4.03/4.04 Remember the structures and understand the functions of the endocrine system 1

4.04 Understand the functions and disorders of the endocrine system 4.03/4.04 Remember the structures and understand the functions of the ENDOCRINE SYSTEM What are the structures of the endocrine system? What are the functions of the endocrine system? How do you relate the body’s hormones to the endocrine system? 4.04 Understand the functions and disorders of the endocrine system

4.03 Remember the structures of the endocrine system *Gland (endocrine/exocrine) any organ that produces a secretion (hormone/chemical) Endocrine glands -organized groups of tissues that use materials from the blood and lymph to make new compounds called hormones -also called ductless glands; the hormones are secreted directly into the blood stream 4.03 Remember the structures of the endocrine system 3

Exocrine glands Another type of gland in which secretions must go through a duct. -the duct carries the secretion to a body surface or organ -exocrine glands include sweat, salivary, lacrimal, and pancreas

Function of the Endocrine System Human behavior is shaped by the endocrine system and the nervous system working together. *Hormone release provides immediate body responses because the hormones are directed toward target organ cells.

Functions of the ENDOCRINE SYSTEM Hormone Control (negative feedback) Occurs when there is a drop in the level of a hormone. The drop triggers a chain reaction of responses to increase the amount of hormone in the blood. 4.04 Understand the functions and disorders of the endocrine system 6

Major glands of the endocrine system Pituitary Pineal Thyroid Parathyroid Thymus Adrenals Gonads Pancreas

The *Pituitary Gland Known as : The Master Gland because of it’s major influence on the body’s activities Size of a grape *Located at the base of the brain 8 4.03 Remember the structures of the endocrine system

4.03 Remember the structures of the endocrine system The Pituitary Gland The pituitary gland and its hormones *Anterior lobe – produces 6 hormones *Posterior lobe – produces 2 hormones 4.03 Remember the structures of the endocrine system 9

Anterior Pituitary Lobe 1. *Growth hormone (GH) responsible for growth and development * also helps fat to be used as energy, saving glucose and helping to maintain blood sugar levels.

Anterior Pituitary Lobe 2. *Prolactin Hormone develops breast tissue and stimulates the production of milk after childbirth

Anterior Pituitary Lobe 3. Thyroid stimulating hormone (TSH) Stimulates the growth and secretion of the thyroid gland 4. Adrenocorticotropic hormone (ACTH) Stimulates the growth and secretion of the adrenal cortex

Anterior Pituitary Lobe 5. Follicle-stimulating hormone (FSH) Stimulates the growth of the graafian follicle and the production of estrogen in females, and stimulates the production of sperm in the male. 6. Luteinizing hormone Stimulates the growth of the graafian follicle and the production of estrogen and the formation of the corpus luteum after ovulation, which produces progesterone in the female. In the male, it is necessary for the production of testosterone.

*Posterior Pituitary Lobe 1.Vasopressin – Anti-diuretic hormone (ADH) Maintains water balance by reducing urinary output 2.*Oxytocin Promotes milk ejection and causes contraction of the smooth muscles of the uterus *a synthetic derivative of this hormone (oxytocin) could be given to induce labor 4.04 Understand the functions and disorders of the endocrine system 14

Pineal Gland Located in the 3rd ventricle in the brain Small pinecone shaped organ Produces the hormone melatonin. There are no clear answers as to the function of melatonin; however, melatonin causes body temperature to drop. Falling asleep is associated with lowered body temperature.

4.03 Remember the structures of the endocrine system *Thyroid Gland - Butterfly shaped -Located in the anterior neck on either side of the larynx, over the trachea *Secretes thyroxine, triiodothyronine, and calcitonin 4.03 Remember the structures of the endocrine system 16

Thyroid Gland Thyroxine – controls the rate of cellular metabolism, heat production, and oxidation of all cells. Calcitonin – Maintains proper calcium level in the bloodstream

4.03 Remember the structures of the endocrine system Parathyroid Glands -Four glands; Size of a grain of rice -Attached to the posterior thyroid -Secretes the hormone parathormone which, like calcitonin, also controls the concentration of calcium in the bloodstream. 4.03 Remember the structures of the endocrine system 18

4.03 Remember the structures of the endocrine system *Thymus Gland -Serves both the endocrine system and the lymphatic system -*Located under (posterior) the sternum -Large during childhood but disappears with age. (puberty) -Secretes hormone, thymosin, which helps to stimulate the lymphoid cells that are responsible for the production of T cells, which fight certain diseases *The thymus is critical to the development of the immune system 4.03 Remember the structures of the endocrine system 19

4.03 Remember the structures of the endocrine system *Adrenal Gland There are two adrenal glands. -*One is located on top of each kidney. - *Each gland has two parts: 1. *Cortex – outside (stimulated by ACTH) – hormones secreted by the adrenal cortex are known as corticoids which are very effective as anti-inflammatory drugs. The cortex secretes 3 groups of corticoids: *Mineralocorticoids-aldosterone (reabsorption) *Glucocorticoids-increase glucose in the blood *Androgens (male sex hormones) 4.03 Remember the structures of the endocrine system 20

Adrenal Gland 2. *Medulla – inside – secretes epinephrine (adrenalin), a powerful cardiac stimulant, and norepinephrine. *The adrenal medulla responds to the sympathetic nervous system. The hormones produced are referred to as the “fight-or-flight” hormones, because they prepare the body for an emergency. The adrenalin (EPINEPHRINE) causes the heart rate, respiratory rate, and blood pressure to increase, and mental alertness increases.

4.03 Remember the structures of the endocrine system Gonads Sex glands Testes (male) – responsible for producing sperm and the hormone testosterone. - Produced by the interstitual cells of the testes, *testosterone is responsible for the development of the male reproductive organs and secondary male characteristics. (beard and body hair, deepening of the voice, increase in musculature, and the production of sperm.) 4.03 Remember the structures of the endocrine system 22

4.03 Remember the structures of the endocrine system Gonads Sex glands: Ovaries (female) – responsible for producing the ova or egg and the hormones estrogen and progesterone. *Estrogen – stimulates the development of the reproductive organs, including the breast, and secondary sex characteristics such as pubic and axillary hair, prepares for menstruation. Progesterone – works with estrogen to build up the lining of the uterus for the fertilized egg 4.03 Remember the structures of the endocrine system 23

4.03 Remember the structures of the endocrine system *Pancreas *Located behind the stomach; also a digestive organ Both an endocrine and exocrine gland The endocrine portion is involved in the production of insulin (regulates blood glucose) by the B cells of the Islets of Langerhans *Contains the Islets of Langerhans-specialized cells in the pancreas that produce insulin *Lack of insulin secretion by the islet cells causes diabetes mellitus. 4.03 Remember the structures of the endocrine system 24

4.03 Remember the structures of the endocrine system 4.03 Remember Structures of the endocrine system 4.04 Understand the Functions of the endocrine system 4.03 Remember the structures of the endocrine system 25