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 HORMONE

S– 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!!!