| Question | Answer |
|---|
| Neurons- | primary cells |
| Glial cells- | support cells for other neurons (like those that make up myelin) |
| What are the three types of neurons? | Sensory neurons, interneuron, motor neuron |
| Sensory neuron- | take environmental stimuli to CNS (sends signals to CNS) |
| Interneuron- | in CNS only and integrates signals from sensory neurons |
| Motor neuron- | sends signals from central nervous system to an effector |
| What are the two parts of the PNS? | Afferent and efferent division |
| Afferent division- | transmits sensory information to CNS (sensory functions) |
| Efferent division- | carries commands from the CNS to the body (motor functions) |
| What are the two parts of the efferent division? | Somatic and autonomic nervous system |
| Somatic nervous system- | controls skeletal muscles and voluntary movement |
| Autonomic nervous system- | controls internal processes like digestion and heart rate (involuntary processes) |
| What are the to parts of the autonomic nervous system? | Sympathetic and parasympathetic division |
| Sympathetic division- | fight or flight response prepare organs for stressful situations by speeding up heart rate,inhibiting action by digestive organs etc |
| Parasympathetic division- | rest and digest -promotes relaxation and digestion by slowing down heart rate etc |
| How is the brain structured? | In four different divisions those at the top being the most advanced while those at the bottom are more primitive |
| Medulla oblingata- | autonomic center for regulating heart lungs and digestive system and which connects spinal cord to brain (primitive) makes up brain stem |
| Pons- | relays sensory info to cerebellum and controls urination (primitive) makes up brain stem |
| Cerebellum- | coordinates complex motor patterns (primitive) |
| Cerebrum- | conscious though and memory (higher more advanced part of brain) |
| What are nerves made up of? | Millions o neurons |
| Dendrites- | collect electrical signals |
| Cell body- | integrates incoming signals and generates outgoing signal to axon |
| Axon- | passes electrical signals to dendrites of another cell or to an effector cell |
| What do Na+K+ATPase pumps create? | A resting membrane potential of -70 mV by having a ton of Na+ on outside of cell and K+ on inside of cell |
| When are voltage-gated Na+ channels closed? | At resting potential |
| When do the voltage-gated Na+ channels open? | When the membrane is depolarized |
| If Na+K+ATPase pumps were not there what would happen? | There would be no concentration gradient and therefore the neurons couldn’t generate action potentials |
| Where are Na+ and Cl- ions more concentrated? | Outside of cell |
| Where are K+ ions more concentrated? | Inside of cell |
| Ion channels- | K+ leak channel is always open creating K+ to diffuse to outside of cell causing the inside with a net negative charge and creating an electroconcentration gradient (other leakages Na+ and Cl-nhappen but not as much) |
| What do voltage-gated channels do? | Produce a neural signal by making rapid changes in membrane potential |
| Why do voltage gated channels open? | Open in response to changes in voltage when cell is stimulated by another cell |
| Where are the voltage-gated channels located? | In the nodes of Ranvier |
| What are myelin made of and what are they good for? | They are made of Schwann cells which are fat/protein and are good because they make transmittion faster there are no Na+KATPase pumps in them and they don’t leak ions |
| Multiple sclerosis- | autoimmune disease where antibodies in blood stream eat away at myelin sheath and this slows down neural transmission |
| What happens when the voltage-gated channels open? | Cations get repulsed and move to the next node of ranvier (they get repulsed in both directions) |
| Action potential- | stereotyped all or none change in membrane potential in response to stimuli |
| What are the four steps of an action potential? | Polarization, Depolarization phase, re-polarization phase, and undershoot |
| Polarization- | occurs at resting potential when there are more positively charged ions on the outside of cell rather than the inside. This is caused by the Na+K+ATPase pump |
| Depolarization- | occurs when Na+ channels open making Na+ flow into cell by diffusion and K+ channels open making K+ flow out of cell by diffusion |
| Re-polarization- | occurs as ions flow out of the axon (K+ flows out of cell) |
| Undershoot or hyper polarization- | occurs when K+ channels stay open longer |
| Why do voltage gated channels only open in one direction? | The other direction is refractory meaning once they have opened and closed they are less likely to open again for a short period of time and its not at resting potential yet |
| How do nerves stimulate other nerves, glands or muscles? | By releasing a neurotransmitter into a synapse |
| What does the action potential activate? | It opens the voltage gated Ca+2 channels which causes Ca+2 to rush in which stimulates exocytose of vesicles filled with neurotransmitters into synapse |
| What are the three parts of releasing neurotransmitter? | First the action potential arrives and triggers entry of Ca+2 then in response to this synaptic vesicles fuse with presynapstic membrane and release neurotransmitter then ion channels open when neurotransmitter binds and ion flows cause change in postsynaptic cell potential |
| Examples of neurotransmitters | nor epinephrine, dopamine, seratonin |
| What happens if there is too much seratonin in body? | Neurons get rid of receptors so when you get off a high you come way down since the receptors aren’t as sensitive |
| How does Prozac work? | Theres selective seratonin reuptake it acts like an inhibitor and keeps seratonin in the synapse longer |
| How does stimuli go through neuron? | From dendrite to axon only! |
| Electrochemical gradient- | when you have both an electrical and concentration gradient together |
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