nervous system

Question 1

what is the basic structure of a neurone?

Answer 1

Dendron, cell body(which contains nucleus and cytoplasm) and axon

Question 2

what are dendrons?

Answer 2

they are nerve fibres which send nerve impulses towards the cell body

Question 3

what are axons?

Answer 3

they are nerve fibres which carry nerve impulses away from the cell body

Question 4

transport of nerve impulse in the motor neurone

Answer 4

cell body in the motor neurone is irregular in shape. dendrites of the dendrons receives nerve impulses from other neurones and these nerve impulses are transmitted from node to node to the axon and to the axites where nerve impulses are transmitted to the effector

Question 5

what is the myelin sheath?

Answer 5

it is a layer of fatty substances that shields and insulates the nerve fibre and it is surrounded by a membrane aka neurilemma

Question 6

what is the node of Ranvier?

Answer 6

it is the region where myelin sheath is absent. it speeds up transmission by allowing nerve impulses to jump from node to node

Question 7

what is the motor end plate?

Answer 7

the junction between the axite and the muscle fibre

Question 8

what do sensory neurones do?

Answer 8

they transmit nerve impulses from sense organs to the central nervous system

Question 9

what is the Axon Hillock?

Answer 9

it is the specialised part of the cell body that connects to the axon

Question 10

what is the schwann cell?

Answer 10

it is myelin secreting cell

Question 11

what is the synapse?

Answer 11

it is the junction between 2 neurones. nerve impulses from axon are transmitted to dendron by chemical means. nerve impulses are converted into neurotransmitters in the synapse

Question 12

what are nerves?

Answer 12

nerves are a bundle of nerve fibres enclosed in a sheath of connective tissues

Question 13

what is a nerve fibre?

Answer 13

it is a strand of cytoplasm extending out from the cell body

Question 14

what do the brain and spinal cord consist of?

Answer 14

grey matter and white matter

Question 15

what is the grey matter?

Answer 15

it composes of the cell bodies of the neurones and is located on the outer layers of the brain and central parts of the spinal cord

Question 16

what is the white matter?

Answer 16

it composes of the nerve fibres of the neurone and is located in the central parts of the brain and outer parts of the spinal cord

Question 17

what surrounds the spinal cord?

Answer 17

the spinal cord is encased within the vertebral column which serves as protection

Question 18

what runs through the middle of the spinal cord?

Answer 18

a narrow canal containing cerebrospinal fluid

Question 19

what do the spinal nerves divide into?

Answer 19

dorsal root containing only sensory neurone and ventral root only containing motor neruone. cell bodies of the sensory neurones are clustered together in the dorsal root ganglion. the grey matter in the spinal cord mainly contains cell bodies of the motor and relay neurones

Question 20

how does the central nervous sytem process information?

Answer 20

information is gathered by receptors and is converted in electrical signals aka nerve impulses from the sensory neurone to the relay neruone in CNS. brain processes information based on the pattern of the nerve impulses and sends nerve impulses to the effector via the motor neurones for the intended action to be carried out

Question 21

what is reflex action?

Answer 21

it is the immediate response to a specific stimulus without conscious control of the brain

Question 22

what is the reflex arc?

Answer 22

it is the shortest pathway of nerve impulses from the receptor to the effector

Question 23

types of reflex actions?

Answer 23

cranial reflex and spinal reflex