Hormones, the perfect storm?Artifact 4

By: Group B

Introduction:

The endocrine system is responsible for the regulation of hormones in the body. It works with nervous system by stimulating the brain to release hormone to stimulate

glands like thyroid glands to secrete thyroid hormones.

Maintaining a healthy endocrine system helps your body perform many of its vital functions, such as growth, development, reproduction and immunity. The endocrine

system may also affect some aspects of personality and behavior. An unhealthy endocrine system can result in thyroid diseases, osteoporosis and a variety of other

problems, both large and small. Here's how to maintain the endocrine system.

Hormones Substance secreted by an endocrine gland into the blood stream

that acts as on a specific target tissue to produce a given response.

Functions:Tropics- Hormones that target other endocrine glands and stimulate their growth and secretion.Sex Hormones- target reproductive tissues Anabolic- Hormones that stimulate anabolism in their target cells.All hormones can be identified as either Steroid or Nonsteroid.

Hormones

SteroidNonsteroid

CortisolAldosteroneEstrogenProgesteroneTestosterone

Proteins

GlycoproteinsGrowth HormoneProlactinParathyroidCalcitoninAdrenocorticotropicInsulinGlucagon

FSHLH

TSHCG

Peptides

Antidiuretic hormoneOxytocinMSHSomatostatinTRHGnRHAtrial natriuretic hormone

Amino acid derivatives

AminesNorepinephrineEpinephrineMelatonin

Iodinated amino acidsThyroxinTriiodothyronine

The Difference?

Steroid hormone molecules are manufactured by endocrine cells from cholesterol, an important type of lipid in the human body.

Nonsteroid hormones are synthesized primarily from amino acids rather than from cholesterol.

Lock and Key

The amino acid structure of the ________ is the key and the receptor is a ______. In order for the key, hormone, to fit the lock, receptor, the hormone-receptor complex must be an exact ________. It for any reason this lock and key do not fit, cellular binding is ______, hormonal signals are ________ and the communication is not complete.In effect the "chemical / hormonal" phone lines are down.

Hormone

Lock

Disrupted

Match

Interrupted

Prostaglandins

Structure

Prostaglandins are unsaturated carboxylic acids, consisting of of a 20 carbon skeleton that also contains a five member ring and are based upon the fatty acid, arachidonic acid. There are a variety of structures one, two, or three double bonds. On the five member ring there may also be double bonds, a ketone, or alcohol groups. A typical structure is on the left graphic.

Function

1. Activation of the inflammatory response, production of pain, and fever. When tissues are damaged, white blood cells flood to the site to try to minimize tissue destruction. Prostaglandins are produced as a result.2. Blood clots form when a blood vessel is damaged. A type of prostaglandin called thromboxane stimulates constriction and clotting of platelets. Conversely, PGI2, is produced to have the opposite effect on the walls of blood vessels where clots should not be forming.3. Certain prostaglandins are involved with the induction of labor and other reproductive processes. PGE2 causes uterine contractions and has been used to induce labor. 4. Prostaglandins are involved in several other organs such as the gastrointestinal tract (inhibit acid synthesis and increase secretion of protective mucus), increase blood flow in kidneys, and leukotriens promote constriction of bronchi associated with asthma

Pituitary Gland

The pituitary gland is divided anatomically into two parts. These are the anterior lobe and the posterior lobe. The anterior lobe of the pituitary glandproduces and secretes five types of hormones. All of them are regulated by a positive feedback

from hormones in the hypothalamus.The hormones of the anterior lobe are: first, the growth hormone which is

secreted by cells that are called somatotropes. Growth hormone secretion is regulated by two hormones that are produced and secreted by the hypothalamus.

These are the growth hormone releasing hormone, in which its secretion increases the level of growth hormone in the blood. The other hormone that is

secreted by the hypothalamus is somatostatin. its secretion inhibits the secretion of growth hormone by the pituitary gland.

