Cells of the Nervous System and Brain Anatomy

Vocabulary practice flashcards covering cell types, glial cell functions, blood-brain barrier components, neural development stages, and central nervous system structures from lecture notes.

Golgi Stain

A special staining method developed by Camillo Golgi that allowed scientists to see individual neurons under a light microscope.

Neuron Doctrine

The concept proposed by Santiago Ramón y Cajal using the Golgi stain, stating that the nervous system is made up of separate individual cells called neurons, rather than one continuous network.

Postmitotic

A state of a cell, such as a neuron, in which it has stopped dividing and will not go through mitosis.

Integration Zone

The region of a neuron (specifically the axon hillock) that processes incoming inputs and decides whether to initiate an action potential.

Synaptic Cleft

The extracellular space located between the presynaptic axon terminal and the postsynaptic soma or dendrite.

Ganglion

A group or collection of neuron cell bodies located within the Peripheral Nervous System (PNS).

Nucleus (CNS)

A group or collection of neuron cell bodies located within the Central Nervous System (CNS) sharing common location, function, connections, or neurotransmitters.

Nerve

A bundle or group of axons located within the Peripheral Nervous System (PNS).

Tract

A bundle or group of axons located within the Central Nervous System (CNS).

Oligodendrocytes

Glial cells responsible for myelinating axons within the Central Nervous System (CNS).

Schwann Cells

Glial cells responsible for myelinating axons within the Peripheral Nervous System (PNS).

Multiple Sclerosis

An autoimmune disease that attacks oligodendrocytes, causing demyelination of axons in the Central Nervous System (CNS).

Microglia

Glial cells that search for and respond to injury and disease by engulfing and destroying debris.

Astrocytes

Glial cells that wrap around axon terminals, remove waste and excess ions or neurotransmitters, provide structural support, form dense scars upon injury, dilate blood vessels, and help form the Blood-Brain Barrier (BBB).

Circumventricular Organs

Brain regions containing an incomplete Blood-Brain Barrier (BBB) that allow the brain to sample the periphery and enact compensatory changes to homeostatic challenges.

Neurogenesis

The first stage of neural development, characterized by cell division to produce neural and glial precursor cells.

Cell Differentiation

The third stage of neural development in which cells express specific genes to become particular types of neurons or glia, heavily influenced by their physical location.

Apoptosis

The programmed cell death mechanism by which unnecessary neurons die during the pruning stage of neural development.

Brainstem

A structure continuous with the spinal cord where cranial nerves enter and exit, containing ascending sensory pathways, descending motor pathways, and reflex centers for head sensory inputs.

Medulla

A brainstem structure that controls vital reflexes and functions including respiration, blood pressure, and heart rate.

Locus Coeruleus

A nucleus located within the pons that serves as the major source of norepinephrine in the brain.

Substantia Nigra

A midbrain structure containing dopamine-producing neurons involved in movement, which degenerate in Parkinson's Disease.

Ventral Tegmental Area (VTA)

A midbrain dopamine source that projects to the cortex for cognition and to limbic regions for reinforcement.

Cerebellum

A brain structure containing about $70\text{ billion}$ neurons that regulates movement coordination (rate, range, force, direction), posture, balance, well-learned movements, and cognitive processes like language.

Thalamus

A forebrain structure containing distinct nuclei that acts as a sensory and neural pathway relay station sending information to the appropriate cortex.

Hypothalamus

A forebrain structure that controls the pituitary gland and regulates homeostatic functions such as circadian rhythms, sleep, hunger, satiety, thirst, thermoregulation, and reproductive behaviors.