Term
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Definition
| All calls produce & maintain a difference in electric charge across their membrane. |
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Term
| How do cells control membrane potential? |
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Definition
| By controlling the distribution of ions across the membrane. |
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Term
| What do ordinary cells use membrane potential for? |
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Definition
| to aid in transport across the membrane. |
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Term
| Which cells can change their membrane potential? |
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Definition
| Nerve and muscle cells-- is crutial to their function |
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Term
| For a neuron, what is the resting membrane potential? |
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Definition
| -70 mV ((70 mV more negative inside) |
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Term
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Definition
| More negative inside than -70mV |
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Term
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Definition
| Less negaive inside than -70mV |
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Term
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Definition
| if the charge difference goes to 0 in the neuron |
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Term
| How can you monitor the changes inside the neuron? |
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Definition
| w/ micro electrodes- one inside, one outside and an oscilioscope |
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Term
Na concentration in neurons?
K concentration in neurons? |
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Definition
20X higher outside than inside
40X highter inside than outside |
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Term
| 3 Factors that operate to produce and maintain the difference in ion concentration: |
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Definition
1) "fixed" negative charges w/i cell draw positive ions in
2) The membrane is by nature more permeable to K therefore more k enters
3) the Na/K pump-an ion pumping protein in cell membranes [pushes 3 Na out for every 2 K it pulls in] |
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Term
| Do Na and K have their own gates? |
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Definition
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Term
| At resting potential what gates are shut? |
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Definition
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Term
| At resting potential what gates are slightly open? |
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Definition
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Term
| Does Na or K slowly diffuse out keeping the resting potential stable? |
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Definition
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Term
| If a neuron is slightly hypopolarized to -55mV what will happen? |
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Definition
| It will hit its threshold potential causing the Na gates to open wide. The Na rushes in and the neuron depolarizes so much that the charge reverses to 30mV. |
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Term
| What is the change from -55mV to 30mV called? |
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Definition
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Term
| As soon as the neuron hits 30mV what happens? |
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Definition
| The K gates open wide and K rushes out and the neuron repolarized. So much that it overpolarizes to -90-100mV. |
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Term
| When a neuron overpolarizes what is it called? |
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Definition
| K equilibrium potential-K gate closes and resting point is gradually restored. |
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Term
| Action potentials are "--------- or -------------" |
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Definition
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Term
| Are action potentials always the same strength? |
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Definition
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Term
| Will an increased stimulus increase the the strength of an action potential? |
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Definition
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Term
| During what period can a neuron not be forced to produce another action potential? Why? |
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Definition
Absolute Refractory Period
B/c Na gates are already open or blocked and unusable |
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Term
| During what period can a neuron be pushed to produce another action potential? why? |
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Definition
| Relative Refractory Period- BUT a stronger that usual stimulus is needed because the neuron is hyperpolarized |
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Term
| How much time exists between Resting potential to AP to resting poential? |
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Definition
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Term
| What does an increased stimulus intensity effect? |
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Definition
| Increased neuron and effector activity |
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Term
| What 2 ways does the stimulus intensity effect neuron and effectors? |
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Definition
1) Increae the frequency of AP's on a nerve fiber [but they can't get closer than the Absoult Refractory Period]
2)Recructement-since different neuron and effector cells have different thresholds. As stimulus strength increases, activity inccreases as more hit their threshold. This allows graded responses. > graded contraction of skeletal muscles |
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Term
| What is a cable property? |
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Definition
| the ability to conduct electric charge |
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Term
| Are the cable proterties of nerve fibers good? Why? |
