Neurons First Test Part Two

Question 1

three characteristics distinguish axons from dendrites

Answer 1

axons carry messages/neurotransmitters to other cells while dendrites receive messages
dendrites have polyribosomes while axons don’t
axons are trunks and dendrites are closer to branches

Question 2

site of protein synthesis for proteins destined for membrane

Answer 2

rough er

Question 3

scaffolding of cell

Answer 3

cytoskeleton

Question 4

site of protein synthesis for proteins destined for cytosol

Answer 4

free ribosome

Question 5

protein folding may take place here

Answer 5

smooth er

Question 6

sorting of proteins for delivery, some processing

Answer 6

golgi body

Question 7

site of cellular respiration

Answer 7

mitochondria

Question 8

neurofibrillary tangles

Answer 8

the tombstones of dead and dying neurons

contain protein tau

Question 9

how does tau normally function, what is responsible for its malfunction

Answer 9

normally is a bridge between the microtubules in an axon and ensures they run straight and parallel to one another
abnormal secretion of amyloid leads to malfunction

Question 10

what happens to neurons in alzheimer’s

Answer 10

cytoskeleton is disrupted, their ability fades, and they eventually die

Question 11

differences between soma and axon

Answer 11

1. no rough er extends into the axon and few if any free ribosomes
2. protein composition of axon membrane fundamentally different from soma membrane
3. axon transfers info whereas soma is cell body

Question 12

characteristics of neurons

Answer 12

extreme longevity (can live for a long time if supported)
amitotic (can't reproduce/do mitosis)
exceptionally high metabolic rate (needs lots of energy and oxygen)

Question 13

cytoplasm at axon terminal vs cytoplasm in remainder of axon

Answer 13

1. microtubules don’t extend into terminal
2. terminal has numerous small bubbles of membrane called synaptic vesicles
3. inside surface of membrane that faces synapse has particularly dense covering of proteins and numerous mitochondria (high energy demand)

Question 14

effect of colchicine (drug that causes microtubules to break apart of depolymerize) on anterograde transport

Answer 14

inhibit anterograde transport

Question 15

how is fast anterograde transport by axons studied

Answer 15

inject soma with radioactive amino acids then use autoradiography to determine location of radioactive axon terminals

Question 16

two viruses that use retrograde transport to gain access to neuron’s cell body

Answer 16

oral herpes, remains dormant until physical or emotional stress occurs
rabies, destroys the host neuron right away

Question 17

PKU

Answer 17

a deficit in the liver enzyme that metabolizes the dietary amino acid phenylalanine
infants born with PKU have abnormally high level of amino acid in blood and brain, stunting brain growth

Question 18

3 more causes of developmental disabilities

Answer 18

accidents during pregnancy and childbirth
poor nutrition during pregnancy
environmental impoverishment
sensory stimulation during infancy

Question 19

how does early stimulation affect neuron development

Answer 19

makes neurons and connections between neurons stronger, aiding in child development

Question 20

changes that marin-padilla and purpura discover about dendritic spines of kids with cognitive disabilities

Answer 20

dendrites of kids with cognitive disabilities had many fewer dendritic spines and the spines they did have were unusually long and thin

Question 21

how improve cog function

Answer 21

intervention, early enough, start to form more connections

Question 22

ways to classify neurons

Answer 22

numer of neurites (unipolar, bipolar, multipolar)
dendrites (stellate cells, pyramidal cells, alpha cells)
connections (primary sensory neurons, motor neurons, interneurons)
axon length (golgi type I, type II)
neurotransmitter (acetylcholine, cholinergic)