AP Pysch

Nervous System

The network of nerve cells and fibers that transmits signals between different parts of the body, allowing communication and coordination.

Central Nervous System (CNS)

The part of the nervous system consisting of the brain and spinal cord; it integrates sensory information and coordinates bodily functions.

Nerves

Bundles of fibers that transmit electrical signals between the brain, spinal cord, and the rest of the body.

Reflex

An automatic, rapid response to a stimulus that bypasses conscious thought, often to protect the body.

Autonomic Nervous System (ANS)

The part of the peripheral nervous system responsible for controlling involuntary bodily functions like heart rate, digestion, and respiration.

Sympathetic Nervous System

A division of the ANS that prepares the body for stress-related activities, often referred to as the "fight-or-flight" system.

Peripheral Nervous System (PNS)

All nerves outside the brain and spinal cord, connecting the CNS to limbs and organs.

Somatic Nervous System

A part of the PNS responsible for voluntary movements by controlling skeletal muscles.

Parasympathetic Nervous System

A division of the ANS that calms the body and conserves energy, often referred to as the "rest-and-digest" system.

Neurons

Specialized cells that transmit electrical signals in the nervous system.

Cell Body (Soma)

The part of the neuron that contains the nucleus and is responsible for maintaining the life of the cell.

Dendrites

Branchlike extensions of the neuron that receive signals from other neurons and transmit them to the cell body.

Axon

A long, thin projection that transmits electrical impulses away from the neuron's cell body toward other neurons or muscles.

Myelin

A fatty substance that covers and insulates the axon, speeding up the transmission of nerve impulses.

Synapse

The gap between two neurons where neurotransmitters are released to transmit signals to the next neuron.

Glial Cells

Supportive cells in the nervous system that provide nutrients, protect neurons, and maintain the extracellular environment.

Reflex Arc

The neural pathway that mediates a reflex action, usually involving sensory neurons, interneurons, and motor neurons.

Sensory Neurons (Afferent Neurons)

Neurons that carry incoming information from sensory receptors to the CNS.

Motor Neurons (Efferent Neurons)

Neurons that carry outgoing information from the CNS to muscles and glands.

Interneurons

Neurons that communicate internally within the CNS, connecting sensory and motor neurons.

Action Potential

A brief electrical charge that travels down the axon when a neuron sends a signal, resulting from the movement of ions in and out of the neuron.

All-or-Nothing Principle

The concept that a neuron either fires at full strength or doesn't fire at all.

Reuptake

The process by which neurotransmitters are reabsorbed by the sending neuron after the signal has been transmitted.

Multiple Sclerosis (MS)

A chronic illness where the immune system attacks the myelin sheath, leading to communication issues between the brain and body.

Neurotransmitters

Chemical messengers that cross the synapse to transmit signals from one neuron to another.

Excitatory Neurotransmitters

Neurotransmitters that increase the likelihood of the receiving neuron firing an action potential.

Dopamine

A neurotransmitter associated with reward, pleasure, and motor control; imbalances can be linked to conditions like Parkinson's and schizophrenia.

Hormones

Chemical messengers released by glands into the bloodstream that regulate bodily functions like growth, metabolism, and mood.

Leptin

A hormone that helps regulate body weight by signaling to the brain that the body has had enough to eat.

Melatonin

A hormone produced by the pineal gland that regulates sleep-wake cycles.

Refractory Period

The brief period after an action potential during which a neuron is unable to fire again.

Resting Potential

The state of a neuron when it is not firing a signal, characterized by a negative charge inside the cell.

Threshold

The level of stimulation required to trigger an action potential in a neuron.

Myasthenia Gravis

A chronic autoimmune disease that weakens muscles, caused by a breakdown in communication between nerves and muscles.

Inhibitory Neurotransmitters

Neurotransmitters that decrease the likelihood of the receiving neuron firing an action potential.

Serotonin

A neurotransmitter that regulates mood, appetite, and sleep; imbalances are linked to depression and anxiety.

Glutamate

The most common excitatory neurotransmitter in the CNS, playing a key role in learning and memory.

Acetylcholine

A neurotransmitter involved in muscle movement, attention, arousal, and memory

Endocrine System

A network of glands that release hormones into the bloodstream to regulate bodily functions

Adrenaline

A hormone and neurotransmitter involved in the body’s fight-or-flight response

Ghrelin

A hormone that stimulates hunger and increases food intake

Oxytocin

A hormone involved in social bonding, reproduction, and childbirth.

Norepinephrine

A neurotransmitter and hormone involved in arousal, alertness, and the body’s stress response

GABA (Gamma-Aminobutyric Acid)

The primary inhibitory neurotransmitter in the brain, helping to calm neural activity and reduce anxiety

Substance P

A neurotransmitter involved in the transmission of pain signals to the brain

Agonist

A substance that mimics or enhances the effect of a neurotransmitter.

Antagonist

A substance that blocks or inhibits the effects of a neurotransmitter

39. Endorphins

: Neurotransmitters that act as natural painkillers and are also linked to feelings of pleasure or euphoria.