According to the karmic background from your previous birth cycle, you choose your next body. Your body is the result of your life review in your afterlife. Karma from the previous birth cycle thoroughly influences the elemental composition of your body. Your zodiac sign is fixed in regard to the elemental composition. Your body is the mixture of combined energy from your parents, but the shape, stature, weight and quality of your body is determined according to the karmic vibratory quality of your soul. It's the same that's responsible for your inborn skills, phobias, manias, and allergies. Before the process of ensoulment itself, the embryonic development of your body is done. When you leave the body, you leave with every single experience, you had with the body on and during life review later as a spirit, you tend to regret how you misused your valuable body. With a body on, you tend to misuse it without actually learning how precious it is. You have to learn how to grow from the inside out and you can keep yourself intact. Your body does have the self healing capacity. With a body on, you get all sorts of physical experience, which is never possible without a body, be it the food you like or the person you love.
A) The embryonic development of your system: Spiritually speaking, your body is the biological vessel or system for your soul to be evolved further. Before your spirit enters your system by itself, the so called embryonic development is processed. From week three of the pregnancy, three distinctive cell layers called the mesoderm, endoderm and ectoderm are formed through the process called gastrulation. These are the primary cell layers from which the organs develop later. The endoderm helps the formation of the gastrointestinal and respiratory systems. The ectoderm helps the formation of your skin, nervous system and portions of sensory organs. The mesoderm is responsible for your circulatory system including blood, lymphatic system, muscles, cartilage, bone and many internal organs like spleen, kidney, ureters and adrenal cortex. The organogenesis or the development of your organs starts when the spirit enters your system or body. The heart is the first organ, being developed and it beats for the first time once your spirit enters your system. The vibration of your spirit is the hidden force with which your system maintains its upkeep. The spirit forms a new soul out of your body with a new set of vibratory frequency which plays a dominant role in your next birth cycle. You come here to play the simulated game with a life span, already fixed all by yourself according to your karmic background. Even though you can make some changes in the life span by using your free will while living, most of you tend to leave at the exact time you fixed or way before it. As a species, your life span can be extended more when you acquire higher planetary vibration, reducing your collective negative karma. It's the time when you guys keep balance between your spiritual and technological advances. The embryonic development reaches its maturation at the end of week eight with organ systems, being developed. The fetal period begins by week nine, involving the development of your anatomical structures and the period lasts until your birth. For example, within four to six weeks, the cardiovascular system develops with four chambers of the heart and cardiac outflow separation and descent of the heart and lungs into the thorax. The lung development begins from the early embryonic period with the development of right and left lung buds and continues up to birth. From weeks six through eight, you can also see the development of gastrointestinal system. The anal opening is established during week seven. The formation of your liver starts during the third week of gestation. During weeks five to ten, it undergoes rapid growth. The central nervous system develops during weeks five through eight, which is the early derivative of the brain and spinal cord. During week seven cells of your brain start making new neurons. You can see many other organs like the pituitary gland, adrenal cortex and thymus, being developed during weeks six through eight. The ocular retina begins to develop at week seven and the head and face contours emerge with upper and lower limbs and facial structures like eyelids, lips, ears, nostrils, palate etc.
