Brain Facts: Key Concepts from Chapters 1-18

Largest part of the human brain.

Cerebrum

Part of the brain that controls balance and coordination.

Cerebellum

Controls basic life functions like breathing, heart rate, and digestion.

Brainstem

Responsible for higher-level thinking, sensory perception, and voluntary movements.

Cerebral Cortex

Controls decision-making, problem-solving, and voluntary movement.

Frontal Lobe

Processes sensory information like touch and pain.

Parietal Lobe

Responsible for visual processing.

Occipital Lobe

Involved in hearing, memory, and language.

Temporal Lobe

Regulates body temperature, hunger, and hormones.

Hypothalamus

Relays sensory signals to the cerebral cortex.

Thalamus

Contains neuron cell bodies for processing information.

Gray Matter

Made of axons that connect different brain regions.

White Matter

Structure that connects the two hemispheres of the brain.

Corpus Callosum

Disorder caused by the loss of dopamine-producing neurons in the brain.

Parkinson's Disease

Regulating temperature, hydration, and energy balance.

Homeostasis

Basic building block of the nervous system.

Neuron

Receive signals from other neurons.

Dendrites

Sends electrical impulses away from the cell body.

Axon

Speeds up signal transmission along the axon.

Myelin Sheath

Support cells that provide nutrients, insulation, and protection.

Glial Cells

Provide structural support and maintain the blood-brain barrier.

Astrocytes

Immune cells that remove dead neurons and fight infections.

Microglia

Produce myelin in the peripheral nervous system.

Schwann Cells

Junction where neurons communicate.

Synapse

Around -70 mV.

Resting Membrane Potential

Triggered when the neuron's membrane potential reaches the threshold (-55 mV).

Action Potential

Outer surface of the dendrite that looks thick or dense in highly magnified images

Postsynaptic Density

Neurotransmitter binds directly to part of an ion channel

Ionotropic receptor

Tay Sach’s disease is caused by mutations in genes that codes for part of a

fat-metabolizing enzyme called beta-hexosaminidase A

Occurs when potassium ions exit the neuron, restoring negative charge inside.

Repolarization

Chemical messenger that transmits signals between neurons.

Neurotransmitter

Primary excitatory neurotransmitter in the brain.

Glutamate

Glutamate binds to several Ionotropic receptors, the most important of these are _____ and ______ receptors

AMPA, NMDA

_____ receptors are fast and brief, _____ receptors activate more slowly

AMPA, NMDA

Interactions between AMPA and NMDA receptors seem to be important in

learning and memory

Primary inhibitory neurotransmitter in the brain.

GABA

_____ can bind to ionotropic and metabotropic receptors

GABA

Ionotropic GABA receptors have ion channels that

let Cl- into the cell

Metabotropic GABA receptors open ion channels that

release K+ ions from the cell

Involved in reward, mood, and motor control.

Dopamine

Regulates mood, appetite, and sleep.

Serotonin

Important for muscle contraction and memory.

Acetylcholine

Disorder linked to low serotonin levels.

Depression

Proteins that recycle neurotransmitters back into the presynaptic neuron.

Reuptake Transporters

Largest part of the brain, responsible for voluntary actions, divided into two hemispheres.

Cerebrum

Bundle of nerve fibers connecting the two cerebral hemispheres.

Corpus Callosum

Involved in decision-making, problem-solving, and voluntary movements.

Frontal Lobe

Processes sensory information such as touch and spatial orientation.

Parietal Lobe

Associated with memory, language, and hearing.

Temporal Lobe

Essential for forming new memories.

Hippocampus

Regulates emotions such as fear and pleasure.

Amygdala

Group of structures controlling voluntary motor movements and procedural learning.

Basal Ganglia

Controls autonomic functions like heart rate and breathing.

Medulla

Coordinates voluntary movements and balance.

Cerebellum

Relays sensory and motor signals to the cerebral cortex.

Thalamus

Distinct bundle of nerve fibers of region-spanning neurons

Nerve tract

Nerve tract that transmits signals between the left and right temporal lobes

Anterior Commissure

A group of nerve tracts connecting a series of regions in the brain

Neural Network

Approximately how much of the brain’s neurons are excitatory

80%

Most common type of excitatory neuron

Pyramidal cell

Seizure disorders like epilepsy could be caused by imbalances in the activity of

excitatory and inhibitory neurons

Chemicals like dopamine, serotonin, and glutamate that transmit signals between neurons.

Neurotransmitters

Electrical signal traveling down a neuron.

Action Potential

Junction between two neurons where neurotransmitters are released.

Synapse

The visual system involves about _____ of humans’ cerebral cortex, more than any other sense

30%

Knowledge of how light energy is converted into electrical signals comes primarily from studies on

Drosophila fruit flies and mice

Higher level visual processing has mostly been studied in

monkeys and cats

Light-sensitive cells in the retina (rods and cones).

Photoreceptors

Detect dim light, responsible for night vision.

Rods

Detect color and fine detail.

Cones

Central area of the retina with the highest concentration of cones.

Fovea

The fovea contains only

Red and Green cones

Approximately ____ of photoreceptors are rods

95%

Crossover point for optic nerve fibers.

Optic Chiasm

Thalamic relay for visual information.

Lateral Geniculate Nucleus (LGN)

Structure in the forebrain that processes smell.

Olfactory Bulb

Spiral-shaped organ that converts sound vibrations into electrical signals.

Cochlea

Sensory organs on the tongue that detect taste.

Taste Buds

Processes touch, pain, and temperature information.

Somatosensory Cortex

Conversion of sensory stimuli into electrical signals.

Transduction

Light-sensitive layer of tissue at the back of the eye.

Retina

Area where the optic nerve exits the eye, lacking photoreceptors.

Blind Spot

Region of the brain responsible for processing sound.

Auditory Cortex

Membrane above stereocilia

Tectorial Membrane

Sense of body position and movement.

Proprioception

Controls voluntary muscle movements.

Motor Cortex

Regulates initiation of voluntary movements.

Basal Ganglia

Coordinates muscle movements and balance.

Cerebellum

Neurons that directly control muscle contractions.

Alpha Motor Neurons

Automatic response to stimuli without brain involvement.

Reflex Arc

Disorder caused by degeneration of dopamine-producing neurons.

Parkinson's Disease

Sensory receptor that detects muscle stretch.

Muscle Spindle

Located in the frontal lobe, controls voluntary movement.

Primary Motor Cortex

Transmits signals between the brain and the body.

Spinal Cord

Neurotransmitter that triggers muscle contractions.

Acetylcholine

Bend joints to bring bones closer together.

Flexor Muscles

Straighten joints, increasing the angle between bones.

Extensor Muscles

An alpha motor neuron and all the muscle fibers it controls.

Motor Unit

Simultaneous activation of agonist and antagonist muscles.

Co-Contraction

Disease where motor neurons degenerate, causing muscle weakness.

ALS (Amyotrophic Lateral Sclerosis)