This document summarizes key concepts about the endocrine system and hormone function. It describes the major endocrine glands like the hypothalamus, pituitary gland, thyroid gland, parathyroid gland, adrenal glands, pancreas and reproductive organs. It explains the different classes of hormones, the mechanisms of hormone action, and feedback loops involved in hormonal regulation. Key hormone types and their functions are defined, including examples like insulin, glucagon, estrogen and mechanisms of hormonal disorders.

1. Endocrinology and reproduction
Endocrine glands, basic mechanism of hormone action, hormones and diseases;
physiology of reproductive processes, neuroendocrine regulation (menstrual
cycle)

2. Hormones: are a chemical signal that is secreted in circulatory system
(mostly blood) and communicates regulatory messages within the body
Reaches all body parts but certain cells ie. Only Target cells can respond
SPECIFIC RESPONSE ie. CHANGE IN METABOLISM BY TARGET CELLS
HELP MAINTAIN HOMEOSTASIS
HELP IN REGULATING GROWTH, DEVELOPMENT AND REPRODUCTION
BIOLOGICAL CONTROL SYSTEM AND HORMONAL SYSTEMS
ENDOCRINE SYSTEM NERVOUS SYSTEM
Independent and in co-ordination
neurons
Endocrine
glands

3. Autocrine: cell secretes and binds to receptors on itself, cause change
Paracrine: communication over short distances (target cells are near the releasing cells)
(neurotransmitters)
Endocrine: communication over large distances (in blood stream)
Exocrine: released in a duct (methods of secretion:Apocrine, holocrine, merocrine)
Intracrine: hormone acting inside a cell which produces it
Juxtacrine: communication via direct contact
Intercellular Cell signaling mechanisms

4. ENDOCRINE SYSTEM
Collective system of hormone secreting cells present in endocrine organs or glands
Basically release their secretions in blood hence ductless and from there diffuse into
circulation
ENDOCRINE SYSTEM NERVOUS SYSTEM
Hypothalamus
Neurosecretory cells
Hormones in blood
Neurohormones (different
than endocrine hormones)
Epinephrine
(fight or flight)
Serves as hormone
in endocrine syst
(adrenal medulla)
and chemical signal
in nervous system
(neurotransmitter)
Help in controlling daily rhythm
Reproductive cycles
NEUROENDOCRINE SYSTEM
Estrogen
Epinephrine
Norepinephrine
O2
Nitric oxide
Hormones: peptides, steroids, neuroamines
Neurotransmitter: neurons to target cells via synapse

5. CONTROL PATHWAYS AND FEEDBACK LOOPS
Receptor or
Sensor
Detects a stimulus
Thermostat
CONTROL CENTRE
Brain
Thermometer
(RECEPTOR) Heater
(EFFECTOR)
Set point 20 - 37oC
Detects rise
Responds to signal
Hormone
Efferent signal
Acts on
Effector tissues
Physiological response
Or dev changes
Complex neuroendocrine pathways: 2 endocrine tissues and 2 hormones which affects
target tissues

6. Basic principles of simple hormonal control pathways
Receptor: blue
Control centre: gold
Efferent signal or hormone: red circles
Neurohormone: red squares

7. POSITIVE AND NEGATIVE FEEDBACK LOOPS
Positive Feedback: change in some variable that trigger mechanisms to
amplify rather than reverse the change. Amplifies the response of
effector.
Negative Feedback: Control mechanism which counteracts change in the
same direction. Diminishes the response of effector and finally response
stops. Helps to maintain homeostasis.
Both are important in regulation of endocrine and neuroendocrine
pathways

8. MECHANISMS OF SIGNAL TRANSDUCTION VIA HORMONES
AND NEUROHORMONES
[Proteins and peptides (30aa), amines] (water soluble)
[steroids] (fat soluble)
1. Reception: binding of signal moc to specific receptor on or in target cell
2. Signal transduction: events within a target cell
3. Response : change in behavior of target cell
Molecules used in ST

9. Cell surface
Receptors
Receptor in plasma membrane
Water soluble surface receptors
Receptor in cell nucleus
Lipid soluble intracellular receptors
Signal receptor
complex acts as
Transcription
factor
To activate
gene expression
Interaction of
hormone and
specific surface
receptor is
necessary for
hormone action.

