Week 5 - The Nervous System

Question 1

What two main divisions make up the nervous system?

Answer 1

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

Question 2

What structures comprise the CNS?

Answer 2

Brain and spinal cord.

Question 3

What is the primary function of the CNS?

Answer 3

To integrate and process information.

Question 4

What does the PNS consist of?

Answer 4

Cranial nerves, spinal nerves, ganglia, and sensory receptors.

Question 5

What are the two main subdivisions of the PNS?

Answer 5

Somatic Nervous System (SNS) and Autonomic Nervous System (ANS).

Question 6

What is the function of the Somatic Nervous System?

Answer 6

Controls voluntary movement of skeletal muscles.

Question 7

What is the function of the Autonomic Nervous System?

Answer 7

Controls involuntary activities like heart rate and digestion.

Question 8

What is the Enteric Nervous System?

Answer 8

A subsystem of the ANS that controls the gastrointestinal tract.

Question 9

What are the three functional components of the nervous system?

Answer 9

Sensory (afferent), integrative, and motor (efferent) functions.

Question 10

What does the sensory component do?

Answer 10

Carries information from PNS to CNS.

Question 11

What percentage of nervous system cells are neurons?

Answer 11

About 10%.

Question 12

What are the main functions of neurons?

Answer 12

Excitability, conductivity, and secretion of neurotransmitters.

Question 13

Name the main parts of a neuron.

Answer 13

Dendrites, cell body (soma), axon, myelin sheath, and axon terminals.

Question 14

What is the function of dendrites?

Answer 14

To receive signals from other neurons.

Question 15

What role does the myelin sheath play?

Answer 15

It insulates axons and speeds up electrical conduction.

Question 16

What percentage of nervous system cells are neuroglial cells?

Answer 16

About 90%.

Question 17

Name four types of neuroglial cells found in the CNS.

Answer 17

Astrocytes, microglia, ependymal cells, oligodendrocytes.

Question 18

What is the function of astrocytes?

Answer 18

They maintain the blood-brain barrier and provide structural support.

Question 19

Which neuroglial cells act as immune cells in the CNS?

Answer 19

Microglia.

Question 20

Which neuroglial cells produce cerebrospinal fluid?

Answer 20

Ependymal cells.

Question 21

What is the function of oligodendrocytes?

Answer 21

They myelinate CNS axons.

Question 22

Which neuroglial cells myelinate PNS axons?

Answer 22

Schwann cells.

Question 23

What do satellite cells do?

Answer 23

They support and protect neuron cell bodies in the PNS.

Question 24

What are the four structural types of neurons?

Answer 24

Unipolar, bipolar, pseudounipolar, and multipolar.

Question 25

Which structural type is most common?

Answer 25

Multipolar neurons.

Question 26

What is the functional classification of neurons?

Answer 26

Sensory (afferent), motor (efferent), and interneurons.

Question 27

What do sensory neurons do?

Answer 27

Transmit impulses from sensory receptors to the CNS.

Question 28

What type of neuron connects sensory and motor neurons?

Answer 28

Interneurons.

Question 29

Which functional class of neurons are mostly multipolar?

Answer 29

Motor neurons and interneurons.

Question 30

What structural neuron type is typical for sensory neurons?

Answer 30

Pseudounipolar.

Question 31

What is the connective tissue covering a single neuron called?

Answer 31

Endoneurium.

Question 32

What surrounds a fascicle (bundle) of neurons?

Answer 32

Perineurium.

Question 33

What is the outermost layer surrounding the entire nerve?

Answer 33

Epineurium.

Question 34

What is the typical resting membrane potential of a neuron?

Answer 34

Approximately -70 millivolts (mV).

Question 35

What ion pump maintains resting membrane potential?

Answer 35

The sodium-potassium (Na+/K+) pump.

Question 36

What triggers the opening of voltage-gated sodium channels?

Answer 36

The membrane reaching the threshold potential (~ -55 mV).

Question 37

What happens during depolarisation?

Answer 37

Sodium ions enter the neuron, making the inside more positive.

Question 38

At what voltage does the action potential peak?

Answer 38

About +40 mV.

Question 39

What occurs during repolarisation?

Answer 39

Potassium ions leave the cell, restoring negative membrane potential.

Question 40

What is hyperpolarisation?

Answer 40

When the membrane potential becomes more negative than resting due to excess K+ efflux.

Question 41

How is the resting potential restored after hyperpolarisation?

Answer 41

Via the sodium-potassium pump and leakage channels.

Question 42

What is saltatory conduction?

Answer 42

The jumping of action potentials between nodes of Ranvier on myelinated axons.

Question 43

Is saltatory conduction faster or slower than continuous conduction?

Answer 43

Faster.

Question 44

What are the four major regions of the brain?

Answer 44

Cerebrum, diencephalon, brainstem, and cerebellum.

Question 45

What is the primary function of the cerebrum?

Answer 45

Conscious thought, sensory processing, and voluntary movement.

Question 46

Name the lobes of the cerebrum.

Answer 46

Frontal, parietal, temporal, and occipital lobes.

Question 47

What does the thalamus do?

Answer 47

Acts as a sensory relay station to the cerebral cortex.

Question 48

What are key functions of the hypothalamus?

Answer 48

Hormone regulation and homeostasis control.

Question 49

What basic life functions are controlled by the brainstem?

Answer 49

Heart rate, breathing, and autonomic functions.

Question 50

What is the role of the cerebellum?

Answer 50

Coordination, balance, and motor learning.

Question 51

Which lobe contains the primary motor cortex?

Answer 51

Frontal lobe.

Question 52

Which lobe contains the primary somatosensory cortex?

Answer 52

Parietal lobe.

Question 53

Which lobe contains the auditory cortex?

Answer 53

Temporal lobe.

Question 54

Which lobe contains the visual cortex?

Answer 54

Occipital lobe.

Question 55

What two roots form a spinal nerve?

Answer 55

Ventral (motor) root and dorsal (sensory) root.

Question 56

What type of nerve is a spinal nerve?

Answer 56

Mixed nerve (contains both motor and sensory fibers).

Question 57

How many spinal nerve segments are there?

Answer 57

31 pairs (cervical, thoracic, lumbar, sacral, coccygeal).

Question 58

What do thermoreceptors detect?

Answer 58

Temperature changes.

Question 59

What stimuli do mechanoreceptors respond to?

Answer 59

Touch, pressure, stretch, and vibration.

Question 60

What is the function of nociceptors?

Answer 60

Detect pain and harmful stimuli.