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Flashcards in The mammalian nervous system Deck (166)
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1

What is the nervous system made up of

Interconnected neurons specialized for the rapid transmissions of impulses throughout the body

2

What do neurons carry

Impulses from special receptor cells and specialized effector cells

3

Where are sense organs

Eyes, ear

4

What are sensory neurons

Neurons that only carry information from the internal or external environment into the central processing areas of the nervous system

5

What happens as animals increase in size and complexity

They develop more specialized concentrations of nerve cells, which form the central nervous system

6

What is the central nervous system (CNS)

Incoming information from sensory neurons is processed, and from where impulses are sent out through motor neurons

7

Where is the CNS in vertebrates

Brain and spinal cord

8

What are neurons made up of

Individual cells and each one has a long nerve fibre that carries the nerve impulse

9

What are nerves

Bundles of nerve fibres called axons and dendrons

10

What are:
motor nerves
sensory nerves

Nerves that only carry motor fibres
Nerves that only carry sensory fibres

11

What is the peripheral nervous system (PNS)

The parts of the nervous system that are not within the central nervous system

12

What are neurons

The basic unit of a nervous system

13

What are nerve impulses

Neuron cells specialized in the transmission of electrical signals

14

What is the structure of a neuron
Why does it contain these components

The cell body contains:
cell nucleus
mitochondria
RER
Needed for the synthesis of the neurotransmitter molecules

15

What are dendrites
What does it do

The cell body of the neurons have slender finger-like processes
connects to the neighboring nerve cells

16

What is the most distinctive feature on a nerve cell
How does it look

Nerve fibre
extremely long and thin and carries the nerve impulse

17

What are axons

Fibres that carry impulses away from the nerve cell body

18

What are dendrons

Fibres that transmit impulses towards the cell body

19

What connects the motor and sensory neurons

Short relay neurons that are found in the CNS

20

What does a Schwann cell do
What is a myelin sheath

The membrane wraps itself repeatedly around the nerve fibre, forming a fatty layer known as a myelin sheath

21

What are the nodes of Ranvier

Gaps between the Schwann cell

22

Give two reasons why the myelin sheath is important

1)It protects the nerves from damage
2)Speeds up the transmission of nerve impulse

23

What is the role of the nervous system

To quickly carry electrical impulses from one area of the body to another

24

What two factors do the speed at which impulses can be carried in the nervous system depend on

1)Diameter of the nerve fibre (The thicker the fibre, The more rapidly impulses travel)
2)Presence or absence of the myelin sheath (myelinated nerve fibes carry impulses faster)

25

Which of the two don't have myelin sheath on the nerves:
Invertebrates
Vertebrates

Invertebrates hence the reason they travel so slow

26

In Vertebrate animals which neurons are myelinated
and which are unmyelinated

Voluntary motor neurons
Autonomic neurons

27

What is one of the most effective ways you can investigate nerve impulses

Nerve impulses are electrical so to record and measure the tiny electrical changes

28

What is the basis of nerve impulse

The fact that the concentration of sodium ions, potassium ions, and other charged particles outside the axon is different from the inside

29

Is the membrane of the axon permeable

YES

30

What gives the axon its special conducting properties

The difference in permeability of this membrane to positively charged sodium and potassium ions