Endocrine System

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Endocrine System
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Endocrine SystemGeneral Info

• Works WITH the Nervous system
• Main function is to produce hormoneschemical
  messenger influencing other tissues/organs.
• Differs from NS with regard to speed
• NSbody will make rapid adjustments to changes
• ESuses chemical messengers (hormones) to affect
  change. Hormones travel via bloodstream.
  Generally longer lasting.

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Endocrine vs Exocrine glands

• Endocrine glandssecrete hormones directly into
  the blood
• anterior pituitary
• thyroid
• adrenal
• Exocrine glandsdeliver hormones into the blood
  via tubes leading from the gland
• sweat glands
• salivary glands
• mammary glands

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Major body processes regulated by ES

• Reproduction
• Growth and development
• Maintaining homeostasis of electrolytes, water
  and nutrients
• Regulation of cellular metabolism

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Target cells and controlling the ES

• Hormones travels through the entire body via the
  blood, but only affect specific target tissues.
• The body primarily uses negative feedback loops
  to determine when to turn on/shut off hormone
  production.
• Other ways the body controls the ES is through
  the nervous system and biorhythms.

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ENDOCRINE REGULATION
A fuzzy balancing act Receive, Reaction,
Refine
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• Sensory/Humoral input
• response to substance in the blood (Iodine,
  glucose)
• Hormonal regulation
• responds to upstream gland regulation (TSH,
  LH...)
• Neural regulation
• response short term stress

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Endocrine RegulationREACT

• Hormones travel through the blood and bind to
  receptor proteins
• Steroid hormones (cholesterol derived)
• Are lipid soluble and cross the plasma membrane,
  bind to receptors inside the cell and affect DNA
  transcription.
• Animation
• Non-steroid hormones (protein based)
• Bind to specific membrane receptors and trigger a
  signaling cascade inside the target cell which
  activates necessary enzymes.
• Animation

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• Steroids
• Lipid soluble - readily enter cells
• stimulus leads to biosynthesis
• transport in blood assisted by carrier proteins
  (serum albumin)

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• Non steroids
• Water Soluble can travel through blood freely,
  but have to interact with membrane receptors
  (cant cross lipid bilayer). Once docked, will
  set cause changes within cell.
• Protein is synthesized, packaged into vesicles
  via golgi bodies
• vesicles migrate to and collect at release site
• exocytosis to dump contents into bloodstream

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REFINE Negative Feedback loops

• Works like a thermostat in your house to maintain
  a constant environment of 68oF.

• Turns on the furnace to produce heat if the
  temperature is too cold and off when the desired
  temp is reached.
• Turns on AC to cool the house if temp is too
  high and shuts it off when back to the desired
  temp.

http//www.endocrinesurgeon.co.uk/endocrine_condit
ions/What-is-negative-feedback.html
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REFINEHomeostasis

• ensure the body returns to normal conditions
  after stimulus.

www.mdmaterials.com
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http//www.thetruthisbliss.com/wp-content/uploads/
2009/11/Calcium-Regulation.jpg
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Endocrine System

• Down Regulation-Negative Feedback loop

Parathyroids
stimulates
Blood Ca2 levels Decrease

inhibits
-
Blood Ca2 levels Increase
PTH
Bone is degraded
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Glucose Regulation
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Biology, Campbell. 1987. pg 896
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• Hypothalamus receives input and reacts to
  stimulate specific organs to achieve the desired
  effect.

