Download The Endocrine System

The Endocrine System
Are your hormones runnin’ wild?
Glands
 Exocrine - Secrete into ducts or onto a
free surface - sweat, sebaceous,
mucous, digestive
 Endocrine - secrete into cellular space
then into blood - hormones
Hormones
 Hormones are chemical messages
 Regulate the chemical composition and
volume of the internal environment
 What are some examples of regulation of
chemical composition of blood. How about
volume
 Glucose, Water
 Regulated by insulin and a hormone called ADH
(antidiuretic hormone)
Hormones

Help regulate organic metabolism and energy
balance
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Thyroid gland
Help body cope with emergency environmental
demands - infection, trauma, emotional stress,
dehydration, starvation, hemorrhage, and
temperature extremes.
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Adrenaline (epinephrine)
Fight or flight syndrome
Sympathetic
 Hormone producing cells are sent
information from sensing and signaling
systems - permit regulation of amount
and duration of hormone release
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Examples: Blood glucose, Na+, K+, Ca++,
O2
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Target cells - cells that are affected by specific
hormones
Receptors - most cells have receptors that
bind to one or more hormones
There are about 50 different hormones - cells
only respond to specific hormones
Once a hormone binds to a cell’s receptors,
there is a set of reactions within the target cell
to produce the desired effects
Feedback Systems
 “Circular situation in which information
about the status of something is
continually reported (fed back) to a
central control region.”

Like a thermostat.
 Negative feedback system - reverses the
direction of the initial condition
 Negative - response is opposite to the
stimulus
Hypothalamus
Thalamus
Pituitary Gland
Thyroid
Parathyroids
Pancreas
Thymus
Adrenals
Ovaries
Testes
Posterior Pituitary
 ADH (Anti-Diuretic Hormone)
 Controls Kidneys
 Oxytocin
 Stimulates mammary glands to produce milk
 Stimulates uterine contractions
Anterior Pituitary
 HGH (Human Growth Hormone)
 Stimulates cell division, protein synthesis,
bone growth
 Prolactin
 Milk production
 MSH (melanocyte-stimulating hormone)
 Skin color in lower verts, unknown in humans
Anterior Pituitary
 TSH (Thyroid Stimulating Hormone)
 Stimulates thyroid
 ACTH (adrenocorticotropic hormone)
 Stimulates adrenal cortex
 Gonadotropic Hormones
 Gamete and sex hormones
Thyroid
 Thyroxin
 Increases metabolic rate
 regulates growth and development
 Calcitonin
 Lowers blood Calcium levels
Parathyroid
 PTH
 Raises blood Calcium levels
Adrenal Medulla
 Epinepherine and Norepinephrine
 Adrenaline
 Cardiac and other muscles
Adrenal Cortex
 Glucocorticoids
 Raise blood glucose level, stimulates
breakdown of protein
 Mineralcorticoids
 Stimulates kidneys to reabsorb sodium and
excrete potassium
 Sex Hormones
 puberty
Pancreas
 Insulin
 Lowers blood glucose
 Promotes formation of glycogen, proteins, fats
 Glucagon
 Raises blood glucose
 Promotes breakdown of glycogen, proteins, fats
Gonads
 Testes
 Androgens (Testosterone)
 Stimulates spermatogenesis
 Develop and maintain male characteristics
 Ovaries
 Estrogen and Progesterone
 Growth of uterine lining
 Develop and maintain female characteristics
Thymus
 Tymosins
 Stimulates maturation of T Lymphocytes
Disorders of Endocrine Glands
 Diabetes Mellitus: Insulin Lack and Insensitive
Cells
 Symptoms:
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Sugar in urine
Frequent urination
Abnormal thirst
Rapid Weight Loss
Itching
Visual Disturbances
Skin disorders - boils, infections
Diabetes
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Sugar is not being metabolized
Liver fails to store glucose as glycogen
Cells fail to utilize glucose efficiently
Body turns to breakdown of protein and
fats