10. One chemical signal different effects: due to interaction b/w diff receptors

11. Receptors can be present inside the cell: Intracellular
Estrogen and progesterone: necessary for female reproductive function
Only cells of the female reproductive tract respond to these hormones
Not any other cells which shows that only these cells possess receptors to
identify these hormones
Steroid hormones, thyroid hormones and hormonal form of Vitamin D
Can diffuse thro cell membranes
Often receptor is present on nucleus where it enters and stimulates a
transcription factor which alters gene expression or stimulates
transcription of specific genes.
Birds
Estrogen stimulates prodn of ovoalbumin and also liver to make proteins
Thyroxine in humans regulates metabolism but in amphibians like frogs it
stimulates metamorphosis ie tadpole to frog and other changes[ different
effects in diff species]

12. Paracrine signalling
Certain cells secrete signaling molecules which act on neighboring cells and
response is several times faster hence known as local regulators
Many cpd act like local regulators like
1. Cytokines (immune response)
2. Growth factors
3. Nitric oxic (NO):
4. Prostaglandins: (FA) derived from lipids in PM. Help contraction of female uterine
wall and let sperm reach the egg. Female placental cells release PG to help contractions
in uterus to induce labor during childbirth.
PG also help induce fever and inflammation and intensify pain used as alarm signal
ASPRIN and IBUPROFEN inhibits PG synthesis and hence have anti inflammatory and
analgesic effects.
Decr in Blood O2
Endothelial cells
Release NO
Activates enzyme
Relaxes smooth muscles
Dilation of blood vessels
Male sexual function
Incr blood flow to penis
Erection
Highly reactive and toxic breaks
down immediately after contact
VIAGRA (Sildenafil citrate): prevents
breakdown of NO, treat erectile
dysfunction
NO is also a neurotransmitter and is present in WBCs to kill bacteria also cancer cells

13. There are three general classes of hormones:
1. Proteins and polypeptides, including hormones
secreted by the anterior and posterior pituitary gland, the pancreas (insulin and
glucagon), the parathyroid gland (parathyroid hormone), and many others.
2. Steroids secreted by the adrenal cortex (cortisol and aldosterone), the ovaries
(estrogen and progesterone), the testes (testosterone), and the placenta (estrogen
and progesterone).
3. Derivatives of the amino acid tyrosine, secreted by the thyroid (thyroxine and
triiodothyronine) and the adrenal medullae (epinephrine and norepinephrine). There
are no known polysaccharides or nucleic acid hormones.

14. The hypothalamic-pituitary-adrenal axis (HPA or HTPA axis), also known as
the limbic-hypothalamic-pituitary-adrenal axis (LHPA axis) and, occasionally,
as the hypothalamic-pituitary-adrenal-gonadotropic axis,
is a complex set of direct influences and feedback interactions among
the hypothalamus, the pituitary gland (a pea-shaped structure located
below the hypothalamus), and the adrenal (or suprarenal) glands (small,
conical organs on top of the kidneys).
The interactions among these organs constitute the HPA axis, a major part
of the neuroendocrine system that controls reactions to stress and
regulates many body processes, including digestion, the immune system,
mood and emotions, sexuality, and energy storage and expenditure.
HYPOTHALAMUS AND PITUTARY INTEGRATE MANY
FUNCTIONS OF ENDOCRINE SYSTEM

15. Endocrine glands in the head and neck region

16. HYPOTHALAMUS is connected to nerves and gets information from different
parts of the body and brain and sends endocrine signals to appropriate
environmental conditions. Main fn is to link nervous with endocrine system.
Two sets of neurosecretory cells
Whose Secretions are stored in
PITUTARY
(Hypophysis)
Base of HT
Anterior Pitutary or
Adenohypophysis
Posterior Pitutary or
Neurohypophysis
Intermediate Lobe
Pars intermedia
Pineal Gland (epiphysis)
Releasing hormones Inhibiting Hormones
+ -
PITUTARY HORMONES

