| 1. central nervous system (CNS)
2. peripheral nervous system (PNS) | two divisions of the nervous system |
| brain & spinal cord | components of the CNS |
| control system of the brain | CNS is known as the ... |
| all nerves that extend to/from CNS | components of the PNS |
| 1. PNS takes in information through sensory neurons & sends to CNS to be processed
2. after processing, CNS tells PNS what to do
3. PNS makes happen through muscle control | how does the general flow of information in the NS work? (3 steps) |
| 1. higher brain aka cortical level
2. lower brain aka subcortical level | two main parts of the brain |
| cerebral cortex= large and highly developed
-essential for cognitive skills (memory, attention, sequencing)
-LARGE memory store house
-w/o this the functioning of the lower brain centers would be imprecise | higher brain/cortical level |
| -contains: medulla, pons, cerebellum, hypothalamus, thalamus, and basal ganglia
-function= subconscious activities: blood pressure, breathing, feeding reflexes and emotional patterns | lower brain/subcortical levels |
| -long, thin, tubular bundle of nervous tissue
-conducts info from periphery to brain and back or vice versa
-neural circuits in cord can cause
--walking movements
--reflected to withdraw from pain
--reflexes to stiffen legs in response to gravity
--reflexes to control blood vessels
--GI movements | basics of spinal cord |
| from brain stem to lumbar region of vertebral column | how far does spinal cord extend? |
| 1. dendrites= collect electrical signals
2. cell body= integrates incoming signals & generates outgoing signal to axon
3. axon= passes electrical signals to dendrites of another cell/effector cell | basic components of functional unit (nerve) |
| -kinds= visual, tactile, auditory, olfactory, taste buds
-most activities of n.s. initiated by sensory experiences that excite sensory receptors
-conduct info to CNS multisensory areas | function of sensory receptors |
| -processing of information
-process incoming information and ensure appropriate mental/motor response occurs
-->99% of sensory info discarded as irrelevant/unimportant | whats the integrative function of the nerve? |
| -carry responses from CNS-> PNS
-ex. muscles, glands
-motor functions of NS
--contract sk m
--contract smooth m
--secrete substances by exocrine/endocrine glands | what are the basics and role of effectors? |
| -formed, processed and stored in cerebral cortex by synapses
-synapses become capable of transmitting same type of signals
-once memories stored-> become part of brain processing mechanism for future "thinking" | how does memory form? |
| 1. electrical
2. chemical | two types of synapses |
| 1. directly link cytoplasm of adjacent cell (gap junctions)
2. provide low-resistance path for ion movement
3. bi-directional transmission (post-> pre or pre-> post synaptic cells) | what are the basics of electrical synapses? |
| visceral smooth & cardiac m | what kinds of tissue are electrical synapse VERY important in (2)? |
| -chemical substance= neurotransmitter
- binds to next neuron to excite, inhibit, modify sensitivity
- ONE-way transmission (pre-> postsynaptic cell) | what are the basics of chemical synapses? |
| ELECTRICAL | which synapse is bidirectional: electrical or chemical? |
| CHEMICAL | which synapse in one-way: electrical or chemical? |
| TRUE | T/F: chemical synapse in CNS similar to neuromuscular junction. |
| TRUE | T/F: chemical synapses make up ALL synapses in the CNS. |
| -acetylcholine
-norepinephrine
-epinephrine
-histamine
-serotonin
-GABA
-glycine | what are some of the best known neurotransmitters? |
| 1. small-molecule
2. neuropeptides | two types of neurotransmitters |
| 1. fasting acting
2. acute effects
3. increase or decrease conductance through ion channels | characteristics of small molecule neurotransmitters |
| 1. large
2. slow acting
3. prolonged/long term actions-> long term opening of ion channels | characteristics of neuropeptide neurotransmitters |
| 1. acetylcholine
2. norepinephrine
3. glycine
4. GABA
5. Nitric Oxide | important small-molecule neurotransmitters |
| -small molecule NT
-most excitatory
-secreted by: motor cortex, basal ganglia, skeletal muscle, preganglionic ANS, postganglionic PNS | acetylcholine |
