The Endocrine System

1
The Endocrine System

• HORMONES!!

2
Two systems control all physiological processes

• Nervous system
• Electrical and fast
• Endocrine system
• Not as fast
• Usually slow
• Cells must have a receptor

3
Two types of glands in the endocrine system

• Endocrine glands ductless
• Exocrine glands have ducts

4
Endocrinology

• The study of the endocrine glands which secrete
  hormones

5
Hormones

• Are chemical messengers
• Tropic or non tropic
• Evoke a specific response
• Are secreted into the bloodstream
• Regulate the metabolic rate of other cells

6
The Pituitary Gland

• Master gland
• Has two divisions
• Anterior 75 of total gland weight
• Posterior

7
Glands of the Anterior Pituitary

• GH
• Prolactin
• FSH
• LH
• TSH
• ACTH

8
GH (Growth Hormone)

• Affects all parts of the body associated with
  growth, not target cells
• Too much
• Gigantism
• Too little
• Dwarfism

9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
Dwarfism

• Stubby arms and legs
• Large chest and head
• Flat faced facial features

17
Acromegaly

• After normal bone growth has stopped Growth
  hormone is produced making bones in head, hands
  and feet thick

18
Acromegaly
19
Prolactin

• Affects females only
• Allows milk production stimulates and maintains
  milk production

20
ACTH

• Regulates the activity of adrenal cortex gland

21
TSH (Thyroid stimulating hormone)

• Growth and activity of the thyroid gland

22
Sex Hormones

• FSH (follicle stimulating hormone)
• Follicle development, one egg per month in
  females
• Stimulates the cells of testes that produce sperm
  in males
• LH
• Stimulates egg ovulation
• In males stimulates secretion of testosterone and
  interstitial fluid of testes

23
Posterior Pituitary

• Oxytocin
• Stimulates uterine contractions
• Stimulates ejection of milk from mammary glands
• Can be artificially produced to induce labor
• ADH
• Inhibits or prevents urine production
• kidneys reabsorb more water
• urine volume decreases
• blood volume increases
• Hemmorhaging would cause an increase

24
The thyroid gland

• At the base of the throat, just inferior to the
  Adams apple
• Secretes
• Thyroxine
• Major metabolic hormone
• Controls rate of oxidation of glucose to give O2
  to burn for energy.
• Calcitonin
• Takes calcium from blood and puts in bones

25
Problems with thyroid

• Hyperthyroidism over production TSH
• Graves
• Hypothyroidism
• Cretinism
• Myxedema
• Dwarfism

26
What are goiters

• An enlargement of the thyroid gland
• Occasionally caused by lack of iodine, but not in
  US

27
Goiters
28
(No Transcript)
29
Parathormone

• Absolute control over calcium levels. The very
  narrow range allows the nervous and muscular
  systems can properly function.
• Works in opposition to thyroid
• Imbalance can cause
• Nerve impulses altered transmissions
• Bone tissue destroyed
• Bone growth hampered

30
Adrenals

• Two separate glands wrapped around each other
• Medulla
• Inner adrenals
• Non essential to life
• Epinephrine (adrenalin) and norepinephrine
• Fight or flight response
• Cortex (too much can cause sterility)
• 90 of gland
• Steroids (an excess can lead to sterility)
• Essential to life
• Helps provide more energy

31
Pancreas, a mixed gland

• Exocrine
• Ducts goes into hollow cavities
• Digestive organ
• Makes digestive enzymes that flow into small
  intestine

• Endocrine
• No ducts
• Into bloodstream

32
Pancreas

• Islets of Langerhaus
• Alpha raises blood glucose level
• Beta lowers blood glucose level
• Delta inhibits secretion of glucagon and insulin
  and GH
• Insulin secreted when glucose levels rise and
  increases their transport into your cells

33
Pineal gland

• Secrete melatonin in response to light conditions
  outside the body
• Sleep regulation
• Body clocks

34
Thymus

• Large in infancy and childhood
• Atrophies with age
• Processes T cells

35
Gonads

• Hormones androgen and estrogen
• Primary sex characteristics
• Sperm production
• Ovulation
• Puberty maturation
• Secondary sex characteristics
• Hair
• Beard

36
Sex hormones

• Too much androgen in females can lead to some
  masculine traits

37
Miscellaneous hormones

• Erythropoietin kidneys
• Gastrin digestive system
• Estrogen, progesterone placenta (maintaining
  pregnancy)
• Melatonin - helps regulate wake/sleep cycle