18. Posterior Pitutary or
Neurohypophysis
Collection of axons from HT (PVN and SON) ending
in post. Pit
Secrete peptide hormones

20. Anterior Pitutary or
Adenohypophysis

21. Posterior Pitutary Hormones or Neurohypophysis
ADH Oxytocin
•Incr water retention
•Decr urine volume
•Regulate osmolarity of blood
•Negative Feedback mech to
maintain homeostasis
•Induces target cells in uterus to
contract during childbirth
•Causes mammary glands to eject milk
during nursing in a positive feedback
Milk sucking by infant
Causes more secretion of milk
Targets
Uterus and mammary glands
Causes
Uterine contractions and lactation
Targets
Kidneys and arterioles
Causes
Stimulates water retention;
raises blood pressure by
contracting arterioles,
induces male aggression
Source
PVN and SON
Less secretion of Vasopressin:
Diabetes insipidus (inability to concentrate urine)
More dilute urine (20L/day)

22. Anterior Pitutary Hormones or Adenohypophysis
Tropic Hormones: have other endocrine glands as target
FSH
LH
TSH
Similar in structure
Similar glycoproteins, CHO
and proteins attached
Stimulate Ova and sperm
Stimulate steroid hormones in gonads
(ovary and testes)
Stimulate thyroid gland
gonadotropins
ACTH
Peptide hormone
Stimulates production and secretion of
Steroid hormones
HT -----> receives signal-----> secretes ------> stimulates AP------> tropic hormone
<------Target
endocrine
tissue
<------Hormone
secreted
Metabolic or
developmental effects
Releasing
hormone

23. Non Tropic Hormones: directly
stimulate target cells
Anterior Pitutary Hormones or Adenohypophysis
1. Prolactin (PRL)
2. MSH (melanocyte stimulating hormone)
3. -endorphin
Prolactin
•Stimulates mammary gland growth and milk synthesis
•Regulate fat metabolism and reproduction in birds
•Delays metamorphosis in amphibians (larval growth hormone)
•Regulation of salt and water balance in fishes
MSH
•Activity of pigment containing cells in fishes, amphibians,
reptiles
•Humans help in inhibiting hunger by acting on neurons
•Skin darkening
-endorphin; type of endorphins
•Bind to receptors in brain and dull the perception of pain
•Released when stress and pain in the body reaches a critical high
•“Runners high”; during excessive exercise
Ovaries and
mammary glands
TARGET
Melanocytes in
skin and hair
Opioid receptors

24. Tropic and Non Tropic Hormone: Growth Hormone
Anterior Pitutary Hormones or Adenohypophysis
Liver---> Insulin like growth factors (IGF)-----> stimulate bone and cartilage growth
also involved in raising blood glucose
Hypersecretion Hyposecretion
Gigantism (8ft) Dwarfism (4ft)
Acromegaly (adulthood) (hands, face, feet) retards growth of long bones
Administration of recombinant GH
before puberty can treat disorder
If hormone deficient, GH has no effect on muscle mass and strength

25. Acromegaly
Gigantism
Dwarfism

26. NON PITUTARY HORMONES
THYROID HORMONES
Derived from tyrosine----> Triiodothyronine (T3) [3 I2 atoms]
Tetraiodothyronine or Thyroxine (T4) [4 I2 atoms]
Thyroid-----> T4 -----> T3 (receptors have more affinity for T3 than T4)
Removal of one I2
Response in target
cells (brain)
HT
Pit
Calcitonin <------------------> parathyroid hormone [ calcium homeostasis]
Protein thyroglobulin
Thyroid epithelial cells or follicular cells
TRH
TSH
Hypercalciemia
Ca movement from blood to bone
Reduces blood Ca levels
Hypocalciemia
Ca from bone to blood
Increases blood Ca levels
Thyroid gland
TRH: thyrotropin releasing hormone

