Nervous System
Includes the brain and spinal cord. It serves as the control center of the body, processing incoming sensory information and sending out instructions for behavior and bodily functions.
The Central Nervous System (CNS)
The basic building blocks of the nervous system, responsible for transmitting information throughout the body. They use electrical impulses and chemical signals to communicate with muscles and glands.
Neurons
A neurotransmitter involved in muscle movement, learning, and memory. It plays a key role in the communication between motor neurons and muscles and is also important in the brain for attention and arousal.
Acetylcholine (ACh
Acts as the brain's relay station, directing sensory information (except smell) to the appropriate areas of the cerebral cortex for processing. It plays a crucial role in attention, alertness, and perception
Thalamus
This part of the peripheral nervous system that controls voluntary movements. It transmits sensory information from the body to the CNS and motor commands from the CNS to the skeletal muscles.
Somatic Nervous System
Consists of all the nerves outside the brain and spinal cord. It connects the CNS to the rest of the body, carrying sensory information to the CNS and motor commands from the CNS to muscles and organs.
Peripheral Nervous System (PNS)
Found in the brain and spinal cord and act as connectors between sensory and motor neurons. They play a key role in processing information and coordinating responses within the central nervous system.
Interneurons
Helps regulate alertness, arousal, and the body's stress response. It is involved in the "fight or flight" reaction and can also affect mood and attention. Also known as adrenaline.
Norepinephrine
Helps maintain the body's internal balance (homeostasis) by regulating functions like hunger, thirst, body temperature, and sleep. It also controls the pituitary gland, linking the nervous system to the endocrine system.
Hypothalamus
This is a neurotransmitter involved in reward, motivation, movement, and pleasure. It plays a key role in the brain's reward system and is also critical for motor control—imbalances are linked to conditions like Parkinson’s disease and schizophrenia.
Dopamine
Is a branch of the PNS that controls involuntary functions like heart rate, digestion, and breathing. It operates automatically to maintain homeostasis without conscious effort.
Autonomic Nervous System (ANS)
Carry information from sensory receptors (like those in the skin, eyes, or ears) toward the central nervous system. They allow the brain to interpret stimuli such as touch, light, sound, and temperature.
Sensory Neurons
Is the brain’s main excitatory neurotransmitter, meaning it increases the likelihood that the next neuron will fire. It is vital for learning, memory, and overall brain function but can be toxic in excessive amounts
Glutamate
Often called the "master gland," this releases hormones that influence growth, reproduction, and metabolism. It is controlled by the hypothalamus and regulates other endocrine glands in the body.
Pituitary Gland
This helps regulate mood, appetite, sleep, and emotional well-being. Low levels of this are commonly associated with depression and anxiety, and many antidepressants work by increasing these levels in the brain.
Serotonin
Part of the autonomic nervous system and is responsible for the body’s “fight or flight” response. It prepares the body for stressful situations by increasing heart rate, dilating pupils, and redirecting blood flow to muscles.
Sympathetic Nervous System
Transmit signals from the central nervous system to muscles and glands, enabling movement and bodily responses. They are essential for voluntary actions like walking as well as involuntary responses like reflexes.
Motor Neurons
Is the brain’s primary inhibitory neurotransmitter, which means it reduces neural activity. It helps calm the nervous system, aiding in relaxation and sleep, and imbalances in this are linked to anxiety disorders
GABA (Gamma-Aminobutyric Acid)
This is essential for forming new long-term memories and is involved in learning and spatial navigation. Damage to the hippocampus can result in difficulty forming new memories (anterograde amnesia).
Hippocampus
This involved in transmitting pain signals to the brain. It also plays a role in inflammation, mood regulation, and the body’s stress response.
Substance P
Is the counterpart to the sympathetic system, promoting the “rest and digest” response. It helps the body conserve energy by slowing the heart rate and stimulating digestion and other calming processes
Parasympathetic Nervous System
Support and protect neurons by providing nutrients, removing waste, and maintaining the environment around neurons. They also help form myelin, which speeds up the transmission of neural signals.
Glial Cells
Neurotransmitters that act as natural painkillers and mood elevators. They are released during activities like exercise, excitement, or injury and help reduce pain and boost feelings of pleasure or well-being.
Endorphins
This is involved in processing emotions, especially fear and aggression. It helps the brain recognize emotional stimuli and is important for emotional learning and memory.
Amygdala
These are located at the back of the brain and are primarily responsible for processing visual information. They interpret signals from the eyes, helping us recognize shapes, colors, and motion. Damage to this area can lead to visual impairments or difficulties in identifying objects.
Occipital Lobes