• Hypothalamus regulates the internal environment.–Body temp, heart rate, water balance.–Serves as link between nervous and
endocrine systems.
–Stimulates Pituitary gland:• Master Gland
Fig. 10.2
• ADH: Anti-diuretic hormone–Acts in kidneys.–Causes water retention to dilute blood.–Negative feedback
• Oxytocin:–Uterine contraction and milk production.–Positive feedback
• TSH: Thyroid stimulating hormone– Stimulates thyroid to produce it’s hormones.
• ACTH: Adrenocorticotropic hormone– Stimulates adrenal cortex
• Gonadotropic hormones:– Stimulate gonads
• Make gametes and sex hormones
• Prolactin–Milk production as well as fat and
carbohydrate metabolism.
• Growth hormone:–Stimulates protein production in tissues.–Leads to growth.–Amount affects height of individual.–Abnormalities can lead to disease.
• Thyroid–T3 and T4 hormones-both
contain iodine.–Deficiency in Iodine =
Goiter.
• Thyroid hormones increase metabolic rate.
• Diseases:– Cretinism– Myxedema– Graves disease
• Calcitonin is involved in regulation of blood calcium levels.– Stimulates Ca uptake and storage in bones.
• Parathyroid:–Parathyroid hormone (PTH)
• Increases blood Ca levels and decreases the level of blood phosphate.
• Pg 192 regulation of Ca levels.
Fig. 10.7
• Adrenal Glands:–Sit on top of kidneys.–React to stress.–Two Parts:
• Cortex (outside part): Under ACTH control.
• Medulla (inside part): Under direct nervous control.
Adrenal Medulla:
– Make Epinephrine and norepinephrine.–Short term response to stress.–Fight or flight.
• Increase heart rate• Blood sugar increases• Muscle strength and endurance increases.
Adrenal Cortex:
– Make mineralocorticoids and glucocorticoids.
–Also makes a small amount of male and female sex hormones.
–Long term response to stress.
Adrenal Cortex:• Glucocorticoids
–Regulate metabolism of fats, protein and carbohydrates.
–Cortisol: raises blood sugar levels.• Stimulates breakdown of proteins to make sugar.
• Promotes breakdown of fats rather than sugars.
• Counteracts the inflammatory response.
Adrenal Cortex:• Mineralocorticoids:
–Regulate salt and water balance.
–Aldosterone• Targets kidney cells.• Uptake of Na, and excretion of K.
Fig. 10.8
Fig. 10.9
• Addisons Disease:• Hyposecretion (low)• Low blood pressure.• Dehydration.• Bronzing
–Cushing Syndrome:• Hypersecretion• High Blood pressure.• Metabolism disorders.
• Pancreas–Pancreatic islet cells
• Insulin and glucagon• Antagonistic hormones = Balance
–Insulin: stimulates uptake of glucose.–Glucagon: stimulates glucose release.
Fig. 10.12
• Diabetes Mellitus–Two types.
• Insulin dependent (IDDM)
• Non-insulin dependent (NIDDM)
• Other Endocrine Glands and Hormones:–Gonads (Testes and Ovaries)
• Testosterone (androgen)–Hair growth, voice changes, muscle buildup, etc.
• Estrogen and progesterone.–Hair growth, fat buildup, body development, and mensus cycles.
• Other Endocrine Glands and Hormones:–Thymus: hormones involved in immune
system function.
–Pineal Gland: Melatonin and sleep cycles.
–Leptin: Made by adipose tissue and regulates eating.
–Growth factors:–Prostaglandins:
• Chemical signals and hormones work at different distances.–Autocrine: act on the same cell.–Paracrine: act on nearby cells.–Endocrine: travel some distance to target
cells.
–Pheromones: Chemical signals between individuals. Can regulate behavior and cycles.• Perfumes and colognes.
• Endocrine System and Homeostatsis:
–Regulation of digestion.–Regulate fuel metabolism.–Regulate blood pressure and volume.–Regulate ion balance in blood.–Regulate response to external enviroment.
Fig. 10.14
Fig. 10.15
