1. The Endocrine System Chapter 13

2. Endocrinology The study of hormones
Like nervous system- helps control the body and aid in communication
Hormone- chemical messenger, travels through the bloodstream to target cells, effective at very low concentration

3. Hormones 1) Secreted Glands- pituitary, thyroid, etc.
Into the bloodstream

4. Hormones 2) Travel through the blood stream to a distant target
3) Exert their effect at very low concentrations

5. General characteristics
Some hormones are produced by small groups of specialized cells
Other hormones are produced by larger endocrine glands
Pituitary gland
Thyroid gland
Parathyroid glands
Adrenal glands
Pancreas
Hypothalamus
Pituitary gland
Pineal gland
Parathyroid gland
Thyroid gland
Thymus
Adrenal gland
Kidney
Pancreas
Ovary
(in female)
Testis
(in male)

6. Terminating hormone action

7. Terminating hormone action
Degraded in the bloodstream
Degraded on the receptor
Endocytosis of receptor-hormone complex

8. Everyone needs a little regulation…

9. Regulation of endocrine response
Governed by negative feedback
Feedback guided by multiple variables
Change in physiological variable
Hormone concentration

10. Chief cells

11. HPA axis
Hypothalamic-Pituitary-Adrenal
Complex regulation

12. Governs many key endocrine functions
Deemed “Master Gland”
Governs many key endocrine functions
Growth
Blood pressure
Water regulation
Others

13. Parts of the Pituitary gland
Posterior pituitary
Neural tissue
Secretes neurohormones
Oxytocin, vasopressin
Vasopressin- regulates water balance

14. Parts of the Pituitary gland
Anterior pituitary
“True” endocrine gland
Synthesizes/releases peptide hormones

15. Anterior Pituitary function
Hypothalamus (part of the brain) releases hormones
Those hormones signal to the anterior pituitary
Anterior pituitary releases hormones that affect peripheral endocrine glands
Peripheral endocrine glands release hormone to target cells

16. Peripheral endocrine gland–
Hypothalamus –
Releasing
hormone
(Hormone 1) + –
Anterior pituitary
Anterior pituitary
hormone
(Hormone 2) +
Peripheral endocrine gland
(Hormone 3)
Stimulation +
Inhibition
Target cells

17. Trophic hormones

18. Trophic hormone- a hormone that controls the secretion of another hormone
All end in “tropin”

21. Endocrine pathologies
Hormone excess, hormone deficiency, or abnormal responsiveness of target tissue
Can be primary (last endocrine gland in a reflex) or secondary (further up, in gland producing trophic hormone)

22. Hypersecretion Increase in hormone secretion Tumors
Causes dysfunction in feedback pathway
Can occur at any point in the axis
Hypothalamus
Pituitary gland
Adrenal gland

24. Hypersecretion Hypersecretion of GH Acromegaly (adult) Bones ossified
Prominent brow
Reduced testosterone
Soft tissue swelling

25. Hypersecretion Excess production of GH Gigantism (children)
Exaggerated and prolonged growth in long bones

30. Hyposecretion Dysfunction of the pituitary Decreased secretion of GH
Dwarfism
Born normal height/weight
Failure to grow by age 2 yr

31. Receptor failure Plenty of hormone Decrease or lack of receptors
Initially thought lack of GH production, but actually lack of receptors

32. Diabetes When you eat, food is broken down into glucose
Cells use glucose as energy
The pancreas secretes insulin (hormone), which helps glucose get into the cells
Diabetes is a lack of insulin (type 1) or decreased response of cells to insulin (type 2)
Glucose can’t get to cells

33. Type 1

34. Type 2

35. Yum…

36. http://www. mayoclinic

37. Signals from nervous and endocrine systems

38. Nervous v. Endocrine Nervous Endocrine Each neuron has a target cell
Every cell

39. Nervous v. Endocrine Nervous Endocrine Each neuron has a target cell
Electrical/chemical
Every cell
Chemical (hormones)

40. Nervous v. Endocrine Nervous Endocrine Each neuron has a target cell
Electrical/chemical
Fast
Every cell
Chemical (hormones)
Slower

41. Nervous v. Endocrine Nervous Endocrine Each neuron has a target cell
Electrical/chemical
Fast
Short duration
Every cell
Chemical (hormones)
Slower
Longer lasting

42. Nervous v. Endocrine Nervous Endocrine Each neuron has a target cell
Electrical/chemical
Fast
Short duration
Intensity control via frequency
Every cell
Chemical (hormones)
Slower
Longer lasting
Intensity control via quantity