Endocrine System (hormone secreting system)

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Endocrine System(hormone secreting system)

• A. How?
• Hormones
• Are chemical messengers that are released by
  ductless glands into the bloodstream and carried
  throughout body via circulatory system
• B. WHY?
• Messages are sent to target tissue or organs in
  order to increase or decrease an activity
• Hormones are very specific

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• B. WHY? Messages are sent to target tissue or
  organs in order to increase or decrease an
  activity
• TARGET CELLS
• CELLS THAT HAVE RECEPTORS FOR A PARTICULAR
  HORMONE
• Hormones are very specific and the hormone must
  fit perfectly with the receptor

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• Hormones have specific shapes that fit receptors
  or the surface of the target organ or structure
  they are going to influence
• Bind with cell receptors

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Hormones Feedback

• Steroid, thyroid hormones and the endocrine
  system Anatomy Biology - Free Biology Video
  Lecture

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GLANDS

• PRODUCE AND RELEASE SUBSTANCES OR SECRETIONS
• EXOCRINE GLANDS
• SECRETE SUBSTANCES THROUGH DUCTS
• EX SWEAT AND TEARS
• ENDOCRINE GLANDS
• RELEASE SECRETIONS (HORMONES) DIRECTLY INTO BLOOD
  STREAM

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HORMONES

• WHAT HAPPENS IF A TYPE OF CELL DOES NOT HAVE
  RECEPTORS??
• CELL WILL NOT RESPOND TO THAT HORMONE!
• Ex. Testosterone will not affect heart cells,
  but adrenaline will
• SLOWER AND LONGER-LASTING THAN NERVE RESPONSES

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Concept Map
Section 39-2
The Endocrine System
regulates
by meansof the
by meansof the
by meansof the
by meansof the
by meansof the
by meansof the
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 The Endocrine Glands
Section 39-1
Pineal gland The pineal gland releases melatonin,
which is involved in rhythmic activities, such as
daily sleep-wake cycles.
Hypothalamus The hypothalamus makes hormones that
control the pituitary gland. In addition, it
makes hormones that are stored in the pituitary
gland.
Thyroid The thyroid produces thyroxine, which
regulates metabolism.
Pituitary gland The pituitary gland produces
hormones that regulate many of the other
endocrine glands.
Pancreas The pancreas produces insulin and
glucagon, which regulate the level of glucose in
the blood.
Parathyroid glands These four glands release
parathyroid hormone, which regulate the level of
calcium in the blood.
Ovary The ovaries produce estrogen and
progesterone. Estrogen is required for the
development of secondary sex characteristics and
for the development of eggs. Progesterone
prepares the uterus for a fertilized egg.
Thymus During childhood, the thymus releases
thymosin, which stimulates Tcell development.
Testis The testes produce testosterone, which is
responsible for sperm production and the
development of male secondary sex characteristics
Adrenal glands The adrenal glands release
epinephrine and nonepinephrine, which help the
body deal with stress.
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Endocrine Disorders

• 1. Goiter
• Enlargement of the thyroid gland due to the
  inability to manufacture thyroxin
  (hypothyroidism)
• Graves Disease
• Hyperthyroidism- over secretion of thyroxin
• 2. Diabetes
• Insulin deficiency which results in elevated
  blood sugar level

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Symptoms of Diabetes

• Excessive thirst
• Frequent urination
• Extreme hunger
• Unexplained weight loss
• Glucose in urine
• Fatigue
• Vision problems
• Numbness tingling in extremities
• High infection rate

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Negative Feedback

• The level of one hormone in the blood inhibits or
  stimulates the production of another hormone or
  substance
• Homeostasis biology Animation

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CONTROL OF THE ENDOCRINE SYSTEM

• REGULATED BY FEEDBACK MECHANISMS
• EX HEATING SYSTEMS(LINK)

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 Actions of Insulin and Glucagon
Beta cells release insulin into the blood
Body cells absorb glucose
Blood glucose level decreases
Blood glucose level increases
Liver converts glycogen to glucose
Homeostasis Normal blood glucose level
Blood glucose level decreases
Blood glucose level increases
Alpha cells release glucagon into blood
Liver converts glycogen to glucose
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The Brain
Pituitary gland biology Animation Endocrine
Glands biology Animation
Section 35-3