The document discusses the neuroendocrine system, which involves the nervous system and endocrine system working together to control and regulate various functions in the body. It describes the major endocrine glands - the hypothalamus and pituitary gland, thyroid gland, parathyroid gland, adrenal gland, and pancreas. It explains how each gland secretes specific hormones that help regulate processes like metabolism, growth, and electrolyte balance. The concentration of hormones in the blood depends on the rates of secretion from the glands and removal by the liver and kidneys. Hormones act by binding to receptors on target tissues.

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NEUROENDOCRINE

2. NEUROENDOCRINOLOGY
 Two major homeostatic systems involved in the
control and regulation of various functions.
 systems involved are:
 NERVOUS SYSTEM AND
 ENDOCRINE SYSTEM,
 working together these system are termed as
neuroendocrine system or response

3.  Neuroendocrine system sense information, organize
response and deliver message to appropriate organ
 Endocrine glands release chemical messenger
(hormones) while nervous system send their
information via nerves and neurotransmitter

4.  Hormones are divided in several classes based on
chemical makeup
 Amino acid derivatives, peptides/proteins and
steroids
 Hormones are measured in micro(µ), Nano (symbol
n) and Pico (symbol p) gram

5. BLOOD HORMONE CONCENTRATION
 Hormone concentration in plasma depends on
Rate of secretion of hormone from gland
Rate of excretion or metabolism of hormone
Quantity of transport protein
Changes in the plasma protein
• Effect of hormone exerts on a tissue is directly
related to the number of active receptors

6. BLOOD HORMONE CONCENTRATION
 Endocrine glands release hormone directly into the blood
to alter the activity of tissues
 The plasma hormone concentration shows the
magnitude of the effect at the tissue level
 Concentration can be changed by altering the rate of
secretion or inactivation of hormone
 Alteration can be by quantity of transport protein, and
the plasma volume

7. Metabolism and secretion of hormones
 Concentration of hormones in plasma is influenced
by rate at which it is metabolized, inactivated or
excreted.
 Inactivation takes place at over near receptors in the
liver. “These are major sites of hormones”.
 Kidneys can metabolize and excrete varieties of
hormones in their free forms

8. Rate of excretion of hormone:
 In urine it has been used as indicator of its rate of
excretion during exercise.
 Blood flows to use kidney and liver during exercise
by according to their function
 Rate of excretion and inhibition decreases, and this
results in an elevation of hormones at the plasma
level.

9. Hormone receptor interaction:
 Tissue responses to specific hormones, have specific
protein receptors which are capable of binding those
hormones.
 Number of receptors varies from 500 to 1 lac/cell.
 No. of receptors may be decrease when exposed to a
chronically elevated level of hormone and it is called
“down regulation”
 This down regulation have diminished response for
the same hormone concentration.

10.  Chronically exposure to low concentration of
hormone may lead to increase in receptors number
called “up regulation”
 For example: type I diabetes
 By up regulation tissues become very responsive to
the available hormone. When concentration of
hormone is so high that all receptors are bound to
hormones is called “saturation”

11.  Major endocrine glands
are
 Hypothalamus and
pituitary
 Thyroid gland
 Parathyroid gland
 Adrenal gland
 Pancreas
 gonads

12. HYPOTHALAMUS AND PITUITARY
 Pituitary gland is located
at the base of brain
attach to the
hypothalamus
 It consist of two lobes
anterior pituitary
(adenohypophysis) and
posterior pituitary
(neurohypophysis)

13. ANTERIOR PITUITARY
 Anterior pituitary secretes hormones under the
action of chemical signals by the hypothalamus or
positive or negative feedback system
Major hormones are:
Adrenocorticotropin (ACTH)
Growth hormone (GH)
Thyroid stimulating hormone (TSH)
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Prolactin

14. ANTERIOR PITUITARY
 Hypothalamus controls the activity of both the ant.
Pituitary and posterior Pituitary glands
 GH released from ant. Pituitary gland & it is
essential for normal growth
 GH increases during exercise to mobilize fatty acids
from adipose tissue and to aid in the maintenance of
blood glucose

16. GROWTH HORMONE
 GH is a anabolic hormone it stimulate tissue uptake
of amino acids, protein synthesis and long bone
growth, increase plasma glucose level, increase
mobilization of fatty acids from fatty tissue

17. POSTERIOR PITUITARY
 Release two hormones
 Anti diuretic hormone(vasopressin) Increase water
reabsorption from the kidney tubules , to maintain
blood volume
 Oxytocin stimulator of smooth muscle , specially at
the time of labor.

19. THYROID GLAND
 Thyroid gland is stimulated by TSH(primary stimulus) to
synthesize two iodine –containing hormones
 Trioiodothyroxine T3 (contains 3 iodine atoms)
 Tetraiodothyrosxine (thyroxine) T4 (contains 4 iodine atoms)
 They are free hormone concentration(not bound to plasma
protein)
 T3 and T4 are important in maintaining metabolic rate of
body, it also help other hormone to exert their full affect

20. THYROID GLAND
 Low T3 characterized as lethargic and hypo kinetic.
 Latent period for T3 is 6-12 hours ,& 2-3 days for T4

21. THYROID GLAND
 During Xs free hormone conc. Increases & taken up at a
faster rate by tissues.
Calcitonin:
 Calcitonin also secreted by thyroid gland
 It involves in the regulation of plasma ca++

22. PARATHYROID GLAND
 Prathyroid are four small gland located on the dorsal
aspect of thyroid gland
 It is the primary hormone involved in the regulation
of plasma calcium levels,
 The hormone increase plasma calcium level by
increasing its absorption from renal tubules, GIT and
it also stimulate bone to release calcium in the blood
 It also regulate phosphate level in the blood

23. ADRENAL GLAND
 Adrenal gland has two
component
 Adrenal cortex
 Adrenal medulla

24. ADRENAL MEDULLA
 Situated directly on top of each kidney and stimulated by
the sympathetic nervous system
 Secretes the catecholamines
 Epinephrine: elicits a fight or flight response
 Increase H.R. and B.P.
 Increase respiration
 Increase metabolic rate
 Increase glycogenolysis
 Vasodilation
 Norepinephrine
 Vasoconstriction increasing BP

26. ADRENAL CORTEX
 The three different zones of adrenal cortex release
three different types of hormone
 Mineralocorticoids
 Aldosterone: maintains electrolyte balance specially Na and K
 Glucocorticoids
 Cortisol :Stimulates gluconeogenisis
 Mobilization of free fatty acids
 Glucose sparing
 Anti-inflammatory agent
 Gonadocorticoids(androgens, estrogens)
 testosterone, estrogen, progesterone

28. PANCREASE
 Located slightly behind the stomach , pancreases act
both as exocrine gland and endocrine gland
 Exocrine portion release digestive juices
 Endocrine portion release
 Insulin
 Gucagon (insulin antagonist)
 Pancreatic somatostatin

29. INSULIN
 Insulin is released from beta cells of islet of
langerhans
 Insulin stimulate tissue uptake of glucose and amino
acids, and gluconeogenesis
 Insulin secretion is influenced by plasma glucose
concentration, amino acid concentration,
sympathetic and parasympathetic stimulation
 Decreased concentration or improper functioning
insulin receptors results in raised levels of plasma
glucose called diabetes mellitus