Introduction to CNS and PNS

Question 1

What are the main functions of the nervous system (NS)?

Answer 1

Detects changes in external and internal environments and brings about responses in muscles, organs, and glands.

Question 2

What higher functions have evolved in the nervous system?

Answer 2

Learning, memory, cognition, self-awareness, intellect, and personality.

Question 3

Why is understanding neuroanatomy important in clinical neuroscience?

Answer 3

Why is understanding neuroanatomy important in clinical neuroscience?

Question 4

What are the two main components of the nervous system?

Answer 4

CNS: Brain and spinal cord; PNS: Links CNS to body, receives sensory info, and sends controlling impulses.

Question 4

What is the CNS, and what are its characteristics?

Answer 4

Brain and spinal cord protected by cranium and vertebral column; harbors most nerve cell bodies and synapses.

Question 5

What is the PNS, and what are its characteristics?

Answer 5

Connects CNS to peripheral body; includes cranial and spinal nerves, forming brachial and lumbar plexuses.

Question 6

What is the structure of a neuron?

Answer 6

Cell body with dendrites (receptors) and axon (sends impulses), ending in terminal boutons for synaptic transfer.

Question 7

How is information passed between neurons?

Answer 7

Through synapses, where adjacent cell membranes closely interact for signal transfer.

Question 8

What are afferent neurons and their function?

Answer 8

Carry information from peripheral receptors to the CNS; sensory if conscious level is reached.

Question 9

What are efferent neurons and their function?

Answer 9

Carry impulses away from the CNS; motor neurons if innervating skeletal muscles.

Question 10

What are interneurons?

Answer 10

Neurons entirely within CNS, acting as cortical afferents or efferents depending on direction.

Question 11

What is the function of neurons?

Answer 11

Receive, integrate, and transmit information to other neurons or effector organs.

Question 11

What are neuroglia, and what roles do they play?

Answer 11

Support neurons; types include oligodendrocytes, astrocytes, and microglia.

Question 12

How does nerve conduction occur in neurons?

Answer 12

Through changes in electrical energy (action potentials), driven by ion movement across cell membranes.

Question 13

What is an action potential?

Answer 13

Brief polarity reversal due to ion exchange, propagated along the axon, leading to neurotransmitter release.

Question 14

What are the divisions of the autonomic nervous system (ANS)?

Answer 14

Sympathetic: Fight or flight response; Parasympathetic: Rest and digest functions.

Question 15

What does the ANS control?

Answer 15

Smooth muscle, cardiac muscle, and secretory glands; regulates homeostasis.

Question 16

What is the difference between grey and white matter?

Answer 16

Grey matter: Nerve cell bodies; White matter: Myelinated nerve processes.

Question 17

What are nuclei and tracts in the CNS?

Answer 17

Nuclei: Groups of related nerve cell bodies; Tracts: Nerve processes following shared pathways.

Question 17

Why do sensory and motor pathways decussate in the CNS?

Answer 17

To ensure each cerebral hemisphere controls the contralateral side of the body.

Question 18

What protects the CNS?

Answer 18

Skull, vertebral column, and meninges (dura mater, arachnoid mater, pia mater).

Question 19

What are the functions of cerebrospinal fluid (CSF)?

Answer 19

Provides protection, buoyancy, and chemical stability for the CNS.

Question 20

What are the four ventricles in the brain, and their roles?

Answer 20

Lateral, third, and fourth ventricles: Produce, circulate, and remove CSF.

Question 20

What are the major landmarks of the brainstem?

Answer 20

Medulla oblongata, pons, and midbrain; control vital functions like respiration and cardiovascular activity.

Question 20

What is the cerebellum’s function?

Answer 20

Coordinates balance, movement, and unconscious voluntary actions.

Question 21

What is the frontal lobe responsible for?

Answer 21

Emotion, personality, motor function, memory, language understanding, and attention regulation.

Question 22

What are the functions of the temporal lobe?

Answer 22

Auditory processing, memory encoding, emotion regulation, and language comprehension.

Question 23

What is the role of the parietal lobe?

Answer 23

Integrates sensory information, constructs spatial coordination, and assists cognition.

Question 24

What is the primary role of the occipital lobe?

Answer 24

Visual processing center with the primary visual cortex in Brodmann Area 17.