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
– STEROID
HORMONES
– NON-STEROID
HORMONES
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 SIGNALTRANSDUCTION 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
CAUSES
GLYCOGEN
BREAKDOWN
IN LIVER,
BUT MUSCLE
CONTRACTION IN
HEART CELLS
CHEMICAL REGULATION
• OVERVIEW: THE VERTEBRATE ENDOCRINE
SYSTEM
– ENDOCRINE SYSTEM CONSISTS
OF MORE THAN A DOZEN
MAJOR GLANDS
– PINEAL GLAND
• OUTGROWTH OF BRAIN THAT
SECRETES MELATONIN; NOT
FULLY UNDERSTOOD
– THYMUS
• CLOSELY LINKED TO IMMUNE
SYSTEM; STIMULATES T CELL
DEVELOPMENT
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 THYROIDSTIMULATING 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 BY
THYROID 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 PLAY
A LARGE ROLE IN
MANAGING THE BODY’S
ENERGY SUPPLIES
CHEMICAL REGULATION
• PANCREATIC HORMONES MANAGE CELLULAR FUEL
– INSULIN
• LOWERS BLOOD-SUGAR
LEVEL
• PRODUCED BY ISLET CELLS
– SPECIALIEZ CELLS OF
PANCREAS
– GLUCAGAON
• RAISES BLOOD-SUGAR
LEVEL BY BREAKING DOWN
GLYCOGEN
• 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 GLANDS
IN ONE
• ADRENAL MEDULLA
• ADRENAL CORTEX
CHEMICAL REGULATION
• THE ADRENAL GLAND MOBILIZE RESPONSES
TO STRESS
– ADRENAL MEDULLA
• INVOLVED IN FLIGHT-ORFLIGHT 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!!!