Nervous System- nervous tissue, neurons, neuroglia

Question 1

3 neuron characteristics

Answer 1

• extreme longevity
• amitotic
• high metabolic rate

Question 2

The biosynthetic centre of a neuron

Answer 2

Neuron cell body

Question 3

Which part of the neuron contains an axon hillcock?

Answer 3

Neuron cell body

Question 4

Does a neuron cell body contain a nucleus?

Answer 4

Yes, a large nucleus with nucleolus

Question 5

Structure of a dendrite

Answer 5

Short, branched processes

Question 6

The receptive region of a neuron

Answer 6

Dendrites

Question 7

How do dendrites convey incoming information to a cell body?

Answer 7

As graded potentials

Question 8

Axon contains vesicles of…

Answer 8

Neurotransmitter

Question 9

Axons do not contain…

Answer 9

Ribosomes or golgi = no protein synthesis

Question 10

Distal endings of an axon

Answer 10

Axon terminals/Terminal boutons

Question 11

Axon function

Where are nerve impulses/action potential generated?

Answer 11

At the axon initial segment (AIS), conducted along axolemma to axon terminal

Question 12

What happens if an axon gets cut or damaged?

Answer 12

-Anterograde degeneration-

Question 13

Two functions of myelin sheath

Answer 13

• Protect and electrically insulate axon

- Increase speed of nerve impulse conduction

Question 14

What are myelinated fibres?

Answer 14

Segmented sheath that surrounds most long/large-diameter axons

Question 15

How is myelination in the PNS formed?

Answer 15

By Schwann cells

Question 16

Myelination in the PNS-

What are the gaps called?

Answer 16

Nodes of Ranvier

Question 17

How is myelination in the CNS formed?

Answer 17

By processes of oligodendrocytes

Question 18

What is the white matter made of in CNS division?

Answer 18

Myelinated fibres

Question 19

What is the grey matter made of in CNS division?

Answer 19

Neuron cell bodies

Question 20

Anterograde axoplasmic transport

Answer 20

From terminal/membrane towards soma

Question 21

3 different types of neurons

Answer 21

• Sensory/afferent neurons
• Motor/Efferent neurons
• Interneurons/association neurons

Question 22

Function classification of sensory/afferent neurons

Answer 22

• Transmit impulses from sensory receptors to CNS
• Almost all are pseudounipolar
• Soma in ganglia in PNS

Question 23

Function of somatic sensory neurons

Answer 23

Receptors monitor outside conditions

Question 24

Function of visceral sensory neurons

Answer 24

Receptors monitor internal conditions

Question 25

Functional classification of motor/efferent neurons

Answer 25

- Transmit commands from CNS to effectors | - Mostly multipolar

Question 26

Function of somatic motor neuron

Answer 26

- Innervate skeletal muscle | - Conscious control or reflexes

Question 27

Function of visceral/autonomic motor neurons

Answer 27

Innervate effectors on smooth muscle, cardiac muscle, glands, adipose

Question 28

Functional classification of interneurons/association neurons

Answer 28

- Distribute sensory information and coordinate motor activity - In brain, spinal cord, autonomic ganglia

Question 29

Functions of neuroglia

Answer 29

- Surround neurons - Insulate - Supply nutrients and oxygen - Destroy pathogens and remove dead neurons

Question 30

What are the four main neuroglia that support CNS neurons?

Answer 30

- Astrocytes - Microglial cells - Ependymal cells - Oligodendrocytes

Question 31

Structure of astrocytes

Answer 31

Most abundant, versatile and highly branched

Question 32

Functions of astrocytes (6)

Answer 32

- Blood brain barrier - Control chemical environment - Support neurons - Repair - Guide neuron development - Information processing

Question 33

Structure of microglia

Answer 33

Small, ovoid cells with thorny processes that touch monitor neurons

Question 34

Function of microglia

Answer 34

CNS defence

Question 35

Structure of oligodendrocytes

Answer 35

Wide, flat processes wrap local axons

Question 36

Function of oligodendrocytes

Answer 36

Forms myelin sheath and node of Ranvier= faster action potential conduction

Question 37

Structure of ependymal cells

Answer 37

- Columnar shape - Line ventricles of brain and central canal of spinal cord - Have cilia= circulate CSF (cerebrospinal fluid)

Question 38

Functions of ependymal cells (2)

Answer 38

- Cushions brain | - Nutrients and gas exchange between CSF and nervous system

Question 39

What are the two cells in neuroglia in PNS?

Answer 39

- Satellite cells | - Schwann cells

Question 40

Structure of satellite cells

Answer 40

Surround soma in ganglia

Question 41

Function of satellite cells

Answer 41

Regulate chemical environment of ganglia

Question 42

Structure of Schwann cells

Answer 42

Whole cell wraps axon to form myelin sheath

Question 43

Functions of Schwann cells (2)

Answer 43

- Forms node of Ranvier= faster AP conduction | - Vital for regeneration of damaged nerve fibres