed from the synaptic cleft by 1 of 3 ways: |
|
Definition
1. reuptake by the presynaptic cell or glia
2. diffuse away from the site
3. enzymatically inactivated |
|
|
Term
| A major neurotransmitter of PNS at NMJ and the brain |
|
Definition
|
|
Term
| ACh is synthesized from __ and __ in the cytoplasm of synaptic terminals |
|
Definition
|
|
Term
| The enzyme that breaks down ACh in the synaptic cleft |
|
Definition
|
|
Term
|
Definition
|
|
Term
| What 2 things stimulate nicotinic receptors? |
|
Definition
|
|
Term
| What 2 things stimulate muscarinic receptors? |
|
Definition
|
|
Term
| This ACh receptor is permeable to Na+ and K+ with net effect of depolarization. It is present at the NMJ |
|
Definition
|
|
Term
| This ACh receptor is a g-protein coupled receptor, it has a large role in the PSNS. |
|
Definition
|
|
Term
| An antagonist to the muscarinic receptor? |
|
Definition
|
|
Term
| This disease involves a degeneration of cholinergic neurons |
|
Definition
|
|
Term
| Are nicotinic or muscarinic receptors present at the NMJ? |
|
Definition
|
|
Term
| Biogenic Amines are small or large charged particles? |
|
Definition
|
|
Term
| Name 2 main biogenic amines |
|
Definition
|
|
Term
|
Definition
Dopamine
Norepinephrine
Epineprine |
|
|
Term
| Synthesis of this begins with the conversion of tyrosine to L-dopa by tyrosine hydroxylase. |
|
Definition
|
|
Term
| What are catecholamines broken down by? |
|
Definition
|
|
Term
| Neurons that secrete norepi and epi are said to be what? |
|
Definition
|
|
Term
| Name 2 main classes of receptors for epi and norepi |
|
Definition
Alpha-adrenergic: a1 and 2
Beta-adrenergic: b1, 2, and 3 |
|
|
Term
| Serotonin is produced by what? |
|
Definition
|
|
Term
| Serotonin has at least __ different receptor types |
|
Definition
|
|
Term
| This biogenic amine has an excitatory effect on muscles and an inhibitory effect on sensory |
|
Definition
|
|
Term
| All of these share a very similar molecular structure |
|
Definition
|
|
Term
| Amino acids are most prevalent in the __ and affect most neurons |
|
Definition
|
|
Term
|
Definition
|
|
Term
| The most common excitatory amino acid |
|
Definition
|
|
Term
| Name the 2 types of receptors for Glutamate |
|
Definition
Ionotropic (AMPA and NMDA)
Metabotropic |
|
|
Term
| This type of receptor is associated with excitotoxicity |
|
Definition
|
|
Term
| The major inhibitory neurotransmitter of the brain |
|
Definition
|
|
Term
| Injury or death to cells that rapidly spreads to adjacent regions |
|
Definition
|
|
Term
| Excessive glutamate release over-stimulates ___ receptors causing an excess accumulation of __ (toxic to a cell), which causes it to rupture and continure the process. |
|
Definition
|
|
Term
| A modified form of glutamate |
|
Definition
|
|
Term
| Most GABA receptors increase Cl- influx into the cell leading to what? |
|
Definition
|
|
Term
| GABA has several binding sites which are sensitive to what? |
|
Definition
| Bensodiazepines (Xanax and Valium) |
|
|
Term
| A major inhibitory neurotransmitter of the brainstem and spinal cord |
|
Definition
|
|
Term
| Some neuropeptide receptors bind to what? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| The efferent portion of the PNS that includes all nerve fibers traveling from the CNS to skeletal muscle cells. |
|
Definition
|
|
Term
| Where are the cell bodies of the somatic nervous system located? |
|
Definition
| brainstem of ventral horn of the spinal cord |
|
|
Term
| Every motor neuron is ___ |
|
Definition
|
|
Term
| Somatic nervous system typically has large diameter, __ axons |
|
Definition
|
|
Term
| All neurons in the somatic nervous system are __ and ___ |
|
Definition
| Cholinergic and excitatory |
|
|
Term
| Are their somatic neurons that inhibit skeletal muscle? |
|
Definition
|
|
Term
| Relaxation involved __ of the motor neurons in the spinal cord |
|
Definition
|
|
Term
|
Definition
|
|
Term
| 2 division of the autonomic nervous system |
|
Definition
sympathetic
parasympathetic |
|
|
Term
| Innervates smooth and cardiac muscle cells, glands, neurons in the GI tract. Can be excitatory or inhibitory |
|
Definition
|
|
Term
| The autonomic nervous system has what type of neurons? |
|
Definition
|
|
Term
| All ___ neurons are cholinergic and activate nicotinic receptors at the postsynaptic site |
|
Definition
|
|
Term
| __ neurons can either be cholinergic or adrenergic |
|
Definition
|
|
Term
| Organized to mobilize the body for activity. Effects are widespread. |
|
Definition
| Sympathetic nervous system |
|
|
Term
| Organized for energy conservation. Effects tend to be local |
|
Definition
| parasympathetic nervous system |
|
|
Term
| ALL ___ are nicotinic cholinergic |
|
Definition
|
|
Term
| The SNS has primarily __ preganglionics |
|
Definition
|
|
Term
| Most adrenergic preganglionics release __, and some __ |
|
Definition
|
|
Term
| Name the main targets of the SNS |
|
Definition
Smooth muscle
Cardiac muscle
Gland cells
some CNS |
|
|
Term
| The adrenal medulla is a collection of __ neurons |
|
Definition
|
|
Term
| Upon activation by preganglionics, the adrenal medulla releases what 2 things into the bloodstream? |
|
Definition
|
|
Term
| The parasympathetic nervous system is primarily ___ postganglionics that activate mostly muscarinic cholinergic receptors at the postsynaptic site |
|
Definition
|
|
Term
| Name the main targets of the parasympathetic nervous system |
|
Definition
Smooth muscle
Cardiac muscle
Gland cells
Some CNS
Some ganglia |
|
|
Term
| Does the SNS and PSNS function independently of one another? |
|
Definition
|
|
Term
| Name 2 ways to slow heart beat by the autonomic nervous system. |
|
Definition
1. Increase parasympathetic stimulation
2. Decrease sympathetic stimulation |
|
|
Term
| Contains the junction of a motor neuron axon terminal with a motor end plate |
|
Definition
|
|
Term
| The region of the muscle fiber plasma membrane that lies directly beneath the axon terminal |
|
Definition
|
|
Term
| Contains one motor neuron and all the motor fibers innervated by that neuron. All fibers are located within the same muscle, but not necessarily adjacent to each other |
|
Definition
|
|
Term
| Contains the junction of a motor neuron axon terminal with a motor end plate |
|
Definition
|
|
Term
| Analogous to EPSP in neuron-neuron synapses in that they involve depolarization of a "postsynaptic" membrane via Na/K ion channels |
|
Definition
| End Plate Potential (EPP) |
|
|
Term
| Magnitude of __ is much larger than EPSP |
|
Definition
|
|
Term
| Every action potential in a motor neuron produces an action potential in the motor fiber of its motor unit. This is very different than neuronal __ |
|
Definition
|
|
Term
|
Definition
|
|
Term
| IPSP in neurons are usually __ |
|
Definition
|
|
