CHEMICAL REGULATION
CHEMICAL REGULATION
• CHEMICAL SIGNALS COORDINATE BODY FUNCTIONS– HORMONE• A REGULATORY CHEMICAL THAT TRAVELS IN THE
BLOOD FROM ITS PRODUCTION SITE AND AFFECTS OTHER SITES IN THE BODY
– ENDOCRINE GLANDS• ORGANS THAT PRODUCE HORMONES
– TARGET CELLS• CELLS THAT RESPOND TO A HORMONE
CHEMICAL REGULATION
• CHEMICAL SIGNALS COORDINATE BODY FUNCTIONS– NEUROSECRETORY CELL
• SPECIALIZED NERVE CELL THAT, IN ADDITION TO CONDUCTING NERVE SIGNALS, MAKES AND SECRETES HORMONES
– NEUROTRANSMITTERS• CHEMICALS THAT CARRY INFORMATION FROM ONE NERVE CELL
TO ANOTHER, OR FROM A NERVE CELL TO ANOTHER KIND OF CELL THAT WILL REACT, SUCH AS A MUSCLE CELL OR AN ENDOCRINE CELL
– LOCAL REGULATOR• SECRETED INTO THE INTERSTITIAL FLUID AND AFFECTS CELLS VERY
NEAR THE POINT OF SECRETION• EXAMPLE: PROSTAGLANDINS
CHEMICAL REGULATION
• ENDOCRINE SYSTEM– THE BODY’S MAIN
CHEMICAL-REGULATING SYSTEM
– WORKS CLOSELY WITH THE NERVOUS SYSTEM
CHEMICAL REGULATION
CHEMICAL REGULATION
CHEMICAL REGULATION
• HORMONES AFFECT TARGET CELLS BY TWO MAIN SIGNALING MECHANISMS– STEROIDHORMONES– NON-STEROIDHORMONES
CHEMICAL REGULATION
• NON-STEROID HORMONES– HORMONE ATTACHES TO
RECEPTOR ON CELL MEMBRANE; BINDING OCCURS OUTSIDE OF CELL
– EX. EPINEPHRINE (A.K.A. ADRENALINE)
– INITIATES A SIGNAL-TRANSDUCTION PATHWAY
– ALWAYS MADE FROM AMINO ACIDS (PROTEIN BASED)
• STEROID HORMONES– LIPIDS MADE FROM
CHOLESTEROL– EX. TESTOSTERONE– HORMONE-RECEPTOR
COMPLEX ACTS BY TURNING GENES ON OR OFF
CHEMICAL REGULATION
• HORMONES CAN BIND TO A VARIETY OF RECEPTORS– EPINEPRHINE
CAUSESGLYCOGENBREAKDOWNIN LIVER,BUT MUSCLECONTRACTION IN HEART CELLS
CHEMICAL REGULATION
• OVERVIEW: THE VERTEBRATE ENDOCRINE SYSTEM– ENDOCRINE SYSTEM CONSISTS
OF MORE THAN A DOZENMAJOR GLANDS
– PINEAL GLAND• OUTGROWTH OF BRAIN THAT
SECRETES MELATONIN; NOTFULLY UNDERSTOOD
– THYMUS• CLOSELY LINKED TO IMMUNE
SYSTEM; STIMULATES T CELLDEVELOPMENT
CHEMICAL REGULATION
• THE HYPOTHALAMUS, CLOSELY TIED TO THE PITUITARY, CONNECTS THE NERVOUS AND ENDOCRINE SYSTEMS– HYPOTHALAMUS• MASTER CONTROL CENTER OF THE ENDOCRINE
SYSTEM; PART OF THE BRAIN• ITS ENDOCRINE SIGNALS DIRECTLY CONTROLS THE
PITUITARY GLAND
CHEMICAL REGULATION
• THE HYPOTHALAMUS, CLOSELY TIED TO THE PITUITARY, CONNECTS THE NERVOUS AND ENDOCRINE SYSTEMS– PITUITARY CONSISTS OF TWO
DISTINCT PARTS• POSTERIOR PITUITARY
