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Anatomy Physiology (Chapter 20 Development, Heredity and Aging)
Anatomy and Physiology (ANPH111)
Our Lady of Fatima University
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DEVELOPMENT,
HEREDITY & AGING
Chapter 20
SEELEY'S ESSENTIALS OF ANATOMY AND
PHYSIOLOGY, 9TH EDITION.
Created by: Johmel De Ocampo
####### The prenatal period, the period from conception to birth, can be divided
####### into three parts:
####### (1) During approximately the first 2 weeks of development, the primitive
####### germ layers are formed;
####### (2) from about the second to the eighth week of development, the major
####### organ systems come into existence; and
####### (3) during the last 7 months of the prenatal period, the organ systems
####### grow and become more mature.
####### Between the time of fertilization and 8 weeks of development, the
####### developing human is called an embryo. From 8 weeks to birth, the
####### developing human is called a fetus.
####### Fertilization is the union of a sperm cell and an oocyte, along with their
####### genetic material (chromosomes), to produce a new individual. After sperm
####### cells are ejaculated into the vagina, they are transported through the
####### cervix and the body of the uterus to the uterine tubes, where fertilization
####### occurs.
DEVELOPMENT, HEREDITY & AGING
PRENATAL DEVELOPMENT
FERTILIZATION
DEVELOPMENT, HEREDITY & AGING
INTERFACE BETWEEN MATERNAL AND
FETAL CIRCULATION
DEVELOPMENT, HEREDITY & AGING
CHANGES IN HORMONE
CONCENTRATION DURING PREGNANCY
DEVELOPMENT, HEREDITY & AGING
FORMATION OF
NEURAL TUBE
DEVELOPMENT OF
THE FACE
DEVELOPMENT, HEREDITY & AGING
DEVELOPMENT OF THE ORGAN SYSTEMS
DEVELOPMENT, HEREDITY & AGING
DEVELOPMENT, HEREDITY & AGING
DEVELOPMENT, HEREDITY & AGING
The newborn, or neonate, experiences several dramatic changes a the time of birth. The major and earliest changes are the separation of the infant from the maternal circulation and the transfer from a fluid to a gaseous environment.
THE NEWBORN
DEVELOPMENT, HEREDITY & AGING
Lactation is the production of milk by the mammary glands. It normally occurs in women following parturition and may continue for up to 2 or 3 years. During pregnancy, the high concentration and continuous presence of estrogen and progesterone cause expansion of the duct system and the secretory units within the breast. Other hormones, including a prolactin-like hormone produced by the placenta, help support the development of the breasts. Also, additional adipose tissue is deposited; thus, the size of the breasts increases throughout pregnancy. Estrogen and progesterone prevent the secretory part of the breast from producing milk during pregnancy.
DEVELOPMENT, HEREDITY & AGING
LACTATION
The stages of life from fertilization to death are divided into three prenatal stages and five postnatal stages as follows: 1. Germinal (jer′mi-n̆ l) period, fertilization to 14 days 2. Embryo, 14–56 days after fertilization 3. Fetus, 56 days after fertilization to birth 4. Neonate, birth to 1 month after birth 5. Infant (in′f̆nt), 1 month to 1 or 2 years after birth (the end of infancy is sometimes set at the time that the child begins to walk) 6. Child, 1 or 2 years old to puberty (about 11–14 years) 7. Adolescent (ad-̄-les′ent), teenage years, from puberty to 20 years old 8. Adult, 20 years old to death Adulthood is sometimes divided into three periods: young adult, 20–40 years old; middle age, 40–65 years old; and older adult, or senior citizen, 65 years old to death.
DEVELOPMENT, HEREDITY & AGING
LIFE STAGES
Each chromosome contains thousands of genes. Each gene consists of a certain portion of a DNA molecule, but not necessarily a continuous stretch of DNA. Genes determine the proteins in a cell. Both chromosomes of a given pair contain similar but not necessarily identical genes. Similar genes on homologous chromosomes are called alleles. If the two allelic genes are identical, the person is homozygous for the trait specified by that gene. If the two alleles are slightly different, the person is heterozygous for the trait. All the genes in one homologous set of 23 chromosomes in one individual constitute that person’s genome.
DEVELOPMENT, HEREDITY & AGING
GENES
DEVELOPMENT, HEREDITY & AGING
Anatomy Physiology (Chapter 20 Development, Heredity and Aging)
Course: Anatomy and Physiology (ANPH111)
University: Our Lady of Fatima University
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