Nervous System (Intro)

Question 1

Master control and communication system and has 3 overlapping functions

Answer 1

Nervous System

Question 2

Uses its millions of sensory receptors to monitor changes occurring both inside and outside the body

Answer 2

Sensory Input

Question 3

processes and interprets the sensory input and decides what should b done at each moment

Answer 3

Integration

Question 4

Causes a response, or effect, by activating muscles, or glands

Answer 4

Motor Output

Question 5

2 organisations of Nervous System

Answer 5

Structural Classification
Functional Classification

Question 6

Give the structural classification of the nervous system

Answer 6

Nervous System (central nervous system and peripheral nervous system)
CNS (brain and spinal cord)
PNS (cranial and spinal nerves)

Question 7

Give the functional classification of the nervous system

Answer 7

Peripheral Nervous System
(Autonomic Nervous System and Somatic Nervous System)
Autonomic
- Sympathetic
- Parasympathetic

Question 8

Aka glial cells. Supports the nerve cells/ neurons. Non-excitable (do not produce action potential) cells and support cells

Answer 8

Neuroglia

Question 9

Different Kinds of Neuroglia

Answer 9

• Microglia
• Oligodendrocytes
• Astrocytes
• Ependymal Cells
• Schwann Cells
• Satellite Cells

Question 10

Macrophages in the central nervous system. Acts as defense against infection and injury

Answer 10

Microglia

Question 11

Forms and maintain myelin sheath in the central nervous system

Answer 11

Oligodendrocytes

Question 12

Star shaped cells and most numerous and abundant.

Answer 12

Astrocytes

Question 13

Functions of Astrocytes

Answer 13

-Provides structural support to the central nervous system.
-Takes up extracellular potassium (K) ions.
- Regulates the extracellular concentration of neurotransmitter.
- Glycogen storage
- Capable of cell- multiplication/ replacement gliosis.

Question 14

Located in the ventricle and central canal of the spinal cord. Assists in the circulation of cerebrospinal fluid (provides nourishment)

Answer 14

Ependymal Cells

Question 15

Forms the myelin sheaths around nerve fibers in the peripheral nervous system

Answer 15

Schwann cells

Question 16

Act as protective, cushioning cells for peripheral neuron cell bodies

Answer 16

Satellite cells

Question 17

What are the parts of neuron

Answer 17

• Cell body
• Dendrites
• Axon
• Axon terminals
• Myelin Sheaths
• Nodes of Ranvier

Question 18

Has nuclei, cytoplasm with typical organelles. (Action potential happens here)

Answer 18

Cell body

Question 19

Highly branched structures that carry impulses (towards) to the cell body

Answer 19

Dendrites

Question 20

Emerges at cone-shaped axon hillock. Conducts AWAY from cell body towards another neuron, muscle, or gland.

Answer 20

Axon

Question 21

Contains synaptic vesicle that can release neurotransmitter

Answer 21

Axon terminals

Question 22

Whitish, fatty material which has a waxy appearance. It protects and insulates the fibers and increases the transmission rate of the nerve impulses

Answer 22

Myelin Sheaths

Question 23

Gaps or indentations and facilitates saltatory conduction

Answer 23

Nodes of Ranvier

Question 24

Collection of cell bodies inside the CNS

Answer 24

Nuclei

Question 25

Collection of cell bodies outside the CNS

Answer 25

Ganglia

Question 26

Bundles of nerve fibers running through the CNS

Answer 26

Tracts

Question 27

Bundles of nerve running through the PNS

Answer 27

Nerves

Question 28

Found inside the brain but found outside of the spinal cord. Consists of dense collection of myelinated fibers (tracts)

Answer 28

White Matter

Question 29

Found outside the brain but inside the spinal cord. Contains mostly of unmyelinated fibers and cell bodies.

Answer 29

Gray Matter

Question 30

What are the functional classes of neurons

Answer 30

- Sensory ( Afferent ) - Motor ( Efferent ) - Interneuron

Question 31

Conveys impulses into the CNS Examples are dorsal root ganglion, cutaneous sense organ, and proprioceptor (sense of direction and place)

Answer 31

Sensory (Afferent)

Question 32

Convey impulses from brain / spinal cord out through PNS to effector (muscle or organ)

Answer 32

Motor (Efferent)

Question 33

aka "associated neurons" most are within the cns and it transmits impulses between sensory and motor neuron. Acts as a bridge

Answer 33

Interneuron

Question 34

Structural Classes of Neurons

Answer 34

- Multipolar - Bipolar - Unipolar

Question 35

Have several/ many dendrites and 1 axon. Most common type in the CNS. Examples are; motor pyramidal, purkinje cell.

Answer 35

Multipolar

Question 36

One dendrite and 2 axon. Example are Retina of the eye, inner ear, and nose.

Answer 36

Bipolar

Question 37

Have fused dendrite and axon. Touch and pain sensory neuron. Example (sensory neuron of spinal nerves)

Answer 37

Unipolar

Question 38

Two major functional properties of nervous system

Answer 38

- Irritability - Conductivity

Question 39

also called as the nerve impulse in neurons

Answer 39

Action Potential

Question 40

What is the normal resting potential

Answer 40

-70 mv

Question 41

An increase in membrane potential of 15-30 mV usually is required to cause an explosive development of action potential.

Answer 41

All or none principle

Question 42

Overshoot period/ phase caused by the fast opening of the voltage gated Na channel (opening of activation gate). There is also a sodium influx and the charge of the cell becomes positive.

Answer 42

Depolarization

Question 43

How many mv does depolarization starts

Answer 43

-55mv

Question 44

Cause by the fast closure of voltage gated sodium channels. There is a potassium efflux and the charge of the cell becomes negative.

Answer 44

Repolarization

Question 45

Aka positive after potential. Caused by the slow and late closure of voltage gated potassium channels. The charge of the cell becomes more negative.

Answer 45

Hyperpolarization

Question 46

A state wherein a positive charge is outside and negative charge inside the cell. This is due to the activation of sodium- potasium atpase pump. This is where the charge of the cell returns to normal membrane potential

Answer 46

Resting membrane potential

Question 47

How many NA and K is in the resting membrane potential?

Answer 47

- 3 NA (OUTSIDE) + 2 K (INSIDE)

Question 48

What are the normal resting membrane potential of each system

Answer 48

NN -70mV Skeletal Muscle -90mV Cardiac Muscle -85mV Smooth muscle - 40mV to -60mV GI tract -56mV

Question 49

What are the phases of action potential?

Answer 49

Depolarization Repolarization Hyperpolarization Resting Membrane Potential

Question 50

2 Refractory Period

Answer 50

Absolute Refractory Period Relative Refractory Period

Question 51

Period during which a 2nd action potential cannot be elicited even with a strong stimulus. At the (30mV) peak of depolarization.

Answer 51

Absolute Refractory Period

Question 52

Starts at the 1/3 of repolarization onwards. Stronger than normal stimulus and elicits new action potential.

Answer 52

Relative Refractory Period

Question 53

Explain Neuromuscular Junction

Answer 53

- Action potential reaches presynaptic terminal - Depolarization in PT opens ion channel that allows calcium into the cell - Calcium trigger release of neurotransmitter from vesicles. - Neurotransmitter binds to receptor sites - Opening and closing of channels causes change in postsynaptic membrane potential - Action potential propagates through next cell - Neurotransmitter is inactivated

Question 54

3 overlapping function of Nervous system

Answer 54

Sensory Input Integration Motor Output