Transcript Endocrine PPT

Endocrine System Overview
Anatomy & Physiology
Endocrine System Overview
Endocrine system works with nervous
system to coordinate activities of body
cells
 Endocrine glands- ductless; make
hormones

Hormones influence metabolic activities
Exocrine glands- external secretions onto
surface or other organ; sweat, mammary,
lacrimal, salivary glands
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Endocrine System Overview
(continued)
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Hormones: chemicals released into
blood to regulate metabolic functions of
body cells
Hormones can be circulating or local
Main Types of Hormones
1.
2.
1.
2.
Circulating Hormones:
Amino acid based: most common
Steroids: made from cholesterol
Local Hormones
Autocrines: affect cells that secrete them
Paracrines: affect local and other cells
Control of Hormone Release

Typically regulated by negative feedback
system; receptors (upregulated or down)
3 Stimuli that Release Hormones
Neural: nerve fibers stimulate hormone
release
1.
1.
Fight-or-flight
Hormonal: release in response to hormones
made by other endocrine organs
2.
1.
Chain of command (pg. 271)
Humoral: secrete in response to changing
levels of nutrients in blood
3.
1.
glucagon
Major Endocrine Organs
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Pituitary gland- “Vice president”;
secretes 6 hormones from anterior; 2
posterior
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Includes: Growth Hormone (GH), PRO,
ACTH, TSH, FSH, LH; posterior: ADH and
oxytocin
Thyroid gland- butterfly shaped; in neck
Thyroid hormone (TH)- body’s major metabolic
hormone
 Calcitonin- regulates blood levels of calcium
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Major Endocrine Organs (continued)
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Parathyroid gland- found behind thyroid;
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Secretes parathyroid hormone (PTH)
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Adrenal gland- pyramid shaped; top of kidneys
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A. cortex-makes corticosteroids including
gonadocorticoids (sex hormones)
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Important in controlling blood Ca+ levels
Androgens: testosterone and estrogens
A. Medulla: epinephrine & norepinephrine
Pancreas- endocrine/exocrine gland
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insulin and glucagon
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Regulate blood sugar
Major Endocrine Organs (continued)
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Gonads(Ovaries or Testes- sex hormones
Female: estrogens and progesterones
 Male: testosterone
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Pineal gland- pine cone-shaped; secretes
melatonin (regulates sleep cycles)
 Thymus- beneath sternum; shrinks from
child to adulthood.
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Makes peptide hormones; T lymphocytes
Other Hormone-Producing
Structures
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GI tract, placenta, kidneys, skin, and
adipose tissue can produce hormones
Adipose & fatty tissue- leptin &
prostaglandins
 Kidneys- erythropoietin (EPO)
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