HOMEOSTASIS, STRUCTURE AND FUNCTION, AND TRANSDUCTION IN THE BODY SYSTEMS.
Homeostasis within the endocrine system is vital for the metabolic activities of cells. The endocrine system uses hormones to administer and integrate major processes such as reproduction; growth and development; and maintaining electrolyte, water, and nutrient balance of the blood. .
Peptide hormones bind to receptors on target cell membranes. This process activates a signal transduction pathway inside the target cell causing the appropriate response within the cell.
Steriod hormones can pass through the lipid bilayer and bind to receptors inside the cell. This process creates a transcription factor that can turn certain genes on or off thus leading to the appropriate response within the cell. .
To maintain homeostasis the body must regulate the levels of specific hormones at all times through feedback interactions between hormones and their glands.
If the pituitary gland stopped releasing enough GH (growth hormone) it would result in a condition called pituitary dwarfism (the affected person only reaches about 4 ft. tall). An excessive amount of GH in the preteen years results in a pituitary giant. .
Immunity refers to the body's capacity to resist invading organisms and toxins to prevent tissue and organ damage. It is designed to recognize, respond to, and eliminate antigens. It also maintains homeostasis by scavenging dead or damaged cells and patrolling for antigens.
The body's main line of defense if specific immunity. Specific responses are classified as either humoral immunity or cell mediated immunity.
In humoral response an antigen causes B cells to divide and differentiate into plasma cells. Each plasma cell then produces and secretes large amounts of antigen-specific immunoglobulin into the blood stream. Immunoglobulins have a special Y shape. The crook of the Y is designed to attach to a particular antigen.