Diapositiva 1

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Endocrine System
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• The endocrine system is a coordinator and
  effector system. It is made up of a set of
  endocrine glands which are named after the
  substances they produce, (hormones) which are
  secreted into the bloodstream (inner secretion).

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Types of glands

• Apart from the endocrine glands there is another
  type of gland called exocrine glands (like those
  of the digestive and respiratory organs) which
  release secretions out of the body or directly
  into a duct of the inner cavities of the
  organism.
• There are also mixed glands like the pancreas,
  which secretes pancreatic juice (exocrine
  secretion) and hormones (endocrine secretion)
  like insulin and glucagon.

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Endocrine glands

• Endocrine glands are glands of the endocrine
  system that secrete its products, hormones,
  directly into the blood rather than through a
  duct. The main endocrine glands include the
  pituitary gland (hypophysis), the pancreas, the
  ovaries, the testes, the thyroid gland, and the
  adrenal glands. The hypothalamus is a
  neuroendocrine organ. Other organs which are not
  so well known for their endocrine activity
  include the stomach, which produces hormones such
  as ghrelin.

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Hormones

• Hormones are organic molecules made up of a
  variety of chemical compositions. Hormones
  coordinate, control and regulate different
  organs, which make the organism function properly
  as a whole.
• Each hormone has an effect only on some specific
  cells, which are called target cells.
• The hormone-specific receptors are located in the
  cytoplasmic membrane or in the cytoplasm of the
  target cells. These receptors are made up of
  protein molecules where hormones bind to these
  receptors, resulting in the activation of a
  signal transduction mechanism that ultimately
  leads to cell type-specific responses.

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Functions
Nervous System Endocrine System
The information is transmitted by nervous impulse (electric nature) The information is transmitted by the secretion of some substances (chemical nature)
The action (effect) is fast The action (effect) is slower
The action is short lasting The action is longer lasting

• Both the endocrine and nervous systems coordinate
  the organism, but there are some differences
  between them

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• The endocrine system also depends on the commands
  of the nervous system, mainly those coming from
  the Hypothalamus which is directly connected with
  the pituitary gland (also called hypophysis).

Endocrine system
Hormones
Nervous system
Coordination regulation
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• Hormones are released and act in very little
  quantities, so small changes in these quantities
  can have an important impact. Therefore, hormone
  production levels are of high importance. The
  endocrine system controls hormone production as
  follows

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• The pituitary gland is a gland that regulates the
  activity of other endocrine glands by releasing
  different Stimulating Hormones (SH)When an
  endocrine gland receives an SH it begins to
  produce a specific hormone (H), which carries out
  its specific action.The concentration of this
  hormone in the blood gets increasingly higher.
  When the hormone concentration is high enough it
  begins to have an effect on the pituitary itself,
  inhibiting the release of the SH. This is called
  a negative feed-back effect.

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Endocrines glands
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Released hormones
Pituitary gland Occipital lobe The
antidiuretic hormone (ADH) decreases the amount
of water that is eliminated in the urine
Oxytocin it is related with milk production in
females, pregnancy, and orgasm. Frontal lobe
Hormones that stimulate other glands Growth
Hormone (GH) promotes the elongation of bones
and growth in general.
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Thyroid and Parathyroid
Thyroxine increases the intensity of metabolism
Parathyroid hormone regulates calcium and
phosphorus in the blood
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Adrenal glands
Adrenaline It conditions the body for strong
physical activities and its actions are similar
to those of the sympathetic nervous system.
Corticosteroids It regulates various metabolic
processes and the amount of water in tissues.
Aldosterone It controls the concentration of
sodium and potassium in the blood.  
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Pancreas
Insulin increases the use of glucose by muscle
and other tissues. Glucagon stimulates the
conversion of liver glycogen into glucose, which
is transferred to the blood.
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Ovaries and Testes

• TesticlesAndrogens produce and maintain male
  sexual activities and characteristics.
• Testosterone is a steroid hormone from the
  androgen group.- Ovaries Estrogens produce
  and maintain female sexual activities and
  characteristics. Progesterone allows the
  implantation of the embryo in the uterus.

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Diseases

• Diabetes is a metabolic disorder related to the
  process that converts the food we eat into
  energy. Insulin is the most important factor in
  this process. During digestion food is broken
  down to obtain glucose, the main source of fuel
  for the body. This glucose enters the
  bloodstream, where insulin allows it to enter
  cells. (Insulin is a hormone secreted by the
  pancreas, a large gland behind the stomach).In
  people suffering from diabetes, one of the two
  following components of this system fails
• The pancreas produces too little insulin or it
  doesnt produce anything at all (Type I).
• The body's cells dont respond to insulin that is
  produced (Type II).
•  

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• Hypothyroidism
• is a situation in which there is an insufficient
  amount of circulating thyroid hormones. This is
  usually due to the functioning of the thyroid
  gland below its normal levels of activity.
  Hypothyroidism makes the thyroid gland grow
  (hyperplasia) which causes goitre. Hypothyroidism
  is the most common disease of the thyroid.
• Causes of Hypothyroidism Lack of iodine.
  thyroiditis. Thyroidectomy. Drugs.
  Congenital hypothyroidism (cretinism).

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• Hyperthyroidism (also called toxic goitre)  is a
  situation in which there is an excessive amount
  of circulating thyroid hormones, usually due to
  the thyroid gland being overworked (an overactive
  thyroid).Causes of HyperthyroidismGraves'
  disease (toxic diffuse goiter)Thyroiditis.Toxi
  c nodules

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Healthy habits
- Do not use drugs- Avoid obesity- Consume
enough iron with food
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By
Inmaculada Marmolejo García María Martínez
Morales Elena Castro Garrido Inmaculada Domínguez
Rodríguez