BIOLOGY 20 Lecture Notes - Lecture 27: Glycogenolysis, Cortisol, East Los Angeles College
Document Summary
Surrounds adrenal medulla and produces major steroid hormones called corticosteroids. Secretes 3 major categories of steroid hormones from three layers of glandular tissue. Zona glomerulosa (thin, outer layer: cells are arranged in round cluster, secretes mineralocorticoids eg. aldosterone regulate the body"s electrolyte balance ie. sodium retention. Zone fasciculate (thick, middle layer: cells arranged in fascicles separated by capillaries, secretes glucocorticoids eg. cortisol regulate metabolism of glucose, suppresses immune system, helps body adapt to stress and repair tissues. Zona reticularis (narrow, inner layer: cells in branching network, secretes sex steroids eg. androgens, estrogen. Mainly dhea is converted to testosterone in other tissues. Adrenal medulla inner core, 10% to 20% of gland which is surrounded by a much thicker adrenal cortex constituting 80%-90% Consists primarily of modified sympathetic neurons called chromaffin cells which have no dendrites or axons but receive sympathetic input and release their products directly into the blood stream.
