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Endocrine Control Chapter 32.

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Presentation on theme: "Endocrine Control Chapter 32."— Presentation transcript:

1 Endocrine Control Chapter 32

2 An Orchestra of Hormones
Hormones influence the growth, development, and reproductive cycles of nearly all animals They influence behavior, physical appearance, and well-being

3 Hormones Secreted by endocrine glands, endocrine cells, and certain neurons Animal hormones travel through the bloodstream to nonadjacent target cells

4 Other Signaling Molecules
Neurotransmitters Local signaling molecules Pheromones

5 Endocrine System Main Sources Pituitary gland Adrenal glands
Thyroid gland Parathyroid glands Pineal gland Thymus gland


7 Responses to Hormones Vary
Different hormones activate different responses in the same target cell Not all types of cells respond to a particular hormone

8 Two Main Hormone Types Steroid hormones Peptide hormones
Derived from cholesterol Estrogens, progestins, androgens (such as testosterone), cortisol, aldosterone Peptide hormones Peptides, proteins, or glycoproteins Glucagon, ADH, oxytocin, TRH, insulin, somatotropin, prolactin, FSH, LH, TSH

9 Steroid Hormone Action
Most diffuse across the plasma membrane and bind to a receptor Hormone-receptor complex acts in nucleus to inhibit or enhance transcription (protein synthesis)

10 hormone-receptor complex
Steroid Hormones hormone Most diffuse across the plasma membrane and bind to a receptor Hormone-receptor complex acts in nucleus to inhibit or enhance transcription receptor hormone-receptor complex gene product

11 Protein Hormone Hormone binds to a receptor at cell surface
glucagon Hormone binds to a receptor at cell surface Binding triggers a change in activity of enzymes inside the cell glucagon receptor cyclic AMP + Pi ATP cAMP activates protein kinase A Protein kinase A converts phosphorylase kinase to active form and inhibits an enzyme required for glucagon synthesis.

12 The Hypothalamus Region in the brain Contains hormone-secreting cells
Interacts with pituitary pituitary gland

bone at base of cranial cavity anterior lobe posterior lobe Fig. 32.2a, p. 522

14 Pituitary Gland Two lobes
Posterior lobe (neurohypophysis) stores and secretes hormones that were synthesized in the hypothalamus Anterior lobe (adenohypophysis) produces and secretes its own hormones

15 Posterior Lobe Antidiuretic hormone (ADH ) Oxytocin (OCT)
cell body in hypothalmus Antidiuretic hormone (ADH ) Oxytocin (OCT) axons to the general circulation

16 cell body in hypothalmus
POSTERIOR LOBE OF PITUITARY oxytocin ADH axons kidney tubules mammary glands smooth muscle in wall of the uterus to the general circulation Fig. 32.5, p. 527

17 Anterior Pituitary ACTH TSH FSH LH PRL STH

18 Cell bodies secrete releasing and inhibiting hormones
growth-promoting effects on most cells ANTERIOR LOBE OF PITUITARY STH (GH) ACTH PRL Capillary bed at base of hypothalmus TSH FSH LH both act on: adrenal cortex thyroid gonads mammary glands Capillary bed in anterior pituitary Fig. 32.6, p. 527

19 Feedback Mechanisms Negative feedback Positive feedback
An increase in concentration of a hormone triggers activities that inhibit further secretion Positive feedback An increase in concentration of a hormone triggers activities that stimulate further secretion

20 Control of Cortisol Secretion (1)
Hypothalamus senses decline in glucose and secretes a releasing hormone (CRH) CRH stimulates anterior pituitary to secrete ACTH ACTH acts on the adrenal cortex to stimulate cortisol secretion

21 Control of Cortisol Secretion (2)
Inhibits blood glucose uptake by muscle and other tissues Causes breakdown of proteins to amino acids and conversion to glucose Causes degradation of adipose tissue to fatty acids for use as energy source

22 Control of Cortisol Secretion (3)
Decrease in glucose uptake and release of glucose from protein breakdown causes blood glucose level to rise Hypothalamus and anterior pituitary detect the increase and decrease secretion of CRH and ACTH Adrenal cortex decreases cortisol secretion

23 Thyroid Gland Disorders
Goiter Hyperthyroidism Hypothyroidism

24 Feedback Control of Ovaries
Pituitary produces hormones (LH, FSH) that stimulate egg maturation and ovulation in the ovary They also stimulate ovary to produce progesterone and estrogen After ovulation, rising levels of these hormones inhibit further secretion of LH and FSH

25 Control of Glucose Metabolism
insulin Glucose uptake Glucose to glycogen Glucose falls Glucose is absorbed Cells use glucose Glucose rises Glycogen to glucose glucagon

26 Diabetes Mellitis Disease in which excess glucose accumulates in blood, then urine Effects include Excessive urination Constant thirst Weight loss Ketone formation and acid-base imbalances

27 Two Types of Diabetes Type 1 Type 2 Auto-immune disease
Usually appears in childhood Treated with insulin injections Type 2 Target cells don’t respond Usually appears in adults Treated with diet, drugs

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