1. what do fluctuations in membrane potential serve as?
2. cells that produce electrical signals when stimulated are called ____tissues? what are the two cells?

1. signaling mechanisms
2. excitable tissues; nerve cells and muscle cells

1. what are the 4 functions of nerve cells?
2. what type of communication do they serve?
3. what do they coordinate?

1. what are the 2 functions of muscle cells?

1. receive, process, initiate, and trasnmit messages
2. short and long distance communication
3. coordinate activities b/w cells

1. contraction and force generation

1. normal, unpolarized equilibrium
2. polarized
3. resting membrane potential
4. depolarization
5. repolarization
6. hyperpolarization

1. no diff in polarity, charge, or concentration
2. diff in charge (+ or -) across membrane
3. membrane potential of the cell at rest
4. membrane pot. becomes less neg. than resting level
5. membrane pot. returnign to resting level
6. membrane pot. more neg than resting level

membrane pot. caused by changes in --> ion movement --> permeability--> triggering events (stimulus)

what are the types of stimulus? (4)

1. sound waves stimulating nerve ending
2. change in electrical field in neural endings
3. an interaction of a ligand with a receptor
4. spontaneous change in pot. caused by leak channels

2 types of channels:

1. what is the main property of leak channels?
2. when do gated channels open?
   -what are the 3 kinds of gated channels?
3. what are the 2 electrical signals generated by movement of ions across membrane?

1. remain open
2. open and close in response to some triggering event
   -voltage-gated channels, chemically (ligand) gated channels, mechanically gated channels (respond to stretch or other deformation)
3. graded potential and action potentials

1. what are graded potentials?
2. how does amplitude related to stimulus?
3. how does amplitude relate to distance?
4. where does it begin?
5. what is the duration based on?
6. different graded potentials can be ___?
7. graded potentials can travel to ___.
8. what 2 things can graded potentials be?

1. local changes in membrane pot. that occur in varying grades or degrees of magnitude or strength
2. amp directly related to level of stimulus
3. inversely related to distance-- local event (active area)
4. begins at a pt. where ions enter ECF
5. duration directly related to duration of stimulus
6. diff graded pot. can be added- SUMMED
7. can be depolarizing and hyperpolarizing

Graded potentials:

1. what is decremental?
2. two types of conduction involved?
3. signal distance?
4. what are the 4 types of graded potentials

1. Decremental: gradually dec. from initial site
2. passive conduction and electrotonic conduction
3. limited signal distance
4. postsynaptic, receptor, end-plate, pacemaker, slow-wave potentials

non spiking or local circuit

can have summation

1. what is an action potential?
2. what changes are made to the membrane?
3. where is the change conducted?
4. short or long distance?
5. decrimental or nondecrimental?

1. stereotypical response in membrane potential due to a threshold level stimulus
2. brief, rapid change in membrane pot.; change is large; membrane pot reverses
3. conducted thru the membrane
4. conducted over long distance-- stable duration
5. nondecrimental

Anatomy of Neuron:

1. what is input zone and what is its function?
2. trigger zone?
3. conducting zone?
4. output zone?

(2 for each)

1. cell body and dendrites (receptive portion);part where incoming signals from other neurons are received
2. axon hillock and initial segment;part were ap's are initiated
3. axon or nerve fiber and collaterals; part taht conducts ap's in undiminshing fashion, often over long distances
4. zxon terminal and synaptic terminals; part that releases a neurotransmitter that influences other cells

1. where does contiguous conduction take place and what does it do?
2. what does the refractory period ensure will not occur?

1. occurs along nonmyelinated portion of neuron; spread of action potential along every patch
2. ensures unidirectional propagation and limits the frequency of ap's

Mylenation:

1. what are axons covered with and what species is it usually found?
   
2. what does myelin consist of and what does it act as?
3. what does this prevent
4. what does this consive?
5. what are the myelin-forming cells doe sit consist of and what are the spaces b/w myelin called?
6. what type of conduction does it allow?

