cns and pns

Question 1

What does ‘afferent’ mean?

Answer 1

Coming towards CNS

Question 2

What does ‘efferent’ mean?

Answer 2

Coming out of/away from CNS

Question 3

Define ‘nerve’.

Answer 3

Cable-like bundle of nerve fibers (axons) in the periphery, grouped in fascicles

Question 4

What are ‘ganglia’?

Answer 4

Collection of neural cells (neurons + satellite cells) in the periphery

Question 5

Define ‘plexus’.

Answer 5

A network of nerves that branch out and intersect

Question 6

What is a ‘system’ in the context of biological organization?

Answer 6

Collection of organs (e.g., nervous system)

Question 7

What is an ‘organ’?

Answer 7

A collection of different tissues that work together to perform a function

Question 8

What is ‘tissue’?

Answer 8

A collection of cells that work together to perform a particular task

Question 9

What are ‘cells’?

Answer 9

The basic building blocks of tissues

Question 10

What is the main function of neurons?

Answer 10

Detect inputs, integrate info, send signals to other cells

Question 11

What do glial cells do?

Answer 11

Provide functional and structural support to neurons

Question 12

List the components of a neuron.

Answer 12

• Soma (cell body)
• Axon
• Dendrites

Question 13

What is the function of the axon?

Answer 13

Transmits electrical impulses from cell body of a neuron to other neurons

Question 14

What are dendrites?

Answer 14

Branching extensions of neuron that receive messages from other nerve cells

Question 15

What is the hillock in a neuron?

Answer 15

The last site in the soma where synaptic inputs are summated/integrated

Question 16

What is the AIS in a neuron?

Answer 16

Earliest site of action potential initiation, non-myelinated axon

Question 18

What type of neuron transmits sensory information such as touch, sound, and light to the CNS?

Answer 18

Sensory neurons

Sensory neurons are responsible for conveying external stimuli to the central nervous system.

Question 19

What is the function of motor neurons?

Answer 19

Carries signals from the CNS to muscles and glands to initiate a response

Motor neurons play a critical role in executing bodily responses.

Question 20

What type of neuron transmits signals between sensory and motor neurons within the CNS?

Answer 20

Interneuron

Interneurons are essential for processing information within the central nervous system.

Question 21

What is the role of astrocytes in the CNS?

Answer 21

Buffer ions and neurotransmitters, secrete chemicals for synaptogenesis, part of blood-brain barrier, provide nutrients, repair damage

Astrocytes support neuronal function and help maintain a stable environment.

Question 22

What cells are responsible for myelinating axons in the CNS?

Answer 22

Oligodendrocytes

Myelination is crucial for efficient signal transmission in the nervous system.

Question 23

What is the function of microglia?

Answer 23

Macrophage activity, phagocytic, debris removal, immune defense

Microglia act as the immune cells of the CNS, protecting against pathogens and clearing waste.

Question 24

What do ependymal cells line and what is their function?

Answer 24

Line the ventricles and central canal; create CSF

Ependymal cells are involved in the production and circulation of cerebrospinal fluid.

Question 25

What is the role of Schwann cells in the PNS?

Answer 25

Myelinate axons, protect unmyelinated axons, provide trophic support ## Footnote Schwann cells facilitate nerve regeneration and support neuronal health.

Question 26

What do satellite cells do in the PNS?

Answer 26

Surround somata of neurons; assist in regulating the external chemical environment ## Footnote Satellite cells help maintain homeostasis for neurons in ganglia.

Question 27

What does CNS stand for?

Answer 27

Central Nervous System

Question 28

What is the role of the CNS?

Answer 28

Central processing center that receives, integrates, interprets info from periphery and sends info back to periphery

Question 29

What is Gray Matter composed of?

Answer 29

Neuronal and glial cell bodies and unmyelinated axons

Question 30

What does White Matter represent?

Answer 30

Networking between processing centers through myelinated axons

Question 31

What is the primary function of the Spinal Cord?

Answer 31

Communicates signals to and from the body via spinal nerves

Question 32

How is the Spinal Cord divided?

Answer 32

Into segments, each connecting to a pair of sensory and motor nerves

Question 33

What type of information do axons and cell bodies in the dorsal spinal cord convey?

Answer 33

Mostly sensory info

Question 34

What is the primary function of axons and cell bodies in the ventral spinal cord?

Answer 34

Transmit signals controlling movement

Question 35

What are the two divisions of the PNS?

Answer 35

Somatic and autonomic

Question 36

What does the Somatic Nervous System control?

Answer 36

Skeletal muscle through voluntary and involuntary movements

Question 37

What are afferents in the context of the Somatic Nervous System?

Answer 37

Sensory info to the CNS

Question 38

What are efferents in the context of the Somatic Nervous System?

Answer 38

Motor info from the CNS

Question 39

What are cranial and spinal nerves responsible for?

Answer 39

Afferent and efferent pathways to and from the CNS

Question 40

What is a neural circuit?

Answer 40

Arrangement of neurons interconnected by synapses that perform a particular function

Question 41

What does the Autonomic Nervous System control?

Answer 41

Internal organs and functions such as breathing, heartbeat, and digestion

Question 42

Where does the Sympathetic division originate?

Answer 42

Thoracic and lumbar levels

Question 43

Where does the Parasympathetic division originate?

Answer 43

Brainstem (cranial) and sacral levels

Question 44

What is the primary function of the Enteric division?

Answer 44

Embedded in the wall of the gastrointestinal tract

Question 45

Are sympathetic preganglionic axons short or long?

Answer 45

Short

Question 46

Are parasympathetic preganglionic axons short or long?

Answer 46

Long

Question 47

What neurotransmitter is used by sympathetic postganglionic neurons?

Answer 47

NE (norepinephrine)

Question 48

What neurotransmitter is used by parasympathetic postganglionic neurons?

Answer 48

Ach (acetylcholine)