Exam 23: Pregnancy, Growth, and Development

Conjoined twins result from incomplete twinning, which occurs during the first month of gestation.

The period of preactive dying takes

During development of the hands and feet in the late embryonic stage, the fingers and toes form as extensions of muscular, nervous, and connective tissue from the limb buds. Completion of finger and toe extension triggers a process in which the webbed tissue between each digit is signaled/programmed to die. This process is known as ________.

Factors that can cause congenital malformations by affecting an embryo during its periods of rapid growth and development are called teratogens.

A major difference between fetal blood flow and adult blood flow is that in the fetus the

The cells of a blastocyst that help form the chorion constitute the

Development is a continuous process and includes growth.

Which of the following provides the main source of energy for a newborn during its first few days?

The primary function of surfactant is to increase surface tension in the newborn's lungs.

Some reproductive tumors produce hormones. One sign of the presence of a reproductive cancer is a positive result from a basic pregnancy test when pregnancy is not possible/very unlikely. These cancers produce a positive test result because they are secreting

During the embryonic stage, the primary germ layers develop from the

In an adult heart, the previous location of the foramen ovale is marked by a depression called the ________.

A relatively new theory has arisen regarding the development of twins at fertilization. In addition to the phenomena of identical and fraternal twins, the theory suggests that semi-identical twins called polar body twins can occur if fertilization occurs in the second polar body immediately after fertilization of the oocyte (different sperm fertilizing each). If this is true, what should be true about the zygotes?

Considering the roles of estrogen and progesterone in the female reproductive cycle, how would fertility be affected if a woman had a hormonal disorder involving a constant high secretion of progesterone?

After birth, the ductus arteriosus constricts and becomes the ligamentum arteriosum.

Changes that occur as death approaches include

The postnatal period extends from

After birth, the foramen ovale is closed as a result of

Proteolytic enzymes from the trophoblast aid implantation of an embryo.

Fetal hemoglobin becomes largely replaced with adult hemoglobin