Hormones & Endocrine System
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Transcript Hormones & Endocrine System
Hormones & Endocrine System
Introduction
Endocrine System – Sum of all hormone secreting cells and
tissues
Endocrine Gland – ductless glands that secrete hormones
directly into body fluids
Hormones – chemical signals that cause a response in target
cells
Affect body tissues or other endocrine glands (tropic hormone)
Endocrine secretion is determined by Positive & Negative
Feedback
Target Cell Receptors
Cell-Surface Receptors
Most common receptor for initiating a signal transduction
pathway
Receptor Transduction Response
Intracellular Receptors
ONLY lipid-soluble ligands are able to pass through the
membrane & bind intracellular receptors
Testosterone & estrogen (transcription factors)
The Boss…
Hypothalamus
Receives signals from
nervous system
Initiates endocrine
signal response
Pituitary Gland
Note Hypothalamus
Pituitary Gland
Anterior Pituitary
Regulated by hypothalamus
Growth hormone (GH)
Thyroid-stimulating hormone (TSH) – seriously?
FSH – (Follicle stimulating Hormone)
Stimulates development of ovarian follicles (female) or
spermatogenesis in seminiferous tubules (male)
Luteinizing Hormone
Triggers ovulation in females
Stimulates testosterone production production in testes
Thyroid Gland
Stimulates & maintain metabolic processes
Controls calcium level in blood
Calcitonin
Adrenal Gland
Epinephrine – Increase metabolic level
Constrict blood vessels
Raise blood-glucose levels
Glucocorticoids