Nervous System

Question 1

What are the two main systems within the Nervous System?

Answer 1

CNS: brain and spinal cord
–> information processing

PNS: somatic and autonomic system
–> sensory neurons
|
autonomic
–> involuntary physiological processes

-sympathetic -Fight/Flight
-parasympathetic -rest/digestion
-enteric divisions -gut digestion

Question 2

What are the three basic structures vertebrate brains share?

Answer 2

Forebrain: higher level cognitive thinking (memory, sensory processing)

Midbrain: relay station for sensory info (modulate info -strengthen/dampen)

Hindbrain: controls basic homeostatic life functions (breathing, heart rate, balance)

Question 3

What is the signaling process of neurons? Where do the neurons exist?

Answer 3

–> Sensory neurons (afferent, to CNS)
convert stimuli to action pot.

–> Interneuron (within CNS) connects neurons to one another

–> Motor (efferent, from CNS)
receive + transmit info from other neurons to muscles, organs, glands

Question 4

What are the main parts of a neuron, what do they do?

Answer 4

Cell body: contains nucleus (genetic info) and organelles

Axon: transmits signals

Axon Hillock: sums up incoming signals + site of action pot. generation

Dendrites: receives signals

Question 5

What are the glial cells what do they do?

Answer 5

Support neurons:

Oligodendrocytes/Schwann (myelinate axons increasing conduction speed of axon pot.)

Astrocytes (provide nutrients, maintain environment)

Microglia (brain macrophages, immunity)

Question 6

What is RMP, how does it work/relate to neurons?

Answer 6

Resting membrane potential: the electrical charge difference across cell’s membrane at rest.

Maintained by ion conc. gradients (sodium-potassium pump + leak channels).

3Na+ out, 2K+ in ion dist leads to ~-70mV RPM in neurons