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Definition
No
1) Fixed charges w/i fiber resist flow
2) Membrane is "leaky"-charge leaks off w/ distance |
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Term
| What is the effection conduction distance alone a fiber? |
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Definition
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Term
| What happens as an impulse travels along a nerve fiber? |
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Definition
| It propeogates as a series of AP's generated one after another along the fiber. |
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Term
| What is better pure conduction or propogating? Why? |
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Definition
| Propogation b/c since AP's are all or none the last in a series will be just as strong as the first regardless of distance.--no loss of signal strendth |
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Term
| The process of conduction differs depending on what? |
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Definition
| Whether the fibers are unmyelinated or myelinated |
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Term
| What is the difference between unmyelinated and myelinated fibers? |
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Definition
1)un-AP's occur at every suitable site alone the fiber. Since these sites are just fraction of a micrometer apart and since each AP is a seperate event and the last must end before the nest starts---Slows conduction
2)My-In these, ions can only cross the membrane at the gaps in the sheath(Nodes of Ranvier) These are 1mm apart. Thus that requires fewer AP's----Speeds Conduction |
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Term
| What 2 factors effect inpulse speed? |
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Definition
Type of fiber-Myelinated or un
Diameter-Large=faster |
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Term
| Synapses connect --------to----------- OR -------to-------------. |
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Definition
1. neuron
2. Neuron
3. Neuron
4. effector cell |
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Term
| 4 structure types of synapses: |
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Definition
1. axodendritic- connects bouton to dendrite
2. Axosomatic-connects bouton to cell body
3. Axoaxonic- connects bouton to axon
4. Dendrodendritic- dendrite to dendrite |
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Term
| Function types of synapses: |
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Definition
1)Electrical-Dendordendritic type-either direction-RARE (certain areas of brain) The neurons are coupled by special gap junction that form direct cell to cell ion channels.
2)Chemical-Axodendritic, axosomatic, and axoaxonic-one way (bouton to next cell)-Rely on neurotransmitters b/c there is a gap b/w the cells(=synapic cleft) that must be jumped chemically(ACh) |
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Term
| What is the hypolarization produced by an excitatory neurotransmitter called? |
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Definition
| excitatiory Postsynapitc Potential (EPSP) |
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Term
| What is the hyperpolarization produced by an inhibitory neurotransmitter called? |
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Definition
| Inhibitory Postsynaptic Potential (IPSP) |
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Term
| What are the 2 types of summation of EPSP's? |
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Definition
1. Temporal summation-several EPSP's are deflivered at one synapse in a short period of time
2. Spatical Summation-EPSP's are delivered at several synapses relatively simultaneously.
**Both may be occuring |
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Term
| Can EPSP's and IPSP's be delivered at the same time? |
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Definition
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Term
| What determines whether a cell reaches threshold or is inhibited? |
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Definition
| the ratio of EPSP's to IPSP's |
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Term
| 3 Examples of catecholamine Neurotransmitters? |
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Definition
| epinephrine, norepinephrine, and dopamine |
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Term
| Do catecholamine neurotransmitters open the chemically regualted gates? |
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Definition
| No thhey bind to a receptor in the post synapic cell that converts the ATP to cAMP which acts as a second messenger and opens the gates. |
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Term
| Are catecholamine neurotransmitters destoryed after use? |
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Definition
| No reabsorbed by the bouton and reused |
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Term
| 4 substances that have been id that act as neurotransmitters |
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Definition
1) Seratonin-amine-affects moods anf level of consciousness
2)GABA(Gamma Amino Butynic Acid)-inhibitory CNS neurotransmitter
3)Glycine-amino acid-acts at motor synapses in the spinal cord
4)Endorphins-tenkephalins-bind to or at CNS "opiate" receprots (pain receptors) -BLOCK PAIN |
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Term
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Definition
| Layers of CT surrounding the CNS |
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Term
| What are the 5 major brain regions? |
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Definition
1. Telencephalon
2. diencephalon
3. Mesencephalon
4. Metencephalon
5. Myelencephalon |
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Term
| What is the largest single discrete structure in the brain that constitutes about 80% of brain mass? |
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Definition
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Term
| The cerebrum is divided by the longitudinal ------------- -----------into right and left ------------- ---------------------and they are connected by the ------------- -------------. |
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Definition
cerebral
fissure
cerebral
hemispheres
corpus
collosom |
|
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Term
| What does the left hemisphere handle? |
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Definition
