Chapter 26 Chemical Regulation

Figure 26.1A Hormone from an endocrine cell Secretory vesicles Endocrine cell Hormone molecules Blood vessel Target cell

Figure 26.2A A hormone that binds a plasma-membrane receptor Water-soluble hormone (epinephrine) 1 Receptor protein 2 Target cell Relay molecules Plasma membrane Signal transduction pathway 3 Glycogen Glucose Cellular response (in this example, glycogen breakdown)

Figure 26.3 The major endocrine glands in humans Hypothalamus Pineal gland Pituitary gland Thyroid gland Parathyroid glands Thymus Adrenal glands (atop kidneys) Pancreas Ovary (female) Testes (male)

Figure 26.7 Blood Glucose homeostasis Body cells Blood glucose level Stimulus: Alpha cells Liver Homeostasis : Beta cells

Figure 26.7 Blood Glucose homeostasis Body cells Blood glucose level Stimulus: Alpha cells Liver Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells

Figure 26.7 Blood Glucose homeostasis Body cells Blood glucose level Stimulus: Alpha cells Liver Stimulus: Rising blood glucose level (eg., Eating food) Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells

Figure 26.7 Blood Glucose homeostasis Body cells Blood glucose level Stimulus: Alpha cells Liver Stimulus: Rising blood glucose level (eg. Eating food) Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells High blood glucose level

Figure 26.7 Glucose homeostasis Body cells Blood glucose level Stimulus: Alpha cells Liver Stimulus:: Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells of pancreas stimulated to release insulin into the blood High blood glucose level

Figure 26.7 Glucose homeostasis Body cells Blood glucose level Stimulus: Alpha cells Liver Stimulus:: Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells of pancreas stimulated to release insulin into the blood insulin High blood glucose level

Figure 26.7 Glucose homeostasis Body cells take up more glucose Blood glucose level Stimulus: Alpha cells Liver Stimulus: Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells of pancreas stimulated to release insulin into the blood insulin High blood glucose level

Figure 26.7 Glucose homeostasis Body Cells take up more glucose Blood glucose level Stimulus: Alpha cells Liver Stimulus: Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells of pancreas stimulated to release insulin into the blood Liver takes up glucose. Stores it as glycogen insulin High blood glucose level

Figure 26.7 Glucose homeostasis Body Cells take up more glucose Blood glucose level declines to a set point; stimulus for insulin release diminishes Stimulus: Alpha cells Liver Blood glucose level Stimulus: Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells of pancreas stimulated to release insulin into the blood Liver takes up glucose and stores it as glycogen insulin High blood glucose level

Figure 26.7 Glucose homeostasis Body Cells take up more glucose Blood glucose level declines to a set point; stimulus for insulin release diminishes Stimulus: Declining BG (e.g., skipping a meal) Alpha cells Liver Blood glucose level Stimulus: Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells of pancreas stimulated to release insulin into the blood Liver takes up glucose and stores it as glycogen insulin High blood glucose level

Figure 26.7 Glucose homeostasis Body Cells take up more glucose Blood glucose level declines to a set point; stimulus for insulin release diminishes Stimulus: Declining blood glucose level (e.g., after skipping a meal) Alpha cells of pancreas stimulated to release glucagon into the blood Liver Blood glucose level Stimulus: Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells of pancreas stimulated to release insulin into the blood Liver takes up glucose and stores it as glycogen insulin High blood glucose level

Figure 26.7 Glucose homeostasis Body Cells take up more glucose Blood glucose level declines to a set point; stimulus for insulin release diminishes Stimulus: Declining blood glucose level (e.g., after skipping a meal) Alpha cells of pancreas stimulated to release glucagon into the blood glucagon Liver Blood glucose level Stimulus: Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) : Beta cells of pancreas stimulated to release insulin into the blood Liver takes up glucose and stores it as glycogen insulin High blood glucose level

Figure 26.7 Glucose homeostasis Body cells take up more glucose Insulin Blood glucose level declines to a set point; stimulus for insulin release diminishes Stimulus: Declining blood glucose level (e.g., after skipping a meal) Alpha cells of pancreas stimulated to release glucagon into the blood Glucagon Liver breaks down glycogen and releases glucose to the blood Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) Beta cells of pancreas stimulated to release insulin into the blood Liver takes up glucose and stores it as glycogen High blood glucose level

Figure 26.7 Blood Glucose homeostasis Body cells take up more glucose Insulin Blood glucose level declines to a set point; stimulus for insulin release diminishes Stimulus: Declining blood glucose level (e.g., after skipping a meal) Alpha cells of pancreas stimulated to release glucagon into the blood Glucagon Liver breaks down glycogen and releases glucose to the blood Blood glucose level rises to set point; stimulus for glucagon release diminishes Rising blood glucose level Homeostasis: Normal blood glucose level (about 90 mg/100mL) Beta cells of pancreas stimulated to release insulin into the blood Liver takes up glucose and stores it as glycogen High blood glucose level

