chapter 12, nervous tissue

Question 1

What does the Central Nervous System (CNS) consist of?

Answer 1

The brain and spinal cord.

Question 2

What does the Peripheral Nervous System (PNS) consist of?

Answer 2

Nerves and ganglia outside the CNS.

Question 3

What is the role of the Sensory (Afferent) Division?

Answer 3

Carries sensory signals from receptors to the CNS.

Question 4

What is the function of the Motor (Efferent) Division?

Answer 4

Carries motor signals from the CNS to muscles and glands.

Question 5

What does the Somatic Nervous System (SNS) control?

Answer 5

Voluntary movement and skeletal muscles.

Question 6

What functions does the Autonomic Nervous System (ANS) control?

Answer 6

Involuntary functions, such as heart rate and digestion.

Question 7

What is the role of the Sympathetic Division?

Answer 7

Prepares the body for ‘fight or flight’ responses.

Question 8

What does the Parasympathetic Division support?

Answer 8

‘Rest and digest’ functions.

Question 9

What is a Neuron?

Answer 9

The functional unit of the nervous system.

Question 10

Define Excitability in the context of neurons.

Answer 10

Ability of neurons to respond to stimuli.

Question 11

What is Conductivity in neurons?

Answer 11

Ability of neurons to transmit electrical signals.

Question 12

What is Secretion in neurons?

Answer 12

Release of neurotransmitters to communicate with other cells.

Question 13

What is the Soma (Cell Body) of a neuron?

Answer 13

The control center of the neuron.

Question 14

What are Dendrites?

Answer 14

Short, branched extensions of a neuron that receive signals.

Question 15

What is the Axon?

Answer 15

The long projection that carries nerve impulses away from the soma.

Question 16

What is the Axon Hillock?

Answer 16

The region where the axon begins; important for action potential initiation.

Question 17

Define Synapse.

Answer 17

The junction between two neurons where communication occurs.

Question 18

What is the Myelin Sheath?

Answer 18

Fatty covering around axons that speeds up nerve impulses.

Question 19

What are Nodes of Ranvier?

Answer 19

Gaps in the myelin sheath that allow saltatory conduction.

Question 20

What do Sensory (Afferent) Neurons do?

Answer 20

Carry signals from sensory receptors to the CNS.

Question 21

What are Interneurons (Association Neurons)?

Answer 21

Process information within the CNS.

Question 22

What do Motor (Efferent) Neurons do?

Answer 22

Carry signals from the CNS to effectors (muscles/glands).

Question 23

What are Astrocytes?

Answer 23

Star-shaped cells that provide structural support and help maintain the blood-brain barrier.

Question 24

What is the role of Oligodendrocytes?

Answer 24

Form myelin sheaths in the CNS.

Question 25

What do Microglia do?

Answer 25

Small, phagocytic cells that remove debris and pathogens in the CNS.

Question 26

What are Ependymal Cells responsible for?

Answer 26

Line the ventricles of the brain and help produce cerebrospinal fluid (CSF).

Question 27

What is the function of Schwann Cells?

Answer 27

Form myelin sheaths around axons in the PNS.

Question 28

What do Satellite Cells do?

Answer 28

Support and regulate the environment around neurons in the PNS.

Question 29

What is Resting Membrane Potential (RMP)?

Answer 29

The baseline electrical charge of a neuron at rest (-70mV).

Question 30

Define Depolarization.

Answer 30

When the inside of a neuron becomes more positive due to sodium (Na⁺) entering.

Question 31

What is Repolarization?

Answer 31

When the neuron returns to a negative charge due to potassium (K⁺) exiting.

Question 32

What is Hyperpolarization?

Answer 32

When the inside of the neuron becomes too negative before returning to RMP.

Question 33

What is the Threshold in neuronal activity?

Answer 33

The minimum voltage needed to trigger an action potential (-55mV).

Question 34

What is an Action Potential?

Answer 34

A rapid electrical signal that travels along the axon.

Question 35

What does the All-or-None Principle state?

Answer 35

If a neuron reaches the threshold, it will fire an action potential completely.

Question 36

Define Saltatory Conduction.

Answer 36

The jumping of action potentials between the Nodes of Ranvier in myelinated neurons, increasing speed.

Question 37

What is a Presynaptic Neuron?

Answer 37

The neuron that sends the signal.

Question 38

What is a Postsynaptic Neuron?

Answer 38

The neuron that receives the signal.

Question 39

What is a Neurotransmitter?

Answer 39

A chemical that transmits signals across a synapse.

Question 40

What are Excitatory Neurotransmitters?

Answer 40

Increase the likelihood of an action potential (e.g., glutamate, acetylcholine).

Question 41

What are Inhibitory Neurotransmitters?

Answer 41

Decrease the likelihood of an action potential (e.g., GABA, glycine).

Question 42

What are Synaptic Vesicles?

Answer 42

Small sacs that store neurotransmitters.

Question 43

What are Receptor Proteins?

Answer 43

Proteins on the postsynaptic neuron that bind neurotransmitters.

Question 44

What is Reuptake?

Answer 44

The process of neurotransmitters being absorbed back into the presynaptic neuron.

Question 45

What is Enzymatic Degradation?

Answer 45

Breakdown of neurotransmitters (e.g., acetylcholinesterase breaking down acetylcholine).

Question 46

What is a Diverging Circuit?

Answer 46

One neuron triggers multiple neurons, spreading the signal.

Question 47

What is a Converging Circuit?

Answer 47

Multiple neurons send signals to a single neuron.

Question 48

Define Reverberating Circuit.

Answer 48

Neurons loop back to previous neurons for prolonged signals.

Question 49

What is a Parallel After-Discharge Circuit?

Answer 49

A single neuron activates multiple pathways that converge on a common output.

Question 50

What is Multiple Sclerosis (MS)?

Answer 50

An autoimmune disease that damages myelin in the CNS, slowing nerve conduction.

Question 51

What is Guillain-Barré Syndrome?

Answer 51

A disorder where the immune system attacks the PNS myelin.

Question 52

What is Amyotrophic Lateral Sclerosis (ALS)?

Answer 52

A degenerative disease that affects motor neurons, leading to muscle weakness.

Question 53

What is Parkinson’s Disease?

Answer 53

A neurodegenerative disorder caused by dopamine deficiency.

Question 54

What is Epilepsy?

Answer 54

A condition characterized by recurring seizures due to excessive electrical activity in the brain.

Question 55

What is Alzheimer’s Disease?

Answer 55

A progressive neurodegenerative disease causing memory loss and cognitive decline.