27. I2 required for
Low
Negative feedback stops
Positive feedback occurs
+
+
+
More
TSH
Enlarge
REGULATION
High
TSH is reduced
• Cold exposure
• Stomatostatin
• Incr Glucocort.
• Sex hormones

28. Involved in development and maturation
Development of bone forming cells
Branching of nerve cells during embryonic dev
Cretinism
Thyroid deficiency
Retarded skeletal growth and poor mental dev
HOMEOSTATIC FUNCTIONS
BP
Heart rate
Muscle tone
Digestion
Reproductive functions
Impt in bioenegetics: incr rate of
O2 consumption and cellular metabolism
Hyperthyroidism Hypothyroidism
Overproduction of T3 and T4 Under production of T3, T4
Autoimmunity (Ab stimulate more) High body temp
High BP lethargy
Profuse sweating cold intolerance
Decr appetite, Wt. loss wt gain
Irritability cretinism in infants
Beta blockers
for treatment

29. Graves disease (hyperthyroidism)
Exopthalmos
Fluid accumulation behind eyes
Cretinism (infant congenital
hypothyroidism)
Mental retardation
Goitre
Deficiency of I2 in diet leads to enlargement
of Thyroid gland

30. Calcitonin <---------> PARATHYROID HORMONE [ calcium homeostasis]
Blood Ca2+
LOW
Contraction of
Skeletal muscle
Tetany---> fatal
10mg/100ml (normal)
PTH releases--------> raise blood Ca2+ level
PTH gland------->
Osteoclasts
Decompose
In bone
Release Ca2+
Ca2+ Reabsorbed in kidneys
Vitamin D active form
Incr Ca2+ uptake from intestines
Stimulus for PTH
Decr Ca2+
Decr Mg2+
Incr PO4

32. INSULIN AND GLUCAGON
Glucose homeostasis
Glucose is major fuel for
cellular respiration and for
syn of organic cpds
Pancreas: endocrine
gland and exocrine
(digestive enzymes in
pancreatic duct)
Islet of langerhans
-cells: glucagon
-cells: insulin
d-cells: somatostatin
(growth hormone-
inhibiting hormone (GHIH)
Negative feedback
All cells
contain
receptors
Except
Brain

35. Diabetes Mellitus
Symptoms
Deficiency of Insulin
No regulation of glucose
Excess circulating blood glucose
More urine volume, more urination (polyuria)
Incr Thirst (polydipsia)
Incr Hunger (polyphagia)
More glucose excreted in urine
Fat becomes main substrate
Fat breakdown releases acidic metabolites
Acidosis: blood pH rises
Fatal if not controlled
Diabetes mellitus
Type I
Insulin dependent
Autoimmune disorder
Immune cells destroys b-cells of pancreas
Childhood or juvenile diabetes
Insulin injections
Recombinant insulin
Diabetes mellitus
Type II
Non Insulin Dependent
Deficiency of insulin or
Reduced responsiveness of target cells
due to change in insulin receptors
Obesity
Lack of exercise
Regular exercise can control it though it
can be controlled by drugs

36. ADRENAL HORMONES: ADRENAL GLANDS
Adrenal cortex (outer): endocrine
Adrenal medulla (central): neuroendocrine
Endocrine and neuroendocrine gland
Adrenal Cortex
1. Zona glomerulosa (mineralocorticoids: Aldosterone (RAAS system with kidneys)
2. Zona fascilulata (glucocorticoids: corticosterone, cortisol, 11-deoxycorticosterone)
3. Zona reticularis (androgens: Dehydroepiandosterone (DHEA), DHEA-sulfate (S),
androstenidione (precursor of testosterone)
Adrenal Medulla (secretions from chromaffin cells produce catecholamines which
are derived from aa tyrosine responsible for fight or flight response)
1. Nor epinephrine (20%) or nor adrenaline
2. Epinephrine (80%) or adrenaline
3. Small amount of dopamine (reward driven learning)
Receives input from sympathetic NS

