1. Endocrine System Ref: Principles of Anatomy and Physiology, Tortora and Derickson, 14th Ed: 615-756.

2. Communications between cells
Cells releasing Signaling molecules:- Hormones, Factors and Neurotransmitters released by specific cells and Acting by:
- Endocrine signaling
- Paracrine signaling
- Autocrine signaling

3. (a) Endocrine signaling
Blood vessel
Response
(a) Endocrine signaling
Response
(b) Paracrine signaling
Figure 45.2 Intercellular communication by secreted molecules.
Response
(c) Autocrine signaling

4. Endocrine GLANDS are releasing Hormones

5. Exocrine (Glands with Duct system)
vs Endocrine (Ductless glands) and their release
Fig. 11-1

6. Endocrine Organs Purely endocrine organs
Pituitary gland
Pineal gland
Thyroid gland
Parathyroid glands
Adrenal glands:
Cortex
Medulla
Endocrine cells in other organs
Pancreas
Thymus
Gonads
Hypothalamus
Kidney
GI system

7. Table 45.1a
Table 45.1 Major Human Endocrine Glands and Some of Their Hormones

8. Table 45.1b
Table 45.1 Major Human Endocrine Glands and Some of Their Hormones

9. General characteristics of Endocrine signaling
System of ductless glands that secrete hormones
Hormones are “messenger molecules”
Released into blood from endocrine structures
Act on distant target cells
Target cells respond to hormones for which they have specific receptors
The effects on target cells are dependent on the induced responses.
Hormones are just molecular triggers

11. Hormonal Receptors
The ability of a cell to respond to a hormone depends upon the presence of receptors for that hormone:
on (over plasma membrane)=Extracellular Receptors
in (Inside) the target cell. (Intracellular Receptors).

12. Water- soluble hormone Lipid- soluble hormone
SECRETORY CELL
Water- soluble hormone
Lipid- soluble hormone
VIA BLOOD
Transport protein
Signal receptor
TARGET CELL OR
Signal receptor
Figure 45.6 Receptor location varies with hormone type.
Cytoplasmic response
Gene regulation
Cytoplasmic response
Gene regulation
NUCLEUS
(a)
(b)

15. General Control of Hormones
- Metabolism
- Growth and development
- Red cell production
- Reproduction
- Adaptive changes like stress responses
- Fluid-electrolyte balance
- Acid-base balance
- Energy balance

16. Effectiveness of a hormone
Depends on:
- Plasma Concentration:
- Responsiveness of Target Cells.

17. Effectiveness of a hormone
Depends on:
- Plasma Concentration depends on:
-Rate of secretion: control mechanisms:
- Negative feed back
- Neuro-Endocrine reflexes
- Diurnal (Circadian) rhythm of secretion
-Transport in plasma
-Peripheral conversion
-Inactivation
-Excretion

18. Effectiveness of a hormone
Depends on:
- Responsiveness of Target Cells.
- Depends on the Number of receptors:
- An increase in the number of receptors for a hormone is called up-regulation.
- A decrease in the number of receptors for a hormone is called down-regulation.
- Concentration of other hormones:

19. Effectiveness of a hormone
- Concentration of other hormones:
- Permissiveness:
Example: Thyroid hormones increases number of receptors
for epinephrine over target cells
- Antagonistic actions by other hormones:
Example: Progesterone and estrogen effects over uterine
smooth cells. (Progesterone reducing estrogen receptors)
- Synergistic actions:
Example FSH and Testosterone which are both needed to
maintain sperm production by testis.

20. Permissive Actions of Hormones
Fig. 11-9

22. Pituitary Gland

23. The Hypothalamus and Pituitary Gland
Fig

25. Summary of Posterior Pituitary Hormones
The posterior pituitary does not synthesize any hormones; it only secretes them.
Oxytocin is involved in:
Milk ejection reflex of nursing mothers and
emotional bonding.
- Contraction of uterus
Antidiuretic hormone (ADH)(also called Vasopressin) is involved in regulation of:
- Water balance and osmolarity.
- Blood Pressure

26. Anterior pituitary gland Hormones
Tropic effects: (FSH, LH, TSH, ACTH) Nontropic effects: (Prolactin, MSH). Tropic and Nontropic: (GH)

27. Anterior Pituitary Gland Hormones

28. Anterior Pituitary Hormones and the Hypothalamus
Fig

29. Anterior Pituitary Hormones
Fig

30. http://anatomyofthefoot. com/function-of-the-anterior-pituitary-gland