Ch 2 Hormones

Hypothalamus

Hypothalamus secretes releasing or inhibiting factors and hormones to the pituitary gland.

Pituitary gland

Anterior

• Thyroid stimulating hormone (TSH) - regulates the thyroid gland - thryotropin RH

• Adrenocorticotropic hormone (ACTH) - adrenal cortex - corticotropin RH

• Gonadotrophic hormone (e.G FSH + LH) - regulates gonads - Gonadotropin RH

• Prolactin - regulates milk production - prolactin RH.

Pineal gland

Melatonin - regulates sleep patterns (stimulated by darkness)

Thyroid gland

Calcitonin - lowers calcium ion concentrations in the blood + inhibits the reabsorption of Ca ions in the kidneys and intesstines and inhibits osteoclasts and unhibits osteoblasts.

thyroxine + triidothyronine - stimulate metabolism, growth and development and releases glucose

Parathyroid

parathyroid hormone (PTH) - increases calcium levels in the blood and increase phosphate secretion in urine.

Thymus

Thymosins - inlfuence maturations of t-cells (t-lymphocytes) advance immune responses

Adrenal cortex

corticosteroids (20 different types)

• aldosterone (mineralcorticoids) - targets kidneys and reduces doium and increases potassium

• cortisol (glucortidoids) - promotes normal metabolism, helps withstand stress + repairs damaged tissues

Adrenal medulla

Adrenaline - prepares the body for action.

Noradrenaline - similar effect to adrenaline but specfically increases the rate and force of a heart beat

Pancreas (gland - islets of langerhan)

Beta cells - * insulin (lowers blood sugar)

Alpha cells - *glucagon (raises blood sugar levels)

Gonads

Androgen:

testosterone - development of sex characteristics

oestrogen + progesterone - develops and mainatians female sex characteristics.

Gonadotropins (FSH + LH) - regulat menstrul cycle and pregancy changes