Chemical co-ordination Main Function: It releases hormones into the blood to signal other cells to behave in certain ways. It is a slow but widespread form of communication.

CHEMICAL COORDINATION COORDINATION Hormones and nerves enable the body to: 1. respond to internal and external changes 2.co-ordinate the various activities of the body CHEMICAL COORDINATION NERVOUS COORDINATION INVOLVES STIMULI INVOLVES HORMONES

The Endocrine System Consists of: Endocrine glands Release hormones into the bloodstream. Hormones are chemicals released in one part of the body that travel through the bloodstream and affect the activities of cells in other parts of the body.

ADRENALIN, ALDOSTERONE PITUITARY FSH, TSH,GH, LH, Prolactin HYPOTHALAMUS ADH THYROID THYROXIN ADRENALIN, ALDOSTERONE ADRENAL ENDOCRINE GLANDS PANCREAS INSULIN & GLUCAGON OESTROGEN & PROGESTERONE OVARIES TESTIS TESTOSTERONE

The hormonal glands and their functions Pituitary gland secretes: . Growth hormone(GH) which stimulates growth in the body . Thyroid stimulating hormone(TSH) which stimulate the thyroid to secrete thyroxin . Follicle stimulating hormone (FSH) which stimulates the formation of follicles in the ovary. . Luteinising hormone (LH) bringing about ovulation, oestrogen production and corpus luteum development. . Prolactin which stimulates the mammary glands to secrete milk. Hypothalamus Secretes anti-diuretic hormone (ADH) which stimulate the re-absorption of water from the tubules back into the blood Thyroid gland Secretes thyroxin (Iodine is necessary in the production of thyroxin) Thyroxin controls metabolic rate, particularly cellular respiration in mitochondria Pancreas secretes: . Insulin which decrease blood sugar levels . Glucagon which increase blood sugar levels Ovaries secrete: . Oestrogen Stimulates the female sex organs stimulate secondary sexual characteristics . Progesterone: Prepare uterus to receive fertilised ovum. Maintains the uterus during pregnancy Testes Secretes testosterone which stimulate the male sex organs stimulates secondary sexual characteristics Adrenal glands which secrete: . Adrenalin which prepares the body for a crisis by increasing the: Heart rate Breathing Glucose levels in the blood Tone of the skeletal muscles . Aldosterone which prepares the re-absorption of Na+ from the loop of Henlé. The hormonal glands and their functions

Pituitary gland Hypophysis (Pituitary gland) also known as the master gland situated in the small bony cavity on the floor of the skull, below the hypothalamus has two lobes viz., the anterior lobe and the posterior lobe the anterior lobe of the pituitary gland

Thyroid Gland Function: plays a major role in regulation the body’s metabolism. Disorders: If the Thyroid Gland produces to much Thyroxin, it can cause a condition known as Hyperthyroidism. If to little thyroxin produces it is called Hypothyroidism.

NEGATAIVE FEEDBACK

The pancreas and Diabetes Cause of diabetes: the pancreas makes little or no insulin

DIABETES

Islets of Langerhans Small patches of special cells found in the pancreas Secretes the hormones insulin and glucagons Insulin decreases the blood glucose level by stimulating the liver and muscle cells to absorb more glucose from the blood promotes the conversion of glucose into glycogen and fat by the liver deficiency of insulin results in diabetes mellitus Glucagon increases the blood glucose level by encouraging the conversion of glycogen to glucose (energy needed in emergency situations)

Week circulation of blood to the legs and feet often causes limbs to be amputated.

Diabetes affects the circulatory system of the retina Diabetes affects the circulatory system of the retina. The arteries in the retina become weakened and leak, forming small forming small, dot-like haemorrhages. These leaking vessels often lead to swelling or edema in the retina and decreased vision. In a later stage circulation problems cause areas of the retina to become oxygen deprived and new, fragile vessels develop as the circulatory system attempts to maintain adequate oxygen levels. These vessels haemorrhage (weaken) easily and blood may leak into the retina causing decreased vision

Prevention of diabetes 1. Eat healthy, balanced meals A should be followed to keep the glucose levels constant

Prevention of diabetes: 2. Control the glucose levels Prevention of diabetes: 2. Control the glucose levels. Normal glucose levels in the blood of a human should be between 3.5 – 5.5 mmol/l

Prevention of diabetes: 3 Prevention of diabetes: 3. Exercise regularly and keep the weight down (especially around the belly)

Study the following poster and discuss things which a diabetic should do and things which they should avoid

If diabetes is not managed well it may also cause kidney problems

GROWTH DISORDERS UNER PROCTION OF GH IN CHILDHOOD RESULT IN DWARFISM

OVER SECRETION OF GH IN CHILDHOOD RESULT IN GIANTISM

OVER SECRETION IN ADULTHOOD – ACROMEGALY (The bones become thicker, this is normally caused by a tumor of the pituitary gland)

Acromegaly – it causes enlarged feet and hands

THYROID GLAND

Thyroid Gland Thyroid Gland consists of two lobes, one on each side of the trachea, just below the larynx secretes the hormone thyroxin Functions of Thyroxin maintains general metabolism at an optimum rate essential for normal growth and functioning of the heart and nervous system Iodine is essential for the production of thyroxin. A deficiency of iodine in the diet causes swelling of the thyroid gland (condition is called goitre) Thyroid Gland

THYROID GLAND SECRETES Which is rich THYROXIN in Iodine FUNCTIONS Controls 1. metabolic rate of cells how fast the heart beats & the force with which it beats Growth of cells & body tissue( eg bone % teeth sexual development nerve reactivity 5 Mental development CONTROLLED BY TSH

THYROID DISORDERS Thyroxin regulates the body’s metabolic rate THYROID DISORDERS Thyroxin regulates the body’s metabolic rate. Iodine is necessary in the production of thyroxin. A lack of iodine in the diet leads to an enlarged thyroid gland. This is known as goitre.

Negative feedback

Hypothyroidism (under-secretion of thyroxin) Accumulation of body fluids in adults – hormone replacement tablets are prescribed

HYPERTHYROIDISM

Adrenal Gland situated on top of each kidney secrets the hormone adrenalin which prepares the body to cope with emergency, danger and stress in the following ways: constricts blood vessels of the skin but dilates blood vessels to heart, muscles and brain (important organs during an emergency) increases the heartbeat promotes conversion of glycogen into glucose in the liver to be released into the blood increase the rate and depth of breathing increases skeletal muscle tone the metabolic activity of the body cells increases to release more energy.

Cross section through the adrenal gland

Adrenal Gland Functions: -The adrenal glands release Adrenaline in the body that helps prepare for and deal with stress. -Also regulates kidney function.

Ovaries Functions: Pair of reproductive organs found in women that produce eggs. Also secrete estrogen and progesterone, which control ovulation and menstruation.

Testes Pair of reproductive glands that produces sperm. Functions: Pair of reproductive glands that produces sperm. Also secrete Testosterone to give the body its masculine characteristics.

INFERTILITY Causes of infertility No FSH secreted, no eggs will be released and the female will be infertile Low sperm count in males, sexually transmitted diseases Symptoms Inability to have children Prevention Reduce behaviour that may increase chances of contracting STD’s  Treatment of infertility Gynaecologist treats these women by giving them fertility drugs that contain FSH and LH to stimulate their ovaries to produce ova. These drugs may cause many ova to be released resulting in multiple births.