37. ADRENAL HORMONES: ADRENAL GLANDS
ADRENAL MEDULLA: FIGHT OR FLIGHT HORMONES
Epinephrine (adrenaline) Nor-epinephrine (noradrenaline)
Help cope up with stressful situation: heart beats faster, goose bumps etc
Both act as neurotransmitters in nervous system
Incr heart rate , BP, vasoconstriction, incr metabolism
Sympathetic stimulation ------> Amedulla ---- tyr to CCA --- release hormones
Used as a drug to treat
• Cardiac arrest
• Anaphylaxis
• Asthma
• Excess can cause
Palpitaions
Tachycardia
Arrythmia
Anxiety, hypertension
Incr heart rate
Release of glucose
Blood flow to skeletal muscles
Incr O2 flow to brain
In stress, helps in attention and
decision making
-adrenergic receptor G- protein
coupled receptor (GPCR) -adrenergic receptor

38. Robert Joseph Lefkowitz and Brian Kent Kobilka
Won the Nobel prize in chemistry for 2012 on their work on GPCR (2-
adrenergic receptor for adrenaline)
Their work focused on identifying receptors present on cells which are
capable of transmitting signals for fight and flight and mechanisms of cell
signalling and signal transduction
Implications for this research are for recognizing drug targets on cells
because GPCRs are important targets for pharmaceutical therapeutics
Their work has been already in use for designing drugs for treatment and
nearly 40% of modern drugs based on use of this principle.
AND ON (11TH OCT 2012) WAS ANNOUNCED THE…….
NOBEL PRIZE IN CHEMISTRY, 2012

39. ADRENAL CORTEX
Steroid hormones: corticosteroids (negative feedback; excess causes decr in
ACTH)
1. Glucocorticoids or cortisol 2. Mineralocorticoids or aldosterone
Glucose metabolism from non CHO sources salt and water balance
Anti-inflammatory effects, suppress immune system Na+ and water reabsorption
Side effects on excess use from kidneys, BP incr
It increases
• Urinary excretion of K+
• interstitial levels of sodium ions
• water retention and blood
volume
It stimulates
• the release of amino acids
• Lipolysis
• Gluconeogenesis
• Incr blood glucose in response to stress
by inhibiting glucose uptake into muscle
and fat cells
• Strengthens cardiac muscle contractions
• increases water retention
• has anti-inflammatory and anti-allergic
effects

40. Autonomic
nervous
system

41. 3. Corticosteroids that function as sex hormones: ANDROGENS
• Dehydroepiandosterone (DHEA), DHEA-sulfate (S), androstenidione (precursor
of testosterone), dihydrotestosterone
• synthesized from cholesterol
Male hormones (ANDROGENS)
Female hormones (ESTROGEN and PROGESTERONE) small amts

42. GONADAL SEX HORMONES
Primary source of sex hormones
Produce major category of steroid hormones: andogens, estrogen, progestins
All three types are found in males and females in different proportions
Testes: synthesize androgens mainly testosterone
Development and maintenance of male reproductive system
Androgens are produced early in the embryo to determine sex of the foetus
Androgens produced during puberty are responsible for
male secondary sexual characters
voice changes, male pattern hair growth, incr in bone and
muscle mass (anabolic steroids help build muscle)
Ovary:synthesize mainly estrogens (estradiol)
Development and maintenance of female reproductive system and female secondary
sexual characters
Progestins (progesterone) are responsible for preparing and maintenance of uterus to
support growth and development of embryo
These hormones are part of neuroendocrine pathways
Gn RH -----> FSH and LH

43. MELATONIN AND BIORHYTHMS
Pineal gland secretes serotonin (derived from aa tryptophan) derivative melatonin
and has light sensitive (photosensitive) cells with connections to eyes
Regulates
• modulation of wake/sleep patterns and seasonal functions
• biological rhythms associated with daily (circardian), seasonal or reproduction
rhythms
More melatonin secreted during night and during winter (long nights)
MAINTAINS BIOLOGICAL CLOCK
Target cells are suprachiasmatic nucleus in brain which functions as biological clock
• Third eye
• Spiritual thinking
• Near death experience (NDE) [dimethyl tryptamine]
• Influences reactions towards recreational drugs (cocaine)
• Melatonin protects against neurodegeneration, is an antioxidant
• Serotonin regulates mood, appetite and sleep
• Related to depression, stress and ageing etc
PINEAL GLAND

