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