THE ENDOCRINE SYSTEM

Concept 45.3 The endocrine and nervous systems act individually

and together in regulating animal physiology

Coordination of Endocrine and Nervous Systems in Invertebrates

All animals except the simplest invertebrates' reproduction and development are controlled by the endocrine system.

For example in a molting insect, a peptide neurohormone from the insects endocrine system, PTTH, promotes each successful molt until it reaches the final stage.

Most hormonal glands are located in the brain of the animal.

A prominently known gland the pituitary gland is often known as the “master” gland of the endocrine system. This is so because it controls the main functions of all other glands.

The pituitary gland has 2 lobes the posterior and anterior pituitary. Both of which secrete different hormones.

posterior= Oxytocin and antidiuretic hormone.

Anterior= prolactin, adrenocorticotropic hormone, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone

Pituitary System

Cross sections of the pituitary gland, with a labeled drawing.

Concept 45.4 Endocrine glands respond to diverse stimuli in regulating

metabolism, homeostasis, development, and behavior

Thyroid : consists of lobes on the ventral side of the trachea.

Thyroid hormone refers to a pair of similar hormones known as Triiodothyronine(T3) and Thyroxine(T4), which have corresponding iodine atoms T3 has 3 and T4 has 4.

The thyroid mainly produces T4

atoms in humans but the body changes them to T3 because iodine is dedicated to the production of the Thyroid hormone.

Also a dietary iodine is a must. This may be ingested by eating seafood or iodized salts with out this dietary iodine goiter may occur which is a swelling in the neck.

Glands Con’t

Parathyroid glands regulate the release of calcium into the body.

Unregulated release of calcium can result in organ damage.

Adrenal glands are associated with the kidneys.

Made up of two parts, the outer part known as the adrenal cortex, and the central portion known as the adrenal medulla.

The adrenal gland also plays a role in releasing adrenaline (also known as epinephrine) when the body senses danger or is excited.

Sex Hormones

Sex hormones affect growth, development, and reproductive cycles. The gonads produce three hormones which are all produced in both genders just in different proportions, androgens, estrogens, and testosterone.

Testosterone is more prominent in males hence the deeper tone of voice.

Estrogen is more prominent in females hence larger breasts and a higher pitched voice

Some Disorders of the Endocrine Diabetes

Growth disorders

Osteoporosis

Thyroid disorders (ex. Thyroid cancer)

Works cited

http://www.umm.edu/endocrin/pitgland.htm