44. HORMONE REGULATION IN INSECT DEVELOPMENT: METAMORPHOSIS

45. REPRODUCTION
Asexual
Gametes come from one parent
Without fusion of egg and sperm
Produces lot of offsprings and
favorable genotypes
Sexual
Gametes from male and female (2 parents)
Fusion of (haploid gametes) egg and sperm
to form zygote (diploid)
Increases genetic variability
Budding
Fragmentation: regeneration
Parthenogenesis: egg develops without fertilization; haploid adults (no meiosis)
Honeybees

46. MALE REPRODUCTIVE SYSTEM
Androgens: testosterone
Produced by Leydig cells
of
Testes responsible for
Primary: dev of VD and
ducts
Reproductive structures
Sperm production
Secondary: voice, pubic
hair formation,
Muscle growth,
aggressiveness controlled
by hormones from HT
and anterior pituitary
Epididymis: maturation and storage
VD: sperm duct
Accessory glands: cowpers and BU gland: nourishment to sperms
Seminal vesicles: sticky, yellow fluid, fructose, 70% secretion is semen
Prostrate gland: ejaculation of semen

48. SPERMATOGENESIS:
Male reproductive cycle
n=23

49. Germinal epithelium of the testicle.
1: basal lamina
2: spermatogonia
3: spermatocyte 1st order
4: spermatocyte 2nd order
5: spermatid
6: mature spermatid
7: Sertoli cell
8: tight junction (blood testis barrier)

50. Hormonal control of Male reproductive System

51. • A follicle is one egg cell surrounded by several layers of follicle cells for
nourishment
• 400,000 present before birth only several 100 release eggs during reproductive
years
• Starting at puberty and ending in menopause
• Follicle cells also produce secondary sexual characters
• Egg is expelled (ovulation) remaining follicular mass within ovary is corpus luteum
(estrogens and progesterons), if egg not fertilized CL disintegrates and new follicle
matures during next cycle.
FEMALE REPRODUCTIVE SYSTEM
Vulva (external)
Hymen (external)
Vestibule (external)
Labia minora (external)
Labia majora (external)
Clitoris (female sexual organ)
Bartholin glands (produce mucus)

53. OOGENESIS:
Female reproductive cycle
Differentiation of primordial
germ cells
Unequal cytokinesis
FSH
At puberty
dictyate or
dictyotene

54. dictyate or dictyotene: resting stage in oogenesis during meiotic prophase.
Terminates before LH triggered ovulation starts
Menarche: first menstrual cycle in female humans; influenced by genetic
and environmental factors especially nutritional factors. Other factors like
race, ethinicity, geographical conditions etc are also responsible.
Average age is 12-14....showing a decreasing trend worldwide.
• Amount of body fat
• Estrogen secretion by oestrogen by stimulation of ant pit
• Stimulates uterus, breast development, adipose tissue, widening of pelvis
• Vascularity of uterus
• Washing down of endometrial tissue with blood due to hormones
When menarche has failed to occur for more than 3 years after the beyond 16
years of age, the delay is referred to as primary amenhorrea. It is absence of
menstrual period.
Secondary amenorrhoea (menstruation cycles ceasing) is often caused by hormonal
disturbances from the Hypothalamus and pitutary, from menopause or intrauterine
scaring.

