Genome Complexity; amazing immune system (Introduction)

by David Turell , Thursday, February 04, 2016, 15:01 (3216 days ago) @ David Turell

Not only are there antibody producing cells which are modified with a memory to take on any return of a previous pathogen, there are literally white cells ( not red) which roam the blood stream to chomp up invading bacteria:-http://www.evolutionnews.org/2016/01/defending_the_b102559.html-"Neutrophils are produced in the bone marrow and with maturation move out into the blood. Neutrophils are usually the first immune cells from the blood to come to the field of battle. They are attracted to the war zone by cytokines, which are chemical messengers released from injured tissue and activated mast cells, macrophages, and dendritic cells. The process by which they move into the field of battle and toward invading microbes is called chemotaxis. This involves using specific receptors on their plasma membrane to move toward areas of increasing concentration of these chemicals. It's similar to how a bloodhound moves towards its prey by sensing the increasing concentration of the scent, or a shark to blood. Moreover, the same cells that send out cytokines to attract neutrophils and other immune cells also release chemicals that cause inflammation. Inflammation allows the neutrophils to squeeze through the narrow openings between the cells that line the capillaries into the tissues so they can seek out and destroy the enemy.-"Once inside the tissues and brought toward the invading microbes by chemotaxis, the neutrophils activate by using specific receptors on their plasma membrane to attach to specific chemicals on the surface of the intruder. The activated neutrophil usually engulfs the microbe in a process called phagocytosis . Once the microbe is inside, the neutrophil releases various chemicals and enzymes to kill and literally digest it. Neutrophils also kill microbes by releasing the chemical contents of their granules into the tissues.-***-"After neutrophils do their job, they usually die and are phagocytosed by macrophages. Dead neutrophils make up most of the cellular content of pus. Finally, like all activated immune cells, neutrophils release cytokines to promote inflammation, attract other immune cells to the battlefield, and increase the metabolism, often causing fever. -***- "That means the body makes about one million neutrophils per second! -Furthermore, to maintain this constant production, support cells in the bone marrow release a cytokine called Granulocyte Colony Stimulating Factor (G-CSF), which attaches to specific G-CSF receptors on the stem cells in the bone marrow, stimulating them to develop into neutrophils. -Finally, in response to infection and inflammation, some immune cells also release G-CSF, which can often result in a doubling or even tripling of the amount of neutrophils. So, although neutrophils cannot multiply on their own (like microbes can), in response to infection and inflammation some immune cells stimulate the bone marrow to increase neutrophil production. This increase makes more defenders available that can be sent to the battlefield. It is by the release of these cytokines that the body not only develops a fever, but also raises the white blood cell count (leukocytosis), the two main tell-tale signs of infection.-***-"Evolutionary biologists seek to explain how life came into being but they pay attention predominantly to how it looks, not how it must work within the laws of nature to survive. They may speculate on how neutrophils and the control mechanisms involved in their production must have come into being by chance and the laws of nature alone. But this doesn't take into account that this system is irreducibly complex, requiring cells that can produce G-CSF and ones that have specific G-CSF receptors, so they can be instructed to become neutrophils, and cytokines to allow neutrophils to leave the bloodstream, and with specific receptors move toward their prey."-Comment: As a physician I went from simply accepting evolution created this to realizing that evolution cannot create this as an unguided chance process!