Neuroscience: Brain Structures, Functions, and Nervous System Overview

Nuclei

Clusters of neuron cell bodies within the central nervous system (CNS).

Circuits

Networks of interconnected neurons that process specific kinds of information.

Networks

Large-scale systems of neural connections across different brain regions.

Central Nervous System (CNS)

The brain and spinal cord; integrates and processes information.

Peripheral Nervous System (PNS)

All nerves outside the CNS that connect it to the rest of the body.

Brain

The main control center of the CNS that coordinates thought, emotion, and behavior.

Spinal Cord

A bundle of nerve fibers that transmits information between the brain and body.

Retina

A light-sensitive layer in the back of the eye that converts light into neural signals.

Forebrain

The largest brain division; includes the cerebral cortex, thalamus, hypothalamus, hippocampus, and amygdala.

Midbrain

The middle portion of the brainstem involved in vision, hearing, and motor control.

Hindbrain

The lower portion of the brain including the cerebellum, pons, and medulla.

Somatic Nervous System

Controls voluntary muscle movements and sensory input.

Afferent Nervous System

Carries sensory information to the CNS.

Efferent Nervous System

Carries motor commands from the CNS to muscles and glands.

Autonomic Nervous System

Controls involuntary body functions (heart rate, digestion, etc.).

Sympathetic Nervous System

Prepares the body for "fight or flight" responses.

Parasympathetic Nervous System

Promotes "rest and digest" activities.

Sensory Neuron Entry

Sensory neurons enter the spinal cord through the dorsal (back) side.

Motor Neuron Exit

Motor neurons exit the spinal cord through the ventral (front) side.

Dorsal

Toward the back or top side.

Ventral

Toward the belly or underside.

Brain Protection Methods

(1) Skull, (2) Meninges, (3) Cerebrospinal fluid (CSF).

Meninges Protection

Three protective layers (dura mater, arachnoid mater, pia mater) that cushion and protect the CNS.

Cerebrospinal Fluid (CSF) Functions

Cushions the brain, maintains pressure, removes waste, and delivers nutrients.

Ventricles

Cavities in the brain that produce and circulate cerebrospinal fluid.

Ventricle Disease Sign

Enlarged or shrunken ventricles, indicating conditions like hydrocephalus or Alzheimer's.

Three Subdivisions of the Brain

Forebrain, Midbrain, Hindbrain.

Oldest Brain Subdivision Evolutionarily

Hindbrain.

Most Similar Brain Subdivision Across Species

Hindbrain.

Least Similar Brain Subdivision Across Species

Forebrain.

Lobe

A large region of the brain separated by fissures (e.g., frontal, parietal).

Cortex

The outer layer of the brain made of gray matter involved in higher thinking.

Subcortex

Structures beneath the cortex involved in emotion, memory, and basic drives.

Hindbrain Areas

Medulla, pons, cerebellum.

Forebrain Areas

Thalamus, hypothalamus, hippocampus, amygdala, cerebral cortex, corpus callosum.

Cerebellum Function

Coordinates movement, balance, and motor learning.

Cerebellum Demonstration

Shown by impaired balance or coordination when damaged (e.g., "drunk" walking).

Cerebellum Location

On the lower back of the brain beneath the occipital lobe.

Reticular Formation Function

Controls arousal, attention, and sleep-wake cycles.

Reticular Formation Location

Extends through the hindbrain and midbrain.

Medulla Function

Controls vital reflexes like breathing, heart rate, and blood pressure.

Medulla Location

Hindbrain.

Midbrain Function

Coordinates sensory information and motor movement, especially vision and hearing.

Superior Colliculus Function

Controls visual reflexes and eye movement.

Inferior Colliculus Function

Processes auditory information.

Substantia Nigra Function

Produces dopamine and helps control movement.

Midbrain Neurotransmitter

Dopamine.

Low Dopamine Effect

Parkinson's disease.

High Dopamine Effect

Schizophrenia.

Thalamus Function

Relays sensory information to the cortex.

Hypothalamus Function

Regulates hunger, thirst, temperature, and hormones.

Hippocampus Function

Forms and retrieves memories.

Amygdala Function

Processes fear, emotion, and aggression.

Corpus Callosum Function

Connects the two hemispheres and allows communication between them.

Lobe vs Cortex

A lobe is an anatomical region; the cortex is its functional outer surface.

Frontal Lobe Function

Decision making, planning, movement, speech production.

Parietal Lobe Function

Processes touch, spatial orientation, and body awareness.

Temporal Lobe Function

Hearing, language comprehension, and memory.

Occipital Lobe Function

Visual processing.

Cerebellum Location (Label)

Lower back of the brain under the occipital lobe.

Motor Cortex Location

In the rear of the frontal lobe; controls voluntary movement.

Somatosensory Cortex Location

In the front of the parietal lobe; processes touch and body sensations.

Auditory Cortex Location

In the temporal lobe; processes sound.

Broca's Area

Located in the left frontal lobe; responsible for speech production.

Wernicke's Area

Located in the left temporal lobe; responsible for language comprehension.

Coronal Plane

A vertical cut dividing the brain into front and back parts.

Sagittal Plane

A vertical cut dividing the brain into left and right halves.

Horizontal Plane

A cut dividing the brain into upper and lower parts.