The Endocrine System


With nervous system coordinates the
function of all body systems
Regulates homeostasis through hormones
Hormones
Over 50 hormones
 Secretions enter blood
 Effect target cell, tissue organ
 Most only affect a few types of cells

FUNCTIONS OF HORMONES






Helps regulate:
1. metabolism
2. ICF & ECF balance
3. contraction of smooth
and cardiac muscle
4. Reproductive system
Control growth &
development
Hormone Function
Pituitary Gland
Thyroid
Parathyroid
Adrenal glands
Pancreas


The endocrine tissue of
the pancreas is called
the Pancreatic Islets or
Islets of Langerhans
Alpha Cells - secrete
Glucagon
– raises blood sugar

Beta Cells - secrete
Insulin
– lowers blood sugar
STRESS



Anything that
disrupts
homeostasis
May be physical
May be related to
life situations
General Adaptation
syndrome (GAS)


Three stages
Body’s response to
stress
Alarm Stage


Body is preparing
for stress
Body’s way of
dealing with a
stressor
Body changes during alarm




Increase blood pressure
Increase heart rate
Muscles tense
Decrease in blood supply
to digestive system
Body changes during alarm





More mentally alert
Better hearing and
eyesight
Sweating
Dry mouth
More blood and
glucose to muscles
Resistance stage



Body is dealing
with the stress
Body is trying to
keep going
Body’s way of
dealing with
prolonged stress
Exhaustion stage






Body is worn out
Major fatigue
Increase in cortisol
levels
Decrease in K+
Immune system is
depressed
Illness may occur
Metabolic Diseases and
Disorders of the
Endocrine System
Dwarfism

caused by a hyposecretion of hGH
during the growth years
– causes slow bone growth
– epiphyseal plates close before normal
height is reached
– other organs of the body may also fail to
grow and develop

treatment requires administration of
hGH during childhood
Gigantism

caused by the hypersecretion of hGH
during childhood
– abnormal increase in bone length and size
of other organs

the person is very tall with normal body
proportions
Acromegaly
caused by the hypersecretion of hGH
during adulthood
 also caused by steroid and hGH use

– bones of hands, feet, and skull thicken
– eyelids, lips, and tongue enlarge
– skin thickens and develops furrows
Cushing’s Syndrome
caused by hypersecretion of
glucocorticoids, especially cortisol
 results in redistribution of body fat

– spindly arms and legs
– rounded moon - faced appearance
– hanging abdomen with stretch marks or
Striae
individuals often bruises easily
 poor wound healing

Cretinism

caused by hyposecretion of thyroid
hormones during fetal development
– exhibits dwarfism because the skeleton
fails to grow
– individuals are usually severely mentally
retarded
– retarded sexual development
– usually have a yellowish skin color
Myxedema
caused by hypothyroidism during the
adult years
 causes facial tissue to swell and look
puffy
 about 5 times more common in females
 other symptoms include:

–
–
–
–
bradycardia
lethargy
dry skin and hair
sensitivity to cold
- low body temperature
- muscle weakness
- easily gains weight
- hypersensitive to drugs
Graves’ Disease
caused by hyperthyroidism
 an autoimmune disorder

–
–
–
–
increased metabolism
increased sweating
weight loss
tremors of hands
- heat intolerance
- insomnia
- nervousness
may have a slightly enlarged thyroid
gland (Goiter)
 causes the eyes to protrude
(Exophthalmos)

Diabetes Mellitus
a group of disorders that leads to an
elevation of blood glucose
(Hyperglycemia)
 symptoms include:

– polyuria
– polyphagia

- polydipsia
- glucosuria
Two Types or Categories of Diabetes
– Type I Diabetes = Insulin Dependent
Diabetes Mellitus (IDDM)
– Type II Diabetes = Non Insulin Dependent
Diabetes Mellitus (NIDDM)
Type I Diabetes (IDDM)
pancreas does not produce insulin due
to the destruction of Beta cells in the
Islets of Langerhans
 requires regular injections of insulin to
prevent death
 most commonly develops in
individuals younger than 20 years old
(Juvenile Onset Diabetes Mellitus)
 appears to be an autoimmune disorder

Type II Diabetes (NIDDM)
also called Maturity Onset Diabetes
 much more common type of Diabetes
(over 90% of Diabetes cases)
 most often occurs in individuals over 40
 most individuals are overweight or
clinically obese
 blood glucose levels can usually be
controlled by diet, exercise, and weight
loss and control

Complications from Diabetes
atherosclerosis
 heart disease
 peripheral vascular disease
 severe kidney damage
 glaucoma
 gangrene
 ketoacidosis
 weight loss

Treatments for Diabetes
regular insulin injections
 artificial pancreas
 transplantation of the pancreas
 transplantation of clusters of Islet Cells
 injection of fetal Islet Cells
