BY: DR. JAMALUDDIN BIN HJ. MUHAMAD ENDOCRINE SYSTEM BY: DR. JAMALUDDIN BIN HJ. MUHAMAD PAKAR PERUNDING PEDIATRIK HOSPITAL TUANKU FAUZIAH KANGAR, PERLIS.

FUNCTION OF THE ENDOCRINE SYSTEM Water balance – controlling the solute concentration of the blood. Uterine contractions and milk release-delivery of the newborn and breast milk flow Growth, metabolism and tissue maturation-many tissues, adult features. Ion regulations-regulates Na+, K+ and Ca2+ in the blood. Heart rate and blood pressure regulation-for physical activity. Blood glucose control Immune system regulations Reproductive functions control

Hormones Defination: secreted by the endocrine glands (ductless gland), its effect away from the glands-target tissue. Intracellular chemical signals transported in the blood. Receptors-membrane bound. intracellular Hormone bound with the receptor to produce effect.

ENDOCRINE SYSTEM:

Hormone – peptide / proteins - steroids / lipid Regulation of Hormone secretions some times regulated by other hormones Other hormones: Prostaglandins inflamation Erythroproeitin production Human chronic gonadotophris (placenta)

Hormones – protein, lipids or peptides Protein / most peptide hormones bind to receptor on the cell membrane cause Permeability changes Production of intracellular chemical signals Lipid – soluble hormones eg: steroid and thyroid hormone Effect : enter the cell and bind to receptor inside the cell effects.

REGULATOR OF HORMON SECRETION Secretion of hormones is control by negative – feedback mechanism Secretion of hormones controlled by Chemical Other hormones Nervous system

PITUITARY AND HYPOTHALAMUS Pituitary – infundibulum – brain. Anterior and posterior pituitary Section of hormones from anterior pituitary controlled by hormones from hypothalamus Section of hormones from posterior pituitary control by action potentions caried by axchy from the hypothalamus.

Anterior pituitary : Growth hormone (GH) Thyroid-stimulating hormone (TSH) Adrenocorticotropic hormone (ACTH) Luteinizing hormone (LH) Follicle stimulating hormone (FSH) Prolactin Melanocyte stimulating hormone (MSH)

POSTERIOR PITUITARY HORMON : Antidiuretic hormone (ADH) oxytocin GH : Increase protein synthesis Breakdown of lipids Glucose level Somatic growth TSH : T4, T3 secretions

ACTH : glucocorticoid secretion eg: cortisol skin pigmentation MSH : melanin production LH : Ovulation progesterone production; testosterone production

FSH : Follicle maturation and estrogen secretion in ovary ; sperm production PROLACTIN : Stemulates milk production ADH : water reabsorption (regulation of blood volume)

OXYTOCIN : urine contraction milk “let-down” THYROID GLAND : Thyroid hormones - thyroxine (T4) and triiodothyronine (T3) Function : metabolic rates Normal process of growth and maturation

CALCITONIN : parafollicular cells Function : Ca2+ level (resulate Ca2+ level) rate of bone breakdown

PARATHYROID GLANDS : PTH (parathyroid hormone) Function: bone breakdown by osteoclasts vitamin D synthesis Ca2+ levels

ADRENAL : Medulla - epinephrine, norepinephrine Epinephrine, norepinephrine : - cardiac output - blood flow to skeletal muscles, heart, glucose in the blood, fatty acids # prepare body for physical activity

ii) Cortex - Mineralocorticoids (aldosterone), glucocorticoids (cortisol) and androgens - Na+ reabsorption & water retention - H2O Excretion (blood concentration)

PANCREAS Pancreas: insulin - glucose & amino acids uptake in tissue (liver) skeletal muscle, adipose tissue Islets of langerhans alpha cell glycogen B cell insulin

b. Cortisol : - fat and protein breakdown - glucose (CHO metabolism) - maintain blood pressure - inhibit inflamation and immune response c. Androgens : - female sexual drive, pubic hair and axillary hair growth

Glucogen glucogen breakdown glucose level Renin (pathway) angiotensionogen BP Renin angiotensin I angiotensin II aldosterone secretion Vasocontraction BP Na+ retention K+ excretion H2O retention

Reproductive organs Testes Testosterone - sperm cell production - maintenance of functional reproductive organs, secondary sexual characteritics - male sex behavior Ovaries Estrogen & - Uterine and mammary gland progesterone development & function - external genitalia - secondary sexual characteristic - sexual behavior - menstrual cycle

Thymus gland thymosin - promotes immune system development and function Pineal body melatonin - regulate the onsent of puberty

Calcium Metabolism Calcium level is maintain If Ca2+ PTH secretion calcitonin breakdown of bone matrix secretion by osteoclasts Ca2+ release breakdown of Ca2+ reabsorption in the kidneys bone maxtrix by Ca2+ reabsorption from small intestine osteoclasts (through Vit. D)

If Ca2+ level stimulate parathyroid gland PTH secretions calcitonin breakdown of bone matrix by osteoclast secretion Ca2+ release Ca2+ reabsorption by the kidneys breakdown Vitamin D synthesis Ca2+ of bone matrix Absorption from the small intestine

Regulation of Blood Glucose Level glucose pancreatic islets cells insulin secretions uptake of glucose by the tissues glucose glycogen (skeletal muscle, liver) glucose adipose tissue glucose level

glucose pancreatic islets cell insulin secretions Insulin is an anabolic hormone