Endocrine System Answers

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Endocrine System Answers
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8 organs/tissues that make up the endocrine
system

• Hypothalamus
• Pituitary gland
• Thyroid gland
• Parathyroid gland
• Adrenal glands
• Pancreas
• Ovaries/Testes
• Pineal gland

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Difference between an endocrine and exocrine gland
Endocrine glands are ductless tissues surrounded
by vascular tissue that produce and secrete
chemical messengers (hormones) directly into the
bloodstream, where they act upon specific target
tissues
Endocrine glands are glands that secrete their
proteins into ducts leading directly to the
external environment
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What is a neurohormone?How does the hypothalamus
control hormone release by the anterior pituitary
gland?
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Neurosecretory (neuroendocrine) cells
specialized neurons that releasehormones (as
opposed to transmitting an electrical signal) A
neurohormone is secreted into circulation BY
neurosecretory cells
When stimulated, hypothalamic neurons secrete
releasing /inhibiting hormones into the
hypophyseal portal system A portal system is when
one capillary bed pools into another through
veins (without first going through the heart) So
the blood its getting from the hypothalamus is
deoxygenated, but its full of hormones (so if it
needs oxygenated blood it gets it from its own
arteries) Hypothalamic hormones travel through
the portal veins to the ANTERIOR PITUITARY where
they stimulate or inhibit release of hormones
from the anterior pituitary
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Why is the pituitary gland the master gland?

• Primary influencer of how other glands operate
• Stores/secretes hormones to stimulate other
  glands

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What is the function of a hormone?

• Hormones are specialized substances that
  coordinate the activities of specific target
  cells in certain areas of the body

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3 ways by which a gland can be stimulated to
release a particular hormone

• In response to another hormone (e.g. GHRH from
  the hypothalamus will stimulate GH release from
  the pituitary)
• By nerve impulses (e.g. nerve impulses can
  stimulate ACh release into the synaptic cleft)
• Directly via internal changes (e.g. high blood
  sugar will cause the pancreas to release insulin)

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Anterior pituitary hormones

• Adrenocorticotropic hormone (ACTH)
• Thyroid stimulating hormone (TSH)
• Follicle stimulating hormone (FSH)
• Luteinizing hormones (LH)
• Prolactin (PRL)
• Growth hormone (GH)
• Endorphins (could anybody find the short form??)
• Melanocyte-stimulating hormone (MSH)

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2 hormones stored/released from the posterior
pituitary. What stimulates their release?

• Oxytocin
• Anti-diuretic hormone (ADH)
• Stimulated by the hypothalamus (during such times
  as increased plasma osmolality or infant suckling)

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How does a steroid hormone impact a target cell
versus a non-steroid hormone?