Bone marrow is a sponge-like tissue found inside the bones. That is where most immune system cells are produced and then also multiply. These cells move to other organs and tissues through the blood. At birth, many bones contain red bone marrow, which actively creates immune system cells. Over the course of our life, more and more red bone marrow turns into fatty tissue. In adulthood, only a few of our bones still contain red bone marrow, including the ribs, breastbone and the pelvis.
The thymus is located behind the breastbone above the heart. This gland-like organ reaches full maturity only in children, and is then slowly transformed to fatty tissue. Special types of immune system cells called thymus cell lymphocytes (T cells) mature in the thymus. Among other tasks, these cells coordinate the processes of the innate and adaptive immune systems. T cells move through the body and constantly monitor the surfaces of all cells for changes.
Lymph nodes are small bean-shaped tissues found along the lymphatic vessels. The lymph nodes act as filters. Various immune system cells trap germs in the lymph nodes and activate the creation of special antibodies in the blood. Swollen or painful lymph nodes are a sign that the immune system is active, for example to fight an infection.
The bowel plays a central role in defending the body against germs: More than half of all the body's cells that produce antibodies are found in the bowel wall, especially in the last part of the small bowel and in the appendix. These cells detect foreign substances, and then mark and destroy them. They also save information about the substances in order to be able to react more quickly the next time. The large bowel also contains harmless bacteria called gastrointestinal or gut flora. Healthy gut flora make it difficult for germs to spread and enter the body.
Mucous membranes support the immune system in other parts of the body, too, such as the respiratory and urinary tracts, and the lining of the vagina. The immune system cells are directly beneath the mucous membranes, where they prevent bacteria and viruses from attaching.
The tonsils are also part of the immune system. Because of their location at the throat and palate, they can stop germs entering the body through the mouth or the nose. The tonsils also contain a lot of white blood cells, which are responsible for killing germs. There are different types of tonsils: palatine tonsils, adenoids and the lingual tonsil. All of these tonsillar structures together are sometimes called Waldeyer's ring since they form a ring around the opening to the throat from the mouth and nose.
There is also lymphatic tissue on the side of the throat, which can perform the functions of the palatine tonsils if they are removed.
The spleen is located in the left upper abdomen, beneath the diaphragm, and is responsible for different kinds of jobs:
It stores various immune system cells. When needed, they move through the blood to other organs. Scavenger cells (phagocytes) in the spleen act as a filter for germs that get into the bloodstream. It breaks down red blood cells (erythrocytes). It stores and breaks down platelets (thrombocytes), which are responsible for the clotting of blood, among other things. There is always a lot of blood flowing through the spleen tissue. At the same time this tissue is very soft. In the event of severe injury, for example in an accident, the spleen may rupture easily. Surgery is then usually necessary because otherwise there is a danger of bleeding to death. If the spleen needs to be removed completely, other immune system organs can carry out its roles.
Primary lymphoid organs: These organs include the bone marrow and the thymus. They create special immune system cells called lymphocytes. Secondary lymphoid organs: These organs include the lymph nodes, the spleen, the tonsils and certain tissue in various mucous membrane layers in the body (for instance in the bowel)
Cerebrospinal fluids is a colorless fluid that is secreted in the choroid plexus,and circulates in the ventricles system and sub -aranchinoid space of the brain and spinal cord. its provides nutrients to the surrounding neurons, cushions the effects of trauma, pressure, acts as buffer and provides protection through immune system .
it plays a vital role in regulating blood flow, through a process called cerebral auto regulation,This is needed to maintain efficient cerebral blood flow of oxygen and other metabolites, and withdraw of metabolic wastes from the brain.
in order to analyze it to diagnose some neurological diseases its sample is usually taken out in a process called lumbar puncture.
Traveler's diarrhea is an intestinal infection that occurs as a result of eating or drinking contaminated food or water, food handlers who do not wash their hands after they use the bathroom can transmit the infection to people who consume the contaminated food
Due to diarrhea, kidney don't work properly and level of urea increases in blood
Due to the low carbohydrate intake, ketosis occurs in which stored fat is metabolized which results in build up of acids called ketones
If the body starts to use energy sources other than carbohydrates then it means it is using the stored energy, gluconeogenesis fulfills glucose requirement of cell by synthesis of glucose from non carbohydrate material
To supply with energy lipid metabolism occurs, fatty acids are oxidized and energy in the form of ATP is produced
DNA is the genetic material of all the organisms except some viruses. DNA has the ability to replicate and produce daughter DNA cells by the process of replication.
DNA is made of polymers of nucleotides. DNA consists of nitrogenous base, in which adenine is linked with thymine, cytosine with guanine thriugh hydrogen bonding ,shows complementary base pairing. Pentose deoxyribose sugar and phosphate group. The DNA molecules are linked together through phosphodiester bonds. Amino acids is present in protein.
