1. ENDOCRINE SYSTEM Review
PETER REONISTO, MD
MOORPARK COLLEGE

2. Nervous System vs. Endocrine System
3) Hormones travel more slowly than nerve impulses, the endocrine system tends to regulate slow processes such as growth and metabolism.

3. 1. “Pure” endocrine organs
Major Endocrine Organs
Pineal gland
Pituitary gland
Thyroid gland
Parathyroid gland
Endocrine cells of the
body contained in:
Adrenal gland
1. “Pure” endocrine organs

4. Major Endocrine Organs
Hypothalamus
Endocrine cells of the
body contained in:
Thymus
Pancreas
2. “Partly” endocrine organs
Gonads

5. CLASSES OF HORMONES AMINO ACID-BASED Most hormones Proteins
Modified amino acid peptides
STEROIDS
Lipid molecules derived from cholesterol
Sex hormones
Adrenal cortex hormones

6. CONTROL OF HORMONE SECRETION
Humoral
Neural
Hormonal

7. CONTROL OF HORMONE SECRETION
Humoral- influenced by
plasma concentration of the
substance.
Low Ca2+ blood
concentration
Parathyroid
gland
Parathyroid gland
Parathormone secretion
Nephron, intestinal cells
Action

8. CONTROL OF HORMONE SECRETION
2. Neural- SNS stimulation
Preganglionic SNS
fibers
Adrenal
medulla
Medulla of adrenal
gland
Adrenaline secretion
Body
Actions: “Fight, flight, or fright” response

9. CONTROL OF HORMONE SECRETION
3. Hormonal-influenced by the amount
of hormones in the plasma
Releasing
hormones
Hypothalamus
Releasing hormones
Adenohypohysis
Stimulating Hormones
Thyroid
gland
Adrenal
cortex
Gonads
(Testis)
Thyroxine
Cortisol
Androgens
Body
Cortisol
Androgens
Increase
Metabolic
rate
Anti-stress
Sperm
formation

10. MAJOR ENDOCRINE ORGAN
PITUITARY GLAND

11. > Hypophyseal fossa
PITUITARY GLAND
Or, hypohysis
Secretes at least 9 major hormones
Location:
> Hypophyseal fossa
Depression in the
Sella turcica of the
Spenoid bone

12. ANATOMY: PITUITARY GLAND
infundibulum

13. Anterior Pituitary Gland

14. Adenohypophysis
Pars distalis
Pars intermedia
Pars tuberalis

15. Adenohypophysis Pars distalis Largest division
Contains 5 different endocrine cells that make and secrete 7 different hormones

16. Pars distalis 5 CELL CLASSES:
1. Somatotrophic cell (most abundant)
2. Mammotrophic cells
3. Thyrotrophic cells
4. Corticotrophic cells
5. Gonadotrophic cells
Growth Hormone (Somatotrophic Hormone / Somatotropin / GH)
Growth of the entire body
Prolactin (PRL)
Breast milk production
Thyroid Stimulating Hormone (TSH)
Thyroid gland stimulation to release thyroid hormone
Adrenocorticotropic Hormone (ACTH)
Adrenal Cortex stimulation to release glucocorticoids
Melanocyte Stimulating Hormone (MSH)
Stimulates melanocytes to produce melanin pigment
Follicle Stimulating Hormone (FSH)
Gonads: maturation of sex cells; secretes sex hormones
Gonadotropins
Leutenizing Hormone (LH)
Gonads: maturation of sex cells; secretes sex hormones

17. Pars distalis 5 CELL CLASSES:
Growth Hormone (Somatotrophic Hormone / Somatotropin / GH)
Growth of the entire body
Act directly on
non-endocrine
target tissues
Prolactin (PRL)
Breast milk production M P G
Thyroid Stimulating Hormone (TSH)
Thyroid gland stimulation to release thyroid hormone
Tropic Hormones -
Regulate the secretion
of hormones by other
Endocrine glands
Adrenocorticotropic Hormone (ACTH)
Adrenal Cortex stimulation to release glucocorticoids F L A T
Melanocyte Stimulating Hormone (MSH)
Stimulates melanocytes to produce melanin pigment
Follicle Stimulating Hormone (FSH)
Gonads: maturation of sex cells; secretes sex hormones
Leutenizing Hormone (LH)
Gonads: maturation of sex cells; secretes sex hormones

18. HYPOTHALAMIC CONTROL OF THE ADENOHYPOPHYSIS
Controlled by RELEASING HORMONES and INHIBITING HORMONES -
Peripheral
Endocrine
gland
Peripheral
Endocrine
gland
Peripheral
Endocrine
gland
Target cell
Target cell

19. HYPOPHYSEAL PORTAL SYSTEM
Hypothalamic neurons
Releasing hormones are made in
Hypothalamic neurons
Primary capillary complex
Releasing hormones are secreted at
the neuron synapse
To the primary capillary complex
Releasing hormones goes to the
Hypophyseal portal vein
To the secondary capillary complex
Secondary
Capillary
complex
Releasing hormones leaves the plexus &
attach to the adenohypophyseal cells
Somatotropic
Mammotropic
Thyrotropic
Corticotropic
Gonatotropic

20. Posterior Pituitary Gland

21. Neurohypophysis
1. Median eminence 2. Infundibular stalk 3. Pars nervosa
Median
eminence
Infundibular
stalk
Pars
nervosa

22. NEUROHYPOPHYSIS HORMONE PRODUCTION
Hormone produced at neuron cell
bodies located at the SUPRAOPTIC
and PARAVENTRICULAR nuclei of
the Hypothalamus
Hormones are transported
along the axons
(Hypothalamic-hypophyseal
Tract)
Upon stimulation, stored
hormones are released in the
capillary bed for distribution
throughout the body
Hormones are stored in
dilated axon terminals
called HERRING BODIES
ADH
Oxytocin

23. NEUROHYPOPHYSIS: Hormones
CELL TYPE
HORMONE
TARGET/EFFECTS
Neurons from supraoptic nucleus of hypothalamus
Antidiuretic hormone (ADH, vasopressin)
Stimulates kidneys (distal tubules and collecting tubules) to reclaim water from urine.
Raises blood pressure by constricting peripheral arterioles when blood volume is low.
Neurons from paraventricular nucleus of hypothalamus
Oxytocin
Initiates labor through uterine contraction
Facilitates milk ejection from breast

25. MAJOR ENDOCRINE ORGAN
THYROID GLAND

26. THYROID GLAND
located in the
anterior neck; on the
trachea just
inferior to the larynx

27. PARATHYROID GLAND Located at the posterior surface of the thyroid

28. PARATHORMONE
FUNCTION:
Increase blood
Calcium level

29. ADRENAL GLAND ADRENAL CORTEX ADRENAL MEDULLA Mineralocorticoid
Balance electrolyte
Concentration (Na+/K+)
--Inc Na+ Reabsorption
--Inc K+ excretion
--Inc water reabsorption
Mineralocorticoid
(Aldosterone)
Glucocorticoid
(Cortisol)
Stress control
Glucocorticoid
(Cortisol)
Produce sex hormone precursor (DHEA)
----Dehydroepiandrosterone---

30. ADRENAL MEDULLA: Hormones
Simulate a “fight, fright, flight response”

31. PANCREAS

32. Other Endocrine Glands
Pineal Gland
secretes melatonin
regulates circadian rhythms
Thymus Gland
secretes thymosins
promotes development of certain lymphocytes
important in role of immunity
Reproductive
ovaries produce estrogens and progesterone
testes produce testosterone
placenta produces estrogens, progesterone, and gonadotropins

33. END