CHEMICAL COORDINATION AND INTEGRATION for NEET UG

1. INTRODUCTION
DR.ABHINAV BHANDARI
(BVSc and AH)
NEET BIOLOGY FACULTY
NEET 2016
AIR – 14,861
PERCENTILE – 97.94

2. CHEMICAL COORDINATION AND INTEGRATION

3. NEED FOR ENDOCRINE SYSTEM
NERVOUS SYSTEM:
• Point to point rapid coordination among organs
• Fast Conduction

4. BUT……
• Neurons can’t reach to each and every cell of the body.
• Nerve conduction are fast but short lived and cellular functions need
to be continuously regulated.

5. This Function is carried out by HORMONES
 HORMONES ???
 Non-nutrient Chemicals (liquid)
 Act as Intercellular messenger
 Produced in trace amounts (nanograms/ml)

7. Hormones are secreted by Endocrine Glands
 ENDOCRINE GLANDS ARE:
 Ductless glands
 Secretions = Hormones
 Released into blood
 Distantly located Target cell/organ

8. EXOCRINE GLANDS ENDOCRINE GLANDS
THEY HAVE DUCT
Ex = Pancreas
Liver
THEY DON’T HAVE DUCT
Ex = Pituitary
Thyroid
SECRETIONS = ENZYMES
TEARS
SWEAT
OILS
MUCUS etc.
SECRETIONS = HORMONES
TARGET ORGAN IS NEARBY TARGET ORGAN CAN BE FAR

9. HUMAN ENDOCRINE SYSTEM
In addition to these there are some organs also
synthesize/secrete hormones:
• Gastro intestinal tract (GIT)
• Liver
• Kidney
• Heart

10. HYPOTHALAMUS
• Location = Base of diencephalon (part of forebrain)
• Group of neurosecretory cell (Nuclei)
• Affect on Pituitary gland
• Two types of Hormones:
1. Releasing Hormone (+) 2. Inhibiting hormone (-)
Stimulates synthesis and Inhibit synthesis and secretion of
Secretion of Pituitary hormones Pituitary Hormone
Ex = GHRH Ex= Somatostatin
GnRH GnIH

11. POSITIVE/NEGATIVE FEEDBACK MECHANISM

12. HYPOTYHALAMUS
Anterior
Pituitary
Posterior
Pituitary
Portal
Circulatory
system
Long Axons of
Hypothalamic
Neuron
Indirect
Regulation
Direct
Regulation

13. Pituitary Gland (Hypophysis)
• Location = Sella tursica (bony cavity)
• Attached to Hypothalamus by a stalk.
(infundibulum)
• Divided into two parts:
1. Adenohypophysis
Pars distalis (Anterior Pituitary)
Pars intermedia
2. Neurohypophysis
(Pars nervosa) (Posterior Pituitary)

14. Anterior pituitary hormones:
• Growth hormone (GH)
• Prolactin (PRL)
• Thyroid Stimulating hormone (TSH)
• Adrenocorticotrophic hormone (ACTH)
• Luteinizing Hormone (LH)
• Follicle Stimulating Hormone (FSH)
Pars intermedia Hormones:
• Melanocyte Stimulating Hormone (MSH)
Posterior Pituitary Hormones:
• Oxytocin
• Vasopressin (ADH)

15. Growth Hormone (GH) (Somatotropin)
• Function = Normal growth of the body (anabolic effect)
• Hypersecretion = Gigantism (Birth)
Acromegaly (Adult)
• Hyposecretion = Dwarfism

16. Prolactin (PRL)
• Functions = Growth of mammary gland
Formation of milk in them (Lactation)
Thyroid Stimulating Hormone(TSH)
• Release of Thyroid Hormones from Thyroid gland.
Adrenocorticotrophic hormone (ACTH)
• Release of glucocorticoids (steroidal) from Adrenal cortex.

