Neurons & Nervous System Study Guide

This set of flashcards covers key concepts related to the neurons and nervous system, neurotransmitters, brain functions, and genetics as per the lecture notes.

Neuron

Nerve cell that transmits information through electrical and chemical signals.

Neurotransmitters

Chemicals that transmit messages across synapses.

Synapse

Gap between neurons where neurotransmitters cross.

Action Potential

Electrical signal that travels down the axon; characterized by an all-or-nothing response.

Threshold

Level of stimulation needed for a neuron to fire.

Excitatory Signal

Signal that tells a neuron to fire (indicated as 'GO').

Inhibitory Signal

Signal that tells a neuron not to fire (indicated as 'STOP').

Reuptake

Reabsorption of neurotransmitters after they have sent their message.

Sensory Neurons

Nerve cells that carry signals from the body to the brain (e.g., feeling pain when touching a hot stove).

Motor Neurons

Nerve cells that carry signals from the brain to the body (e.g., moving a hand away from danger).

Interneurons

Nerve cells that process information within the brain and spinal cord.

Cell Body (Soma)

Part of a neuron that contains the nucleus and maintains cell life.

Dendrites

Extensions of a neuron that receive signals from other neurons.

Axon

Part of a neuron that sends electrical impulses away from the cell body.

Myelin Sheath

Fatty layer that covers the axon and speeds up electrical signals.

Axon Terminals

Ends of an axon that release neurotransmitters into the synapse.

Acetylcholine (ACh)

A neurotransmitter that facilitates muscle movement; its blockage can cause paralysis.

Endorphins

Neurotransmitters that provide pain relief and feelings of pleasure, released during exercise and mimicked by heroin.

Dopamine

A neurotransmitter involved in reward, mood, and movement; imbalances can lead to conditions like schizophrenia or Parkinson’s disease.

Serotonin

A neurotransmitter that regulates mood, sleep, and appetite; low levels are associated with depression.

Norepinephrine

A neurotransmitter that regulates alertness and arousal, particularly in 'fight-or-flight' responses.

Epinephrine (Adrenaline)

A hormone and neurotransmitter that energizes the body in emergency situations.

GABA

An inhibitory neurotransmitter that calms the nervous system; low levels are linked to anxiety.

Glutamate

An excitatory neurotransmitter involved in learning and memory; excessive amounts can lead to overstimulation.

Histamine

A neurotransmitter that regulates wakefulness and inflammation, related to allergies.

Somatic Nervous System

Part of the peripheral nervous system that controls voluntary movements of skeletal muscles.

Autonomic Nervous System

Part of the peripheral nervous system that regulates involuntary bodily functions such as heartbeat and digestion.

Sympathetic Nervous System

Part of the autonomic nervous system that activates the 'fight or flight' response.

Parasympathetic Nervous System

Part of the autonomic nervous system responsible for 'rest and digest' activities.

Central Nervous System (CNS)

Composed of the brain and spinal cord; processes information and coordinates bodily functions.

Reflex Arc

A neural pathway that bypasses the brain for quick responses; involves sensory neurons, interneurons, and motor neurons.

Pituitary Gland

The 'master gland' of the endocrine system, regulating other glands and growth.

Adrenal Glands

Glands that release epinephrine/adrenaline during stress and emergencies.

Hypothalamus

A brain area that controls hormonal activity and regulates hunger, thirst, temperature, and sex drive.

EEG (Electroencephalogram)

A test that measures the electrical activity of the brain.

PET Scan (Positron Emission Tomography)

Imaging technique that shows active areas of the brain using glucose.

CT/CAT Scan (Computed Tomography)

3D X-ray imaging technique used to visualize brain structure.

MRI (Magnetic Resonance Imaging)

Imaging technique that produces detailed images of soft tissue in the brain.

fMRI (Functional Magnetic Resonance Imaging)

Imaging technique that shows brain activity by detecting blood flow.

Brainstem

Area of the brain responsible for survival functions such as breathing and heartbeat.

Medulla

Part of the brainstem that controls breathing and heartbeat.

Pons

Part of the brainstem involved in movement coordination.

Reticular Formation

Network of neurons in the brainstem that regulates alertness and arousal.

Thalamus

Brain structure that acts as a relay station for sensory information (except smell).

Cerebellum

Brain region that coordinates movement, balance, and fine motor skills.

Amygdala

Structure in the limbic system involved in emotions such as fear and anger.

Hippocampus

Structure in the limbic system crucial for the formation of new memories.

Cerebral Cortex

Outer layer of the brain responsible for higher-level cognitive functions.

Frontal Lobe

Part of the brain involved in planning, judgment, personality, and motor control.

Parietal Lobe

Brain area responsible for touch perception and spatial reasoning.

Occipital Lobe

Brain region primarily responsible for vision.

Temporal Lobe

Part of the brain involved in hearing and facial recognition.

Motor Cortex

Brain area that sends signals for movement.

Sensory Cortex

Brain area that receives touch signals; sensitive areas have more brain space dedicated.

Association Areas

Regions of the cerebral cortex involved in higher thinking and decision making.

Left Hemisphere

Brain hemisphere associated with language, logic, and analytical tasks.

Right Hemisphere

Brain hemisphere associated with creativity, emotions, and intuition.

Corpus Callosum

Bundle of nerve fibers that connects the left and right hemispheres of the brain.

Gene

A segment of DNA that codes for a specific trait.

DNA (Deoxyribonucleic Acid)

Genetic material containing the instructions for life.

Chromosome

Thread-like structures of DNA; humans typically have 46 chromosomes (23 from each parent).

Genome

The complete set of genes present in an organism.

Gene Expression

Whether a gene is turned 'on' (expressed) or 'off' (inactive).