Neroscience And Behavoir Flashcards
Neuron
Neurons are nerve cells and the basic building blocks of our entire nervous systems. The neurons act as sensors for all types of stimuli and communicate the stimuli throughout the body.
Example, neurons communicate to the brain that you should not leave your hand on a hot stove. In addition, the neurons are composed of 3 main components, the axon (the tail), the soma (the body), and the dendrites (the branch-like arms that stem from the soma).
Biological psychology
Biological psychology is a branch or type of psychology that brings together biology and psychology to understand behavior and thought. Biological psychology looks at the link between biology and psychological events such as how information travels thoughout our bodies (neural impulses, axons, dendrites, etc.), how different neurotransmitters effect sleep, dreams, and other behaviors, just to name a few.
Dendrite
Dendrites are the branch-like structures of neurons that extend from the cell body (Soma). The dendrites receive neural impulses (electrical and chemical signals) from the axons of other neurons. The signal always travels in the same direction - the signal comes into the neuron through the dendrites, through the cell body (soma), to the axon, and then out the terminal buttons to the dendrites of the next neuron. In this way information travels all around your body by going from neuron to neuron.
Axon
Axons are the long, spider-thin, tail-like structures found on neurons (nerve cells). Each neuron has a nerve body, dendrites, and axons, all of which are used to send information throughout your body. The axon carries signals (electric voltages) between the dendrites (the neuron’s input sites) and the terminal buttons (the neuron’s output sites that are at the very end of the axon).
The signal always travels in the same direction - the signal comes into the neuron through the dendrites, through the cell body (soma), to the axon, and then out the terminal buttons to the dendrites of the next neuron. In this way information travels all around your body by going from neuron to neuron.
Myelin sheath
Myelin is a fatty substance that covers neurons. Around your neurons is a myelin sheath (a layer of myelin) that helps increase the speed at which information can travel on the neurons. If you could look at a neuron you would see the sheath covering the axon of the neuron in a way that looks like a row of sausage links.
Action potential
once the stimulation (the heat) reaches a certain threshold (come to later) the neural membrane opens at one area and allows the positively charged ions to rush in and the negative ions to rush out. The charge inside the neuron then rises to approx. +40 mv. This only occurs for a brief moment, but it is enough to create a domino effect.
Threshold
The term “threshold” has a couple of different meanings, but let’s start with the simple one. A threshold is the minimum amount of stimulation needed to start a neural impulse (you know, the electrical impulses that travel throughout your body carrying important information). There is a very scientific explanation to this that includes the actual mV (millivolts) of the inside and outside of the neural membrane, how the sodium pottasium channel works, and lots more, but for this definition let’s just leave it as is.
Synapse
The synapse is the entire junction between neurons, including the pre-synaptic neuron’s axon terminal, the synaptic cleft, and the dendrite of the post-synaptic neuron, across which communications flow, usually in the form of neurotransmitter molecules secreted by the pre-synaptic neuron (on its axon terminal) that travel a short distance across the synaptic cleft (this is the actual space between the neurons - the space between the axon terminal of one neuron and the dendrite of the other) to the post-synaptic neuron.
Once at the post-synaptic neuron, some of the neurotransmitters will attach themselves (bind) to some receptors. It is important to know that the neurotransmitters and receptors work like a lock and key; that is, they both have certain shapes and only specific neurotransmitters can fit into certain receptors.
Neurotransmitters
Neural transmission (information being sent from neuron to neuron) works at both the electrical and chemical levels. When the space between two neurons is small enough the electrical signal can simply jump the gap and continue on its way. However, when the gap is too large, the signal must be converted from electricity to chemicals. These chemicals are neurotransmitters, which can be defined as chemicals released by neurons which carry information from one neuron to another. These chemicals are then read or received by a neuron’s synapses.
Acetylcholine
Acetylcholine (ACh) is the most common type of neurotransmitter, and the most well understood. It’s found in parts of the peripheral nervous system, spinal cord, and areas of the brain. In the peripheral nervous system, ACh activates muscles that help the body move. When Ach is released to the muscle cells, the muscle contracts. In the brain, ACh is involved in breathing, attention, arousal, motivation, etc. Obviously there are many problems that can occur if ACh is blocked (muscles can’t contract). One example is the black widow spider uses venom that causes a flood of ACh into muscle cells and results in violent, uncontrollable muscle contractions, paralysis, and death for it’s prey.
Dopamine
Dopamine is both a neurotransmitter and a neurohormone produced in multiple areas of the brain. As a hormone it is often associated with pleasant experiences. Receiving an unexpected reward may cause your heart to speed up and increase your alertness due to the sudden release of dopamine. As a neurotransmitter it transmits signals associated with concentration and motor skills. Conditions such Parkinson’s Disease and schizophrenia are associated with an interruption in the brain’s production of dopamine.
Serotonin
Serotonin is a neurotransmitter with functions in various systems of the body. In the central nervous system serotonin works to regulate mood, appetite, sleep, memory and learning. When present, the neurotransmitter acts as something of a connector between cells, and is associated with a feeling of happiness or decreased anxiety. Serotonin is a major part of many popular drug treatments for depression and anxiety. SSRI’s or Selective Serotonin Re-Uptake Inhibitors (like Prozac and Zoloft) help to maintain the serotonin connection between cells.
Norepinephrine
Norepinephrine, also known as noradrenaline, acts as a neurotransmitter and as a stress hormone, controlling the body’s “fight or flight” response. Secreted by the adrenal gland and by nerve endings in the sympathetic nervous system, norepinephrine regulates arousal in times of physical and mental stress and helps us stay alert in dangerous situations. It is also administered as a drug in medical emergencies to raise blood pressure and heart rate.
GABA
GABA receptor is a neuron (brain cell) shaped to receive the neurotransmitter gamma-aminobutyric acid (GABA). GABA functions as the major chemical messenger that slows and stops chemical reactions throughout the central nervous system. The receptor also reacts to other chemicals, including alcohol, that increase the inhibition of the neuron. When certain muscles are not inhibited and told when to stop moving, they can spasm painfully.
This is the most famous symptom of tetanus, which starts with the nickname of ‘lockjaw’ because the muscle in the face are spasming and the mouth cannot open properly.
Glutamate
Glutamate is an amino acid that acts as a neurotransmitter. Glutamate sends chemical messages in the brain by “exciting” neurons that are sensitive to it. Although it plays a vital role in learning, memory, and brain development, too much glutamate can be toxic. When a person experiences a head injury or stroke, glutamate floods the injured area and kills the neurons by overexciting them, causing brain damage.
