Chapter 520: Growth And Development
21
520
Chapter 21 Growth and Development
Growth and Development
Outline
PRENATAL PERIOD, 522
Fertilization to Implantation, 522
Periods of Development, 527
Formation of the Primary Germ
Layers, 527
Histogenesis and Organogenesis, 527
Birth Defects, 530
BIRTH, OR PARTURITION, 530
Stages of Labor, 530
POSTNATAL PERIOD, 530
Infancy, 533
Childhood, 534
Adolescence and Adulthood, 534
Older Adulthood, 535
EFFECTS OF AGING, 536
Skeletal System, 536
Integumentary System (Skin), 536
Urinary System, 536
Respiratory System, 538
Cardiovascular System, 538
Special Senses, 538
520
Objectives
AFTER YOU HAVE COMPLETED THIS
CHAPTER, YOU SHOULD BE ABLE TO:
1. Discuss the concept of development as a biological process …show more content…
Such abnormalities may be structural or functional, perhaps even involving behavior and personality. Birth defects may be caused by genetic factors such as abnormal genes or inheritance of an abnormal number of chromosomes.
Birth defects also may be caused by exposure to environmental factors called teratogens (TAYR-ahtoh-jenz). Teratogens include radiation (for example, x-rays), chemicals (for example, drugs, cigarettes, or alcohol), and infections in the mother (for example, herpes or rubella). Some teratogens are also mutagens because they do their damage by changing the genetic code in cells of the developing embryo. Nutritional deficiencies during pregnancy also can lead to birth defects.
As Figure 21-7 shows, the period during the first trimester when the tissues are beginning to differentiate and the organs are just starting to develop is the time that teratogens are most likely to cause damage. In fact, teratogens can cause spontaneous abortion (miscarriage) if significant damage occurs during the pre-embryonic stage.
QUICK
1. What is the postnatal period? The prenatal period?
2. What is a zygote? How is it …show more content…
The term quickening has been used for generations to describe these first recognizable movements of the fetus. From an occasional “kick” during months 4 and 5 of pregnancy, the frequency of fetal movements steadily increases as gestation progresses. The frequency of fetal movements is an excellent indicator of the unborn baby’s health.
Recent studies have shown that simply by recording the number of fetal movements each day
after week 28 of pregnancy, a woman can provide her physician with extremely useful information about the health of her unborn child. Ten or more movements during a daily measurement period are considered normal.
Educating pregnant women about fetal movements and how to monitor their frequency is but one example of expanded interest in prenatal home care.
Assisting pregnant women with making informed judgments about nutrition, exercise, lifestyle adjustments, and birthing options before they enter the hospital for delivery of their baby is an important and growing part of home health-care services.
Research, Issues and Trends
Antenatal
520
Chapter 21 Growth and Development
Growth and Development
Outline
PRENATAL PERIOD, 522
Fertilization to Implantation, 522
Periods of Development, 527
Formation of the Primary Germ
Layers, 527
Histogenesis and Organogenesis, 527
Birth Defects, 530
BIRTH, OR PARTURITION, 530
Stages of Labor, 530
POSTNATAL PERIOD, 530
Infancy, 533
Childhood, 534
Adolescence and Adulthood, 534
Older Adulthood, 535
EFFECTS OF AGING, 536
Skeletal System, 536
Integumentary System (Skin), 536
Urinary System, 536
Respiratory System, 538
Cardiovascular System, 538
Special Senses, 538
520
Objectives
AFTER YOU HAVE COMPLETED THIS
CHAPTER, YOU SHOULD BE ABLE TO:
1. Discuss the concept of development as a biological process …show more content…
Such abnormalities may be structural or functional, perhaps even involving behavior and personality. Birth defects may be caused by genetic factors such as abnormal genes or inheritance of an abnormal number of chromosomes.
Birth defects also may be caused by exposure to environmental factors called teratogens (TAYR-ahtoh-jenz). Teratogens include radiation (for example, x-rays), chemicals (for example, drugs, cigarettes, or alcohol), and infections in the mother (for example, herpes or rubella). Some teratogens are also mutagens because they do their damage by changing the genetic code in cells of the developing embryo. Nutritional deficiencies during pregnancy also can lead to birth defects.
As Figure 21-7 shows, the period during the first trimester when the tissues are beginning to differentiate and the organs are just starting to develop is the time that teratogens are most likely to cause damage. In fact, teratogens can cause spontaneous abortion (miscarriage) if significant damage occurs during the pre-embryonic stage.
QUICK
1. What is the postnatal period? The prenatal period?
2. What is a zygote? How is it …show more content…
The term quickening has been used for generations to describe these first recognizable movements of the fetus. From an occasional “kick” during months 4 and 5 of pregnancy, the frequency of fetal movements steadily increases as gestation progresses. The frequency of fetal movements is an excellent indicator of the unborn baby’s health.
Recent studies have shown that simply by recording the number of fetal movements each day
after week 28 of pregnancy, a woman can provide her physician with extremely useful information about the health of her unborn child. Ten or more movements during a daily measurement period are considered normal.
Educating pregnant women about fetal movements and how to monitor their frequency is but one example of expanded interest in prenatal home care.
Assisting pregnant women with making informed judgments about nutrition, exercise, lifestyle adjustments, and birthing options before they enter the hospital for delivery of their baby is an important and growing part of home health-care services.
Research, Issues and Trends
Antenatal