B) The important features of your system: Your body does have system complexities by default. And the vibration of your soul is reflected through your eyes. Your body consists of many systems which help its functionality. The circulatory system with the network of blood vessels, veins and capillaries which can be thousands of miles long helps the movement of blood, oxygen, carbon dioxide, nutrients and hormones throughout your body. It's the digestive system which includes your mouth, stomach, small and large intestines, esophagus, rectum and anus that helps the body to absorb food, removing waste. The liver and pancreas support your digestive system, producing digestive juices which contain enzymes to break down your food into proteins, fats and carbohydrates. The endocrine system, consisting of a network of glands is very important as it secretes different hormones into your blood, which can regulate a number of your body functions including metabolism, growth and sexual function. It's the immune system which protects you from the harmful viruses, bacteria and other pathogens. This defensive mechanism contains white blood cells, the spleen, bone marrow etc. The lymphatic system is also important as it produces white blood cells which can fight the infection. The system includes lymph nodes, lymph ducts and lymph vessels. It's your nervous system that regulates both of your voluntary and involuntary actions including your movement and breathing. It works as a signal system throughout your body. For example, the central nervous system is connected with your brain and spinal cord while the peripheral nervous system connects every other part of the body to the central nervous system. It's the muscular system that helps your movement and blood flow. The system consists of three types of muscle. Your voluntary movement is done with the skeletal muscle, attached to your bones. Smooth muscle, found inside your organs helps the movement of substances through the organs. The blood flow inside is maintained with the help of cardiac muscle, found inside the heart. The reproductive system helps you create a biological vessel for a karmically responsible soul to come in and get embodied through your sexual union. The male reproductive system consists of penis and testicles which produce sperm while the female reproductive system includes the vagina, the uterus and the ovaries which can produce eggs. The karmic quality of your soul ensures the proper functionality of your reproductive system. Your entire body is supported through the skeletal system which helps you move, store calcium and produce blood cells. As an infant, you have 270 bones which get fused together when you grow up, making your adult skeleton which can consist of between 206 and 213 bones. Even though the teeth are part of the system, they are not considered bones. The respiratory system, consisting of the lungs, the diaphragm and the trachea helps you inhale oxygen and exhale carbon dioxide. The urinary system which consists of two kidneys, two ureters, two sphincter muscles, the bladder and the urethra helps you eliminate urea, being produced when foods are broken down. You also have the integumentary system which is nothing but your skin. You can call skin as the largest organ. The system including your hair and nails helps you regulate body temperature. It's not only your defensive layer against viruses, bacteria and other pathogens, but also works as a system that helps you eliminate waste through perspiration.
C) The decomposition of your system: The moment your spirit leaves your body, it starts the process of decomposition. When your respiration stops, your blood circulation also stops. As a result, the excess carbon dioxide inside the body creates an acidic environment which causes the membranes in the cell to rupture. With this, the process of autolysis which is the first stage of decomposition begins. The bacteria in the intestines start devouring the intestinal walls. Cellular enzymes are released and cells lose their structural integrity, triggering the breaking down of the cells and surrounding tissues. This stage of decomposition occurs inside the body and is not so visible outside the body. At the end of this stage the odors emanating from the body attract blowflies, house flies and flesh flies and they arrive to lay eggs. The decomposition enters its second stage called bloating when bacteria get multiplied in the body, producing gases such as hydrogen sulfide, methane, nitrogen and carbon dioxide which can easily bloat the body. This gaseous build up pushes the fluids inside the body through its natural openings like mouth, nose or anus. The hatched eggs on your body produce a lot of maggots within 24 hours. When the maggots start feeding on body tissues, the skin structure is ruptured and collapsed, causing the hair to detach. These additional openings invites more bacteria and insects, quickening the decaying process. Life is exploded in your dead body. The process of bloating emits a lot of gases and fluids, which is what causes the greatest amount of decaying odor. The color of your body turns dark however white you are. With this, the decomposition of your body enters the next stage, called active decay where the skin, muscles and organs get liquefied. The cadaver loses most of the body mass this way. At the end of active decay stage, huge number of rove beetles, clown beetles and dermestid beetles arrive and they start to dominate sooner than later, chowing down on the maggots. This is how decomposition is moved to the advanced decay stage. Some of the maggots can migrate away from the corps to a suitable pupation site which could be usually in the underlying soil. This is how the maggots get transformed into pupa and then from a larval body into an adult fly. It's the life being created out of your body without your knowledge. The very next stage of decomposition is called dry decay which is the skeletonization process where the carcass is reduced into skeleton with bones, cartilage, dried skin and hair. The putrid odor, emanating from the body stops. The dermestid beetles continue to clean the skeleton, finishing the job. A high concentration of nutrients like carbon, phosphorous and nitrogen can be found in the soil beneath the cadaver, which are reused, repurposed, repackaged and recycled for the continuation of life. The complete decomposition of a body takes three weeks to several years, depending on the factors like temperature, humidity, presence of water or insects. The internal organs start to decompose within 24 -72 hours after death. Bloating starts within 3 to 5 days and nails and teeth fall out within several weeks. Your body starts to liquefy in one month after death. Decomposition of your body is done quickly in warm, shallow water while cold water slows the decay. Decomposition of your bones is a comparatively slow process which could take a matter of a decade in humid conditions or thousands of years in a dry climate. Fossils are bones that never decomposed but covered in sediments. It appears that in the absence of oxygen and under high temperature and pressure, the dead bodies of animals including those of humans can be converted into fossil fuels while plant remains turn into coal, the process of which takes millions of years. Your body is the manure for different organism to flourish during your life and even after your death...