Neuroscience Flashcards
Sensory Neurons
Receive information from external world and relays them to the brain via spinal cord
Motor Neurons
Carries signals from the spinal cord to the muscles to produce movement
Interneurons
Connects sensory, motor, and/or other interneurons
Does location matter for nerve cell specialization?
Yep
True or False: We use only 10% of our brains
False.
Why would we only use 10% of our brains? That’s a lot of space and a lot of blood wasted
Central Nervous System (CNS)
-Brain
-Spinal Cord
-Optic Nerve
-Retina
Peripheral Nervous System
Cranial Nerves
Neurons
The cell that receives and sends signals
-Depends on oxygen and glucose being constantly delivered to them
-Cell body, dendrite, axon
Glial Cells
Provide structural, nutritional, and other types of support to the brain
Dendrites
Tapered extensions of the cell body
Receive information from other neurons and pass them to the soma
Axon
Single cylindrical; may be many centimetres long; may be myelinated or unmyelinated
Conduct info to other neurons
Axon terminals
Transmit information to other neurons
Synaptic terminal
Spherical sac containing neurotransmitters
Neurotransmitter
Chemical messengers that move between neurons
Synapse
-Synaptic cleft is the actual gap
-An intracellular site where fast, highly localized transmission of chemical and electrical signals occur
Can any receptor pick up any signal?
NO
Receptors are specific to specific neurotransmitters
Unipolar Neuron
Single process extending from the cell body
-Common in invertebrates
Bipolar Neuron
Two processes extending from the cell body
-Often sensory neurons
Multipolar Neuron
Multiple processes extending front the cell body
-Most common in vertebrates
What is the charge and chemical gradient of a neuron
“The Salty Banana”
Lots of potassium (K) inside the neuron
(-) charge in neuron
Lots of sodium (Na) outside the neuron
(+) charge outside the neuron
Resting potential
~ -60-70 mV Difference in electrical charge across the neurological membrane
-When the neuron is not being stimulated or inhibited
Depolarization
-The reduction of a membrane’s resting potential so it becomes less negative
-Starts a chain reaction
-Leads to action potential
Refractory Period
When the neuron cannot fire = Absolute refractory period
Relative refractory period (action potential ma happen, but it needs to be a lot)
How do neutrons increase the intensity of a response
In order to increase intensity of response, neurons shoot more frequently
What do myelin sheaths do?
They make nerve impulses faster
Do neurotransmitters only trigger neurons?
No. Neurotransmitters can also tell neurons not to fire
Postsynaptic potential (PSP)
A voltage at a receptor site on a postsynaptic cell membrane
Excitatory PSP
A positive voltage shift that increases the likelihood that the postsynaptic neuron will fire action potentials
-Caused by excitatory neurotransmitters
Inhibitory PSP
-Makes membrane potential more negative
-Makes it harder to cause an action potential
Reuptake
Reabsorption of neurotransmitters from the synaptic cleft by the presynaptic membrane
Does a single neuron create a response?
ONE NEURON IS KINDA USELESS
You need millions to send signals
List four neuropeptides
-Endorphins
-Pituitary peptides
-Hypothalamic peptides
-Brain-gut peptides
-Opioid peptides
-Miscellaneous peptides
Acetylcholine (ACh)
First transmitter discovered
-Plays a large role in voluntary muscle movement
-Contributes to the regulation of attention, arousal, and memory
-Plays a role in sleep
-Often found in poisons (black widow spider venom have this)
-Causes massive release of ACh (leads to muscle pain, tremors, nausea)
-Botox causes paralysis by blocking ACh at synapses
-Alzhiemers is associated with low levels of ACh
-Nicotine behaves like ACh by binding to its receptors
Agonist
A chemical that mimics the action of a neurotransmitter
Antagonist
A chemical that fight the neurotransmitter