Feedback System

Acetylcholine Receptor (AChR) Antibody

Alpha-fetoprotein (AFP) Tumor Marker

Anti-Saccharomyces cerevisiae Antibodies (ASCA)

Antimitochondrial Antibody and AMA M2

APOE Genotyping, Cardiovascular Disease

B-cell Immunoglobulin Gene Rearrangement

Clostridium difficile and C. difficile Toxin Testing

Cyclic Citrullinated Peptide Antibody

Cystic Fibrosis (CF) Gene Mutations Testing

Epstein-Barr Virus (EBV) Antibody Tests

Erythrocyte Sedimentation Rate (ESR)

Estimated Glomerular Filtration Rate (eGFR)

Estrogen/Progesterone Receptor Status

Extractable Nuclear Antigen Antibodies (ENA) Panel

Factor V Leiden Mutation and PT 20210 Mutation

Fecal Occult Blood Test and Fecal Immunochemical Test

Genetic Tests for Targeted Cancer Therapy

Heparin-induced Thrombocytopenia PF4 Antibody

High-sensitivity C-reactive Protein (hs-CRP)

HIV Antiretroviral Drug Resistance Testing, Genotypic

Human T-cell Lymphotropic Virus (HTLV) Testing

Insulin-like Growth Factor-1 (IGF-1)

Maternal Serum Screening, Second Trimester

Non-High Density Lipoprotein Cholesterol

Partial Thromboplastin Time (PTT, aPTT)

Prenatal Group B Strep (GBS) Screening

Protein Electrophoresis Immunofixation Electrophoresis

Prothrombin Time and International Normalized Ratio (PT/INR)

Red Blood Cell (RBC) Antibody Identification

Red Blood Cell (RBC) Antibody Screen

Respiratory Syncytial Virus (RSV) Testing

Shiga toxin-producing Escherichia coli

Smooth Muscle Antibody (SMA) and F-actin Antibody

Total Protein and Albumin/Globulin (A/G) Ratio

Transferrin and Iron-binding Capacity (TIBC, UIBC)

Urine Albumin and Albumin/Creatinine Ratio

Urine Protein and Urine Protein to Creatinine Ratio

Adrenal Insufficiency and Addison Disease

Disseminated Intravascular Coagulation (DIC)

Heart Attack and Acute Coronary Syndrome

Nontuberculous Mycobacteria Infections

Pregnancy: First Trimester (Up to 12 Weeks)

Pregnancy: Second Trimester (13 to 27 weeks)

Pregnancy: Third Trimester (28 weeks to delivery)

Primary Aldosteronism (Conn Syndrome)

Screening Tests for Children (Ages 2 to 12)

Screening Tests for Teens (Ages 13-18)

Screening Tests for Young Adults (Ages 19-29)

Screening Tests for Adults (Ages 30-49)

Screening Tests for Adults (50 and Up)

The body uses feedback systems to control certain functions. A feedback system uses one of the products of a pathway, usually the end product, to control the activity of the pathway and to regulate the amount of that product. Feedback control may be positive or negative.

To understand negative feedback, think of how the thermostat in your house controls the temperature. Lets say that the thermostat is set at 70 degrees F (the end product concentration). When the temperature falls below 70 degrees F, the feedback system is triggered and the furnace lights and starts to pump warm air into the house. When the air in the house reaches 70 degrees F, the thermostat shuts off the furnace (no more product made; no more hot air generated). A negative feedback system maintains a steady state or equilibrium and is the one most commonly found in the body.

Positive feedback systems increase the rate of formation of the product. This tends to cause change in the system rather than maintain a steady state. Think of how when a person works hard and is praised for their efforts (given positive feedback), they work harder still, expecting more praise. There are very few positive feedback systems in the body. One example, however, is lactation. The suckling action of an infant produces prolactin, which leads to milk production; more suckling leads to more prolactin, which in turn leads to more lactation. This is a positive feedback system as the product (milk) produces more suckling and more hormone. When the child is no longer breast feeding, the prolactin drops off and milk production goes down.

About the delivery system Ad auctions

Ad Choices Learn More About Our Ads

The more promotions gifts areSilicone WristbandsSilicone Bracelets In UKSilicone bracelets Canada