Embryology

Introduction to embryology

The branch of biology that deals with the study of the growth and development of the embryo are known as embryology. It covers the field of study that researches cellular, molecular as well as structural factors that help in the development of a species. Human embryology deal with the process of evolution of human from fertilized egg to a birth of an infant this period is also known as prenatal development or period. The growth and development of infants do not put stop at birth. Their various changes take place after birth. This time is known as the postnatal period or postnatal changes. With the help of embryology, the medical professional can study the prenatal development of a fetus special in the embryonic stage. The prenatal period is subdivided into the embryonic period and the fetal period. Embryology plays a crucial role in identifying any anomalies that are present during embryo development later that lead to birth defects. Prenatal development is very fast while postnatal changes are slower in comparison to prenatal development but changes are remarkable. In this tutorial, we are going to learn about embryology in depth.

Embryogenesis

Embryogenesis involves the process in which an embryo matured into a fetus. It is a complex procedure that can be described below

Fertilization

• The fusion of sperm with egg leads to the formation of the zygote is known as fertilization.

• If the egg is moving through the fallopian tube at the same time as sperms, then one sperm fuse with an egg. The survival of sperm is 6 days to join with an egg.

• After that fertilized egg known zygote slowly moves towards the uterus from the fallopian tube.

• During the growth and development phase, the zygote cell undergoes many divisions and forms a solid ball-like structure that is known as a morula.

• The solid ball-like structure morula undergoes various changes to form a hollow ball known as a blastocyst. It gets into the uterus about 3-4 days after fertilization.

Blastocyst development

• Shortly after fertilization, the embryo is produced from continuously dividing cells inside the blastocyst. Blastocyst constitutes the cells and fluids.

• At the time of maturation a protective cover known as zona pellucida cover the blastocyst.

• Beneath the zona pellucida, the outer cells are present that will further generate the placenta, and tissues that are present nearby support fetal development in the uterus.

• There are changes happening in the inner layer of the blastocyst and its converted into tissues and finally developed into organs of the human body like bones, muscles, skin, liver, and heart.

• The cells of the blastocyst undergo many changes and rapid growth has happened in these cells and converted them into more specialized cells.

Blastocyst implantation

• Blastocyst implants in the endometrium at the movement when it outreaches the uterus.

• The endometrium is an inner layer that lines the uterus.

Embryo development

• The embryo is formed when the blastocyst reaches the finishing stage of the implementation process into the inner lining of the uterus.

• The placenta is fully functional in this stage.

• This is the time all the internal organs and external structures develop.

• Cartilage is replaced by the first bone.

Fetal development

• The embryo proceeds into an end stage of development by the twelve weeks of fertilisation. This stage is known as the fetal stage.

• We can call the fetus a baby at around eight months.

• The baby can move its whole body towards the end of nine months.

Human development

Human development is a very complex and specific process. In this single cell is transformed into a multicellular human being, This process starts with the fusion of sperm with egg and leads to the formation of the zygote known as fertilization. The zygote undergoes several stages of division of cells, differentiation of cells, and various growth and development that leads to the birth of the fetus.

Duration and stages of pregnancy

The gestation period of human beings is about 40 weeks. These weeks of pregnancy are split up into three trimesters.

First trimester − The first trimester starts from week 1 and ends in week 12. The female experiences many changes during this period. The most common symptoms are

• Tiredness

• Sickness in the morning

• Fickleness

• Tendency of vomiting

• Effect bowel movement

• Gain weight

• Frequent urination

• Burning of heart

• Nausea

Second trimester − The second trimester starts from week 13 and ends in week 28. The second trimester is troublefree as compared to the first trimester. The morning sickness and nausea are not present in this trimester. As the fetus continues to grow the female abdomen also enlarges. The expected mother would feel the movement of the baby at the end of the trimester.

Third trimester − The third trimester starts from week 29 and ends approximately in week 40. As the baby continues to grow it gives more pressure on the uterus as a result frequency of urine passing out is more. Some of the symptoms like shortness of breath, swelling of the ankle and finger, false pain, and trouble sleeping are the most common in the third trimester. The cervix would become thinner and softer as the due date is near.

Essential healthcare strategies

The various health care strategies are listed below

• An alternative method to treat infertility like ovulation induction, IUI, and IVF.

• Give proper medication to stop birth defects.

• Proper diagnosis during prenatal periods.

Types of embryology

• Descriptive embryology (observation and description- development)

• Evolutionary embryology (embryonic homology)

• Comparative embryology (different species)

• Behavioural embryology (developmental neurobiology)

• Chemical embryology (biochemical, biophysical, and biological techniques)

• Experimental embryology (experimentation and different stages)

• Teratology (malfunctions)

Scope of embryology

• Plant taxonomy

• Anatomy and embryology

• Plant physiology and embryology

• Biotechnology

• Organic evolution and embryology

• Histochemistry

Conclusion

The branch of biology that deals with the study of the growth and development of the embryo are known as embryology. Embryogenesis involves the process in which an embryo matured into a fetus. Human beings are developed from single-cell organisms. The gestation period of human beings is about 40 weeks. Embryology has different scopes in taxonomy, anatomy, biotechnology, etc.

FAQs

Q1. What do you understand by descriptive embryology?

Ans. This descriptive embryology deals with the structural development in the embryonic stage of different individual species.

Q2. What is the first sign of pregnancy?

Ans. A missed menstrual period is the first sign of pregnancy.

Q3. What is histochemistry?

Ans. Histochemistry is a branch of biology. It can recognize the dispersal of chemical constituents of the tissues. This can be done with the help of microscopes, stains, and different indicators.

Q4. What is the main aim of behavioural embryology?

Ans. The main aim of behavioural embryology is to study the early development of the nervous system.

Q5. What do you understand by teratology?

Ans. Teratology deals with embryology and pathology together. This identifies the various genetic or environmental factors that affect the normal development fetus. That leads to birth anomalies in babies.