Figure 26.8 Results of glucose tolerance tests Blood glucose (mg/100mL) 50 100 150 200 250 300 350 400 1 2 3 4 5 Diabetic Normal Hours after glucose ingestion

Steroid Abuse? p. 519

Figure 26.4C Hormones of the anterior pituitary Neurosecretory cell Blood vessel Releasing hormones from hypothalamus Pituitary hormones TSH ACTH FSH and LH Growth hormone (GH) Prolactin (PRL) Endorphins Thyroid Adrenal cortex Testes or ovaries Entire body Mammary glands (in mammals) Pain receptors in the brain Endocrine cells of the anterior pituitary

Figure 26.9 How the adrenal glands control our responses to stress medulla cortex Kidney Spinal cord (cross section) Nerve signals cell Nerve cell Adrenal medulla Epinephrine and norepinephrine Short-term stress response Stress Hypothalamus Releasing hormone Anterior pituitary Blood vessel ACTH Adrenal cortex

Figure 26.9 How the adrenal glands control our responses to stress medulla cortex Kidney Spinal cord (cross section) Nerve signals cell Nerve cell Adrenal medulla Epinephrine and norepinephrine Short-term stress response 1. Glycogen broken down to glucose; increased blood glucose Stress Hypothalamus Releasing hormone Anterior pituitary Blood vessel ACTH Adrenal cortex

Figure 26.9 How the adrenal glands control our responses to stress medulla cortex Kidney Spinal cord (cross section) Nerve signals cell Nerve cell Adrenal medulla Epinephrine and norepinephrine Short-term stress response 1. Glycogen broken down to glucose; increased blood glucose 2. Increased blood pressure Stress Hypothalamus Releasing hormone Anterior pituitary Blood vessel ACTH Adrenal cortex

Figure 26.9 How the adrenal glands control our responses to stress medulla cortex Kidney Spinal cord (cross section) Nerve signals cell Nerve cell Adrenal medulla Epinephrine and norepinephrine Short-term stress response 1. Glycogen broken down to glucose; increased blood glucose 2. Increased blood pressure 3. Increased breathing rate Stress Hypothalamus Releasing hormone Anterior pituitary Blood vessel ACTH Adrenal cortex

Figure 26.9 How the adrenal glands control our responses to stress medulla cortex Kidney Spinal cord (cross section) Nerve signals cell Nerve cell Adrenal medulla Epinephrine and norepinephrine Short-term stress response 1. Glycogen broken down to glucose; increased blood glucose 2. Increased blood pressure 3. Increased breathing rate 4. Increased metabolic rate Stress Hypothalamus Releasing hormone Anterior pituitary Blood vessel ACTH Adrenal cortex

Figure 26.9 How the adrenal glands control our responses to stress medulla cortex Kidney Spinal cord (cross section) Nerve signals cell Nerve cell Adrenal medulla Epinephrine and norepinephrine Short-term stress response 1. Glycogen broken down to glucose; increased blood glucose 2. Increased blood pressure 3. Increased breathing rate 4. Increased metabolic rate 5. Change in blood-flow patterns, leading to increased alertness and decreased digestive and kidney activity Stress Hypothalamus Releasing hormone Anterior pituitary Blood vessel ACTH Adrenal cortex

Figure 26.9 How the adrenal glands control our responses to stress medulla cortex Kidney Spinal cord (cross section) Nerve signals cell Nerve cell Adrenal medulla Epinephrine and norepinephrine Short-term stress response 1. Glycogen broken down to glucose; increased blood glucose 2. Increased blood pressure 3. Increased breathing rate 4. Increased metabolic rate 5. Change in blood-flow patterns, leading to increased alertness and decreased digestive and kidney activity Stress Hypothalamus Releasing hormone Anterior pituitary Blood vessel ACTH Adrenal cortex

Figure 26.9 How the adrenal glands control our responses to stress medulla cortex Kidney Spinal cord (cross section) Nerve signals cell Nerve cell Adrenal medulla Epinephrine and norepinephrine Short-term stress response 1. Glycogen broken down to glucose; increased blood glucose 2. Increased blood pressure 3. Increased breathing rate 4. Increased metabolic rate 5. Change in blood-flow patterns, leading to increased alertness and decreased digestive and kidney activity Stress Hypothalamus Releasing hormone Anterior pituitary Blood vessel ACTH Adrenal cortex Mineralocorticoids Glucocorticoids Long-term stress response 1. Retention of sodium ions and water by kidneys 2. Increased blood volume and blood pressure 1. Proteins and fats broken down and converted to glucose, leading to increased blood glucose 2. Immune system may be suppressed

Figure 26.11 Male elephant seals in combat