Ovarian and Uterine Cycle

Uterine Cycle is more commonly known as the menstrual cycle, which occurs every 4 weeks or so. A woman’s body prepares for pregnancy, but when pregnancy does not occur, blood is released as the woman’s endometrial lining of the uterus sheds. Ovarian Cycle is starts with a development of an oocyte. As it begins to mature, it erupts and travels down the oviduct to the uterus. This cycle is called the ovarian cycle.  GnRH is a hormone that stimulates the brain to produce LH and FSH. LH is also known as the luteinizing hormone, and FSH is also known as the follicle stimulating hormone. These two hormones help control how the body produces a specific sex hormone, called Estrogen. Estrogen is a type of hormone found in women, as well as in men. However, it has a stronger role in women’s bodies as it is the main sex hormone and is vital to the menstrual cycle.  It is known to regulate the menstrual cycle and enriches and thickens the endometrium, ultimately preparing the uterus for pregnancy. Progesterone is a type of hormone that is naturally produced in the ovaries of menstruating women. When a woman is pregnant, this substance is produced by the placenta. Progesterone has numerous roles in a woman’s body. It is often ingested by women in birth control pills, menopausal hormone replacement therapy, or just sometimes to induce a menstrual period or regulate abnormal bleeding problems.hCG comes to play when a blastocyst is embedded in the walls of the uterus. It is during this period when a hormone called hCG comes to play. hCG stands for human chorionic gonadotropin, and is released by the cells around the blastocyst. Its main function is to maintain the corpus luteum in the ovary, preventing the pregnant woman from ovulating.

Positive feedback loops occur when there is an increase in the level of the hormones because of the need of hormones to develop the zygote. Negative Feedback Loops occurs because there is no need for hormones any longer, hence decreasing the GnRH level to limit the release of LH and FSH. An easy way to differentiate between menstruation and pregnancy is the fact that hormone levels are much higher during pregnancy because of the need of hormones to reproduce and develop the fetus.

Fetal Development during the Three Trimesters of Pregnancy:

1^st trimester: Various hormonal changes are taking place in the body. The body begins to prepare itself to nurture the fetus. It is within this period when the baby’s heart starts to beat, and its facial features as well as digestive system are beginning to form.

2^nd trimester: The maximum development of the baby takes place during this period. Most of the major organs are completely formed and start to function in the second trimester of pregnancy.

3^rd trimester: By this time the baby would have fully descended into the pelvis from the abdominal region.

Immune System

The four types of pathogens include Bacteria, viruses, fungi, and parasites.

Macrophage- A type of white blood that absorbs material that our bodies are not accustomed to. Macrophages play a vital role by responding immediately t microorganisms that are possibly infectious.

Antigen- foreign microorganisms that the body is not used to, that stimulates an immune response through activating the body’s infection-fighting white blood cells

T cell- a type of lymphocytes that protect the body through identifying, directly attacking and destroying the infectious substances found in the body. These cells activate the B cells and killer T cells.

B cell- these cells are produced in the bone marrow. They develop into plasma cells that become the source of antibodies.

Antibody- the protein that is produced by the body’s immune system whose function is to detect and respond to antigen.

Killer cell- type of cell that is able to kill off cancerous cells or virus-infected cells.

cytotoxic T cell- The cytotoxic T-cells fit as a sub-category of the t-cells. However, it is distinguished from the other t-cells because of its CD8 receptor. These cells are able to detect antigens on the surface of a virus-infected cell. As soon as it spots an infectious cell, the T-cells bind itself to the infected cell and kill it.

Memory cell- These cells are capable of remembering specific intruders. Therefore, as soon as an intruder tries to invade the body for the second time, B and T memory cells help the immune system to activate much faster. The invaders are wiped out before the infected human feels any symptoms.

We are born with Passive immunity. The mother’s immunity is passed down to the newborn in order to protect the baby from infection. The passive immunity stays as the time needed for the body to develop its own immune response. Another form of immunity that we are born with, is called innate immunity. It protects and prevents all of the external diseases from entering into our bodies. However, the adaptive immunity is the immunity where the memory cells kick in. As our bodies are exposed to various different antigen, our adaptive immunity is continuously built.

Selective IgA Deficiency : Selective IgA Deficiency is the most common of the primary Immunodeficiencies. People with this condition have total absence or severe deficiency of IgA because B-lymphocytes  are unable to mature into IgA-producing plasma cells. IgA deficient people have B cells that are stopped at an immature stage. The IgA class of immunoglobulins has the specific function of protecting the body's mucosal surfaces (eyes, mouth, throat, lungs, gastrointestinal, and genitourinary tract) from infection. Therefore, the lack IgA at these places typically causes infection, allergies, chronic diarrhea, or autoimmune diseases. In autoimmune diseases, the immune system mistakenly attacks the body's own tissues.

Hay Fever: is also known as allergic rhinitis.  The body’s  immune system thinks that the allergen (pollen, mold, dander, etc.) as an "foreign invader" and responds by releasing a chemical called histamine into the bloodstream. This chemical, Histamine,  causes inflammation (swelling and redness) of the sinuses, nose, and mucus membranes of the eyes and triggers sneezing. The swelling reaction is designed to block the allergen from entering the body and sneezing is a method to expel it out of the body. Histamine also allows fluids to enter the nasal tissue, resulting in congestion and an itchy, runny nose.