Lecture 11.1-11.5

Question 1

Nervous system

Answer 1

master controlling and communicating system of the body

Question 2

Basic functions of the NS
(3)

Answer 2

• sensory input
• integration
• motor output

Question 3

one NS, divided into two parts. called

Answer 3

Central nervous system (CNS)
Peripheral nervous system (PNS)

Question 4

afferent vs efferent

Answer 4

afferent is sensory, impulses sent TO CNS
efferent is the response, impulse leaves CNS

Question 5

NS is made of two type cells

Answer 5

• neuroglia
• neurons

Question 6

neuralgia

Answer 6

supporting cells, smaller and wrap around delicate neurons

Question 7

neurons

Answer 7

excitable nerve cells

Question 8

astrocytes

Answer 8

• most abundant
• cling to neurons and cover nearby capillaries
• control chemical environment around neurons

Question 9

Microglial cells

Answer 9

• ouch nearby neurons and monitor their health
• phagocytizes

Question 10

Ependymal cells

Answer 10

Form barrier between CSF that fills the cavities and the tissue fluid covering the cells of CNS.

Question 11

Oligodendrocytes

Answer 11

producing an insulating cover called myelin sheath

Question 12

Satellite cells

Answer 12

Same functions as astrocytes

Question 13

Schwann cells

Answer 13

similar to oligodendrocytes

Question 14

Neurons are..

Answer 14

structural units of the NS

Question 15

neuron structural components

Answer 15

• cell body
• axon
• dendrites
• axon terminals
• myelin sheath
• nodes of raniver
• nucleus

Question 16

nucleus vs gangion

Answer 16

Clusters of cell body in CNS = nuclei
clusters of cell body that lie along PNS = ganglia

Question 17

nerve vs tract

Answer 17

Bundles of axons =
tracts (CNS)
nerves (PNS)

Question 18

importance of myelin sheath

Answer 18

Protects and electrically insulates fibers, and increases transmission speed

Question 19

Myelination in PNS

Answer 19

schwann cells (SC)

Wrapping is loose at first but SC cytoplasm is gradually squeezed

Outer collar of perinuclear cytoplasm

Question 20

Myelination in CNS

Answer 20

Has both myelinated and unmyelinated axons

Lack outer collar of perinuclear cytoplasm because the squeezed out cytoplasm is forced back to the nucleus

Question 21

Outer collar of perinuclear cytoplasm

Answer 21

nucleus and cytoplasm of SC end up as a bulge external to MS

Question 22

Voltage

Answer 22

measure of potential energy

Question 23

Current

Answer 23

flow of electrical charge from one point to another

Question 24

Resistance

Answer 24

hindrance to charge flow

Question 25

Ohm’s law

Answer 25

gives relationship between voltage, current and resistance where

current = V/R

Question 26

Chemically gated channels (ligand gated)

Answer 26

open when the right chemical (neurotransmitter) tries to bind

Question 27

Voltage gated channels

Answer 27

open and close to change in membrane potential

Question 28

Mechanically gated channels

Answer 28

open when to physical deformation of receptor

Question 29

Electrochemical gradient

Answer 29

determines the way ions move

Question 30

2 parts Electrochemical gradient:

Answer 30

Concentration gradient: ions move along CG from low to high

Electrical gradient: ions move to opposite charge

Question 31

Change in potential can produce 2 types of signals

Answer 31

Graded potential: incoming signals operating over short distances

Action potential: long distance signals of axons that always have same strength

Question 32

Graded potentials (GP)

Answer 32

short, localized changes in MP, usually in dendrites or cell body

Question 33

GPs are triggered by change, and are given different names 2

Answer 33

Receptor/generator potential: produced when sensory receptor is excited

Postsynaptic potential: when the stimulus is a neurotransmitter released by another neuron.

Question 34

Graded potentials (GP) example

Answer 34

Pacemaker cells in the heart generate graded potentials that initiate the heartbeat.