© 2010 Pearson Education, Inc. Lectures by Chris C. Romero, updated by Edward J. Zalisko PowerPoint ® Lectures for Campbell Essential Biology, Fourth Edition – Eric Simon, Jane Reece, and Jean Dickey Campbell Essential Biology with Physiology, Third Edition – Eric Simon, Jane Reece, and Jean Dickey Chapter 25 Hormones

Biology And Society: A Hormonal Fountain of Youth? Menopause: –Typically occurs around age 50 –Is caused by decreasing levels of –Estrogen –Progesterone © 2010 Pearson Education, Inc.

Figure 25.00

© 2010 Pearson Education, Inc. Hormone replacement therapy (HRT): –Has been used to relieve negative symptoms of menopause but –May cause increased risks of stroke and cancer Bioidenticals are: –Synthetic human hormones –Produced by chemically modifying plant-derived hormones

© 2010 Pearson Education, Inc. HORMONES: AN OVERVIEW Hormones are: –Regulatory chemicals that affect specific sites in the body –Produced by most plants and animals –Made by endocrine glands

© 2010 Pearson Education, Inc. The endocrine system: –Consists of all hormone-secreting cells –Is the body’s main system for internal chemical regulation

© 2010 Pearson Education, Inc. Endocrine cells secrete into the bloodstream hormones that: –Can affect many cells in many different body organs but –Only affect target cells, cells that have receptors for that specific hormone

Endocrine cell Blood vessel Membrane- enclosed sacs Hormone molecules Receptor protein Target cell Adrenal glands (type of endocrine gland), which sit atop the kidneys Figure 25.1

Endocrine cell Blood vessel Membrane- enclosed sacs Hormone molecules Receptor protein Target cell Figure 25.1a

© 2010 Pearson Education, Inc. There are two general mechanisms by which hormones trigger changes in target cells. –Water-soluble hormones trigger responses without ever entering their target cells. Animation: Water-Soluble Hormone

Water- soluble hormone Receptor protein Target cell Plasma membrane Nucleus Figure

Water- soluble hormone Receptor protein Target cell Plasma membrane Relay molecules Signal transduction pathway Nucleus Figure

Water- soluble hormone Receptor protein Target cell Plasma membrane Relay molecules Signal transduction pathway Cytoplasmic response or Gene regulation Nucleus Figure

© 2010 Pearson Education, Inc. –Lipid-soluble hormones trigger responses after entering the target cell. Animation: Lipid-Soluble Hormone

Lipid- soluble hormone Target cell Plasma membrane Nucleus Figure

Lipid- soluble hormone Receptor protein Target cell Plasma membrane Nucleus Figure

Lipid- soluble hormone Receptor protein Target cell Plasma membrane Hormone- receptor complex Nucleus Figure

Lipid- soluble hormone Receptor protein Target cell Plasma membrane Hormone- receptor complex Gene regulation Nucleus Figure

© 2010 Pearson Education, Inc. THE HUMAN ENDOCRINE SYSTEM The human endocrine system consists of about a dozen major glands that may have: –Only endocrine functions or –Endocrine and non-endocrine functions

© 2010 Pearson Education, Inc. The major endocrine glands in humans are spread about the human body.

Thyroid gland Pituitary gland Hypothalamus Parathyroid glands (embedded within thyroid) Adrenal glands (atop kidneys) Testes (male) Pancreas Ovaries (female) Figure 25.4

© 2010 Pearson Education, Inc. Hormones have a wide range of target cells and effects.

Table 25.1

Table 25.1a

Table 25.1b

© 2010 Pearson Education, Inc. The Hypothalamus and Pituitary Gland The hypothalamus: –Is part of the brain –Is the main control center of the endocrine system –Receives information from nerves about the: –Internal condition of the body –External environment

© 2010 Pearson Education, Inc. The pituitary gland: –Is a pea-sized structure that hangs below the hypothalamus –Responds to signals from the hypothalamus –Secretes hormones that influence many body functions

Hypothalamus Posterior pituitary Brain Bone Anterior pituitary Figure 25.5

Brain Figure 25.5a

Hypothalamus Posterior pituitary Bone Anterior pituitary Figure 25.5b

© 2010 Pearson Education, Inc. The pituitary gland consists of two parts: –The posterior pituitary: –Stores hormones –Secretes hormones made in the hypothalamus –The anterior pituitary: –Synthesizes its own hormones, such as FSH and LH –Secretes hormones directly into the blood

© 2010 Pearson Education, Inc. The hypothalamus: –Operates through the posterior pituitary –Directs the activities of the kidneys

Hypothalamus Kidneys Anterior pituitary ADH Posterior pituitary Blood vessel (ADH increases water reabsorption and prevents dehydration) Figure 25.6