– COMPOSED OF NERVOUS TISSUE, AN EXTENSION OF THE HYPOTHALAMUS; STORES AND SECRETES HORMONES MADE IN THE HYPOTHALAMUS
CHEMICAL REGULATION
• THE HYPOTHALAMUS, CLOSELY TIED TO THE PITUITARY, CONNECTS THE NERVOUS AND ENDOCRINE SYSTEMS– PITUITARY CONSISTS OF TWO DISTINCT PARTS• ANTERIOR PITUITARY
– COMPOSED OF NON-NERVOUS, GLANDULAR TISSUE; SYNTHESIZES ITS OWN HORMONES
CHEMICAL REGULATION
CHEMICAL REGULATION
• HYPOTHALAMUS AFFECTS THE PITUITARY IN TWO WAYS– RELEASING HORMONES• CAUSES THE ANTERIOR PITUITARY TO SECRETE
HORMONES
– INHIBITING HORMONES• CAUSES THE ANTERIOR PITUITARY TO STOP SECRETING
HORMONES
CHEMICAL REGULATION
• HYPOTHALAMUS CONTROLS BODY TEMPERATURE BY– SECRETING TSH-RELEASING HORMONE (TRH)
WHICH CAUSES– ANTERIOR PITUITARY TO SECRETE THYROID-
STIMULATING HORMONE (TSH) WHICH CAUSES– THRYOID TO SECRETE THYROXINE• THYROXINE INCREASES METABOLIC RATE, WARMING
BODY
CHEMICAL REGULATION
• HYPOTHALAMUS/POSTERIOR PITUITARY– ENDOCRINE FUNCTION
INCLUDES• OXYTOCIN
– CAUSES UTERINE MUSCLE CONTRACTION DURING CHILDBIRTH, MAMMARY GLANDS TO PUMP MILK
• ANTI-DIURETIC HORMONE (ADH)– HELPS KIDNEY CELLS
REABSORB WATER (COLLECTING DUCT OF THE NEPHRON)
• ANTERIOR PITUITARY– THYROID-STIMULATING
HORMONE (TSH)– ADRENOCORTICOTROPIC
HORMONE (ACTH)– FOLLICLE-STIMULATING
HORMONE (FSH)– LUTENIZING HORMONE (LH)– PROLACTIN– ENDORPHINS
• NATURAL “OPIATE”; PAIN INHIBITOR / PLEASURE INDUCER
CHEMICAL REGULATION
• THE THYROID REGULATES DEVELOPMENT AND METABOLISM– THYROID GLAND• LOCATED JUST UNDER THE VOICE
BOX• THYROXINE
– HORMONE PRODUCED BYTHYROID GLAND
– CONTAINS 4 IODINE ATOMS
CHEMICAL REGULATION
• THE THYROID REGULATES DEVELOPMENT AND METABOLISM– HYPERTHYROIDISM
• CAN LEAD TO OVERHEATING, PROFUSE SWEATING, HIGH BLOOD PRESSURE, WEIGHT LOSS, IRRITABILITY
– HYPOTHYROIDISM• CAUSE WEIGHT GAIN, LETHARGY, INTOLERANCE TO COLD
– GOITER• UNTREATED DIETARY DISORDER LEADS TO AN
ENLARGEMENT OF THE THYROID; RESULTS FROM IODINE DEFICIENCY
CHEMICAL REGULATION
CHEMICAL REGULATION
• HORMONES FROM THE THYROID AND PARATHYROIDS MAINTAIN CALCIUM HOMEOSTASIS– 4 PARATHYROID GLANDS
EMBEDDED IN THE SURFACE OF THE THYROID
CHEMICAL REGULATION
• HORMONES FROM THE THYROID AND PARATHYROIDS MAINTAIN CALCIUM HOMEOSTASIS– CALCITONIC FROM THYROID– PARATHYROID HORMONE (PTH) FROM
PARATHYROID
