Lec 07

Question 1

Nervous system

Answer 1

1- peripheral nervous system
2- central nervous system

Question 2

Central Nervous system

Answer 2

1- Brain
2- Spinal cord

Question 3

Peripheral Nervous System

Answer 3

1- Efferent (outgoing)
2- Afferent (sensory/incoming)

Question 4

Efferent division

Answer 4

Somatic (motor/voluntary) nervous system
Autonomic (visceral/involuntary) nervous system

Question 5

Autonomic nervous system

Answer 5

Parasympathetic
Sympathetic

Question 6

Enteric Nervous system (gut)

Answer 6

Influenced by autonomic nervous system
** But can regulate itself without ans

Question 7

Cells of nervous system

Answer 7

1- Neurons
2- Glial cells/neuroglia

Question 8

Neurons

Answer 8

1- excitable cells
2- carry electrical signal
3- classified based on structure/function

Question 9

Glial cells

Answer 9

-Non-excitable cells
-Physical and biochemical support for neurons
-Classified based on location/function

Question 10

Glial cells in CNS

Answer 10

Ependymal cells — create barriers between compartments
Astrocytes — sweepers
Microglia (immune cells— scavengers)
Oligodendrocytes form Myelin sheath

Question 11

Glial cells in pns

Answer 11

Schwann cells — myelin sheath in pns
Satellite cells — physical support

Question 12

Neuron

Answer 12

1- Nucleus
2- Dendrites
3- Axon hillock
4- axon

Question 13

Axon can have synapses with ——

Answer 13

1- dendrite
2- cell body

Question 14

Nerve

Answer 14

Bundle of axons from multiple neurons

Question 15

Different neural shapes

Answer 15

Different functions

Question 16

Pseudounipolar and bipolar

Answer 16

Sensory neurons

Question 17

Node of Ranvier

Answer 17

-Where action potential regenerated
-Unmyelinated axon membrane

Question 18

Schwann cell nucleus

Answer 18

Pushed to outside of myelin sheath

Question 19

Myelin sheath

Answer 19

Layers of plasma membrane that form insulation

Question 20

Schwann cell form insulation for

Answer 20

Sensory or motor neuron in PNS

Question 21

Disease of dimyelination

Answer 21

-multiple sclerosis: degeneration of CNS myelin
-guillain-barre syndrome: degeneration of PNS myelin— usually temporary

** loss of function depends on nerve affected

Question 22

Electrical signals are

Answer 22

Changes in membrane potential generated by movement of ions

Question 23

———— channels control ion permeability of neural membrane

Answer 23

Voltage gated

Question 24

Graded potential

Answer 24

Depolarization (EPSP) or hyperpolarization (IPSP)
Amplitude depend on -strength of stimulus and density of receptor channel
Signal loose strength with distance traveled

Question 25

Action potential

Answer 25

-Only depolarization
-All-or-none response depend ob threshold
-High density voltage-gated sodium channels required

Question 26

Neuronal electrical signals

Answer 26

1- signal in dendrite (ion permeability)
——graded potential
2- graded potential reach soma
——axon hillock high density of Na channels, if threshold reach, action potential
3- action poten along axon
4- at axon terminal, action potential triggers neurotransmitters release
5- neurotransmitters binds to receptor on postsynaptic dendrite/cell membrane

Question 27

Change in potential will

Answer 27

Reduce by distance from cite of entry

Question 28

Initial amplitude depends on

Answer 28

1- strength of stimulus
2- density of receptor channels

Question 29

Increase strength of stimulus

Answer 29

Increase activation of channels

Question 30

Increase channel density

Answer 30

Increase sensivity to stimuli

Question 31

Membrane resistance R(m)

Answer 31

-Membrane is good insulator— high Rm
-open channel allow ion flow— low Rm

Question 32

Internal resistance of cytoplasm R(i)

Answer 32

Depends on cytoplasm composition
Inversely related to cell diameter