© 2010 Pearson Education, Inc. The anterior lobe of the pituitary also secretes growth hormone (GH), which: –Promotes development and enlargement of all parts of the body –Can lead to: –Dwarfism, if too little GH is produced –Gigantism, if too much GH is produced

(a) Overproduction of GH during development (b) Overproduction of GH during adulthood (c) Underproduction of GH during development Figure 25.7

(a) Overproduction of GH during development Figure 25.7a

(b) Overproduction of GH during adulthood Figure 25.7b

(c) Underproduction of GH during development Figure 25.7c

© 2010 Pearson Education, Inc. Endorphins: –Are produced by the anterior pituitary –Act as natural painkillers

© 2010 Pearson Education, Inc. The Thyroid and Parathyroid Glands The thyroid gland, located in the neck just under the larynx, produces: –Calcitonin, which lowers calcium levels in the blood –Several hormones involved in controlling: –Oxygen consumption –Metabolism –Development

© 2010 Pearson Education, Inc. Hypothyroidism: –Results from too little thyroid hormone in the blood –Can result from: –Dietary deficiencies of iodine –A defective thyroid gland

© 2010 Pearson Education, Inc. Hyperthyroidism –Results from too much thyroid hormone in the blood –Can lead to: –Overheating –Profuse sweating –High blood pressure –Protruding eyeballs

© 2010 Pearson Education, Inc. The parathyroid glands: –Are four disk-shaped glands embedded within the thyroid –Produce parathyroid hormone, which raises calcium levels in the blood

© 2010 Pearson Education, Inc. Calcitonin and parathyroid hormone (PTH) are antagonistic hormones, because they have opposite effects on calcium levels in the blood. Blast Animation: Signaling: Endocrine

Thyroid gland releases calcitonin Homeostasis: Normal blood calcium level Calcitonin Stimulus: Rising blood Ca 2 + level (imbalance) Ca 2 + level Figure

Thyroid gland releases calcitonin Stimulus: Rising blood Ca 2 + level (imbalance) Ca 2 + level Homeostasis: Normal blood calcium level Stimulates Ca 2 + deposition in bones Reduces Ca 2 + uptake in kidneys Calcitonin Figure

Thyroid gland releases calcitonin Stimulus: Rising blood Ca 2 + level (imbalance) Ca 2 + level Homeostasis: Normal blood calcium level Stimulates Ca 2 + deposition in bones Ca 2 + level in blood falls to set point Reduces Ca 2 + uptake in kidneys Calcitonin Figure

Thyroid gland releases calcitonin Stimulus: Rising blood Ca 2 + level (imbalance) Ca 2 + level Parathyroid glands release parathyroid hormone (PTH) Ca 2 + level Stimulus: Falling blood Ca 2 + level (imbalance) PTH Parathyroid gland Homeostasis: Normal blood calcium level Stimulates Ca 2 + deposition in bones Ca 2 + level in blood falls to set point Reduces Ca 2 + uptake in kidneys Calcitonin Figure

Thyroid gland releases calcitonin Stimulus: Rising blood Ca 2 + level (imbalance) Ca 2 + level Stimulates Ca 2 + release from bones Increases Ca 2 + uptake in kidneys Increases Ca 2 + uptake in intestines Parathyroid glands release parathyroid hormone (PTH) Ca 2 + level Stimulus: Falling blood Ca 2 + level (imbalance) PTH Parathyroid gland Homeostasis: Normal blood calcium level Stimulates Ca 2 + deposition in bones Ca 2 + level in blood falls to set point Reduces Ca 2 + uptake in kidneys Calcitonin Figure

Thyroid gland releases calcitonin Stimulus: Rising blood Ca 2 + level (imbalance) Ca 2 + level Ca 2 + level in blood rises to set point Stimulates Ca 2 + release from bones Increases Ca 2 + uptake in kidneys Increases Ca 2 + uptake in intestines Parathyroid glands release parathyroid hormone (PTH) Ca 2 + level Stimulus: Falling blood Ca 2 + level (imbalance) PTH Parathyroid gland Homeostasis: Normal blood calcium level Stimulates Ca 2 + deposition in bones Ca 2 + level in blood falls to set point Reduces Ca 2 + uptake in kidneys Calcitonin Figure

© 2010 Pearson Education, Inc. The Pancreas The pancreas produces two antagonistic hormones that play important roles in managing the body’s energy supplies: –Insulin reduces blood sugar levels –Glucagon increases blood sugar levels

Pancreas releases insulin into the blood Stimulus: Rising blood glucose level (for example, after eating a carbohydrate-rich meal) Glucose level Homeostasis: Normal blood glucose level Insulin Figure