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Negative Feedback Loop--egs

• Feedback system for the control of ovulation

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BiologyAn Exploration of Life, McFaddenKeeton.
1995. pg 546
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Positive Feedback Loop
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Endocrine System

• Removal of hormones
• The bulk of hormone is cleared by the liver and
  kidneys
• Only a small fraction is removed by target tissue
  
• Steroid (and thyroid hormones) are degraded after
  hormone-receptor complex binds to DNA
• action and elimination are slower (hours-days)
• protein and amine hormones (non steroids) bind to
  receptors and are internalized and degraded
• action and elimination is usually quicker
  (minutes)

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Endocrine Problems

• Dwarfism
• Characteristics
• -Short stature
• (proportional)
• Cause
• shortage of GH (hypophysial dwarfism)
• or defective receptor (Laron Syndrome).

www.blogsmonroe.com
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• Gigantism
• Characteristics-
• Extreme height
• (8-9 ft, proportional structures)
• Cause-
• Excessive GH during development

Gigantism is extremely rare (only a few hundred
known cases total). Cause of excess of GH
excess varies but often is linked to Acromegaly
www.endotext.org
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Endocrine Problems

• Acromegaly-
• Characteristics
• abnormal bone growth joint aches
• thick coarse oily skin impaired vision
• excessive sweating sleep apnea
• abnormal menstruation skin odor
• erectile dysfunction headaches
• fatigue and weakness decreased libido
• enlarged lips nose and tongue skin tags
  

Acromegaly- Cause-excess GH in adulthood.
Usually benign adenoma
www.addamsfamily.com
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• Hypothyroidisim
• Characteristics-
• Fatigue, weakness, weight gain or resistance to
  weight loss, course dry hair, dry rough pale
  skin, hair loss, cold intolerance, muscle cramps
  and aches, constipation, depression,
  irritability, memory loss, abnormal menstruation,
  decreased libido.
• High TSH with low T3/T4.

• Cause- Not enough thyroid hormone.
• Hasimotos disease- autoimmune disease
• Medical treatments- hormone replacement

thyroid.about.com
www.datiskharrazian.com
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• Hyperthyroidism
• Characteristics- palpitations, heat intolerance,
  nervousness, insomnia, breathlessness, increased
  BM, decreased menstruation, fatigue, fast heart
  rate, trembling, weight loss, muscle weakness,
  warm moist skin, hair loss, staring gaze.
• Low TSH
• high T3/T4 levels

• Causes-
• Graves Disease autoimmune disease (antibodies
  attach to thyroid and over stimulate T3
  production)
• Benign tumor- nodule (few cells)
• out of regulation
• Thyroiditis- temporary swelling
• of gland (postpartum)

pro.corbis.com
www.avondalevet.com
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Endocrine DisordersHyperthyroidism cont

• Treatment-antithyroid medication, radioactive
  iodine and possibly surgery (if trouble
  swallowing or initial treatments dont work.

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• Cushings Disease
• Characteristics-
• central body obesity Osteoporosis
• glucose intolerance kidney stones
• Hypertension excess hair growth
• menstrual irregularity emotional liability
• Buffalo hump moon face
• Cause- Excess Cortisol
• tumor of the lungs, pituitary or adrenal glands

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• Diabetes-
• Most common Endocrine disorder
• Consistent elevated blood sugar
• Characteristics- frequent hunger, thirst,
  urination, blurred vision, fatigue, weight loss,
  poor wound healing, dry mouth, dry itchy skin,
  impotence, recurrent infections. Erratic blood
  sugar.
• normal blood glucose 80-120mg/100 ml,
• diabetes as much as 600mg/100ml of blood

ourlatinamerica.blogspot.com
www.malluworld.org
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Diabetes Causes- Type 1 -insulin deficiency
Type 2 -insulin resistance hormone
disturbance Agromegaly Cushings Gestat
ional diabetes- temporary condition caused by
pregnancy placenta metabolizes insulin quickly.
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ENDOCRINE DISORDERS
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Review of Endocrine System

• Quick review of info
• Amazing Podcast!

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Endocrine System

• Glands and the hormones they produceyou will
  need to know these for the test.
• Study earlier rather than later!

