Bsc 2011C Exam Three Flash Cards Nervous System

Front 1

What animals DON'T have nervous systems?

Back 1

sponges

Front 2

Transfer information via electrochemical energy?

Back 2

Neurons

Front 3

Support cells for neurons?

Back 3

Glial Cells

Front 4

Three main parts of a Neuron?

Back 4

1. Dendrites
2. Cell Body
3. Axon

Front 5

Dendrites?

Back 5

- bring electrical stimuli from other neurons or sensory epithelial cells to the cell body.
- several to many per neuron

Front 6

Cell Body?

Back 6

- receives stimuli from dendrites or other neurons and propagates to axon
- synthesizes some neurotransmitters (or neurohormones)
- contains nucleus and other cell organelles

Front 7

Axon?

Back 7

- receives stimulus from cell body of neuron and propagates signal to synapse
- only 1/ cell but distal end has several to many branches (thus each neuron can contact many other neurons)
- synthesizes some neurotransmitters in synaptic terminals

Front 8

What can synthesize neurotransmitters?

Back 8

Cell body and Axons

Front 9

Some neurons called ___________ transmit chemicals called ___________ directly into the blood stream

Back 9

neurosecretory cells

neurohormones

Front 10

Difference between neurotransmitters and neurohormones?

Back 10

Neurotransmitters act on specific cells to which they have a synaptic connection vs. neurohormones act on many cells via circulatory system.

Front 11

Afferent Neurons?

Back 11

aka Sensory Neurons
transmit info from external or internal sensors to the brain (or ganglia)

Front 12

Interneurons?

Back 12

-Found exclusively within the spinal cord and brain
-Have many more dendrites than other neuron types (~100k)
-Analyze and interpret sensory input

Front 13

Efferent Neurons

Back 13

Aka Motor Neurons
– transmit signals to muscle and gland cells from the brain (or ganglia)
- primarily stimulated by interneurons

Front 14

Neurosecretory

Back 14

transmit chemicals into blood which act on distant targets

Front 15

Nerves are Bundles of _______

Back 15

-Axons

Front 16

Central Nervous System (CNS) =

Back 16

Brain + spinal cord

Front 17

Peripheral Nervous System (PNS) =

Back 17

Cranial nerves + Spinal nerves + Ganglia
(i.e. nerves only occur in the PNS)

Front 18

- A dense cluster of interconnected neuron cell bodies that, depending on the type, relay sensory (spinal ganglia) information to (afferent) or motor outputs from (efferent) spinal cord.

Back 18

Ganglion

Front 19

Ganglion do not contain _________ or _________; they only contain cell bodies.

Back 19

axons or dendrites

Front 20

Ganglion occur in the ______ of vertebrates but in the _______ of invertebrates

Back 20

In PNS in vertebrates but in CNS in invertebrates

Front 21

What major nerve is NOT a mixed nerve?

Back 21

Optical -- only afferent/sensory

Front 22

How many cranial nerve pairs are there (how many total)? Where do they originate and what do they "Serve"?

Back 22

12 pairs (24 total)

Originate in brain and serve head and neck

Front 23

How many spinal nerve pairs are there (how many total?) Where do they originate and what do they "Serve"?

Back 23

31 pairs (62 total)

Originate in spine and serve body below the head

Front 24

Glial cells occur only in the _____?

Functions?

Back 24

CNS

Anchor neurons
Improve nutrient delivery to neurons
Remove dead neurons
Form myelin sheath around axons
Circulate cerebrospinal fluid

Front 25

Glial cells that form myelin sheath around axons in the PNS?

CNS?

Back 25

Schwann Cells (PNS)
Oligodendrocytes (CNS)

Front 26

membrane potential of a nontransmitting neuron? Numerical value?

Back 26

Resting potential?

-60 to -80mV

Front 27

The inside of the cell has ______ positive ions than the outside of the cell.

Back 27

Fewer = more negative

Front 28

Major intracellular cation and anion?

Back 28

Intracellular:
cation: potassium, anion: protein

Extracellular:
cation: sodium; anion: chloride

Front 29

Open due to binding of chemical to ion channel (e.g. neurotransmitter)

Back 29

Ligand-gated channels

Front 30

__________ is triggered when depolarization allows the membrane potential (mV) to reach a particular “threshold” value of _____ in mammals.

Back 30

Action potential

-55mV

Front 31

Depolarization

Back 31

Sodium channels open and sodium rushes in

Front 32

Rising phase of Action potential

Back 32

Threshold is reached and most of the sodium channels open

Front 33

Myelin sheath is present only in _______

Back 33

vertebrates

Front 34

Myelin sheath allows _______ conduction

Back 34

saltatory

Front 35

Cell bodies, dendrites and unmyelinated axons of interneurons and motorneurons, capillaries glial cells

Back 35

Grey matter

Front 36

Myelinated axons of motor and sensory neurons

Back 36

White matter

Front 37

Area of unmyelinated tissue between sections of myelinated axons?

Only area that contains voltage gated Na channels thus it is the __________

Back 37

Node of Ranvier

region of depolarization

Front 38

-Na+ etc. move from pre- to postsynaptic neuron
-Bidirectional
-Involved in rapid unvarying behaviors (escape reflex)

Back 38

Electrical synapses (gap junctions)

Front 39

-Depolarization of voltage-gated Ca2+ channels (vs Na+ & K+ in rest of axon).
-Ca2+ enters & causes synaptic vessel exocytosis of NT
-NT crosses synapse and binds to ligand-gated ion channels on postsynaptic dendrite or cell body

Back 39

Chemical synapses

Front 40

Function of Ca2+ and Na+ in chemical synapses.

Back 40

Calcium causes exocytosis of neurotransmitter

After the NT binds it opens up sodium channels which causes post-synaptic cell to depolarize