Psych Brain Test Pt 1

Cell Body

Largest part of a typical neuron; contains the nucleus and much of the cytoplasm. (Also known as Soma)

Dendrites

The bushy, branching extensions of a neuron that receives messages and conduct impulses toward the cell body. (Input)

Axon

The extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands.

Myelin sheath

A layer of fatty cells segmentally encasing the fibers of many neurons. (Makes possible vastly greater transmission speed of neural impulses.

Terminal branches of axons

Branched endings of an axon that transmit messages to other neurons by forming synapses with the dendrites and cell bodies of other neurons. (Output)

Resting potential

The difference in electric charge between the inside and outside of a neuron's cell membrane

Action Potential

A neural impulse; a brief electrical charge that travels down an axon. Generated by the movement of positively charged atoms in and out of the channels in the axon's membrane.

Threshold

The level of stimulation required to trigger a neural impulse.

Polarize

Depolarize

All-or-none response

A neuron's reaction of either firing (with a full-strength response) or not firing.

Synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The gap at this junction is called the synaptic gap or cleft.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether it will generate a neural impulse.

Excitatory signal

Increases likelihood that neuron will fire, or that an action potential will take place.

Inhibitory signal

Prevents an action potential.

Reuptake

When the sending neuron reabsorbs the excess neurotransmitters.

Sensory neurons

Neurons that carry incoming information from the sensory receptors to the brain and spinal cord (Central Nervous System)

Interneurons

Neurons that connect spinal motor and sensory neurons. (Exclusively found in the Central Nervous System)

Motor Neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Glial Cells

They are the "glue" of the nervous system, engaging in activities to support typical brain functions.

Brain/Blood Barrier (BBB)

A specialized system of brain microvascular cells that shields the brain from toxic substances in the blood, supplied brain tissue with nutrients, and filter's compounds from the brain back to the bloodstream.

How many neurons does a body have?

135 Billion

How many possible connections?

100 Trillion

Acetylcholine (ACh)

An excitatory neurotransmitter. Movement, Memory, Attention, Learning.

Dopamine

An excitatory neurotransmitter. Participates in motivation, reward, and pleasure.

Serotonin

Inhibitory, participates in mood, appetite, and sleep. (Mood elevator)

Norepinephrine

Excitatory neurotransmitter that helps control alertness and arousal.

GABA

Inhibitory neurotransmitter, lessens the ability of a nerve cell to receive, create or send chemical messages to other nerve cells. Known for producing a calming effect and is thought to play a major role in controlling anxiety, stress, and fear. (CNS)

Glutomate

Excitatory neurotransmitter, important to the CNS where it plays a major role in shaping learning and memory.

Endorphins

Inhibitory neural regulators; involved in pain relief, can alleviate pain, lower stress, improve mood, and enhance your sense of well-being.

Reflex

a simple, automatic response to a sensory stimulus, such as the knee-jerk response

Hormones

Secreted by glands into the blood stream.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons

The Nervous System

Transmits signals between the brain and the rest of the body.

The Peripheral Nervous System (PNS)

Sends info from different areas of the body back to the brain + carries out commands from the brain to the body.

The Somatic Nervous System (PNS - SNS)

Allows you to move and control muscles throughout your body.

The Autonomic Nervous System (PNS - ANS)

Regulates the body's vital functions, such as heartbeat, breathing, digestion, and blood pressure.

Sensory (PNS - SNS - S)

Receives and processes info that generated an individual's awareness of their environment

Motor (PNS - SNS - M)

Generates signals to direct the movement of the body

The Sympathetic Nervous System (PNS - ANS - SNS2)

Carries signals related to the "fight or flight" response.

The Parasympathetic Nervous System (PNS - ANS - PNS2)

Relaxes the body after periods of stress or danger.

The Central Nervous System (CNS)

Receives, processes, and responds to sensory information.

The Spinal Cord (CNS - SC)

Sends motor commands from the brain to the body + sends sensory info from the body to brain and coordinates reflexes.

The Brain (CNS - B)

Controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger and every process that regulated our body.