ENDOCRINE SYSTEM BY: DR. JAMALUDDIN BIN HJ. MUHAMAD PAKAR PERUNDING PEDIATRIK HOSPITAL TUANKU FAUZIAH KANGAR, PERLIS.
ENDOCRINE SYSTEM
BY:
DR. JAMALUDDIN BIN HJ. MUHAMAD
PAKAR PERUNDING PEDIATRIK
HOSPITAL TUANKU FAUZIAH
KANGAR, PERLIS.
FUNCTION OF THE ENDOCRINE SYSTEM
1. Water balance – controlling the solute concentration of the blood.
2. Uterine contractions and milk release-delivery of the newborn and breast milk flow
3. Growth, metabolism and tissue maturation-many tissues, adult features.
4. Ion regulations-regulates Na+, K+ and Ca2+ in the blood.
5. Heart rate and blood pressure regulation-for physical activity.
6. Blood glucose control7. Immune system regulations8. 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 (i) Permeability changes(ii) 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
(i) Chemical
(ii) Other hormones
(iii) 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 productionPROLACTIN :Stemulates milk productionADH : water reabsorption (regulation of blood
volume)
OXYTOCIN : urine contraction milk “let-down”THYROID GLAND :Thyroid hormones - thyroxine (T4) and
triiodothyronine (T3)Function : metabolic ratesNormal 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 :
i) Medulla - epinephrine, norepinephrine
a. 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
a. Aldosterone:
- 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 behaviorOvaries 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