Neurons, Glial Cells, and Nervous System Organization in Psychopharmacology

Neurons

Nerve cells, specialized for the receptions, conduction, and transmission of electrochemical signals.

Glial cells

Support, protection & insulation. Outnumber neurons 10:1.

Dendrites

Branches that serve as detectors of incoming signals.

Soma

Cell body (nucleus, 'manufacturing' hub, etc.). Responsible for metabolic care of neuron.

Axon

Path from soma to the terminal buttons. Its job is to transmit a signal down its length to the axon terminal.

Axon Terminal

The end of the axon, full of neurotransmitter chemicals waiting to be released.

Synapse

A tiny gap between one neuron and the next, so the next neuron can adjust its response to the message.

Pre-synaptic

The sender neuron in a synapse.

Post-synaptic

The receiver neuron in a synapse.

Myelin

Fatty insulation that wraps most axons, increasing conduction speed.

Schwann cells

Insulate peripheral nerves (PNS) - muscles, organs, glands.

Oligodendrocytes

Insulate central nerves - within brain & spinal cord (CNS).

Astrocytes

Large glia, star shaped, with many functions including scaffolding.

Microglia

Involved in response to injury or disease.

Dendritic trees with spines

Dendrites covered with small spines for more surface area.

Convergence

The process by which incoming signals are summed so neurons can decide to activate or not.

Chromosomes/genes

Contained within the soma, responsible for synthesizing needed proteins.

Neurotransmitter chemicals

Chemicals stored in the axon terminal, waiting to be released.

Information flow

The sequence: Dendrites → Axon → Axon terminal → Synapse.

Glial cells communication

cells can talk to each other and help keep neurons healthy.

Central Nervous System (CNS)

Consists of the brain (in skull) and spinal cord (in the spine).

Peripheral Nervous System (PNS)

Located outside of skull/spine and includes the somatic and autonomic nervous systems.

Somatic Nervous System

Controls voluntary muscles and brings sensation (sensory afferents) into CNS.

Afferent Nerves

Nerves that carry sensory information to the CNS.

Efferent Nerves

Nerves that send movement signals out of the CNS.

Autonomic Nervous System

Responsible for internal regulation, controlling body temperature, digestion, heart, and glands.

Sympathetic Division

Part of the autonomic nervous system that prepares the body for 'fight or flight' response, increasing heart rate, blood pressure, and respiration.

Parasympathetic Division

Part of the autonomic nervous system that calms the body and returns it to normal.

Acetylcholine

A neurotransmitter released by the parasympathetic division before and after ganglia.

Norepinephrine

A neurotransmitter released by the sympathetic division after ganglia.

Ganglia

Clusters of nerve cell bodies in the autonomic nervous system.

Psychoactive Drugs

Substances that act on acetylcholine or norepinephrine and can have autonomic side effects.

Blood Flow to the Brain

The brain requires a significant amount of blood to supply oxygen.

Cerebrospinal Fluid

Fluid that cushions the brain and spinal cord.

Sympathetic vs Parasympathetic

Sympathetic division exits from spinal cord; parasympathetic exits from brain.

Spinal Nerves

Nerves that carry signals to and from the spinal cord.

Cranial Nerves

Nerves that carry signals to and from the brain.

Cerebral spinal fluid

Cushions the brain and brings nutrients, hormones, and sugar/glucose; flows through a network of 'rivers' and 'lakes' called ventricles.

Hindbrain

The part of the brain that includes the medulla, cerebellum, and pons.

Medulla

Area Postrema- vomiting center, reduced blood brain barrier here, so can detect blood toxins; origin of the Reticular Formation (activating 'system'- arousal, sleep, attention, muscle tone, reflexes).

Cerebellum

Located on the dorsal surface; responsible for coordination of movement and cognition.

Pons

Located on the ventral surface; acts as a relay between the cerebellum and higher areas.

Thalamus

Sensory 'tollbooth' that routes senses to the correct lobes for processing.

Hypothalamus

Maintains body's internal states and motivations such as hunger, thirst, and body temperature; also controls the Pituitary Gland (hormones).

Autopilot/Reflective behaviors

Behaviors that are automatic and do not require conscious thought.

Pituitary gland

Gland that secretes hormones, including those related to stress, growth, reproduction, and sleep.

Cerebral Cortex

Processes incoming senses, thinks, and sends movements out.

Occipital lobe

Responsible for processing visual information.

Temporal lobe

Responsible for processing sounds and speech, specifically on the left side.

Parietal lobe

Includes the primary sensory area, known as the 'in' box.

Frontal lobe

Responsible for executive functions, forethought, logic, personality, and includes the primary motor area, known as the 'out' box.

Brain symmetry

The brain is mostly symmetrical, with a right and left side of each lobe.

Unlearned Behaviors

Behaviors that are not acquired through experience but are inherent.

Reticular Formation

A network of neurons in the brainstem involved in arousal and attention.