Download Lecture #11 Development of the Nervous System Part II

Lecture #11 Development of the Nervous System Part II
1. Through the secretion of neurotransmitters and hormone, neurons
communicate across synapse and regulate what function?
2. What is the function of the astrocytes?
3. What do oligodendrocytes do?
4. What percentage of oxygen consumption does the adult brain receive?
5. What is part of the brain develops first and why?
6. The forebrain and the cerebellum develop significantly after birth. Why?
7. What is the major source of fetal energy and where does it come from?
8. The fetus stores glucose as glycogen in the liver. What is the hormone
responsible for facilitating this vital storage?
9. In terms of glucose levels, what state is the fetus usually in with respect
to its mother, and why?
10. What is the relationship between glycolysis and respiration?
11. True or false: once neurons die, they are never replaced.
12. Levels of education have been shown to increase life expectancy and
decrease rates of disability. Provide some possible explanations for this
phenomenon.
13. There is evidence to show that increased levels of education has
physiological effects on the CNS. Name some of these effects.
14. True of False: Versus other animals, humans have a decreased ability to
learn and incorporate new information as they age.
1. Neurons regulate motor and sensory as well as mental/behavior
responses.
2. Astrocytes are responsible for regulating the extraneuronal environment.
For example, they are responsible for maintaining a proper concentration
of neurotransmitter concentration at the synaptic cleft.
3. Oligodendrocytes are responsible for the production of myelin which
facilitates electrical conduction.
4. While it is only 2% of total body weight, the brain consumes 20% of total
oxygen taken in. It also hogs 15% of cardiac output through the internal
carotid and vertebral arteries.
5. The brainstem (or medulla oblongata) develops first. It is virtually
complete by the time the fetus is 10 weeks old because it is responsible
for regulating all autonomic nervous function (ie circulation, cardiac rate,
etc).
6. The cerebellum and especially forebrain are responsible for higher mental
functioning. In utero, this fetus needs to concentrate resources on protein
synthesis, development of vital organs, fat storage in order to be able to
successfully survive. The higher mental functions are not absolutely vital
to the baby’s survival in the first months of life – a very critical and
vulnerable periods. While crucial for later survival, the cerebellum and
forebrain develop primarily after birth because it is a lower priority than
other systems.
7. The fetus derives most of its energy from glucose which it gets mom via
the placenta.
8. Glucocorticoids, which are produced in the adrenal glands, are responsible
for converting glucose into glycogen in the liver.
9. The fetus is usally hypoglycemic (lower blood sugar) than its mother
because of higher glucose utilization and greater sensitivity to insulin.
10. Glycolysis is a necessary function during gestation and postnatally in
order to assure that the fetus/baby receives enough energy. After birth,
when breathing begins (thus indicating a higher metabolic rate) the
gycolytic enzyme increases as respiration (indicated by an increase in
succinic dehydrogenasse - a respiratory enzyme) increases. This occurs
because the fetus now needs to combat hypoglycemic states due to
increased heat loss and increased cardiac expenditures of energy.
11. False: it was once thought that the nervous system did not have the
capacity for regeneration. Current research shows that in fact the CNS
does have the ability to regenerate and repair to a certain extent.
12. There is a direct correlation between increased level of education and
increased income levels. The rise in income level is correlated with less
risky occupations, better access to medical care, nutrition and recreational
activities. Basically, think of education as potentially having a whole-body
impact on health through access to resources.
13. Increasing educational level from <12th grade to >12th grade is associated
with an increased mean dendrite length, increased total dendrite length
and dendritic segment count.
14. False, as compared to a cat and a bird, a human can learn new
information throughout its entire lifespan. While this ability lessens to a
certain extent in old age, there is no doubt that with humans an :old dog
can learn new tricks.”