AP Biology Endocrine Systems Signal Transduction Pathway Kinases

AP Biology Endocrine Systems

Signal Transduction Pathway

Kinases “turn on” processes Phosphotases “turn off” processes

Basic Hormone Pattern Example Pathway Low blood glucose Stimulus Receptor protein Endocrine cell Pancreas secretes glucagon ( ) Blood vessel Target effectors Response Liver Glycogen breakdown, glucose release into blood Simple endocrine pathway

Remember the “hands” on cell membranes? (In GREEN)

LE 45 -7 Hypothalamus Neurosecretory cells of the hypothalamus Axon Posterior pituitary Anterior pituitary HORMONE TARGET ADH Kidney tubules Oxytocin Mammary glands, uterine muscles

Cytokines IL 1 – Macrophage to Helper T IL 2 – Helper T to B or Cytotoxic T

SECRETORY CELL Polar versus Non-polar Hormone Signal Reception SECRETORY CELL Hormone molecule VIA BLOOD Signal receptor TARGET CELL Signal transduction pathway OR Signal receptor Cytoplasmic response DNA Signal transduction and response m. RNA NUCLEUS Nuclear response NUCLEUS Receptor in plasma membrane Synthesis of specific proteins Receptor in cell nucleus

Examples of Negative Feedback Loops Hypothalamus TRH Anterior pituitary TSH Thyroid T 3 T 4

Positive Feedback Loop

Tropic Hormones of the Posterior. Pituitary Hypothalamus Neurosecretory cells of the hypothalamus Axon Posterior pituitary Anterior pituitary HORMONE TARGET ADH Kidney tubules Oxytocin Mammary glands, uterine muscles

Tropic Hormones of the Anterior Pituitary Tropic Effects Only FSH, follicle-stimulating hormone LH, luteinizing hormone TSH, thyroid-stimulating hormone ACTH, adrenocorticotropic hormone Neurosecretory cells of the hypothalamus Nontropic Effects Only Prolactin MSH, melanocyte-stimulating hormone Endorphin Portal vessels Nontropic and Tropic Effects Growth hormone Hypothalamic releasing hormones (red dots) Endocrine cells of the anterior pituitary Pituitary hormones (blue dots) HORMONE FSH and LH TSH ACTH Prolactin MSH Endorphin TARGET Testes or ovaries Thyroid Adrenal cortex Mammary glands Melanocytes Pain receptors in the brain Growth hormone Liver Bones