| ananlytical and mathmatical ablilities, speech and language abilities |
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Term
| What does the right hemisphere handle? |
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Definition
| artistic and spacial abilities and allso intuitive reasoning and non-verbal communication |
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Term
| Does one side of the brain usually dominate? |
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Definition
|
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Term
| What does the precentral gyrus do? |
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Definition
|
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Term
| What does the post-central gyrus do? |
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Definition
|
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Term
| What does the Wernicks's area do? |
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Definition
| Speech interp and formation(left side only) |
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Term
| What does the broca's area do? |
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Definition
| Motor speech area (Left side only) |
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Term
| What does the frontal lobe do? |
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Definition
| Handles personality and highter emotions. |
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Term
| What does the parietal lobe do? |
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Definition
| Handle spatial and visual relationships and memory aof spacial relationship somatic sensory interpretation(Wernicke's area) |
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Term
| What does the temporal lobe do? |
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Definition
| Handles memory of visual and auditory experience, speech processing and formation |
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Term
| What connects the Broca's area and Wernicke's area? |
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Definition
| A deep nerve tract= arcuate fascisulus. |
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Term
| What does the occipital lobe do? |
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Definition
| recieves and processes incoming info from the retinas they "flip the image", provide depth preception, facial recognition |
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Term
| What is the 5th lobe? What does it do? |
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Definition
| Insula-involved in regulating emotional states |
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Term
| What are the 3 sets of fiber tracts handles the communication with in the brain? |
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Definition
| 1. Association- connect area with in the hemmisphere 2. Commissural-connect the 2 hemispheres via corpus callosum 3. projection-connect the cerebrum with the lower brain via thalamus |
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Term
| What do the olfactory bulbs do? |
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Definition
| Recieve and process incoming olfactory impulses to provide your sense of smell |
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Term
| What 3 parts is the diencephalon divided into? |
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Definition
| Epithalamus, Thalamus, and hypothalamus |
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Term
| What secretes CSF into the ventricle? |
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Definition
| Choroid Plexis(blood vesseles covered w/ ependyma) in the Epithalamus |
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Term
| What connects the 2 superior colliculi of the mesencephalon? |
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Definition
| posterior commissure in the epithalamus |
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Term
| What projects posteriorly from the epithalalmus? what does it do? |
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Definition
| Pineal body=epiphysis remnant of the original 3rd eye. responds to light produces melatonin |
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Term
| What does the Thalamus function as? |
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Definition
| relay center between the cerebrun and lower brain |
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Term
| What is loc. at the Thalamus? What connects the 2 sides? |
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Definition
| 3rd ventricle the interthalamic adhesion connects the 2 sides |
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Term
| What kind of memory is the thalamus involved in? |
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Definition
|
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Term
| What does the hypothalamus regulate? |
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Definition
| autonomic, endocrine, and emotional regulation |
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Term
| What does most of the Hypothalamus consit of? |
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Definition
|
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Term
| What are the eight centers of the Hypothalamus? |
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Definition
1. thermoregulatory center
2. Osmoregulatory center
3. Cardiovascular center
4. Feeding and Gastrointestinal center
5. sleep and wakefullness center
6. sexual center
7. emotional center
8. endocrine control center |
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Term
| What do chemical imbalances in the emotional center cause? examples? |
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Definition
psychiatric disturbances
ex:chronic depression,anxiety, OCD, paranoia, schizophrenia, and psychosis |
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Term
| what do Tricyclic antidepressants do? examples? |
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Definition
| increase serotonin inhibition of mood centers BUT can have harsh side effects EX: elavil & triavil |
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Term
| What do selective serotonin Reuptake inhibitors do? EX? |
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Definition
| Used to treat chronic depression,OCD, no harsh side effects EX:Prozac, Paxil, Zoloft |
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Term
| What do anit-anxiety meds do? EX? |
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Definition