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• The pituitary gland secretes hormones that
  regulate other glands in the body and therefore
  is referred to as the Master Gland.

waukesha.uwc.edu
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Hypothalamus
a region of the brain, between the thalamus and
the midbrain, that functions as the main control
center for the autonomic nervous system by
regulating sleep cycles, body temperature,
appetite, etc., and that acts as an endocrine
gland by producing hormones, including the
releasing factors that control the hormonal
secretions of the pituitary gland.
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Hypothalamus Gland Hormones

• TRF
• Responsible for stimulating Pituitary to release
  TSH

en.wikipedia.org
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Hypothalamus Gland Hormones

• Oxytocin
• Responsible for causing uterine contractions
  during and after birth.

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Hypothalamus Gland Hormones

• GHRH (growth hormone releasing hormone)
• Responsible for triggering release of GH from
  pituitary

www.uscnk.com
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Hypothalamus Gland Hormones

• GnRH (gondatropin releasing hormone)
• Triggers release of FSH from pituitary.

commons.wikimedia.org
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Pituitary

• Known as the master gland as it is not only
  responsible for many hormones, it also acts as a
  regulator for other glands in the endocrine
  system.

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Pituitary Gland Hormones

• ADH (Antidiuretic Hormone)
• Responsible for maintaining water balance in your
  body.

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Pituitary Gland Hormones

• GH (Growth Hormone)
• Causes growth in humansbig surprise huh?

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Pituitary Gland Hormones

• TSH (Thyroid Stimulating Hormone)
• Influences your thyroid gland

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Pituitary Gland Hormones

• ACTH (Adrenocorticotropic Hormone)
• Regulates the adrenal glands

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Pineal Gland
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Pineal Gland Hormone

• Melatonin
• Helps your body adjust to various amounts of
  daylight

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Thyroid Gland

• Location Surrounds windpipe

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Thyroid Hormones

• Thyroxine
• If iodine is present, it will control the
  metabolism of glucose in the body.

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Thyroid Hormones

• Calcitonin
• Responsible for depositing blood calcium into
  bones

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Parathyroid Glands

• Locationattached behind the thyroid
• Years ago, they used to remove the parathyroids
  with the thyroid if the thyroid was damaged.
  This lead to death in patientsOOPS!

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Parathyroid Hormone

• PTH (Parathyroid hormone)
• Responsible for pulling calcium from bones and
  depositing it into the bloodstream.

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Thymus Gland

• Location Longish gland in the middle of your
  chest.

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Thymus Hormone

• Thymosin
• Assists the immune system

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Adrenal Glands

• Location Located right on top of kidneys

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Adrenal hormones

• Aldosterone
• Maintain blood salts (primarily Na, K)

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Adrenal hormones

• Cortisol
• Kicks in to help body with long term stress.

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Adrenal hormones

• Epinephrine
• Kicks in when body undergoes short term stress
• Test-taking, car accident, caught in a lieetc.

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Pancreas

• Location Found right behind the stomach

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Pancreas hormones

• Insulin
• Decreases blood sugar

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Pancreas hormones

• Glucagon
• Increases
• blood sugar

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Ovaries

• Small, almond shaped organs on the ends of the
  fallopian tubes.

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Ovary hormones

• Estrogen and Progesterone
• Responsible for sex characteristics and
  controlling the menstrual cycle

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Testes

• Testosterone
• Responsible for male secondary sex characteristics

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Other structures and the ES

• Heart
• ANP will increase the Na excretion and inhibit
  smooth muscle contraction

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Other structures and the ES

• Kidney
• Renin will cause vasoconstriction of the blood
  vessels (increases blood pressure)

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Other structures and the ES

• G.I. Tract
• There are many polypeptide hormones that act on
  the GI tract.
• Most hormones will increase intestine motion and
  enzyme production

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Other structures and the ES

• Placenta
• HCG maintains embryo growth in first 90 days
  gestation

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Other structures and the ES

• Placenta
• Estrogen and Progesterone help maintain uterus
  health
• Lactogenic Growth hormone help with milk
  production after birth of baby

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www.abbottdiagnostics.com.