Brain function 1

Question 1

what is a neuron ?

Answer 1

chemical and electrical info and communication cells

variable sizes and structure throughout the nervous system

Question 2

what is the neurons cellular constituents ?

Answer 2

microtubules (transportation)
neurofibrils (structural support)
Nissl substances (protein synthesis )

Question 3

what are the three components of the neuron ?

Answer 3

cell body (soma )
dendrites
axons

Question 4

where is cell body located ?

Answer 4

The CNS

Question 5

What is dendrites ?

Answer 5

receptive portion of the neuron

sends impulses to the cell body

Question 6

what is the dendritic zone ?

Answer 6

receptive portion of the neuron receives stimulus and continues further conduction

Question 7

what is the axon?

Answer 7

carry nerve impulses away from cell body

Question 8

what is axon hillock ?

Answer 8

is a cone shaped , organelle - free area where the axon leaves the cell body

Question 9

where does action potential begins ?

Answer 9

axon hillock

Question 10

what insulates the axon ?

Answer 10

myelin maintained and formed by the Schwann cells

Question 11

what are nodes of Ranvier ?

Answer 11

regular interruptions of the myelin sheath

Question 12

what is the neurilemma ?

Answer 12

Schwann sheath

Question 13

how can neurons be classified ?

Answer 13

basis of the number of processes extending from cell body

Question 14

what are multipolar neurons ?

Answer 14

each with one axon and two or more dendrites

most common

Question 15

what are bipolar neuron ?

Answer 15

with one dendrites and one axon

comprise the sensory neurons of the retina , olfactory epithelium and the inner ear

Question 16

what are unipolar / pseudounipolar neuron ?

Answer 16

includes other sensory neurons

each have single process that bifurcates close to the perikaryon

longer branch extending to peripheral ending to CNS

Question 17

What are anaxonic neurons ?

Answer 17

with many dendrites but no true axon

do not produce action potential

Question 18

is a motor neuron multipolar ?

Answer 18

yes

Question 19

what are sensory neurons ?

Answer 19

transmits impulses from peripheral sensory receptor to the CNS

Are transmitted via an afferent pathway

(Afferent = arrive )

Question 20

what are associational / interneurons ?

Answer 20

transmits impulses neuron to neuron

Question 21

what are motor neurons ?

Answer 21

transmits impulse from the CNS to an effector organ

transmitted via efferent pathway ( efferent = exit)

Question 22

what is neuroglia ?

Answer 22

nerve glue

Question 23

what are the four types of neuroglia ?

Answer 23

astrocyte
microglial cell
ependymal cell
oligodendrocyte

Question 24

what are Schwann cells also called ?

Answer 24

neurolemmocytes

Question 25

what type of cells are schwann cells ?

Answer 25

glial

Question 26

what do Schwann cells do ?

Answer 26

form and maintain myelin sheath

Question 27

what is somatic nervous system ?

Answer 27

voluntary movement

Question 28

what is the autonomic nervous system ?

Answer 28

involuntary movement

Question 29

what are synapses?

Answer 29

regions between adjacent neurons

impulses transmitted across synapse by electrical or chemical conduction

Question 30

what is a axoaxonic synapse ?

Answer 30

between axons

Question 31

what is a axosomatic synapse?

Answer 31

axon to cell body

Question 32

what is a axodendritic synapse ?

Answer 32

axon to dendrite

Question 33

what is dendrodentritic synapse ?

Answer 33

dendrite to dendrite

Question 34

what happens to neurons and neuroglia when ageing ?

Answer 34

gradual loss

Question 35

what happens to ventricles when the brain ages?

Answer 35

progressive loss of cell lining ventricles

Question 36

what happens to pigmentation on the brain when ages ?

Answer 36

increase in lipofuscin (brown ) and neuromelanin ( black )

Question 37

what is the hippocampus ?

Answer 37

memory and skill acquisition of the brain

Question 38

what are the NMJ dysfunction ?

Answer 38

inflammation

mitochondrial dysfunction and oxidative stress

neurodegeneration

Question 39

what are some structural changes when ageing in the nervous system ?

Answer 39

decreased number of neurons
decrease brain weight and size
fibrosis and thickening of the meninges
narrowed gyri and widened sulci
increased ventricles

Question 40

what are some cellular changes to the nervous system when ageing ?

Answer 40

decreased myelin
deposition of lipofuscin
presence of senile plaques
multiple neurofibrillary tangles
lewy bodies