Chapter 3 Psychology

Human Nervous System

A system of complex cellular networks that relay and process information.

Neurons

Specialized cells that form the nervous system, which convey messages using electrical signaling.

Neural

Relating to nerve or nervous system

Plasticity

Ability of the nervous system to be constantly changing in response to the environment

Automaticity

Activities that the human brain does without assistance.

Neural Networks

Neurons that form large webs by connecting with one another to serve a larger purpose.

Neuroplasticity

Ability of neurons to shape and prime themselves to better serve functional needs: cutting off useless neurons, forming to better adapt to the environment.

Dendrites

Root-like structures in neuron cells. They receive messages from neighboring neurons through neurotransmitters which interact with their receptor terminals.

Excitatory Messages

“Positive” messages that push the action potential to be transferred beyond the axon hillock. Drivers of charge.

Inhibitory Messages

“Negative” messages that prevent the action potential from being transferred beyond the axon hillock. Prevent change.

Soma

The location within the cell where the dendrites and axon branch from. The location where all of the genetic material and where neurotransmitters are created.

Axon

A long narrow projection that branches from the soma and reaches the axon terminals. Sends messages with electrical signaling and is coated in myelin for efficacy. Only one exists.

Nerves

Bundles of axons that are traveling and sending messages in a general region.

Axon Hillock

The location where charge is either built up or inhibited to be sent across the axon.

Action Potential

The amount of charge required for a message to be sent across the axon. Moves down the length of the axon and through to the terminals.

Axon Terminals

The location where the terminal buttons are located. Within the terminal buttons are vesicles which encapsulate neurotransmitters.

Vesicles

Little bubbles that encapsulate the neurotransmitters.

Myelin

A substance made of protein and lipids that covers the axon to improve structure, stability, and the speed at which the electrical charge is sent down the axon. NOT ALL NEURONS HAVE MYELIN.

Myelinated Neurons

Also referred to as white matter, these can be found on the outer spinal cord and deep within the brain. The white color comes from the neurons being covered in myelin. These help increase the speed of messages and helps connects different regions of the CNS.

Unmyelinated Neurons

Also referred to as grey matter, these can be found in the outer brain (cerebral cortex), basal ganglia, cerebellum, brain stem, thalamus, and the inner spinal cord. These are helpful for motor control, coordinating sensory functions, and, basically more thorough actions.

Synapse

The gap that exists between the neurons and location where the neurotransmitters are released. Neurons are NOT connected.

Presynaptic Neuron

The neuron from which the message is sent and neurotransmitters are released.

Postsynaptic Neuron

The neuron that accepts the neurotransmitters and the message.

Reuptake

The neuron’s ability to be efficient by absorbing any unused neurotransmitters using vesicles that return to the terminal buttons instead of wasting them.

Resting Potential

The stage where no message is being sent through to the axon. The neuron has a negative charge inside the axon but a positive charge on the outside.

Sensory Neurons

These are neurons that take in messages from the environment to the brain and spinal cord.

Motor Neurons

These are neurons that take messages from the brain back to the peripheral nervous system for action and movement.

Interneurons

These neurons are the connecting pieces of other neurons; think of them as extension cables that help connect sensory and motor neurons.

Glutamate

Excitatory; involved in memory and learning

GABA

inhibitory, involved in anxiety regulation

Acetylcholine

excitatory, involved in muscle movement, learning, and memory

Dopamine

Excitatory and inhibitory, involved in reward pathways

Serotonin

excitatory and inhibitory, involved in regulating mood, hunger, sleep, and arousal

Nerepinephrine

Excitatory and inhibitory, involved in regulating attention and arousal.

Endorphins

Excitatory and inhibitory regulation of pain responses.

Central Nervous System

Consists of the brain and spinal cord.

Peripheral Nervous System

Consists of the nerves that are in the extremities of the body and help sense what is happening in the environment. It is split into somatic and autonomic divisions.

Somatic Nervous System

Contains the nerves and neurons that control the muscles for voluntary movement and bring sensory information from the body to the brain. Extremity nerves.

Automatic Nervous System

Nerves that are present for the function of functions that we do not have so much control over: blinking, breathing, heartbeat, etc. Helps in the activation of the sympathetic and parasympathetic nervous systems.

Parasympathetic Nervous System

Designed to return body to homeostasis after arousal, reverse system for sympathetic nervous system.

Sympathetic Nervous System

The division of the nervous system that is responsible for bodily arousal that occurs in response to danger or excitement.

Brainstem

The oldest part of the brain, and its main purpose is to keep us alive. Located at the very bottom of the brain and is connected to the spinal cord. The medulla and pons are housed in this structure. The medulla and pons connect the peripheral and central nervous systems to regulate what we do and pay attention to.

Medulla

The region of the brain directly responsible for vital life functions like breathing, heartbeat, and swallowing. Thus, if the damage is high up the spinal cord, it can be fatal. Drinking impairs this region.

Pons

The region of the brain that regulates awareness/alertness, sleep, and motor functions. Lowest portion of the brain and is the transition point of the brain to the spinal cord. Helps regulate excitement/energy levels, arousal, coordinated senses with the cerebellum to aid balance and motor control, and serves as bridge for information pathways that run from the upper brain to the lower brain. Controls facial expressions, movement of eyes, and where the vestibulocochlear nerve enters the brain.

Vestibulocochlear Nerve

Nerve from the inner ear that helps the brain sense left-right orientation.

Reticular Activating System

A network of neurons that runs through the center of the medulla and the pons, connects spinal cord and thalamus, maintains arousal and attention.

Limbic System

A network of neurons and glia that regulate emotions, endocrine activity, and forming emotional memories. Major structures include the amygdala, hippocampus, thalamus, and hypothalamus, helps feel and react, coordinated higher thinking brain and the lower primitive brainstem.

Amygdala

A network of neurons and glia that become more active when we learn to be fearful and activate our fear and anger responses. One of the most interconnected brain regions, receives input from all senses and uses this information to make calculations about emotional value and intensity of a stimulus. Removal results in no fear and hyperactivity relates to anxiety.

Hypothalamus

Area of the brain that regulates instinctual behavior important to survival, like fight/flight, feeding, and fornication, controls several functions in the autonomic and endocrine systems, helps regulate temperature.

Thalamus

Connects higher and lower regions of the brain, relates sensory information related to threat, everything but scent.

Hippocampus

Part of the brain responsible for memory formation and reconsolidation, recalls memory formation in response to threat, location where memories move from short term to long term, without this portion of the brain, people would forget an experience after a few minutes or even a few seconds. Increases norepinephrine and noradrenaline during fight or flight.

Basal Ganglia

Interconnected groups of neurons near the base of the brain that help us learn movements and coordinate movement patterns. Extremely important in helping us make complex movements more automatic.

Cerebellum

Two lobe shaped part of the brain right behind the brainstem that helps coordinate movements and problem-solving. Receives and organizes input from multiple central nervous systems networks. Helps manage balance by processing information from the inner ear to help adjust posture and balance. Fine tunes sensory input in order to fine-tune movement patterns. Manages connection with the pons and the thalamus to adjust the timing and planning of movements.

Thalamus

Connects regions that are fine tuned for higher levels of thinking and the lower more automated regions of the brainstem. All routes pass through it.