Question

developmental aspects of the nervous system
because the nervous system forms during the first month of embryonic development, maternal infection early in pregnancy can have extremely harmful effects on the (1. ) nervous system. for example, german measles (rubella) in the mother often causes deafness and other types of cns damage. also, because nervous tissue has the highest metabolic rate in the body, lack of oxygen for even a few minutes kills neurons. because smoking decreases the amount of (2. ) that can be carried in the blood, a smoking mother may be sentencing her infant to possible brain damage. radiation and various drugs (alcohol, opiates, cocaine, and others) can also be very damaging if taken during early fetal development.
homeostatic imbalance 7.11
in difficult deliveries, temporary lack of oxygen may lead to cerebral palsy (pawlze), but this is only one of the suspected causes. cerebral palsy is a neuromuscular disability in which the (3. ) muscles are poorly controlled and spastic because of brain damage. about half of its victims have seizures, are intellectually disabled, and/or have impaired hearing or vision. cerebral palsy is the largest single cause of physical disabilities in children. a number of other congenital malformations—triggered by genetic or environmental factors—also plague the cns. most serious are hydrocephalus (see p 250), anencephaly, and spina bifida. anencephaly is a birth defect in which the cerebrum fails to develop. children with anencephaly cannot see, hear, or process sensory information; these babies typically die soon after (4. ). spina bifida (spinah bīfi-dah, \forked spine\) results when the vertebrae form incompletely (typically in the lumbosacral region). there are several varieties of spina bifida. in the least serious, a dimple, and perhaps a tuft of hair, appears over the site of malformation, but no neurological problems occur. in the most serious, meninges, nerve roots, and even parts of the spinal cord protrude from the spine, rendering the lower part of the spinal cord functionless. the child is unable to control the bowels or bladder, and the lower limbs are (5. ).
1 birth 2 paralyzed 3 fetal 4 oxygen 5 voluntary
1 fetal 2 oxygen 3 voluntary 4 birth 5 paralyzed
1 voluntary 2 birth 3 paralyzed 4 fetal 5 oxygen
1 paralyzed 2 fetal 3 oxygen 4 voluntary 5 birth
1 oxygen 2 voluntary 3 birth 4 paralyzed 5 fetal

Explanation:

• For the first blank, since the nervous system forms during embryonic development, "fetal" is appropriate as it relates to the unborn offspring.
• For the second blank, smoking affects the amount of oxygen carried in the blood.
• For the third blank, in cerebral palsy, voluntary muscles (those under conscious control) are affected.
• For the fourth blank, anencephalic babies typically die soon after birth.
• For the fifth blank, in severe spina bifida, the lower limbs are paralyzed.

Answer:

1 fetal 2 oxygen 3 voluntary 4 birth 5 paralyzed