17. Gonadotrophins (LH and FSH)
• Luteinizing Hormone (LH):
Males = synthesis/secretion of Androgen from testis
Females = Ovulation
Maintenance of Corpus luteum
• Follicle Stimulating Hormone (FSH):
Males = Spermatogenesis (along with Androgen)
Females = Growth/development of follicles
Oogenesis

18. Melanocyte Stimulating hormone (MSH)
MSH
Melanocytes (Melanin)
Regulation of Pigmentation
(It darkens the complexion of skin by distributing
melanin pigment evenly under the skin)

19. Oxytocin/Pitocin
• Contraction of Smooth Muscles of the body
• Females = Uterus Contraction during Parturition
(Main parturition hormone)
Milk Ejection from mammary glands
(Milk let down)
Vasopressin (ADH)
• Stimulates Resorption of water and electrolytes in distal tubules of
kidney.
• Reduces loss of water through urine (Diuresis) Anti Diuresis
• Impairment in release/synthesis of ADH leads to Diabetes Insipidus

20. Diabetes Insipidus
• Hyposecretion/decreased synthesis of ADH
• Decreased ability of kidney to conserve water
• Increased water loss in Urine
• Dehydration
• Polyurea
• Polydipsia

21. PINEAL GLAND/PINEAL BODY
• Location = Dorsal side of Diencephalon
• Hormone = Melatonin
• Functions = 24 hour diurnal rhythm/Circadian Rhythm
(Sleep wake cycle)
(Body temperature)
Metabolism
Pigmentation
Menstrual cycle
Defence Capability

22. Don’t confuse Melanin with Melatonin
• Melanin = pigment present on skin
• Melatonin = Hormone produced by pineal gland

23. THYROID GLAND (Largest Endocrine Gland)
• Location = Composed of 2 lobes on either side of trachea(Ventro-laterally)
• Two lobes are interconnected with Isthmus (connective tissue)
• Composed of two types of tissue:
1. Follicles
2. Stromal tissues
• Follicles Follicular cells Thyroid Hormones

24. Thyroid Hormones
1. Tetra-iodothyronine (Thyroxine) (T4)
2. Tri-iodothyronine (T3)
3. Thyrocalcitonin (Para follicular cells)

25. Thyroxine (T4) and T3
• Regulation of Basal Metabolic Rate (BMR)
• RBC and Haemoglobin formation (Erythropoiesis)
• Metabolism of Carbs, Fats, Proteins
• Water/Electrolyte balance
• Normal menstrual Cycle regulation

26. Regulation of Thyroid Hormone Secretion

27. Iodine is essential for synthesis of thyroid hormones its
deficiency can lead to:
 Hypothyroidism:
• Enlarged Thyroid Gland (Simple Goitre) (Endemic Goitre)
• Pregnant Women = Defective development/maturation of growing baby.
(Stunted growth – cretinism)
(mental retardation, low IQ)
(abnormal Skin)
(Deaf – mutism)
• Adult Women = Irregular Menstrual Cycle

29.  Hyperthyroidism:
Cancer of thyroid gland
Nodules Development
Increase synthesis and
secretion of thyroid
hormones
Hyperthyroidism

30.  Exophthalmic Goitre:
• Enlarged thyroid gland
• Protrusion of eyeball
• Weight loss (increased BMR)
• Also known as Grave’s disease

31.  Thyrocalcitonin (TCT):
• Para follicular cells/C-cells
• Decrease Blood Calcium level (Hypo-calcaemic)
(Increases Ca++ deposition in Bone)
(Decreased Ca++ reabsorption from kidney)
(Inhibit Calcium Absorption in intestines)

32. Parathyroid Gland
• Location = 4 glands present on back side of Thyroid gland
(One pair in each lobe of thyroid gland)
Parathyroid Hormone (PTH)
 Its secretion is regulated by Calcium level in blood
 Increases Ca++ in blood (Hypercalcaemic)
 Bone resorption (Demineralisation of bone)
 Stimulates Ca++ absorption by renal tubules
 Increases Ca++ absorption from digested food

33. Regulation of Blood Calcium level

34. Thymus Gland
• Location = Between Lungs (behind Sternum on ventral side of aorta)
(lobular structure)
• Development of Immune system (major role)
 Thymosins
• Differentiation of
T-lymphocytes (major role)
• Production of Antibodies
Cell mediated Immunity
Humoral Immunity
• Thymus
degeneration
(old age)
Decrease level
of Thymosins
Decreased Immunity
(old age)