Pineal Gland

The pineal gland is a pine cone shaped gland of the endocrine system. A structure of the diencephalon of the brain, the pineal gland produces several important hormones including melatonin. Melatonin influences sexual development and sleep-wake cycles. The pineal gland is composed of cells called pinealocytes and

cells of the nervous system called glial cells. The pineal gland connects the endocrine system with the nervous system in that it converts nerve signals from the sympathetic system of the

peripheral nervous system into hormone signals.Function:

The pineal gland is involved in several functions of the body including:Secretion of the Hormone Melatonin

Regulation of Endocrine FunctionsConversion of Nervous System Signals to Endocrine Signals

Causes Feeling of SleepinessInfluences Sexual Development

Location:Directionally, the pineal gland is situated between the cerebral hemispheres, attached to the third ventricle.

Thyroid Gland:

The biggest gland in the neck, known as thyroid gland, is situated in front of neck below the skin and muscle layers. It is butterfly shaped, with two lobes on the left and right side.

Two fundamentally different types of hormones are secreted by thyroid gland. These hormones are essential for normal growth and development, and they play an important role inenergy metabolism.

Thyroid hormones are the only known iodine-containingcompounds with biological activity. They have two important functions in the body of animals and human beings:

1) They are very important for normal growth and development, especially in the central nervous system (CNS).

2) In adults, these hormones play a major role in metabolism, which in turn affects the function of virtually all organ systems.

The thyroid gland contains large stores of preformed hormone in order to meet these requirements. Serum concentrations of thyroid hormones are precisely regulated by the pituitary hormone in a classic negative-

feedback system.

Parathyroid Gland

The parathyroid gland in humans is a 4 glands that are situated in the posterior or behind the thyroid gland. There is a capsule of connective tissue that separates the parathyroid gland from the thyroid gland.The parathyroid gland is supplied with blood from the inferior thyroid artery or one of its branches.

The parathyroid gland is important for living so that without it, life cannot happen. Usually thyroidectomy removes also part of the parathyroid glands as well. Removal of all the parathyroid glands causes death

because of the inability of the body to produce calcium. This condition causes so called tetany or continuous contraction or spasm of the muscles of the body especially the muscles of the larynx which its contraction

causes suffocation and death.The parathyroid glands contain two types of cells. These are the chief cells and the oxyphil cells. The chief

cells are the site of production and secretion of the parathyroid hormone. The oxyphil cells have no apparent role in parathyroid hormone secretion.

Parathyroid hormone is an antagonist to the hormone calcitonin. While calcitonin functions by causing deposition of calcium phosphate on bones, the parathyroid hormone functions as an antagonist by

increasing resorption of calcium phosphate from bones to the extracellular matrix.

Adrenal Gland

Function

The adrenal gland secretes various hormones that affect different parts of the body. Some are necessary for survival, notes Frederic Martini, Ph.D., in “Fundamentals of Anatomy & Physiology.” The anterior pituitary of the brain regulates part of the gland, telling it when certain hormones need to be made. Parts of the nervous

system and the kidneys stimulate the production of other adrenal hormones.Sponsored LinksFoods to NEVER EatBeware of these foods that are making you gain weight.EatHealthySecrets.com

Structure

The outer part of the adrenal gland, the adrenal cortex, constitutes 90 percent of the gland. The cortex has three zones. The zona glomerulosa is the outermost zone and makes the hormone aldosterone from

cholesterol. The next is the zona fasciculata, which makes hormone cortisol, also from cholesterol. The zona reticularis is the third area and is where androgens, or male hormones, are made from cholesterol. The inner

part of the adrenal gland is called the adrenal medulla. It makes substances called epinephrine and norepinephrine.

Pancreatic

The pancreas is a rather unique organ in the human body. It is part of two different organ systems, the endocrine system and the digestive system. Technically, the pancreas is a large gland. A gland is a structure in

the body that secrete hormones. The pancreas creates a wide range of different hormones, some of which are used to trigger internal metabolic reactions, and others which are used to help break down food. This

article we'll take a look at the structure and function of the pancreas.

Structure of the pancreas

The pancreas is located just below the stomach. It develops as two separate parts which are fused together early in life. The pancreas is also located near the first part of the small intestine, known as the duodenum.

The pancreas is broken into several different subsections. The head of the pancreas is located nearest to the duodenum. The body of the pancreas is the largest section, located in the center of the gland just below the

stomach. The pancreas also has a tail, which is furthest from the duodenum.

