LECTURE TWENTY-TWO

PREGNANCY TESTS ARE BASED ON DETECTION
OF THE CHORIONIC GONADOTROPIN



THREE TYPES OF BIRTH CONTROL PILLS:
SEQUENTIAL PILLS, MINIPILLS, AND
MORNING AFTER PILLS



PROGESTERONE SUPPORTS DEVELOPMENT OF THE
MAMMARY GLANDS IN PREPARATION FOR LACTATION

PROLACTIN IS REQUIRED FOR LACTATION AND
SECRETION OF IT RISES DURING THE PREGNANCY



CONTROL OF THE SECRETION OF GROWTH HORMONE
IS NOT COMPLETELY UNDERSTOOD

GROWTH HORMONE CAUSES GROWTH BY STIMULATING
MITOSIS AND SYNTHESIS OF PROTEINS




GIANTS AND DWARFS RESULT WHEN CHILDREN
HAVE HYPER- OR HYPO-SECRETION OF
GROWTH HORMONE

ACROMEGALY RESULTS IF SECRETION OF
GROWTH HORMONE RE-OCCURS IN ADULTS



THE INTERMEDIATE LOBE OF THE PITUITARY
GLAND PRODUCES INTERMEDIN (= MELANOCYTE
STIMULATING HORMONE)




THE POSTERIOR LOBE OF THE PITUITARY GLAND
RELEASES TWO HORMONES, OXYTOCIN AND
VASOPRESSIN (= ANTIDIURETIC HORMONE, ADH)

OXYTOCIN AND VASOPRESSIN ARE PRODUCED IN
THE HYPOTHALAMUS



OXYTOCIN STIMULATES THE CONTRACTION OF
THE MUSCLES OF THE UTERUS DURING
CHILDBIRTH AND IS REQUIRED FOR LACTATION



VASOPRESSIN INCREASES THE PERMEABILITY OF
THE COLLECTING TUBULES TO WATER AND
CAUSES THE CONTRACTION OF SMOOTH MUSCLES




DIGESTIVE ENZYMES ARE RELEASED FROM
EXOCRINE GLANDS CALLED ACINAR CELLS IN
THE PANCREAS

THE ENDOCRINE CELLS IN THE PANCREAS ARE
THE ISLETS OF LANGERHANS




TWO TYPES OF CELLS OCCUR IN THE ISLETS
OF LANGERHANS:
THE ALPHA CELLS PRODUCE GLUCAGON
THE BETA CELLS PRODUCE INSULIN

           INSULIN
GLUCOSE ---------------> GLYCOGEN
       <---------------
           GLUCAGON

INSULIN AND GLUCAGON ACTIVATE ADENYL
CYCLASE




DIABETES MELLITUS RESULTS IF THE PANCREAS
IS HYPOFUNCTIONING WITH RESPECT TO INSULIN
SECRETION

INDICATIONS OF DIABETES MELLITUS:
1. HYPERGLYCEMIA (HIGH GLUCOSE LEVELS IN
   THE BLOOD)
2. GLYCOSURIA (EXCRETION OF LARGE AMOUNTS
   OF GLUCOSE IN THE URINE)
3. DEHYDRATION DESPITE INTAKE OF LARGE
   VOLUMES OF WATER



GLUCOSE IS A KEY METABOLIC INTERMEDIATE
AND HIGH LEVELS OF IT DISRUPT METABOLISM
BOTH DIRECTLY AND INDIRECTLY
INSULIN HAS A DIRECT EFFECT ON METABOLISM
ALSO
PARTIALLY OXIDIZED FATS CALLED KETONE
BODIES OCCUR IN THE BLOOD IN DIABETES
MELLITUS ALSO




TOO MUCH INSULIN CAUSES CONVULSIONS

INSULIN IS A PROTEIN




INSULIN WAS THE FIRST PROTEIN TO HAVE
ITS STRUCTURE FULLY DETERMINED, BY
FREDERICK SANGER IN 1953

INSULIN IS SECRETED FROM THE PANCREAS AS
PROINSULIN WHICH IS ACTIVATED TO INSULIN




DIABETES INSIPIDUS IS CAUSED BY DEFICIENCY
OF ANTIDIURETIC HORMONE




THE CONCEPT OF HORMONE IS VERY SIMILAR IN
PLANTS AND IN ANIMALS

PLANT HORMONES ARE RELATIVELY SMALL
ORGANIC MOLECULES




THERE ARE FIVE MAJOR TYPES OF PLANT
HORMONES: AUXINS, GIBBERELLINS, CYTOKININS,
ABSCISIC ACID AND ETHYLENE




AUXINS WERE THE FIRST PLANT HORMONES TO
BE DISCOVERED

THE MOST COMMON NATURALLY OCCURRING AUXIN
IS INDOLE ACETIC ACID (IAA)




AUXINS MAKE THE CELL WALL MORE PLASTIC




GIBBERELLINS WERE DISCOVERED BY KUROSAWA
IN RICE PLANTS SHOWING BAKANAE (FOOLISH
SEEDLING DISEASE)

GIBBERELLINS ARE THE MOST CHEMICALLY
COMPLEX OF ALL PLANT HORMONES




CYTOKININS WERE DISCOVERED WITH TISSUE
CULTURES AND WERE INITIALLY ISOLATED
FROM COCONUT MILK

THE NAME "CYTOKININ" IS DERIVED FROM
"CYTOKINESIS", THE TECHNICAL NAME FOR
CELL DIVISION




THE DROPPING OF LEAVES OR FRUIT IS CALLED
ABSCISSION, A PROCESS THAT IS ACCELERATED
BY ABSCISIC ACID

ABSCISIC ACID ALSO HELPS TO MAINTAIN
DORMANCY IN PLANTS, AND WAS CALLED DORMIN





ETHYLENE IS A SELF-ACCELERATOR OF FRUIT
RIPENING