36. Adrenal Glands
• Location = Anterior part of kidney (paired glands)
• Outer part = Cortex
• Inner part = Medulla
 Adrenal Medulla Hormones (Catecholamines):
• Adrenaline/Epinephrine
• Noradrenaline/Norepinephrine
 Adrenal Cortex Hormones (Corticoids):
• Glucocorticoids (Cortisol)
• Mineralocorticoids (Aldosterone)
• Androgens (small amounts)

37. Stress/Emergency
Release of Adrenaline / Noradrenaline (Catecholamines)
(Emergency hormone/Hormones of Fight or flight)
Alertness
Pupillary dilation
Piloerection
Sweating
Increases heart beat
Increases Strength of heart contraction
Increases rate of respiration
Glycogenolysis leading to hyperglycaemia
Proteolysis
lipolysis

38.  Glucocorticoids (Cortisol):
• Involved in Carbs metabolism
• Main glucocorticoids = Cortisol
• Stimulate Gluconeogenesis, Lipolysis, Proteolysis
• Inhibit cellular uptake and utilization of Amino acids
• Maintain Cardiovascular system (Cortisol)
• Maintain Kidney functions (Cortisol)
• Anti Inflammatory Reaction
• Immunosuppression (Cortisol)
• Stimulates RBC Production (Cortisol)

39.  Mineralocorticoids (Aldosterone):
• Regulation of Water/Electrolyte balance
• Aldosterone = Main Mineralocorticoids
• Reabsorption of Na+ and water from renal tubules (Aldosterone)
• Excretion of K+ and phosphate ions from renal tubules (Aldosterone)
• Electrolyte maintenance (Aldosterone)
• Body fluid volume maintenance (Aldosterone)
• Osmotic pressure maintenance (Aldosterone)
• Blood pressure maintenance (Aldosterone)

40.  Adrenal Androgens (De hydro epi Androsterone - DHEA):
• Chemically Steroids
• Secreted by Adrenal Cortex
• Growth of Axial Hair
• Growth of Pubic Hair
• Growth of Facial Hair
During Puberty

41. Addison’s Disease (Adrenal insufficiency) (Hyposecretion)
• Underproduction of Adrenal cortex hormones (Corticoids)
• Alteration in Carbohydrate metabolism
• Decreased glucose level (Hypoglycaemia)
• Lethargy
• Acute Weakness
• Fatigue

42. Cushing's syndrome (disease)
• Over secretion of cortisol (Hypersecretion)
• There is excess breakdown of body fat (lipolysis)
• There is deposition of fat at unusual body areas like:
Face – Moon face, Fish mouth
Upper abdominal region

43. Pancreas
• Location = Backside (posterior) of stomach in abdominal cavity.
• Composite gland (Exocrine- 99% + Endocrine – 1-2%)
• Endocrine – Islets of Langerhans (1-2 million) (1-2%)
• Islets of Langerhans consist of 4 types of cells:
a. Alpha cells - Glucagon
b. Beta cells - Insulin
c. Delta/gamma cells - somatostatin
d. F or PP cells - pancreatic polypeptide

44. Glucagon (Hyperglycemic Hormone)
• Peptide hormone
• Function = Maintains normal blood glucose level
• It acts mainly on Liver cells (Hepatocytes):
Glycogen Glucose (Glycogenolysis) – Hyperglycemia
• Also stimulates Gluconeogenesis – Hyperglycemia
• It reduces the cellular glucose uptake/utilization - Hyperglycemia

45. Insulin (Hypoglycemic)
• Peptide hormone
• Function = Major role in regulation of glucose homeostasis
• It acts mainly on Hepatocytes and adipocytes:
Enhances cellular glucose uptake and utilization
Rapid movement of glucose from blood to hepatocytes and Adipocytes (Hypoglycaemia)
• It also stimulates Glycogenesis (Glucose Glycogen) in target cell(liver, Muscle)
• Also inhibits Gluconeogenesis, Glycogenolysis

46. Glucose Homeostasis (Insulin + Glucagon)

47. Diabetes Mellitus (Sugar Disease)
• Cause = Prolonged Hyperglycemia
• Associated with :
a. Glycosuria
b. Polyuria
c. Polydipsia
d. Polyphagia
e. Ketonuria
f. Ketoacidosis
Treatment - Insulin therapy

48. Types of Diabetes mellitus
1. Type – I diabetes or Insulin-dependent diabetes mellitus (IDDM)
2. Type – II diabetes or non insulin-dependent diabetes mellitus (NIDDM)

