*Unit 2: Biological Bases of Behavior Flashcards
True or false? Humans and animals operate similarly when processing information.
True.
What is multiple sclerosis?
Multiple sclerosis, which is caused by a degeneration of myelin sheath, is an autoimmune disease in which people lose communication between nerve cells in the brain and spinal cord. People with MS suffer various neurological symptoms, such as losing control of their muscular movement (i.e. muscles spasms, muscles weakness, loss of balance, speech, etc.).
What is an action potential?
Action potential: a brief electrical charge that travels down an axon and is generated by the movement of positively charged atoms in and out of channels in the axon’s membrane. Sodium ions move inside, potassium ions move outside the axon’s membrane.
What is a resting potential?
Resting potential: Sodium ions outside, potassium ions inside
When the neuron is not stimulated, the fluid interior of the axon carries mostly negatively charged atoms (some potassium but mostly negatively charged proteins and nucleic acids) while the fluid outside has mostly positively charged atoms (sodium and some potassium ions) **neuron is in a polarized state.
What is polarization, depolarization, and hyperpolarization?
Polarization: When a neuron is in its’ resting state
(- charge on inside, + charge on outside).
Depolarization: Occurs when + (sodium) ions move inside the neuron, making it more prone to firing an action potential (if threshold is reached).
Hyperpolarization: Occurs when - ions enter the neuron, making it less prone to firing an action potential (bringing it back to its resting state).
What is a threshold?
The threshold level is the point at which there is no holding back. After the positively charged sodium ions move into the neuron (a.k.a. party animals/stimulus) exceeds the amount of negatively charged ions (a.k.a. party poopers) inside the membrane, the neuron reaches its’ minimum intensity required (called the threshold) to fire an action potential.
When this happens, more gated ion channels open and allow more positively charged sodium (party animals) to enter the neuron. This causes complete depolarization of the neuron, which causes the neuron to fire an action potential
In other words, when there are more party animals than party poopers, the neural impulse is triggered and the party is on.
What is the refractory period?
Refractory Period: After a neuron fires an action potential, it pauses for a short period to recharge itself to fire again (like a resting pause).
What are sodium-potassium pumps?
Sodium-Potassium Pumps: Channels in the axon membrane that pump positive sodium (Na+) and potassium (K+) ions in and out of the negatively charged neuron, making the neuron ready for another action potential (i.e. party on).
What are neurotransmitters?
Neurotransmitters are chemical messengers that are triggered by an action potential (which is released from the sending neuron), travel across the synapse, and bind to receptor sites on the receiving neuron. This process allows electrically charged atoms to enter the receiving neuron and excite (start) or inhibit (stop) a new action potential.
What is reuptake?
Reuptake is a process in which excess neurotransmitters in the synapse are reabsorbed into the sending neurons.
What are the different types of neurotransmitters?
Acetylcholine (ACh), Serotonin, Dopamine, Norepinephrine, GABA, Glutamate, and Endorphins
What is acetylcholine?
Acetylcholine (ACh): The neurotransmitter found at every junction between a motor neuron and skeletal muscle that enables muscle contraction, learning, and memory.
**Alzheimer’s Disease causes ACh-producing neurons to deteriorate.
What is serotonin?
Serotonin: the neurotransmitter involved with mood regulation, hunger, sleep, and arousal.
**Limited serotonin activity is linked to depression. Thus, antidepressants (like Prozac) raise serotonin levels.
What is dopamine?
Dopamine: the neurotransmitter involved with movement, learning, attention, and emotion. It is also our primary reward/pleasure chemical.
**Excess dopamine activity is linked to schizophrenia, as well as the impulsivity of people with Tourette’s Syndrome.
***Limited dopamine activity is linked to the tremors and decreased mobility of people with Parkinson’s disease.
What is norepinephrine?
Norepinephrine/noradrenaline is essentially adrenaline, our “fight or flight” chemical. It kicks in during stressful situations and helps to increase heart rate, breathing, arousal and alertness so we can “fight or flight” the stressor.
What is GABA?
GABA: (gamma-amminobutyric acid) major inhibitory neurotransmitter; undersupply linked to seizures, tremors, and insomnia.
What is glutamate?
Glutamate: major excitatory neurotransmitter; oversupply can over-stimulate the brain, producing migraines or seizures, which is why some people avoid MSG (mono-sodium glutamate) in foods.
What are endorphins?
Endorphins: natural opiate-like neurotransmitters released in response to pain and vigorous exercise (explains the “runner’s high” and indifference to pain in some injured people).
What are agonist and antagonist molecules?
An agonist molecule fills the receptor site and activates it, acting like the neurotransmitter. An antagonist molecule fills the lock so that the neurotransmitter cannot get in and activate the receptor site.
Morphine is an agonist, which mimics the actions of endorphins by stimulating receptors in brain areas involved in mood and pain sensations. Curare is an antagonist that paralyzes its victims by blocking ACh receptors involved in muscle movement.
What is the blood-brain barrier?
BIG IDEA: The blood-brain barrier (BBB) is the brain’s natural defense, which protects it from foreign substances, infection, and diseases. However, there are some diseases that can cross the BBB (such as Multiple Sclerosis, Epilepsy, and Meningitis). Also, the BBB may also keep out chemicals that may be helpful, such as dopamine for Parkinson’s patients.
What is the endocrine system?
The Endocrine System is the body’s “slow” chemical communication system. Communication is synthesized by a set of glands that secrete hormones into the bloodstream.