| -small-molecule NT
-control overall activity & mood of brain (ex. increased level of wakefulness)
-mostly activates excitatory receptors
-secreted by: many neurons in brain stem & hypothalamus | norepinephrine |
| -small-molecule NT
-inhibitory
-secreted @ spinal cord | glycine |
| -inhibitory
-secreted by: spinal column, cerebellum, basal ganglia, cortex | GABA |
| -small-molecule NT
-synthesized instantly & diffused out of presynaptic terminal rapidly
-NOT stored in vesicles
- change in intracellular metabolic function, not membrane potential
-VERY diff from the others
-secreted by: areas responsible for long term behavior and memory | nitric oxide |
| 1. made by ribosomes in neural cells
2. enter ER and Golgi
3. NP-forming protein split into either NP itself or precursor
4. Golgi packages NP into small vesicles
5. vesicles transported to tips of nerve fiber
6. release of transmitter @ neuronal terminals in response to AP | synthesis of neuropeptide (NP) transmitters (6 steps) |
| 1. smaller quantities than small-molecule NT released
2. more potent
3. prolonged actions | characteristics of neuropeptides |
| 1. closure of Ca2+ channels
2. charges in metabolic machinery of cells
3. activation/deactivation of genes
4. alterations in # of excitatory/inhibitory receptors | what are some of the prolonged actions of neuropeptide NT? (4) |
| 1. AP arrives at axon terminal
2. voltage-gated Ca2+ channels open
3. Ca2+ enters cell
4. Ca2+ signals to vesicles
5. vesicles move to membrane
6. docked vesicles release NT by exocytosis
7. NT diffuses across synaptic cleft & binds to receptors | what are the mechanisms/process by AP that causes NT to release Ca2+ ions? (7 steps) |
| TRUE | T/F: quantity of NT that is released is directly related to # of Ca2+ ions that enter the cell. |
| receptor protein | what does a NT bind to on the post-synaptic cell? |
| 1. binding component
2. intracellular component | important components of a receptor protein (2): |
| specific | NT binds to specific/random proteins at postsynaptic terminal. |
| 1. ionotropic= ligand-gated ion channels
2. metabotropic= g-protein coupled proteins | two types of receptor proteins on post-synaptic cell: |
| 1. cation channels
2. anion channels | what are the two types of ionotropic receptor proteins? |
| -ionotropic
-allow + charged ions
-allow Na+ to pass, sometimes K+ and Ca2+
-increased positive charge EXCITES neuron
-NT that opens this called an excitatory transmitter | describe cation channels |
| -ionotropic
-allows - charged ions
-increase negative charge inhibits neuron
-NT that opens this called an inhibition transmitter | describe anion channels |
| TRUE | T/F: ionotropic protein channels open within fraction of a millisecond. |
| g-protein coupled receptor | what is the most common type of metabotropic protein receptor? |
| -prolonged postsynaptic neuronal excitation/inhibition | characteristics of g-protein coupled receptor |
| 1. upon activation the alpha subunit separates & four changes occur
--opening ion channels through postsynaptic membrane
--activation of cyclic AMP/GMP
--activation of intracellular enzymes
--activation of gene transcription | how does a g-protein coupled protein work? |
| 1. open Na+ channels-> increased # of positive molecules enter the cell
2. depression conduction through Cl-/K+/or both
3. change in internal metabolism
--makes postsynaptic cell inside more + so excitatory | what do excitatory receptors do? |
| 1. open Cl- channels
2. increase in K+ out of cell
3. activation receptor enzymes that increase inhibitory receptors or decrease excitatory receptors
--makes postsynaptic cell inside more - so inhibitory | what do inhibitory receptors do? |
| 1. reputake into presynaptic cell
2. broken down by enzymes
3. diffuse away from synapse | termination of NT (3 ways) |
| 1. K+
2. Na+
3. Cl- | what are the MVPs of changing RMP? |
| 1. excitatory NT increases membrane permeability to Na+
2. rapid influx of Na+ increases positivity of cell/membrane
--positive increase called EPSP | describe excitatory postsynaptic potential (EPSP) |
| 1. increase in Cl-, decrease in K+ makes membrane more negative (hyperpolarization)
2. increase in negativity called IPSP | describe inhibitory postsynaptic potential (IPSP) |