1. axons covered with fatty substances; found in vertebrates
2. myelin consists of lipids and acts as an insulator
3. prevents current leakage across the myelinated portion of the membrane
4. oligodendrytes (in CNS), Schwann cells (PNS); spaces b/w myelin are called Nodes of Ranvier
5. allows for saltatory conduction
   

1. which conducts fast: large or small axons?
2. how much faster do mylenated axons conduct?
3. where is speed needed?
4. what is an example of this purpose?

1. large axons conduct faster
2. up to 120 m/s compared to 0.7 m/s
3. speed needed where speed enhances survival (prey or predator)
4. fast fibers to skeletal muscle vs slow fibers to GI tracts; giant nerve axons in squid and crayfish

1. what happens when an AP reaches the end of an axon?
2. what is the region and its connection called?
3. what are the two kinds of transmission points?

1. info is transmiitted to another neuron or effector
2. region is called a synapse; innervation
3. electrical and chemical (both synapses)

electircal synapse:

1. how is the AP trasnmitted?
2. what type of junction does it use?
3. speed of transmission?
4. where are they found?
5. unidirectional or bi-?

1. AP transmitted unperturbed
2. uses gap junctions
3. transmission occurs with negligible delay
4. found in some invertebrates; retinal neurons, smooth and cardiac muscle fibers
5. can be bidirectional

chemical synapse

1. what elements are involved in chemical synapse? (5)
2. unidirectional or bi-?
3. what are the types of chemical synapse? (4)

1. presynaptic element, neurotransmitter, synaptic cleft, postsynaptic element, receptors, operate in one direction
2. axosomatic, axoaxonic, axodendritic, dendrodendritic

what are the events during synaptic transmission?

1. arrival or action potential
2. depolarization of bouton opens Ca2+ voltage-gated channels
3. calcium entry triggers release of NTMR by exocytosis
4. diffusion of NTMR across synaptic cleft to post-synaptic membrane
5. transmitter-receptor complex causes change in conductance in post-synaptic membrane
6. response terminated by removal of NTMR
7. ionic current flow and generation of post-synaptic potential

1. what are the factors that influence transmitter release?  

Hints: ____ of arriving action potential

         nerve terminal's ability to ....(5 actions)

        ____ ___of presynaptic ending

        concentration of ___ in ECF (type of ion)

1. amplitude
   nerve terminals ability to synthesize, package, store, mobilize, and release NTMR
   prior activity of presynaptic ending
   concentration of Ca++ in ECF

Postsynaptic potentials:

1. what do diff NTMR cause in ref. to the permeability changes inthe postsynaptic element?
2. During excitatory synapses:
   -what is occuring? what is happening to the cell? what type of potential?
3. Inhibitory synapses:
   -what is occuring? what is happening to the cell? wht type of potential?

1. diff NTMRs cause diff permeability changes in postsynaptic element
2. net movement of Na+ intno cell; depolarizes cell; excitatory postsynaptic potentials (EPSP)
3. inc. permeability to K+ (moves out) or Cl- (moves in); hyperpolarizes cell; inhibitory postsynaptic potentials (IPSP)

what are the 3 ways neurotransmitters can be removed?

Hints:

         synaptic cleft
         enzymatic activity

         axon terminal

1. NMTR may diffuse away from the synaptic cleft
2. it may be inactivated by enzymatic activity
3. it may be taken back into the axon terminal

1. what is taking place at the neuromuscular junction?

Synaptic Integration:

1. what are the two t ypes of summation?
2. what is the grand postsynaptic potential (GPSP)?

1. motor neuron innervating skeletal muscles

Synaptic Integration:

1. temporal summation and spatial summation
2. summation of all EPSPs and IPSPs

1. what is convergence?
2. what is divergence?

1. neuron having many other inputs to it
2. branching of axon terminals so that a single neuron synapses with many other cells

1. what are the 10 NTMRs? (small, rapid-acting)