| enhance the inhibitory effects of GABA on the anxiety centers EX: Librium, Valium, Xanax **long term cause seizure activity |
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Term
| What do anit-psychotics do? EX? |
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Definition
| Block dopamine receprtors in the mood centers and produce an extreme calm non-excitiable state EX: thorazine, Haldol, Mellaril **long term tardive dyskinesia |
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Term
| What do anit-manic agents do? EX? |
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Definition
| help control manic episodes of Bipolar disorder EX: Lithium, Depakote |
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Term
| What are the 2 pairs of rounded buldges of the roof of the midbrain in the mesencephalon? Each name? |
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Definition
Corpora Quadrigemina
Superior colliculi-control visual reflexes
inferior colliculi-control auditory reflexes |
|
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Term
| What are the 2 important motor neclei deep in the midbrain (mesencephalon)? |
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Definition
1. Red nucleus-connects the cerebellum w/ the motor cerebrum
2. Substantia Nigra- dopaminergic nucleus involved w/inhibiting involuntary motor spasms. DEFICIECY=Parkinsons's |
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Term
| What connects the 3rd and 4th ventricles? |
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Definition
|
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Term
| Venturally the mesenchepalon consists of a pair of bludges called? |
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Definition
|
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Term
|
Definition
| connect cerebellum w/ motor cerebrum via red nucleus |
|
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Term
|
Definition
| conncet motor cerebrum w/ cerebellum via pons |
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Term
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Definition
| carry sensory info from and motor info to body |
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Term
| In the metencephalon what controls respiratory rate? |
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Definition
|
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Term
| What is the myelencephalon? |
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Definition
|
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Term
| What does the myelencephalon resemble? |
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Definition
|
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Term
| Pair of ventral triangular bluges on the medulla oblongata? |
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Definition
|
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Term
| Pair of lateral bulges on the medulla oblongata? |
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Definition
|
|
Term
| 3 centers of the medulla oblongata? |
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Definition
1. cardiac center
2. vasomotor center
3. respiratory rhythmicity center |
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|
Term
| Is the metabolic rate of nervous tissue high or low? |
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Definition
|
|
Term
| Does the metabolic rate of your brain change with activity or consciousness? |
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Definition
|
|
Term
| What is constant blood flow that the brain recieves? |
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Definition
|
|
Term
| What is the flow to the brain under? |
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Definition
| autoregulation ie regulates its own supply |
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Term
| The brain relies exclusively on what for energy? |
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Definition
|
|
Term
| The CSF is higher in what ? |
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Definition
|
|
Term
| the CSF is lower in what? |
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Definition
|
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Term
| What is the major nerve trunk connecting the brain with the body? |
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Definition
|
|
Term
| The spinal cord starts and ends where? |
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Definition
|
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Term
| What are the 2 prominet swellings of the spinal cord? |
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Definition
1.Cervical enlargement(c3-t2)
2.Lumbar enlargement(t9-t12) |
|
|
Term
| Where the cord tapers to an end what is it called? |
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Definition
|
|
Term
| What is the thin thread that extends beyond the end of the spinal cord? |
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Definition
|
|
Term
| What is the brush-like cluster of the last few pairs of spinal nerves called? |
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Definition
|
|
Term
| What are the 3 subdivisions of the white matter of the cord? |
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Definition
1. dorsal funiculi-sensory only
2. lateral funiculi-mixed
3. ventral funiculi-mixed |
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Term
|
Definition
results from failure of vertebrae to fuse properly mid-dorsally. This allows sac of meninges and possibly nervous tissue to protrude thru the gap. most commonly in the lumbar region. CAUSES:locomotor difficulties,possible incoherence, possible paralysis. mild cases=surgery
serious=death |
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Term
| What can help lower the risk of spina bifida? |
|
Definition
| prenatal folic acid supplements |
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Term
|
Definition
|
|
Term
| What developmental anomalie is liked to the prenatal exposure to various aromatic hydrocarbons? |
|
Definition
| Anencephalia and microcephaly |
|
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Term
|
Definition
| "pin head"=incomplete brain formation. severe retardation, often permantly bed ridden |
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Term
|
Definition
| Water on the brain=excessive production or inadquate drainage of CSF. CAuses cranial expasion and brain atrophy.= moderate to severe retardation without TX. peritoneal shut to relieve pressure. |
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