1. Introduction to Anatomy & Physiology

2. Cell Chemistry & Cell Components

3. Energy & Cell Processes

4. Tissues & Histology

5. Integumentary System

6. Bones + Skeletal Tissues

7. Skeletal System

8. Joints

9. Muscles and Muscle Tissue

10. Muscular System

11. Nervous Tissue

12. Central Nervous System

13. Peripheral Nervous System

14. Autonomic Nervous System

15. Special Senses

16. Endocrine System

17. Blood

18. Cardiovascular System: the Heart

19. Cardiovascular System: Blood Vessels

20. Lymphatic System

21. Immune System

22. Respiratory System

23. Digestive System

24. Nutrition, Metabolism, Energy Balance

25. Urinary System

26. Fluid and Electrolyte Balance, Acid Base Balance

27. Reproductive System

28. Pregnancy and Human Development

29. Heredity

Guided Toc

New Guided

The inner layers of trophoblasts lose their plasma membranes and invade the endometrium.

They display L-selectin molecules on their surface after blastocyst hatching.

Which of the following does NOT describe a function of trophoblast cells?

Gastrulation lays down the basic structural framework of the embryo and sets the stage for the rearrangements that occur during organogenesis. The first major event in organogenesis is neurulation.

The first major event in organogenesis is gastrulation.

The outermost extraembryonic membrane is the chorion, which is part of the placenta.

The outermost extraembryonic membrane is the __________.

Urine formation is not a function of the placenta.

Which of the following is NOT a function of the placenta?

Embryonic Development in Humans

After fertilization, the zygote goes through a rapid period of cell divisions called <i>cleavage</i>, resulting in the blastocyst, which has many smaller cells.

After fertilization, the zygote goes through a rapid period of cell divisions called __________.

Neurulation

In humans, the allantois is the structural base for the umbilical cord that links the embryo to the placenta.

In humans, the extraembryonic membrane that composes the structural base for the umbilical cord is the __________.

It takes about 3 to 4 days after fertilization for the egg to travel to the uterus, where it floats for 2 to 3 days before it begins implantation.

Implantation of the blastocyst begins __________ after ovulation.

hCG levels increase throughout gestation.

Estrogen and progesterone levels increase throughout pregnancy.

Estrogen levels increase throughout gestation.

Estrogen levels decline throughout gestation.

hCG levels remain stable throughout gestation.

Progesterone levels decline throughout gestation.

Which statement about maternal hormones during pregnancy is accurate?

Organogenesis

Extraembryonic Membranes

The inner cell mass is not involved in the formation of the placenta. The chronic villi and the decidua basalis form the placenta.

The yolk sac is not involved in the formation of the placenta. The chronic villi and the decidua basalis form the placenta.

The decidua capsularis is not involved in the formation of the placenta. The chronic villi and the decidua basalis form the placenta.

The disc-shaped placenta is formed from the __________.

The ectoderm develops into many neural structures, including the central nervous system, as well as several integumentary structures.

Which of the following structures is/are formed from ectodermal tissues?

Most ectopic pregnancies occur in the uterine tubes.

An implantation that takes place in a site other than the uterus is called __________.

Amnion formation is not the first event in organogenesis. Neurulation is the first event of organogenesis.

Sporulation does not take place in humans. Neurulation is the first event of organogenesis.

The formation of mesenchyme is not the first event in organogenesis. Neurulation is the first event of organogenesis.

The first major event of organogenesis is __________.

Relaxin relaxes pelvic ligaments and joints. This increased flexibility eases birth passage.

Which hormone produced by the placenta causes the mother's pubic symphysis to loosen and widen?

It causes the uterine lining to slough off or shed to maintain pregnancy.

hCG from the fetal trophoblast cells signals the corpus luteum of the ovary to continue producing estrogen and progesterone, which maintains the endometrium and prevents menstruation.

It inhibits the production of estrogen and progesterone by the ovary.

It increases to high levels near birth, helping initiate the birth process.

It signals the corpus luteum to continue producing estrogen and progesterone to maintain the pregnancy.

It stimulates the production of FSH by the pituitary.

What is the function of the hormone hCG (human chorionic gonadotropin)?

Fertilization and Implantation

The Placenta - Development and Function

Implantation of Blastocyst

Ectoderm fashions the structures of the nervous system and the skin epidermis.

The ectoderm is the primary germ layer from which the digestive, respiratory, and urogenital systems and the associated glands form.

Development and Function of Placenta

Embryology - Gastrulation

Embryology - Fertilization, Cleavage, Blastulation

Early Embryogenesis - Cleavage, Blastulation, Gastrulation, and Neurulation

Somites are derived from mesoderm and specialize into sclerotome, myotome, and dermatome.

The notochord is a rod that provides axial support of the embryo and is derived from mesoderm.

During early gastrulation, what structure(s) appear(s) on the dorsal aspect of the embryonic disc and establish(e)s the longitudinal axis of the embryo?

The Process of Gastrulation

Gastrulation

Implantation, which takes about a week, is completed after the blastocyst is entirely surrounded by endometrium (typically 12 days after ovulation).

blastocyst is entirely surrounded by endometrium

Implantation is completed after the __________.

Implantation

The development of the primary germs layers is called <i>gastrulation</i>. The three layers that form are the ectoderm, endoderm, and mesoderm.

The development of the primary germ layers is called __________.

Cleavage and Blastulation

Mesoderm specializes into numerous structures located throughout the body. Nails, hair and the epidermis, however, are derived from ectoderm.

All of the following structures are derived from mesoderm EXCEPT __________.

the day before ovulation; the third day after ovulation

Six to seven days after ovulation, given a properly prepared endometrium, implantation begins. Implantation, when successful, takes about five days; it is usually completed by the twelfth day after ovulation.

two to three days after ovulation; the sixth or seventh day after ovulation

six to seven days after ovulation; the twelfth day after ovulation

the day after ovulation; the third day after ovulation

The process of implantation generally begins __________ and is usually completed by __________.

Germ layer derivatives

The placenta is usually fully functional as a nutritive, respiratory, excretory, and endocrine organ by the end of the third month of pregnancy.

By the end of the third month of pregnancy, the placenta is usually fully functional as a nutritive, respiratory, excretory, and endocrine organ.

Placenta Formation and Functions

Embryonic Development

Meet the placenta!

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