Nervous System

Question 1

Give 4 reasons why we need a nervous system ?

Answer 1

1. Diffusion is too slow beyond cellular level
2. The nervous system provides rapid, precise data transfer allowing animals to analyse and respond to their internal and external environment
3. Highly effective over long distances
4. Evolved in response to the evolution of movement ( hormonal signals also too slow for this )

Question 2

What is the reticular theory and who came up with it ?

Answer 2

means the brains building blocks is a continuous meshwork and theory is by camilla Golgi

Question 3

What is the cell theory and who came up with it ?

Answer 3

is the belief that the brains building blocks are individual cells and theory is by Santiago Ramon y cajal

Question 4

how many times more neurone cells are there than neuroglia cells ?

Answer 4

there are 10 x more neurone cells than neuroglia cells

Question 5

Explain what the cell body is on neurone ?

Answer 5

Bounded by PLASMA MEMBRANE
Diameter is 4-100micrometres

Question 6

Explain what the nucleus is in neurone ?

Answer 6

contains the DNA and template

Question 7

Explain what the mitochondria is in the neurone ?

Answer 7

MITOCHONDRIA - Energy - ATP
HIGH NUMBERS IN NEURONES - Need energy to maintain charge separation across plasma membrane

Question 8

Explain what the ribosomes and rough endoplasmic reticulum is in a neurone ?

Answer 8

• Polypeptide/protein synthesis
• protein assembly/folding
  PRESENT IN CYTOSOL

Question 9

Explain what the Smooth ER and Golgi complex is in the cytosol in the neurone ?

Answer 9

• Lipid/steroid synthesis
• Ca2+ uptake / storage
• protein modification / sorting

Question 10

Explain what the lysosomes and peroxisomes are in the cytosol in the neurone ?

Answer 10

LYSOSOMES - Breakdown and disposal via hydrolytic enzymes
PEROXISOMES - Detoxification via oxidative reactions

Question 11

What are dendrites and what’s there function ?

Answer 11

1. Highly branched processs
2. Increases surface area
3. Receive incoming signals ( via receptor proteins )
4. However some also capable of signal output.

Question 12

What is the myelin sheath and its function ?

Answer 12

1. increase insulation
2. Role od neuroglia
3. Gaps - Nodes of ranvier
4. Many neurones are non - myelinated

Question 13

What is the axon terminal ?

Answer 13

aka boutons or varicosities ( swellings )
many branches
Terminal arbour

Question 14

What is the axon hillock ?

Answer 14

1. Origin of axon
2. Point of nerve impulse ( action potential ) generation

Question 15

What is an action potential ?

Answer 15

The unit of neuronal excitability

Question 16

What is a synapse ?

Answer 16

1. Point of inter-cellular communication
2. Unidirectional

Question 17

What are the 3 main groups of neurotransmitters ?

Answer 17

1. AMINO ACIDS - E.G Glutamate
2. AMINES - E.G adrenaline
3. PEPTIDES - E.G Substance p

Question 18

What is a convergence ?

Answer 18

Multiple input onto an individual neurone

Question 19

What is a divergence ?

Answer 19

An individual neurone outputs onto many others.