Inquiry into Biology: Unit 5

Hypothalamic releasing hormone

regulates anterior pituitary hormones

hormone that targets endocrine glands and stimulates them to release other hormones

1. Thyroid-stimulating hormone (TSH)
2. andrenocorticotropic hormone (ACTH)
3 & 4. gonadotropic hormones (follicle-stimulating hormone, FSH and lutenizing hormone, LH)

1. Human growth hormone (hGH)
2. Prolactin (PRL)

1. Antidiuretic hormone (ADH)
2. oxytocin (OCT)

thyroxine (T4)
calcitonin

parathyroid hormone (PTH)

glucocorticoids (e.g. cortisol)
mineralcorticoids (e.g. aldosterone)
gonadocorticoids

epinephrine and norepinephrine

insulin
glucagon

estrogen
progesterone

testorone

simulates cell division, muscle growth, metabolic functions (anti-tropic)

stimulates thyroid gland (tropic)

stimulates adrenal cortex to secrete glucocorticoids (e.g. cortisol) (tropic)

stimulates ova and sperm production from ovaries and testes (tropic)

stimulates sex hormone production from ovaries/testes; stimulates corpus luteum (in ovaries) to produce progesterone; tropic

stimulates milk production from mammary glands (non-tropic)

promotes water retention by kidneys; made by hypothalamus

stimulates uterine muscle contractions and milk release by mammary glands; made by hypothalamus; part of positive feedback loop

affects all tissues; increases metabolic rate and regulates growth and development

targets bones and kidneys to LOWER blood calcium levels (inhibits release of calcium from bone and reabsorption of calcium by kidneys)

RAISES blood calcium levels by stimulating bone cells to release calcium, intestine to absorb calcium from food, and kidneys to reabsorb calcium

(e.g. cortisol); stimulates tissues to raise blood glucose levels and break down protein

(e.g. aldosterone); promotes reabsorption of sodium and water by kidneys, increasing blood pressure

promotes secondary sexual characteristics

the fight or flight hormones; raise blood glucose levels; also called adrenaline and noradrenaline

LOWERS blood glucose levels and promotes the formation of glycogen in liver

RAISES blood glucose levels by converting glycogen into glucose

stimulates uterine lining growth and promotes formation of glycogen in liver

promotes growth of uterine lining and prevents uterine muscle contractions

promotes sperm formation and development of male secondary sexual characteristics

protein (peptide) hormones
steroid hormones

attaches to a hormone receptor protein in the plasma membrane of a cell

usually this leads to activation of enzyme that changes ATP to cyclic AMP (cAMP) that then activates an enzyme cascade

bind with a receptor protein within nucleus of a cell (is able to pass through lipid bilayer)

activates certain genes within the DNA --> TRANSCRIPTION and TRANSLATION --> protein synthesis

ductless organs that secrete chemical messengers directly into the bloodstream

(exocrine glands are different because they excrete chemicals into ducts)

in forebrain, under thalamus;
centre of the autonomic nervous system that is responsible for neural endocrine functions
helps regulate body's internal environment and behaviour
*coordinates pituitary gland by producing and releasing hormones

butterfly-shaped gland in neck that produces thyroxine and cortisol
helps regulate metabolism and growth

independent pair of organs on top of kidneys
made up of outer cortex and inner medulla
produces hormones

made up of anterior and posterior pituitary
produces hormones for critical life functions (growth, metabolism, reproduction, etc)

a substance that affects cell metabolism or behaviour

Hypothalamus secretes releasing hormone to anterior pituitary

Anterior pituitary secretes stimulating hormone to a target gland

Target gland secretes a target gland hormone into blood

Blood level of last hormone stops secretion of first two hormones

too little hGH during childhood

too much hGH during childhood

too much hGH as adult

The thyroid gland needs iodine to make thyroxine and cortisol

Not enough iodine --> thyroid can't made thyroxine --> no signal to stop TSH secretion by anterior pituitary --> thyroid swells --> goitre

too little thyroxine

-cold, tired, slow metabolism
-in children: cretinism

too much thyroxine

-hot, mood swings, high metabolism

direct nerve impulses

sympathetic nervous system is stimulated (fight/flight)

stress --> hypothalamus sends nerve impulse to spinal cord --> spinal cord sends impulse to adrenal medulla --> medulla secretes epinephrine and norepinephrine

-increased HR, BP, breathing rate, blood glucose levels, cellular metabolism

stress --> hypothalamus secretes releasing hormone to anterior pituitary --> anterior pituitary secretes ACTH --> anterior pituitary secretes glucocorticoids (increase blood sugar) and mineralocorticoids (increase blood pressure)

-kidney absorbs Na+ and water which increases BP
-metabolism of protein and fat to make more glucose
-more cortisol = anti-inflammation and bad immune system

promotes breakdown of muscle proteins into amino acids into glucose
promotes metabolism of fatty acids (instead of carbohydrates) to keep blood glucose levels high
high levels of glucocorticoids suppress immune system because they are anti-inflammatory

-damage to the adrenal cortex
-not enough mineralocorticoids and glucocorticoids
-low blood sugar, weight loss, weak