49. Testis (Males)
• Location = In Scrotal sac (Outside Abdomen)
• Dual function (primary sex organ + endocrine gland)
• Composed of :
a. Seminiferous tubule
b. Stromal/Interstitial tissue
Leydig cells/Interstitial cells (present in intertubular spaces)
Produces group of hormones – Androgen (Testosterone)

50. Androgens
• Regulate the development, maturation and functions of the male accessory sex
organs (Epididymis, Vas deferens, Seminal vesicles, Prostate gland, Urethra etc.)
• Stimulates :
a. Muscular growth
b. Growth of facial/axillary hair
c. Aggressiveness
d. Low pitch of voice
• Major stimulatory role in spermatogenesis
• Acts on CNS and influence male sexual behaviour (Libido)
• Produce anabolic effects on protein/Carbohydrate metabolism

51. Ovary (Females)
• Location = Inside the abdomen
• Primary Female Sex organ (one ovum/menstrual cycle)
Produces two group of hormones (Endocrinal part)
Estrogen Progesterone
• Ovary is composed of:
a. Ovarian follicles
b. Stromal tissues

52. • Estrogen is synthesized and secreted mainly by the growing Ovarian follicles
• After ovulation ruptured follicle is converted to Corpus luteum
• Progesterone is mainly secreted by Corpus luteum
• Estrogen produces wide range of actions such as:
a. Stimulation of growth/activities of female secondary sex organs
b. Development of ovarian follicles
c. Appearance of female secondary sex characters (high pitch of voice)
d. Mammary gland development
e. Regulation of female sexual behavior

53. Functions of Progesterone:
a. Supports pregnancy
b. Acts on Mammary gland and stimulates the formation of Alveoli
(sac like structures which stores milk)
c. Stimulates milk secretion from alveoli

54. Hormones secreted by HEART
• Atrial Natriuretic Factor (ANF)
Increase in Blood pressure
Secretion of ANF (Atrial Wall)
Dilation of Blood vessels
Decrease in Blood pressure (normal)

55. Hormones secreted by KIDNEY
• Erythropoietin (peptide)
• Secreted by Juxta glomerular cells
• Stimulates Erythropoiesis
Hormones secreted by Liver
• Thrombopoietin
• Angiotensinogen
• Insulin like growth factor - I

56. Hormones secreted by GIT
• GIT secrete four major peptide hormones :
a. Gastrin
• Acts on the gastric glands and stimulates the secretion of HCl and pepsinogen
b. Secretin
• Acts on the exocrine pancreas
• Stimulates secretion of Water and bicarbonate ions

57. c. Cholecystokinin (CCK)
• Acts on both pancreas and gall bladder
• Stimulates the secretion of pancreatic enzymes and bile juice
d. Gastric Inhibitory peptide (GIP)
• Inhibits gastric secretion and motility
Several other non-endocrine tissues secrete hormones called
Growth factors
These factors are essential for the normal growth of tissues and
their repairing/regeneration

58. Hormones are of following types:
(On the basis of chemical nature)
a. Peptide, Polypeptide, Proteinaceous :
(Insulin) (Glucagon) (Pituitary Hormones) (Hypothalamic Hormones)
(PTH) (TCT)
b. Steroids :
(Cortisol –Glucocorticoids) (Testosterone) (Estradiol) (Progesterone)
(Mineralocorticoids)
c. Iodothyronine :
(Thyroid Hormones –except TCT)
d. Amino acid derivatives :
(Epinephrine) (Nor-epinephrine)

59. Mechanism of Hormone Action
Hormone receptors (located in Target tissue)
Membrane bound Receptor Intracellular Receptors
(mostly Nuclear receptors)
Hormone + Receptor (Nuclear receptor)
Hormone-Receptor complex
Biochemical Changes in Target tissue
• Each receptor is specific to one hormone only and hence receptors are specific

60. (Proteinaceous) Hormone + Membrane bound receptors
Secondary messenger (cyclic AMP, IP3 , Ca++ etc.)
Regulation of Cellular Metabolism

61. (Steroidal, Iodothyronines) Hormones + Intracellular Receptors
Regulate Gene expression/Chromosome function
(Hormone-receptor Complex)

62. THE END