nervous system

Question 1

What are the two main divisions of the nervous system?

Answer 1

1) Central nervous system (CNS) 2) Peripheral nervous system (PNS)

Question 2

What does the central nervous system comprise?

Answer 2

Brain and spinal cord

Question 3

What are the three parts of the peripheral nervous system?

Answer 3

1) Sensory system 2) Motor system 3) Autonomic system

Question 4

What is the function of sensory neurons?

Answer 4

Transmit information to the CNS

Question 5

What do motor neurons control?

Answer 5

Skeletal muscles

Question 6

What do autonomic system neurons regulate?

Answer 6

Glands, heart, and smooth muscle

Question 7

What is the role of the spinal cord?

Answer 7

Carries messages to and from the brain

Question 8

What happens to all connections below a spinal cord injury?

Answer 8

They will be lost

Question 9

What muscles are affected by a spinal cord injury at C4 and higher?

Answer 9

Intercostal muscles, diaphragm, and abdominal muscles

Question 10

What is the role of glial cells in the nervous system?

Answer 10

Support and insulate neurons

Question 11

What is the structure of a neuron?

Answer 11

Cell body (soma), dendrites, and axon

Question 12

What is myelin?

Answer 12

An insulating substance covering some axons

Question 13

What are nodes of Ranvier?

Answer 13

Gaps in the myelin sheath crucial for impulse conduction

Question 14

What distinguishes Schwann cells from oligodendrocytes?

Answer 14

Schwann cells form myelin in the PNS, oligodendrocytes in the CNS

Question 15

What is a reflex action?

Answer 15

Rapid, automatic responses to stimuli

Question 16

What is a reflex arc?

Answer 16

The nervous pathway taken during a reflex action

Question 17

What are synapses?

Answer 17

Junctions where neurons communicate

Question 18

What neurotransmitter is released at chemical synapses?

Answer 18

Acetylcholine

Question 19

What are excitatory postsynaptic potentials (EPSP)?

Answer 19

Localized changes that make a target cell more likely to fire

Question 20

What are inhibitory postsynaptic potentials (IPSP)?

Answer 20

Localized changes that make a target cell less likely to fire

Question 21

What causes the release of neurotransmitters from the presynaptic neuron?

Answer 21

Influx of calcium ions

Question 22

What happens to acetylcholine after it binds to receptors?

Answer 22

It is broken down by acetylcholinesterase

Question 23

What is the function of acetylcholinesterase?

Answer 23

Breaks down acetylcholine into acetate and choline

Question 24

What is the process of remaking acetylcholine?

Answer 24

Recombining acetate and choline using ATP

Question 25

What is the significance of the synaptic cleft?

Answer 25

It is the gap between neurons where neurotransmitters diffuse

Question 26

What is the main effect of sodium ion influx in postsynaptic neurons?

Answer 26

Depolarization and generation of a new action potential

Question 27

Fill in the blank: The pathway for a reflex action is __________.

Answer 27

stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector → response

Question 28

True or False: Reflex actions require conscious thought.

Answer 28

False

Question 29

What is the first step in neurotransmission at a synapse?

Answer 29

Calcium channels open

Question 30

What happens when neurotransmitters bind to receptors on the postsynaptic membrane?

Answer 30

Ion channels open, leading to depolarization

Question 31

What causes depolarization in muscle cells?

Answer 31

Na+ influx ## Footnote Sodium ions (Na+) entering the cell lead to depolarization, which is crucial for muscle contraction.

Question 32

What is the role of acetylcholine in neuromuscular synapses?

Answer 32

Signal transmission ## Footnote Acetylcholine is released at neuromuscular synapses to facilitate communication between nerves and muscles.

Question 33

Name a toxin that inhibits the release of acetylcholine.

Answer 33

Botulinum toxin ## Footnote Botulinum toxin, produced by Clostridium botulinum, leads to paralysis by blocking acetylcholine release.

Question 34

What is the effect of cobra snake toxin on acetylcholine?

Answer 34

Reduces action of acetylcholine ## Footnote The toxin binds to receptors without opening channels, causing paralysis of skeletal muscles.

Question 35

What are acetylcholinesterase inhibitors?

Answer 35

Substances that inactivate the enzyme breaking down acetylcholine ## Footnote These inhibitors prolong acetylcholine's action at receptors, increasing muscle depolarization.

Question 36

What condition can acetylcholinesterase inhibitors treat?

Answer 36

Myasthenia gravis ## Footnote Myasthenia gravis is characterized by antibodies against acetylcholine receptors, leading to muscle weakness.

Question 37

What are common symptoms of myasthenia gravis?

Answer 37

Eyelid drooping (ptosis) and double vision (diplopia) ## Footnote These symptoms arise due to impaired communication between nerves and muscles.

Question 38

What is multiple sclerosis (MS)?

Answer 38

An autoimmune condition that attacks the myelin sheath ## Footnote MS leads to various neurological symptoms due to damage to the protective covering of nerves.

Question 39

List some symptoms of multiple sclerosis.

Answer 39

* Fatigue * Difficulty walking * Vision problems * Bladder control issues * Numbness or tingling * Balance and coordination issues * Cognitive difficulties ## Footnote MS symptoms vary widely among individuals and can affect daily life significantly.

Question 40

Is there a cure for multiple sclerosis?

Answer 40

No cure, but treatment options exist ## Footnote Steroids are often used to aid recovery from MS flare-ups.

Question 41

Fill in the blank: Acetylcholinesterase inhibitors can lead to _______ due to prolonged muscle depolarization.

Answer 41

muscle spasms (tetany) ## Footnote The continuous stimulation of muscle cells results in spasms.