Gonads

The ovary and the testis, like the adrenal gland, secrete cholesterol-derived steroid hormones under the control of the secretions of the hypothalamo-pituitary axis. The two major functions of the gonads in the

adult are steroid hormone production and gametogenesis. Reproductive hormones are also pivotal in sexual differentiation, fetal development, growth and sexual maturation. The major hormones that control the development and maintenance of the male and female phenotype are the androgens and estrogens and progestagens, respectively. These are regulated by gonadotrophin releasing hormone (GnRH) from the

hypothalamus and the gonadotrophins, luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the anterior pituitary gland.

Placenta

The full-term placenta is a discoid-shaped organ, about 15 to 25 centimetres in diameter. It is made up of a fetal and a maternal component. The fetal component is derived from a tissue that arises from the

conceptus, called the chorion. The placenta features the ‘leafy’ region of the chorion, known as the chorion frondosom. The chorion frondosom comprises a chorionic plate and finger-like projections of chorionic villi. The chorionic villi are the basic structures for exchange between fetal and maternal blood in the placenta.

The maternal part of the placenta is the decidua basalis. It derived from the decidua, which is the transformed uterine lining (endometrium) during pregnancy. The placenta performs a wide array of

functions that are crucial for maintaining normal pregnancy and for the development of the fetus. The primary functions of the placenta include the transport of gases and nutrients, metabolism and endocrine

secretion.

Thymus

The thymus is a pyramid shaped primary lymphoid organ that is located beneath the breastbone, at the same level as the heart. It is the initial site for the development of T cell immunological function and the first

of the lymphoid organs to be formed. The organ is named so because its shape resembles that of a thyme leaf.

The thymus grows rapidly during fetal life and the first year after birth. This is in response to postnatal antigen stimulation and the demand for a large number of mature T cells. The organ continues to grow later, but at a slow pace. At the onset of puberty, the organ begins the slow process of shrinking. It continues to

shrink as the years go by till the end of the individual's life.

Structure of thymus

The thymus is divided into two lobes, which are further subdivided into lobules. The two lobes lie on either side of the midline of the body. The organ is covered by a dense connective-tissue capsule. This sends fibers

into the body of the organ for support. Each lobule has an outer cortex and an inner medulla. The lobules are separated by septa (connective tissue).

Mucosa

The inner surface of the stomach is lined by a mucous membrane known as the gastric mucosa. The mucosa is always covered by a layer of thick mucus that is secreted by tall columnar epithelial cells. Gastric mucus is

a glycoprotein that serves two purposes: the lubrication of food masses in order to facilitate movement within the stomach and the formation of a protective layer over the lining epithelium of the stomach cavity.

This protective layer is a defense mechanism the stomach has against being digested by its own protein-lyzing enzymes, and it is facilitated by the secretion of bicarbonate into the surface layer from the underlying mucosa. The acidity, or hydrogen ion concentration, of the mucous layer measures pH7 (neutral) at the area

immediately adjacent to the epithelium and becomes more acidic (pH2) at the luminal level. When the gastric mucus is removed from the surface epithelium, small pits, called foveolae gastricae, may be observed

with a magnifying glass. There are approximately 90 to 100 gastric pits per square millimetre (58,000 to 65,000 per square inch) of surface epithelium. Three to seven individual gastric glands empty their

secretions into each gastric pit. Beneath the gastric mucosa is a thin layer of smooth muscle called the muscularis mucosae, and below this, in turn, is loose connective tissue, the submucosa, which attaches the

gastric mucosa to the muscles in the walls of the stomach.

Heart

The heart is a specialized organ, and the only one in the body made of cardiac muscle. Heart cells are called cardiomyocytes and make up muscle fibers that conduct electrical impulses. The function of the heart, which

is to keep blood flowing throughout the body, is controlled by involuntary areas of the brain. Blood is necessary for the survival of the tissues because red blood cells carry oxygen, which is necessary for cellular

processes, and the plasma carries nutrients to the tissues and waste away from the tissues.Heart structure

The human heart has four chambers. The upper chambers are called the atria, and the lower chambers are the ventricles. The left and right side of the heart are separated by a thick interventricular (between the

ventricles) and interatrial (between the atria) septum. The thick tissue is called themyocardium. The chambers are lined with a thin membrane called the endocardium, which prevents the blood from clotting as

it passes through the heart. The heart is protected by a membrane called the pericardium. The outer pericardium resembles a fibrous sac and is made of connective tissue, holding the heart in place in the chest.

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The End