Human Anatomy

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Human Anatomy

• The Endocrine System

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Functions

• Works with nervous system to maintain homeostasis
• Homeostasis is a physiological process by which
  the body maintains constant conditions in a
  changing environment.
• Produce and secrete hormones

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Endocrine Glands
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What are Hormones?

• Chemicals released into the bloodstream
• Ductless glands (endocrine glands)
• Very low concentration
• Very profound biological effects (?vs?)
• Very specific effects
• Receptors

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How are hormones controlled?
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1. Hypothalamus

• Produces
• Antidiuretic hormone
• Oxytocin
• Secreted in posterior pituitary gland

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1. Hypothalamus
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Posterior Pituitary Gland
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2. Pituitary Gland

• Secretes 9 hormones
• Controlled by hypothalamus
• Located in sella turcica of sphenoid bone
• Has 2 lobes.posterior and anterior
• Posterior lobe secretes 2 hormones
• Anterior lobe secretes 7 hormones

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2. Pituitary Gland
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2. Pituitary Gland
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3. Thyroid Gland

• Secretes thyroxine
• Regulates rate of metabolism
• Inferior to larynx (inf. to cricoid cartilage)

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3. Thyroid Gland
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4. Parathyroid Gland

• On posterior surface of thyroid gland
• 4 pea sized glands
• Secretes parathyroid hormone (PTH)
• PTH regulates serum (blood) calcium
• PTH essential for life

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4. Parathyroid Gland
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5. Adrenal Gland

• Located on superior border of kidney

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5. Adrenal Gland

• Divided into 2 regions
• Outer cortex
• Inner medulla

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5. Adrenal Gland

• Cortex secretes steroids
• Medulla secretes adrenaline (epinephrine and
  norepinephrine)

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6. Pancreas

• Located deep to the stomach and left of the
  duodenum

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6. Pancreas

• Contains small clusters of endocrine cells called
  islets of Langerhans

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6. Pancreas

• Islets contain cells that secrete
• Glucagon alpha (a) cells
• Elevates glucose in blood
• Insulin beta (ß) cells
• Decreases glucose in blood

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7. Gonads

• Ovary and testis
• Will cover in reproductive system