Neurones and Synapses- topic 4

Question 1

what are the general job of neurones?

Answer 1

-they transmit electrical nerve impulses throughout the body

Question 2

what are the 2 general jobs of synapses?

Answer 2

-fine control and integration

Question 3

is nervous control faster or slower than hormone control?

Answer 3

-it is faster and more precise

Question 4

what are the three pasts of any nervous system?

Answer 4

-the receptor
-effector
-and an interlinking coordinator

Question 5

what are receptors and where are they found?

Answer 5

-receptors are found in any sensory organ e.g. ear, mouth
-their job is to receive a stimulus

Question 6

what is a stimulus and what does it stimulate?

Answer 6

-it is anything that will stimulate a receptor organ e.g. smell, taste

Question 7

what are effectors and where are they found?

Answer 7

-they produce a response and are found in the muscles

Question 8

what system in the body involves coordination?

Answer 8

-the central nervous system (CNS)

Question 9

what is the central nervous system? what is the jobs of neurones in the CNS?

Answer 9

-it contains the brain and the spinal cord
-the neurones in the body travel to the CNS from receptors and from the CNS to effectors

Question 10

what are the 3 types of neurones?

Answer 10

-motor neurones
-sensory neurones
-connector neurones

Question 11

what is the job of motor neurones?

Answer 11

-carry impulses from the CNS to effectors (muscles/ gland)

Question 12

what is the job of sensory neurones?

Answer 12

-carry impulses from receptors to the CNS

Question 13

what is the job of connector neurones?

Answer 13

-connect neurones within the CNS

Question 14

look at the diagram of the different neurones in the book pg 56

Answer 14

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Question 15

what are the two parts that every neurone contains?

Answer 15

-a cell body and extended nerve fiber

Question 16

what are the different parts that the cell body contains? and what is another name for the cell body?

Answer 16

-nucleus
-mitochondria
-large groups of ribosomes
-centron

Question 17

what are the two types of nerve fibers and what are their jobs?

Answer 17

-axon is nerve fibers that carry the impulses away from the cell body
-dendron is nerve fibers that carry the impulse to the cell body

Question 18

what type of neurone has only axon as its nerve fiber? why?

Answer 18

-motor neurone
-because their job is to carry impulses to muscles and glands rather then to the cell body

Question 19

what are dendrites?

Answer 19

-very small extensions which can conduct impulses into the dendron cell body

Question 20

what are synaptic bulbs?

Answer 20

-they are the end of the axon

Question 21

what does myelinated mean?

Answer 21

-it means that the nerve fibers (axon and dendron) are covered with an insulating myelin sheath

Question 22

are all nerve fibers myelinated?

Answer 22

-most but not all

Question 23

how is the myelin sheath formed?

Answer 23

-from Schwann cells which extend the entirety of the cell surface membrane of the axon or dendron

Question 24

what way are the Schwann cells arranged around the nerve fiber? what is found between each cell?

Answer 24

-arranged at intervals along the nerve fiber
-there are small gaps between each cell called nodes of Ranvier where the axon or dendron is exposed

Question 25

what are the 2 jobs of the myelinated sheath?

Answer 25

-protection
-speeds up nervous conduction

Question 26

look at diagrams on page 57

Answer 26

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