KINE 2P09; LECTURE THREE PART ONE

Question 1

What is the central nervous system made of

Answer 1

composed of the brain and spinal cord

Question 2

What is the peripheral nervous system made of

Answer 2

nerves that connect the brain or spinal cord with the body’s muscles, glands, sense, organs, and other tissues

Question 3

What is the Node of Ranvier

Answer 3

Spaces between myelinated segments

Question 4

Efferent

Answer 4

relay information away from CNS

Question 5

Afferent

Answer 5

relay information to CNS

Question 6

Interneurons

Answer 6

Connect neurons within the CNS (responsible for 99%)

Question 7

Nerves

Answer 7

are a collection of afferent and efferent axons that are held together with connective tissue and receive blood supply

Question 8

Glial Cells of the CNS

Answer 8

Surrounding neuronal axons and dendrites providing structural and metabolic support

Question 9

Oligodendrocytes

Answer 9

form myelin sheath around CNS axons

Question 10

Astrocytes

Answer 10

1. regulate extracellular fluid in the CNS by removing potassium ions and neurotransmitters around synapses
2. form tight junctions among cells of CNS capillaries forming the blood-brain barrier (protect brain from drugs)

Question 11

Microglia

Answer 11

specialized, macrophage-like cells that perform immune functions in the CNS and may also contribute to synapse remodeling and plasticity

Question 12

Ependymal cells

Answer 12

Line the fluid-filled cavities within the brain and spinal cord and regulate the production of cerebrospinal fluid.

Question 13

Electrical potential

Answer 13

Potential work achieved if separated electrical charges come together

Question 14

Potential difference

Answer 14

Build up of opposite charges on either side of the membrane
(Measured in volts/millivolts)

Question 15

Current

Answer 15

movement of electrical charge

Question 16

Resistance

Answer 16

hindrance to electrical charge movement

Question 17

Ohms Law

Answer 17

Current (I) = electrical potential (V) / Resistance ®

Question 18

Equilibrium potential

Answer 18

electrical potential required to balance a given ionic concentration gradient across a membrane so that the net flux for that ion is zero

Question 19

Relative permeabilities for neurons (Potassium, Sodium, chloride)

Answer 19

• Potassium: 1 (lots of open K leak channels at rest = high permeability and far greater than other = strongest contributor)
• Sodium: 0.04 (some open Na channels at rest = low permeability)
• Chloride: 0.45 (moderate permeability at rest)

Question 20

Bulk flow

Answer 20

potassium moving out and not so much sodium due to the lack of openings

Question 21

What is the values of the one molecule that is flipped in the equilibrium equation?

Answer 21

Chloride is switched on the equilibrium equation and its values are inside- 7mM and outside 100mM