Neuroscience & Behavior: Neurons, Signaling, Brain Structures, and Functions

Neurons

Building blocks of the nervous system that conduct electricity.

Soma

Cell body of a neuron that contains the nucleus and genetic material.

Dendrites

Receive incoming signals, mostly Na⁺ ions.

Axon

Sends electrical signals and may be myelinated.

Chromosomes

Humans have 46 chromosomes, 23 from each parent.

Genes

Produce proteins, including neurotransmitters and hormones.

Neurotransmitters

Send signals between neurons.

Hormones

Send signals through the bloodstream, produced mainly by the hypothalamus and pituitary gland.

Action Potential

Triggered at the axon hillock if combined signal reaches +10 mV.

All-or-None Law

Action potentials always reach +40 mV; speed varies, strength does not.

Neurotransmission

Involves release of neurotransmitters from vesicles in the presynaptic neuron.

Reuptake

Process after neurotransmitters bind to receptors and are released.

Psychopharmacology

Drugs affect behavior by mimicking neurotransmitter shapes.

Sensory Neurons

Bring information into the brain.

Motor Neurons

Send commands out to muscles.

Interneurons

Connect sensory and motor neurons in brain circuits.

Neuroplasticity

Interneuron connections change daily, allowing learning and adaptation.

Monosynaptic Reflexes

One synapse, spinal cord only, no brain influence.

Polysynaptic Reflexes

Two synapses, can be influenced by the brain.

Central Nervous System (CNS)

Consists of the brain and spinal cord.

Peripheral Nervous System (PNS)

Includes everything else outside the CNS.

Limbic System

Controls emotion and emotional expression; always active.

Cortex

Divided into four lobes: parietal, occipital, temporal, and frontal.

Hippocampus

Indexes and retrieves memories.

Broca's Area

Responsible for language production.

Wernicke's Area

Responsible for language comprehension.

Fusiform Face Area

Controls facial recognition; damage leads to prosopagnosia.

Corpus Callosum

Connects the two hemispheres of the brain.

Medulla

Heart rate & breathing

Cerebellum

Coordination & balance

Reticular formation

Alertness

Thalamus

Sensory relay & integration