Pancreas releases insulin into the blood Stimulus: Rising blood glucose level (for example, after eating a carbohydrate-rich meal) Glucose level Homeostasis: Normal blood glucose level Insulin Liver takes up glucose and stores it as glycogen Body cells take up more glucose Figure

Pancreas releases insulin into the blood Stimulus: Rising blood glucose level (for example, after eating a carbohydrate-rich meal) Glucose level Homeostasis: Normal blood glucose level Insulin Blood glucose level falls to a set point; stimulus for insulin release diminishes Liver takes up glucose and stores it as glycogen Body cells take up more glucose Figure

Pancreas releases insulin into the blood Stimulus: Rising blood glucose level (for example, after eating a carbohydrate-rich meal) Pancreas releases glucagon into the blood Glucagon Glucose level Homeostasis: Normal blood glucose level Insulin Stimulus: Declining blood glucose level (for example, after skipping a meal) Blood glucose level falls to a set point; stimulus for insulin release diminishes Liver takes up glucose and stores it as glycogen Body cells take up more glucose Glucose level Figure

Pancreas releases insulin into the blood Stimulus: Rising blood glucose level (for example, after eating a carbohydrate-rich meal) Pancreas releases glucagon into the blood Glucagon Glucose level Homeostasis: Normal blood glucose level Insulin Liver breaks down glycogen and releases glucose to the blood Stimulus: Declining blood glucose level (for example, after skipping a meal) Blood glucose level falls to a set point; stimulus for insulin release diminishes Liver takes up glucose and stores it as glycogen Body cells take up more glucose Glucose level Figure

Pancreas releases insulin into the blood Stimulus: Rising blood glucose level (for example, after eating a carbohydrate-rich meal) Pancreas releases glucagon into the blood Glucagon Glucose level Homeostasis: Normal blood glucose level Insulin Blood glucose level rises to set point; stimulus for glucagon release diminishes Liver breaks down glycogen and releases glucose to the blood Stimulus: Declining blood glucose level (for example, after skipping a meal) Blood glucose level falls to a set point; stimulus for insulin release diminishes Liver takes up glucose and stores it as glycogen Body cells take up more glucose Glucose level Figure

© 2010 Pearson Education, Inc. Diabetes mellitus is a hormonal disease in which body cells are unable to absorb glucose from the blood either because: –There is not enough insulin produced (type 1, or insulin-dependent diabetes) or –The target cells do not respond normally to insulin (type 2, or non- insulin-dependent diabetes) Diabetes can be treated.

Figure 25.10

Figure 25.10a

Figure 25.10b

© 2010 Pearson Education, Inc. The Adrenal Glands The adrenal glands are paired structures resting atop the kidneys. Each adrenal gland consists of two glands: –The adrenal medulla –The adrenal cortex

© 2010 Pearson Education, Inc. The adrenal medulla secretes epinephrine and norepinephrine, hormones that: –Enable the body to respond to stress –Produce the fight or flight response

© 2010 Pearson Education, Inc. Stressful stimuli activate nerve cells in the hypothalamus that send signals to stimulate the adrenal medulla.

© 2010 Pearson Education, Inc. The adrenal cortex: –Is also stimulated by the hypothalamus –Secretes two hormones that provide a slower, longer-lasting response to stress: –Corticosteroids –Glucocorticoids Blast Animation: Signaling via Steroid Hormones

Adrenal gland Adrenal medulla Adrenal cortex Kidney Adrenal cortex Nerve signals Nerve cell Nerve cell Spinal cord (cross section) Adrenal medulla Epinephrine and norepinephrine Corticosteroids ACTH Anterior pituitary Releasing hormone Blood vessel Hypothalamus STRESS 1.Proteins and fats broken down and converted to glucose, leading to increased blood glucose 2.Immune system may be suppressed Long-term stress response Short-term stress response 1.Glycogen broken down to glucose; increased blood glucose 2.Increased blood pressure, breathing rate, heart rate, and metabolic rate 3.Change in blood flow patterns, leading to increased alertness and decreased digestive activity ACTH Figure 25.11

Adrenal gland Adrenal medulla Adrenal cortex Kidney Figure 25.11a

Adrenal cortex Nerve signals Nerve cell Nerve cell Spinal cord (cross section) Adrenal medulla Anterior pituitary Releasing hormone Blood vessel Hypothalamus STRESS Figure 25.11b-1

Adrenal cortex Nerve signals Nerve cell Nerve cell Spinal cord (cross section) Adrenal medulla Epinephrine and norepinephrine Anterior pituitary Releasing hormone Blood vessel Hypothalamus STRESS Short-term stress response 1.Glycogen broken down to glucose; increased blood glucose 2.Increased blood pressure, breathing rate, heart rate, and metabolic rate 3.Change in blood flow patterns, leading to increased alertness and decreased digestive activity Figure 25.11b-2

