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1.what is the organs invlved in the Endocrine system?
Pituitary, thyroid, parathyroid, adrenal, pineal and thymus glands are all ductless glands of the endocrine system. Within the pancreas, ovaries and testes, there are discrete clusters of hormone producing, endocrine tissue. In addition, the hypothalamus, which principally carries out neural functions, also synthesises and secretes hormones, and hence it can be described as a neuroendocrine organ.
The Pituitary Gland
The pituitary gland, or hypophysis, is located below the hypothalamus at the base of the brain. It is a small gland that secretes at least nine major hormones, and it is divided into two lobes, one glandular and one neural.
The Hypothalamus
The hypothalamus is connected to the pituitary gland via the infundibulum, and it has a neural connection via the nerve bundle called the hypothalamichypophyseal tract. Neurosecretory cells lining this tract produce two neurohormones, and transport them along their axons to the posterior pituitary.
The Thyroid and Parathyroid Glands
The thyroid gland is located at the back of the neck, on the trachea below the larynx. It is composed of two lobes connected by a tissue mass called the isthmus. Embedded within the collagenous connective tissue surrounding the thyroid gland, are the four, small parathyroid glands.
The Adrenal Gland
The paired adrenal, or suprarenal, glands are located on top of the kidneys. Each gland is structurally and functionally two endocrine glands in one. The internal adrenal medulla contains nervous tissue and forms part of the sympathetic nervous system, while the outer adrenal cortex is composed of glandular tissue. Both regions synthesise a distinct array of hormones.
The Pineal Gland
The pineal gland projects from the roof of the diencephalon. Lying between its secretory cells are calcium salts, or ?brain sand?. The secretory activity of the pineal gland is on a diurnal cycle, and it is thought that the pineal gland indirectly receives information about light intensity and period duration from the eyes.
The Thymus
The thymus gland is located deep to the sternum within the thorax. Throughout life, the thymus decreases in size.
The Pancreas
The pancreas is a mixed gland composed of both exocrine (possess ducts) and endocrine (ductless) gland cells. Within the pancreas, the islets of Langerhans, (small cell clusters) are responsible for synthesising the pancreatic hormones.
The Gonads
The male and female gonads, the testes and the ovaries respectively, are responsible for the synthesis of steroidal sex hormones.
2.what dose the Endocrine system do and how?
The Endocrine system is an information signal system much like the nervous system. However, the nervous system uses nerves to conduct information, whereas the endocrine system mainly uses blood vessels as information channels. Glands located in many regions of the body release into the bloodstream specific chemical messengers called hormones. Hormones regulate the many and varied functions of an organism, e.g., mood, growth and development, tissue function, and metabolism, as well as sending messages and acting on them.
3.what are some diseases of the Endocrine system?
Diseases of the endocrine system are common,[3] including diseases such as diabetes mellitus, thyroid disease, and obesity. Endocrine disease is characterised by dysregulated hormone release (a productive Pituitary adenoma), inappropriate response to signalling (Hypothyroidism), lack or destruction of a gland (Diabetes mellitus type 1, diminished erythropoiesis in Chronic renal failure), or structural enlargement in a critical site such as the neck (Toxic multinodular goitre). Hypofunction of endocrine glands can occur as result of loss of reserve, hyposecretion, agenesis, atrophy, or active destruction. Hyperfunction can occur as result of hypersecretion, loss of suppression, hyperplastic, or neoplastic change, or hyperstimulation.
Endocrinopathies are classified as primary, secondary, or tertiary. Primary endocrine disease inhibits the action of downstream glands. Tertiary endocrine disease is associated with dysfunction of the hypothalamus and its releasing hormones.
Cancer can occur in endocrine glands, such as the thyroid, and hormones have been implicated in signalling distant tissues to proliferate, for example the Estrogen receptor has been shown to be involved in certain breast cancers. Endocrine, Paracrine, and autocrine signalling have all been implicated in proliferation, one of the required steps of oncogenesis.[4]
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