• **ANTAGONISTIC HORMONES HORMONES THAT HAVE OPPOSITE EFFECTS
CHEMICAL REGULATION
• PANCREATIC HORMONES MANAGE CELLULAR FUEL– PANCREAS PRODUCES TWO
HORMONES THAT PLAYA LARGE ROLE IN MANAGING THE BODY’SENERGY SUPPLIES
CHEMICAL REGULATION
• PANCREATIC HORMONES MANAGE CELLULAR FUEL– INSULIN
• LOWERS BLOOD-SUGARLEVEL
• PRODUCED BY ISLET CELLS– SPECIALIEZ CELLS OF
PANCREAS
– GLUCAGAON• RAISES BLOOD-SUGAR
LEVEL BY BREAKING DOWNGLYCOGEN
• PRODUCED BY ALPHA CELLS– SPECIALIZED CELLS OF PANCREAS
CHEMICAL REGULATION
• DIABETES IS A COMMON ENDOCRINE DISORDER– DIABETES MELLITUS
• A SERIOUS HORMONAL DISEASE IN WHICH THE BODY CELLS ARE UNABLE TO ABSORB GLUOCSE FROM THE BLOOD
• TYPE I (BORN WITH IT)– AUTOIMMUNE; IMMUNE SYSTEM ATTACKS AND KILLS BETA (ISLET ISLET
CELLS)
• TYPE II (DEVELOP IT LATER IN LIFE)– BODY CELLS FAIL TO RESPOND TO INSULIN
• HYPOGLYCEMIA– OVERPRODUCTION OF INSULIN; BLOOD SUGAR LEVELS
DROP TOO LOW AFTER A MEAL
CHEMICAL REGULATION
• THE ADRENAL GLANDS MOBILIZE RESPONSES TO STRESS– 2 ADRENAL GLANDS
SITTING ATOP THE KIDNEYS– ADRENAL GLAND IS
ACTUALLY TWO GLANDSIN ONE• ADRENAL MEDULLA• ADRENAL CORTEX
CHEMICAL REGULATION
• THE ADRENAL GLAND MOBILIZE RESPONSES TO STRESS– ADRENAL MEDULLA• INVOLVED IN FLIGHT-OR-
FLIGHT REFLX• PRODUCES
EPINEPHRINE (ADRENALIN) AND NOR-EPINEPHRINE (NOR-ADRENALIN)
CHEMICAL REGULATION
• THE ADRENAL GLAND MOBILIZE RESPONSES TO STRESS– ADRENAL CORTEX
• MORE LONG LASTING EFFECTS• ACTIVATED BY ACTH RELEASED BY ANTERIOR PITUITARY• SYNTHESIZES CORTICOSTEROIDS
– 2 TYPES» MINERALOCORTICOIDS
• CONTROL SALT AND WATER BALANCE» GLUCOCORTICOIDS
• AID IN MOBILIZING CELLULAR FUEL• EX. CORTISONE LESSENS INFLAMMATORY RESPONSES, BUT
WEAKENS IMMUNE SYSTEM
CHEMICAL REGULATION
• THE GONADS SECRETE HORMONES– GONADS
• SEX GLANDS; SECRETE SEX HORMONES, IN ADDITION TO PRODUCING GAMETES
• ESTROGENS– MAINTAIN THE FEMALE REPRODUCTIVE SYSTEM AND PROMOTE THE
DEVELOPMENT OF SUCH FEMALE FEATURES AS SMALL BODY SIZE, HIGHER-PITCHED VOICE, BREASTS, AND WIDER HIPS
• PROGESTINS– PRIMARILY INVOLVED IN PREPARING THE UTERUS TO SUPPORT THE
EMBRYO
• ANDROGENS– STIMULATE THE DEVELOPMENT AND MAINTENANCE OF THE MALE
REPRODUCTIVE SYSTEM (EX. TESTOSTERONE)
CHEMICAL REGULATION
• SPEAKING OF THE REPRODUCTIVE ORGANS / GONADS…AND THE REPRODUCTIVE HORMONES…HOW DO BABIES GET MADE??
• THE REPRODUCTIVE SYSTEM IS NEXT!!!