Brain Bee (All Brain Facts Chapters)

cerebrum

Largest part of the brain composed of two hemispheres.

86 billion

Number of neurons in the brain.

corpus callosum

Largest bundle of nerves connecting the two hemispheres of the cerebrum

cerebral cortex

Deeply folded surface tissue of the cerebrum, divided into lobes.

frontal lobes

Lobes responsible for voluntary movement, speech, memory, emotion, and higher cognition, as well as aspects of personality.

parietal lobes

Lobes that process sensory input from skin, taste, and some visual information.

top/middle of brain

location of the parietal lobes

front of brain

location of the frontal lobes

occipital lobes

Lobes that process vision, colors, shapes, and integrate them into a complex visual understanding.

back of brain

location of the occipital lobes.

temporal lobes

Lobes responsible for some visual processing and auditory information.

sides of brain

location of the temporal lobes.

hippocampus

Structure beneath the cerebral cortex, yet within the temporal lobes, that encodes new memories.

amygdala

Structure beneath the cerebral cortex, yet within the temporal lobes, that integrates memories and emotions.

thalamus

Region that integrates sensory input and relays it to the rest of the brain.

hypothalamus

Region that controls the pituitary gland.

pituitary gland

Hormone gland that sends signals to the rest of the body.

hippocampus, amygdala, thalamus, hypothalamus, and pituitary gland.

Components of the limbic system:

cerebrum, limbic system.

Components of the forebrain:

midbrain

Region that sits below the thalamus, controls unconscious eye movement, reflexes to sound, unwanted body movement, coordinates sensory input, and allows for fine motor control.

basal ganglia

Structures found in the midbrain and forebrain that help regulate complex body movements.

hindbrain

Region of the brain with roles in glucose regulation, sleep, some movement control.

cerebellum, pons, and medulla

Components of the hindbrain:

cerebellum

Second-largest part of the brain behind the occipital lobes. Split into two hemispheres and coordinates voluntary movement, learning of new motor skills, as well as spacial and temporal perception.

cerebellum

Over half of the brain's neurons are found here.

pons

Region that influences breathing and posture found below the cerebellum.

medulla

Region that coordinates automatic neural networks for swallowing, heart rate, and breathing.

midbrain, medulla, and pons

Components of the brain stem:

lancelet/amphioxus

Simple chordate with very rudimentary "brain."

Three distinct bulges

The forebrain, midbrain, and hindbrain developed from what structures found in basic vertebrate brains?

nerve tracts

Term for nerves spanning between regions that form distinct bundles.

neural network

Term for groups of nerve tracts that connect a series of brain regions.

thalamocortical loop

A looping neural network responsible for creating brain waves.

electroencephalogram

A device used to record electrical activity in the brain.

alpha waves

Waves originating from parietal and occipital lobes during relaxation.

8 - 13 Hz

Frequency of alpha waves.

beta waves

Waves originating from the frontal and parietal lobes during sensory processing or concentration.

14 - 30 Hz

Frequency of beta waves.

theta waves

Waves that occur during light/early stages of sleep.

delta waves

Waves that occur during deep sleep.

4 - 7 Hz

Frequency of theta waves.

Below 3.5 Hz

Frequency of delta waves.

20 - 200 microvolt

Amplitude of alpha and delta waves.

5 - 10 microvolt

Amplitude of beta and theta waves.

spinal tracts

Structures that pass signals through the brainstem and spinal cord.

neural circuits

Term for interconnected neurons that turn entering signals into output patterns.

columns

Shape of neural circuits in the cerebral cortex.

80%

Percentage of excitatory nerves in the brain.

20%

Percentage of inhibitory nerves in the brain.

feed-forward circuits

Circuits that excite one column and inhibit neighboring columns.

feedback inhibition circuits

Circuits that inhibit their own downstream neurons.

soma

Another name for the cell body of a neuron.

dendrites

Branched receiving threads of a neuron.

axon

Long signalling branch of a neuron.

glia

General term for support cells in the brain.

astrocytes

Cells that manage ion concentrations, provide nutrients, and regulate the formation of connections between neurons in the brain.

microglia

Cells that act as the brain's immune system.

ependymal

Cells that create cerebrospinal fluid to cushion the brain.

oligodendrocytes

Cells that wrap axons in fatty myelin sheaths.

myelin sheaths

Fatty coverings on the axons of cells.

- 70 milivolts

Typical membrane potential of a neuron.

membrane potential

The difference in voltage between the inside and outside of a neuron.

negative

The charge of a neuron is generally:

depolarize

Excitatory neurons send signals that _____ other neurons.

hyperpolarize

Inhibitory neurons send signals that _____ other neurons.

calcium

Ion that enters cell when action potential reaches the axon terminal.

non-peptide neurotransmitters

Neurotransmitters that can be created at the axon terminal.

peptide neurotransmitters

Neurotransmitters that must be created at the soma and shipped to the terminal.

kinesins

Proteins that transport peptides along the axon.

postsynaptic density

Region of the dendrite on the receiving side of the synaptic cleft.

ionotropic

Receptors that change shape to open attached ion channels.

metabotropic

Receptors that trigger a cascade of reactions that open ion channels or have other effects.

reuptake

Retrieval of neurotransmitters from the synaptic cleft is called:

glutamate

Common excitatory neurotransmitter.

gamma-aminobutyric acid (GABA)

Common inhibitory neurotransmitter.

neuromodulators

Compounds that suppress release of neurotransmitters by a neuron.

endocannibinoids

Common class of neuromodulators.

chromatin

Protein that determines how tightly packed DNA is in a cell.

Tay-Sachs disease

A human genetic disease caused by a recessive allele that leads to the accumulation of certain lipids in the brain. Seizures, blindness, and degeneration of motor and mental performance usually become manifest a few months after birth.

beta-hexosaminidase A

Protein that fails to break down fats and leads to a certain disorder.

30%

What percentage of the cerebral cortex does vision processing use?

retina

Light-sensitive layer of the eye.

photoreceptors

Innermost layer of the retina.

Interneurons.

Second layer of the retina.

Ganglion cells

Outermost layer of the retina.

fovea

Center of the retina, which contains an abundance of red and green cones.

macula

Region surrounding the center of the retina, helps with reacting.

receptive field

A region of the retina consisting of a ganglion and the photoreceptors to which it connects.

center-surround antagonism

Sensitivity difference of a receptive field that allows for better contrast and shape detection.

blind spot

Point on the retina where the axons of ganglion cells form optic nerve.

optic chasm

Junction where optic nerves from both eyes cross.

preserve visual map

Function of the primary layer of the visual cortex.

increasingly complex receptive fields.

Layers of neurons further from the primary layer of the visual cortex respond to:

dorsal stream

Stream sent from visual cortex to the parietal lobe. Evaluates spacial relations, motion, timing, and plans for action unconsciously.

ventral stream

Stream sent from the visual cortex to the temporal lobe. Identifies shapes, colors, and compares them to memories and experiences.

strabismus

Condition of crossed eyes.

4

By what age are cross-eyed patients treated in modern medicine?

malleus

The first bone, or "hammer" of the middle ear.

incus

The second bone, or "anvil" of the middle ear.

stapes

The third bone, or "stirrup" of the middle ear.