Adrenal cortex Nerve signals Nerve cell Nerve cell Spinal cord (cross section) Adrenal medulla Epinephrine and norepinephrine Anterior pituitary Releasing hormone Blood vessel Hypothalamus STRESS Short-term stress response 1.Glycogen broken down to glucose; increased blood glucose 2.Increased blood pressure, breathing rate, heart rate, and metabolic rate 3.Change in blood flow patterns, leading to increased alertness and decreased digestive activity Figure 25.11b-3

Adrenal cortex Nerve signals Nerve cell Nerve cell Spinal cord (cross section) Adrenal medulla Epinephrine and norepinephrine ACTH Anterior pituitary Releasing hormone Blood vessel Hypothalamus STRESS Short-term stress response 1.Glycogen broken down to glucose; increased blood glucose 2.Increased blood pressure, breathing rate, heart rate, and metabolic rate 3.Change in blood flow patterns, leading to increased alertness and decreased digestive activity ACTH Figure 25.11b-4

Adrenal cortex Nerve signals Nerve cell Nerve cell Spinal cord (cross section) Adrenal medulla Epinephrine and norepinephrine Corticosteroids ACTH Anterior pituitary Releasing hormone Blood vessel Hypothalamus STRESS 1.Proteins and fats broken down and converted to glucose, leading to increased blood glucose 2.Immune system may be suppressed Long-term stress response Short-term stress response 1.Glycogen broken down to glucose; increased blood glucose 2.Increased blood pressure, breathing rate, heart rate, and metabolic rate 3.Change in blood flow patterns, leading to increased alertness and decreased digestive activity ACTH Figure 25.11b-5

© 2010 Pearson Education, Inc. The Gonads The gonads secrete sex hormones that: –Affect growth and development –Regulate: –Reproductive cycles –Sexual behavior

© 2010 Pearson Education, Inc. Males and females have the same three types of sex hormones: –Estrogens –Progestins –Androgens

© 2010 Pearson Education, Inc. Estrogens: –Maintain the female reproductive system –Promote the development of specific female features

© 2010 Pearson Education, Inc. Progestins, including progesterone, are primarily involved in preparing the uterus to support a developing embryo.

© 2010 Pearson Education, Inc. Androgens, including testosterone, stimulate the development and maintenance of the male reproductive system.

The Process of Science: Can Pollution Cause Sex Changes? Observation: All of the female mosquitofish collected in a Florida stream had anatomical features and behaviors normally found only in males. Question: Was pollution from a nearby paper mill the cause of these changes? Hypothesis: Runoff from the mill contained endocrine disruptors. © 2010 Pearson Education, Inc.

Experiment: Water and fish were analyzed from above and below the paper mill. Results: Female fish with masculine features were found only downstream of the paper mill.

Female with male organ Perdido Bay Paper mill discharging waste water Contaminated sample sites Uncontaminated sample sites Normal male Mile Ele v en re ek C Normal female Figure 25.12

Evolution Connection: Androgens, Anatomy, and Aggression Testosterone and other androgens: –Promote the development and maintenance of the male reproductive system –Play a similar role in all vertebrates © 2010 Pearson Education, Inc.

In addition to determining the male sexual condition, androgens: –Are responsible for male vocalizations –Promote aggressive behavior

Figure 25.13

© 2010 Pearson Education, Inc. The different roles for androgens among vertebrates illustrate two central aspects of life resulting from Darwinian evolution: –The unity of life (a consistent effect on the development of the male gonads) –The diversity of life (the variety of secondary effects)

Figure 25.UN1

Figure 25.UN2

Figure 25.UN3

Figure 25.UN4

Figure 25.UN5

Water- soluble hormone Receptor protein Signal transduction pathway Cytoplasmic response or Lipid- soluble hormone Receptor protein Gene regulation Nucleus Hormone- receptor complex Figure 25.UN6

Water- soluble hormone Receptor protein Signal transduction pathway Cytoplasmic response or Gene regulation Nucleus Figure 25.UN6a

Lipid- soluble hormone Receptor protein Gene regulation Nucleus Hormone- receptor complex Figure 25.UN6b

Hypothalamus: Master control center of the endocrine system Brain Posterior pituitary: Stores and secretes hormones made by hypothalamus Anterior pituitary: Controlled by hypothalamus; produces and secretes its own hormones Figure 25.UN7

Thyroid releases causes Calcitonin Parathyroids release causes Parathyroid hormone Ca 2 + in blood Ca 2 + in blood Figure 25.UN8

Thyroid releases causes Calcitonin Ca 2 + in blood Figure 25.UN8a

Parathyroids release causes Parathyroid hormone Ca 2 + in blood Figure 25.UN8b

releases causes Pancreas releases causes Glucose in blood Glucagon Insulin Glucose in blood Figure 25.UN9