Course Overview/Intro to Neuroscience

Question 1

Describe the 5 major distinguishing features of advanced nervous systems

Answer 1

1) Cellular specializations
2) Areal specializations: collections of cells grouped together for a common purpose
3) Functional cooperation: ensembles of neurons acting in synchrony to produce desired outcome
4) Adaptability
5) High information storage capacity

A critical function of the nervous system is to enable the selection of the most adaptive/ meaningful behaviors. The nervous system accomplishes this by creating multiple representations of the outside world to steer internal decisions.

Question 2

What are the 3 basic functions performed by the nervous system?

Answer 2

1) Sensation: Receive sensory input from internal and external environments
2) Perception: Create internal maps of this information (integration/evaluation)
3) Action: Respond in an adaptive manner to stimuli

Question 3

CNS = ?

Answer 3

Brain + spinal cord (analysis & integration of sensory & motor information)

Question 4

PNS = ?

Answer 4

Cranial nerves + spinal nerves (sensory & motor)

See pg. 11

Question 5

Define the major cell types (including different classes of neurons and glia) found in the nervous system, and what their main functions are

Answer 5

See pgs. 35 - 36

Question 6

Astrocytes

Answer 6

Astrocytes - A glial cell found in the CNS named for its characteristic star-like shape with long cytoplasmic processes which bridge neurons and capillary endothelial cells; these cells provide both mechanical and metabolic support for neurons, regulating the environment where they function; they contribute to the blood-brain barrier and control transport of substances from the blood to neural tissue; they also help coordinate nerve pathway development; they develop from embryonic ectoderm.

Astrocytes are a source & sink for nutrients & molecules. They can become activated if there is injury or illness–which changes their role.

Question 7

Oligodendrocyte

Answer 7

Oligodendrocyte - A glial cell found in the CNS which is named for its characteristic limited number of dendritic processes; those processes provide electrical insulation for a few adjacent neurons by forming a part of the myelin sheath for their axons, and, thereby, increasing the speed of transmission of action potentials along that axon (saltatory conduction); they develop from embryonic ectoderm.

Note: in the PNS, Schwann cells are the principal glia of the peripheral nervous system (PNS) & they make the PNS’s myelin sheath.

Question 8

Microglia

Answer 8

Microglia - A glial cell found in the CNS named for its characteristic small size; these cells are derived from hematopoetic sources and provide a protective function to nervous tissue in that they can become phagocytic.

Microglia are a source & sink for nutrients & molecules. They are the immune cells of the nervous system. They comprise 10% of the nervous system; therefore, 10% of the nervous system are not brain in origin, they are hematopoetic.

Question 9

See pgs. 34- xxx & note how each slide contributes to the distinguishing features of advanced nervous systems

Answer 9

-

Question 10

What are the 3 functional classes of neurons?

Answer 10

1) sensory or afferent neurons
2) motor or efferent neurons
3) interneurons

Question 11

Define sensory or afferent neurons

Answer 11

Typically have a long dendrite & a short axon, & carry messages from sensory receptors to the CNS.

Question 12

Define motor or efferent neurons

Answer 12

Typically have long axons and short dendrites and transmit messages from the CNS to the muscles or glands.

Question 13

Define interneurons

Answer 13

Found only in the CNS, where they interconnect neurons. They bridge afferent & efferent neuron signals.

Question 14

Free nerve endings with little or no myelin are most sensitive to?

Answer 14

Free nerve endings with little or no myelin (most sensitive to pain and temperature)

Question 15

Thicker myelinated axons arise from several classes of mechanoreceptors: Pacinian and Meissner corpuscles (_____ touch and vibration), Ruffini corpuscles and Merkel disks (_____ pressure)

Answer 15

Thicker myelinated axons arise from several classes of mechanoreceptors: Pacinian and Meissner corpuscles (light touch and vibration), Ruffini corpuscles and Merkel disks (sustained pressure)

Question 16

Why do we need high information storage capacity?

Answer 16

To avoid being ruled by our environments (i.e., to make more ‘meaningful’ choices). It allows you to evaluate information & select the most meaningful or adaptive choice (this distinguishes us from simpler animals).