Brain Background

Question 1

Weight of the human brain

Answer 1

3lbs, 2-3% of body weight

Question 2

Cerebellum

Answer 2

little brain; extremely dense and has more than half of our neurons

Question 3

Do we produce new neurons in adulthood

Answer 3

No

Question 4

Neurogenesis

Answer 4

The process of formation of new neurons within the brain. Most neurogenesis happens within the womb, after we are born it happens in very small amounts only

When we are born, we have the maximum amount of neurons we will ever have.

Question 5

Gray matter

Answer 5

Pale parts in the scan

Cell bodies of neuron; found in the outer cortex
Small neurons that don’t have a certain substance– unmyelinated axons

Question 6

White matter

Answer 6

Myelinated axons connecting areas; found near the center of the brain

Question 7

Two basic cell types

Answer 7

1. Neuron
2. Glia

Question 8

Neuron

Answer 8

Extreme fast signal because of action potential; reaction time is in milliseconds

Nerve cells that process and communicate messages and changes throughout the body.

Question 9

Glia

Answer 9

Glue, acts as support, provides nutrition

Ex: Astrocyte and oligodendrocyte

Question 10

Different types of neurons

Answer 10

Pyramidal- cerebral cortex
Stellate- star shape; cerebellum
Purkinje- cerebellum

Question 11

Flow of a neuron signal

The path a neuron signal travels (4 parts of a neuron)

Answer 11

Dendrite → soma → axon → terminals

Question 12

Dendrite

Answer 12

Parts of a neuron that receive information from other neurons.

Spiny neurons- pyramidal, glutamate neurons (they release glutamate)

Non-spiny neurons- specifically referring to GABA neurons

Question 13

Soma

Answer 13

The body of a neuron. Also contains the nucleus of the neuron.

Question 14

Axon

Answer 14

The part of a neuron that sends neurotransmitters to other neurons.

Question 15

Nodes of Ranvier

Answer 15

Little gaps in between the myelin sheaths on an axon. They contain sodium that generates action potentials.

Question 16

Projection Neurons

Answer 16

Neurons that extend from the neuronal cell body within the CNS to 1 or more distant regions of the CNS. Typically have a longer axon and fewer inputs/outputs than an interneuron.

Question 17

Interneurons

Answer 17

Interneurons act as a bridge of communication between the CNS and PNS, transferring signals between the two. Help with synchronization of signals as well as the timing of signals (eg. for motor skills).

local processing and communications within a specific brain region

Question 18

Afferent Nerves/Neurons

Answer 18

Nerves/neurons that arrive at the CNS. They deliver sensory information to the brain. (A for arriving)

Question 19

Efferent Nerves/Neurons

Answer 19

Nerves/neurons that deliver info from the CNS to muscles (in other words, they deliver motor signals). (E for exiting)

Question 20

Macroglia

Answer 20

Schwann cells, oligodendrocytes, astrocytes. Maintain CNS homeostasis.

Question 21

Microglia

Answer 21

Part of the brain’s immune response. Microglia surveil brain cells. When they sense foreign bodies, they go into a prime state.

Question 22

Microglia: Prime state

Answer 22

The state when microglia sense a foreign body. They grow large and digest/”swallow” the foreign bodies.

Question 23

Schwann Cells

Answer 23

Schwann cells create myelin sheaths that speed up action potentials’ travels along the axon (PNS only).

Question 24

Tripartite synapse

Answer 24

Refers to the communication between three parts of the synapse (“A conversation of three”). Astrocytes shape synaptic conditions/wrap around the synapse & the pre- and postsynaptic terminals communicate.

Question 25

Astrocytes

Answer 25

Astrocytes stabilize the BBB that is actively working

• Mediate all the nutrition your brain and neurons need
• A key role of keeping the environment what it should be
• Buffers out sodium if it is too much or buffers in potassium if it’s too little
• All astrocyte works together = glial network

Question 26

Oligodendrocytes

Answer 26

Myelin creating cells (CNS only). Myelinate several different axons. Myelin speeds up the travel of action potentials.

Question 27

Nissl-stain

Answer 27

Stains cell bodies in the brain, shows gray matter

Question 28

Fibre stain

Answer 28

Stains glial cells, see where white matter in the brain is

Question 29

Blood Brain Barrier (BBB)

Answer 29

Tightly packed astrocytes wrapped around tightly packed capillaries, protects the brain from foreign entities.

Question 30

Challenges of studying humans before

Answer 30

neuroscience methods are either invasive or require postmortem tissue

Question 31

Golgi stain

Answer 31

reveal cell type, show cell body and all its branches

Question 32

Central dogma of molecular biology

Answer 32

The theory that genetic information flows only in one direction: From DNA, to RNA, to protein (or from RNA directly to protein).

Question 33

Synapse

Answer 33

Components that make up the connection between neurons. Includes the axon terminals and synaptic cleft.

Question 34

Effect of an increase or decrease in dendrites

Answer 34

Decrease in dendrites can lead to schizophrenia

An increase in dendrites can mean on the spectrum of autism

Question 35

Peripheral Nervous System (PNS)

Somatic Nervous System

Answer 35

Sends voluntary motor signals from the CNS to muscles in the body. Collects sensory information from the body and sends it to the CNS.

Question 36

Synaptic cleft

Answer 36

a
The gap between a pre- and post-synaptic neuron. Neurotransmitters travel along this gap.

Question 37

Amount of neurons the brain has, and where most are located

Answer 37

The brain has <100 billion neurons, more than 50% of these are located in the cerebellum.

Question 38

Peripheral Nervous System (PNS)

Autonomic Nervous System

Answer 38

Controls involuntary bodily functions. Heavily oriented towards internal organs/the internal bodily system

Question 39

Subsystems in Autonomic Nervous System (ANS)

Sympathetic Nervous System

Answer 39

Activate’s the body’s “fight or flight” response. Stimulates secretion of adrenaline (epinephrine) and norepinephrine.

Shuts down the digestive system so the energy can be used elsewhere.
Elevates one’s heartbeat, and stimulates glucose production/release.

Question 40

Subsystems in Autonomic Nervous System (ANS)

Parasympathetic Nervous System

Answer 40

Activates the “rest and digest” aspects of the nervous system. Conserves energy, slows one’s heart rate, and stimulates digestion.

Question 41

Gyrus/gyri

Answer 41

The bumps/ridges in the brain.

Question 42

Sulcus/sulci

Answer 42

The dips/valleys in the brain.

Question 43

Blood-brain barrier (BBB)

Answer 43

Tightly packed astrocytes wrapped around tightly packed capillaries, protects the brain from foreign entities.