embryology, its subdivisons and range

Embryology

Embryology is the branch of science in which we study the prenatal development of gametes, fertilization, development of embryos, and fetus. In this field, we also study the diseases that occur before birth. There are various subdivisions of it such as general, and teratology, etc.

this field has a very long history. Aristotle proposed the theory of epigenesis in which he states that organisms developed from the seeds or eggs. Modern embryology starts from the work of Von Baer.

Subdivisions of embryology

There are many subdivisions of it below are some of them.

1.  General embryology

General embryology handles the development of an individual through the first eight weeks of development after fertilization. This means that general embryology deals with the pre-embryonic and embryonic period. During this period a single cell called a zygote changed into a structure that resembles the external features of an adult. During this period all systems and organs are produced but some of these structures are not developed completely.

Systemic embryology

Systemic embryology handles the maturation of organs and systems that are formed through the embryonic period.

Descriptive embryology

In descriptive embryology, we study the structure of different organs at various stages if development.

Comparative embryology

In comparative embryology, we study the embryos of various species of animals and compare them.

Experimental embryology

In experimental embryology, we perform experiments on embryos and fetuses of lower animals and then analyze the result and try to explain the various complex process.

Chemical

In clinical embryology, we study the biochemical aspect of prenatal development.

Teratology

Teratology is the branch of embryology in which we study unusual or abnormal embryonic development and fetal development. In teratology, we study many diseases that occur before birth. In teratology, we also study delivery defects.

Recent advances in embryology

There are numerous advances made in the field of embryology some of them are

1. Prenatal analysis 
The prenatal analysis is done to detects congenital abnormalities within unborn children. The prenatal analysis is very important because it can save the lives of both baby and mother.
Various techniques that are used for the prenatal analysis are,

a. Amniocentesis
b. Chorionic villus sampling
c.  Ultrasonography
d.  Fetoscopy
e.   Fetal blood sampling
f.    Maternal serum testing
g.   MRI etc.

2. In vitro fertilization
In vitro fertilization is a reproductive technique in which egg is fertilized outside the body and form an embryo. The embryo is then transferred into the uterus for more development. In Vitro Fertilization become a standard method across the world to solve the issue of infertility. On 25th July 1978, the first test tube baby was created. There are also other artificial reproductive techniques that might be used instead of in vitro fertilization. Other reproductive techniques are
Zygote intrafallopian transfer
Gametes intrafallopian transfer

3. Gene therapy
In gene therapy alternative of the deficient gene is placed in the embryo or abnormal genes are corrected. Gene therapy can be done in vitro or in vivo. Gene therapy is an important process because with the help of it some serious type of inherited diseases can be prevented.

4. Cloning
The advancement in the molecular biology results in the invention of some new techniques that are used in the laboratories for many purposes in various fields such as embryology, anatomy, and physiology. Now experts start understanding how chosen genes are turned on and indicating during development.

For example

a. Cloning is possible nowadays. The first mama clone, Dolly sheep was cloned in 1997 using the technique of somatic cell nuclear transfer.

b. Human cloning is banned because it creates interpersonal, moral, honest, and legal issues.

c. Recently the cloning of individual embryo was reported.

5. Stem cell therapy
The stem cells are the cells within multicellular organisms. These cells have the ability to renew themselves and differentiate into specialized cell types.

There are two types of stem cells

a. Embryonic Stem cell. These are the cells that are isolated from the inner cell mass of the blastocyst. These cells are pluripotent which means that these cells have the ability to form different cell types.

b. Mature stem cell. These are the cells that are located in the adult tissues e.g bone marrow. These are limited to create different cell types. Due to this these cells are multipoint.

In stem cell therapy we use these cells for various purposes. For example, embryonic stem cells are used to treat degenerative, malignant, and hereditary diseases.

Utility and Range

A better understanding of embryology is important due to the following reasons

1.  it explains the positions and relationship of various organs in adult gross anatomy.

2.  it helps us to understand the reasons for the development of various congenital anomalies such as tracheoesophageal fistula, polycystic kidney, subhepatic caecum, etc.  The data obtained from these anomalies can be helpful to avoid these factors and implementing preventive measures. The factors that mostly cause congenital anomalies are drugs, smoking, alcohol, viral attacks, and teratogens.

3.  Some areas of general embryology such as gametogenesis, fertilization, and implementation are of great importance because with the help of these process we can find the reason for infertility.

4. it forms the foundation of the concept of growth, repair, and regeneration of tissues and understanding of the development of various embryonic tumors.

5.  Ex-Utero surgery is possible to treat certain congenital anomalies such as congenital diaphragm hernias, repair of Spina Bifida, etc. All these treatments are possible only because of the in-depth study of embryology.

6.  It provides the foundation for the termination of a pregnancy in a variety of congenital diseases that are incompatible with life.

7. it provides an understanding of the use of molecular biology for genetic regulation of human development.

Summary

Embryology is a very important branch of science in which we study gametes, fertilization, fetus, and various diseases that occur before birth. Embryology is divided into many subdivisions some of them are general embryology, systemic, comparative, descriptive, experimental embryology, and teratology. With the advancement in technology, many advances are made in this field. some of the advances are in vitro fertilization, gene therapy, cloning, prenatal analysis, and stem cell therapy.