C2.2 HL only

Question 1

’All or nothing’ system

Answer 1

nerve cells send signals with the same force regardless of the strength impulse causing them to fire

Question 2

threshold potential

Answer 2

the critical level to which a membrane potential must be depolarized to initiate an action potential

Question 3

depolarization

Answer 3

a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell compared to the outside

Question 4

repolarization

Answer 4

the process in which the membrane of a nerve cell returns to its normal electrically charged state after a nerve impulse has passed

Question 5

hyperpolarization

Answer 5

when the membrane potential becomes more negative than the resting potential at a particular spot on the neuron’s membrane

Question 6

refractory period

Answer 6

a period immediately followingstimulationduring which anerveor muscle isunresponsiveto further stimulation

Question 7

oscilloscope

Answer 7

scientific instruments that are used to measure the membrane potential across a neuronal membrane

Question 8

unmyelinated axon

Answer 8

A neuron in which there is no myelin sheath surrounding the axon

Question 9

myelinated sensory neurons

Answer 9

their axon is insulated by a myelin sheath with small uninsulated sections along its length

Question 10

myelinated motor neurons

Answer 10

When the axon is covered with a myelin sheath then the nerve fibre is known as a myelinated motor neuron

Question 11

Saltatory conduction

Answer 11

the rapid method by which nerve impulses move down a myelinated axon with excitation occurring only atnodes of Ranvier

Question 12

nodes of Ranvier

Answer 12

gaps in the myelin sheath coating on the neural axon. The myelin allows the electrical impulse to move quickly down the axon. The nodes of Ranvier allow for ions to diffuse in and out of the neuron, propagating the electrical signal down the axon.

Question 13

Exogenous chemicals

Answer 13

Describes substances within the human body which have arisen from an external source in the diet or environment

Question 14

Neonicotinoid insecticides

Answer 14

a class of insecticides that are chemically similar to nicotine and are used to control harmful insects in agriculture and urban landscapes

Question 15

Cocaine

Answer 15

anaddictivestimulant drug made from the leaves of the coca plant; hightens and prolongs the impact of dopmine on synapse

Question 16

dopamine

Answer 16

a neurotransmitter made in your brain. It plays a role as a “reward center” and in many body functions, including memory, movement, motivation, mood, attention and more

Question 17

Excitatory neurotransmitters

Answer 17

“excite” the neuron and cause it to “fire off the message,” meaning, the message continues to be passed along to the next cell. Examples of excitatory neurotransmitters include glutamate, epinephrine and norepinephrine.

Question 18

Acetylcholine

Answer 18

a neurotransmitter, a chemical that carries messages from your brain to your body through nerve cells

Question 19

Inhibitory neurotransmitters

Answer 19

a type of chemical messenger that prevents or blocks the transmission of a chemical message to another cell

Question 20

GABA (gamma-aminobutyric acid)

Answer 20

an amino acid that serves as the primary inhibitory neurotransmitter in the brain and a major inhibitory neurotransmitter in the spinal cord

Question 21

Excitatory Post-Synaptic Potential (EPSP)

Answer 21

the synaptic activation of a neuron caused by the release of neurotransmitters from a presynaptic neuron, leading to a depolarization of the postsynaptic membrane potential

Question 22

Inhibitory Post-Synaptic Potential (IPSP)

Answer 22

a temporary electrical charge in a neuron’s membrane that makes it harder for the neuron to generate an action potential

Question 23

Summation

Answer 23

the process by which multiple electrical impulses combine to create a response in a multicellular organism with a neurological system

Question 24

Thermoreceptors

Answer 24

specialized parts of neurons, or nerve cell endings, that give the body the ability to detect changes in temperature

Question 25

Photoreceptors

Answer 25

sensory neurons that respond to light by generating electrical signals

Question 26

Chemoreceptors

Answer 26

specialized cells that detect chemical changes in the body and environment, and send that information to the nervous system

Question 27

Electromagnetic receptors

Answer 27

sensory receptors that detect electromagnetic radiation, such as light energy and Earth’s magnetic field

Question 28

Mechanoreceptors

Answer 28

specialized nerve cells that respond to mechanical stimuli, such as pressure, vibration, and sound, by converting them into electrical signals that are sent to the central nervous system

Question 29

Baroreceptors

Answer 29

stretch receptors that sense blood pressure

Question 30

Nociceptors

Answer 30

sensory neurons that detect and respond to potentially damaging stimuli, such as heat, pressure, or chemicals, and are responsible for the sensation of pain

Question 31

pain matrix

Answer 31

a group of brain structures jointly activated by painful stimuli

Question 32

Capsaicin

Answer 32

A component of certain plants, including cayenne and red pepper, used topically for peripheral nerve pain

Question 33

consciousness

Answer 33

a dynamic, integrated, multimodal mental process entailed by physical events occurring in the forebrain

Question 34

neural network

Answer 34

an interconnected population of neurons

Question 35

Reductionism

Answer 35

a philosophical approach that attempts to explain biological phenomena by breaking them down into smaller components

Question 36

Emergence

Answer 36

the process by which new biological structures or species emerge, or the properties of groups that can’t be explained by their individual components