55. Menstrual Cycle, period, menses, menstrual bleeding
Endometrium thickens and develops a rich blood supply preparing the uterus for
implantation
When endometrium is
sloughed/shed off through
cervix and vagina its called
menstruation
Humans and chimpanzees
Endometrium is not shed but
absorbed by the uterus and no
bleeding occurs
More pronounced behavioral change
is seen and there is stronger
effect of climate and seasonal
change and hence receptive to
sexual activity only at that time.
Vagina permits mating at this time
only.
Female is receptive to sexual
activity throughout the year
28 days (20-40 days)
Rat (5 days)
Dogs and bear (one cycle per year)

56. Human Menstrual Cycle
Uterine cycle and ovarian cycle: 2 organs uterus and ovary
Ovarian cycle of hormone production controls uterine cycle

59. Kisspeptin: or metastin
family of peptide in humans is encoded by the KISS1 (metastasis
suppressor gene: suppresses melanoma and breast cancer metastasis)
transcribed in brain, adrenal and pancreas

62. Low estrogen
Negative feedback to HT
Less FSH and LH
High estrogen during
Follicular phase
Cause estrogen to rise
FSH and LH (more)
Positive feedback

63. • LH causes ovulation
• CL (luteal phase)
• Release Estro/proges
• Thickening of
endometrium
• Negative feedback to
HT
• Less estrogen
• Level drop and follicular
phase start

65. Premenstrual syndrome (PMS): mood changes, emotional sensitivity, breast
tenderness, bloating, headaches, depression, stress, anxiety, fatigue, constipation,
acne, muscle pain joint pain, backache, abdominal cramps
Menstruation: abdominal cramps, diarrhea, mood swings
Hypomenhorrea: very less
Polymenhorrea: 21 or less than 21 days cycle
Metrorrhagia: irregular menstruation
Menorrhagia: sudden heavy flow
Menometrorrhagia: heavy flow but irregular
Oligomenhorrea: cycle longer than 35 days
Amenhorrea: more than 6 months cycle
Lactation amenhorrea: no menses during breastfeeding

66. UTERINE CYCLE
1. PROLIFERATIVE PHASE: thickening of
endometrium and growing of follicle of
ovum
Before Ovulation uterus is prepared to
receive embryo
After ovulation estro/proges by CL
continue to maintain the endometrium
and enlargement of arteries and glands
(nutrient fluid)
2. SECRETORY PHASE: coincides with
luteal phase. Drop in hormone levels.
Endometrium and CL disintegrate and
result in menstrual blood flow. During
this process fresh batch of follicles
start to grow.
Estrogen is important for deposition of fat in
breasts and hips, water retention, Ca
metabolism, breast development and female
sexual behavior

67. MENOPAUSE
After 450 cycles cessation of ovulation and menstruation
B/w ages of 45-55 sometimes 60
Ovaries lose responsiveness to estrogens and progesterone
Decline in estrogen production
Can lead to several diseases and effects due to hormonal changes
Osteoporosis, osteopenia, Hot flashes, migraine, dryness, urinary incontinence, joint
pains, skeletal muscle pain, breast changes, can also cause cancers, ovarian and
cervical cancers, fatigue, irritability, thyroid disorders, insomnia, vaginal dryness,
decr in sexual drive, incr in BP
Treatment: hormone replacement therapy, removal of uterus, ovary, Selective
estrogen receptor modulators (SERM) drugs, anti depressants, BP medicines,
therapy and counselling.
Causes: decr in no of eggs, incr in FSH and LH, ultimately low estrogen
Evolutionary significance, promotes longevity in females
Human females make greater investment in gametes than male of humans
Parental care more from females than males evolutionarily
Does not take place in many animals

68. ANDROPAUSE OR “MALE MENOPAUSE” OR MAN-O-PAUSE
Menopause like conditions
Decr in testosterone and dehydroepiandosterone in middle aged men
Similar condition in hypogonadism
Effects: hot flashes, excessive sweating, osteoporosis, insomnia, depression,
memory instability leading to dementia, Alzheimers is common, decr sexual
desire and potency, urinary incontinence, prostrate cancer, hypertension,
diabetes, mood swings
Treatment: hormone replacement therapy, exercise, dietary changes, stress
reduction, selective androgen receptor modulator drugs (SARM), therapy and
counseling.
Androgen deficiency of aging male

69. CONTRACEPTION