hypothalamus and pituitary
DESCRIPTION
Hypothalamus and Pituitary. Hypothalamus and Pituitary. Hypothalamus: Part of the brain, below the thalamus Produces neurohormones , which travel along length of neurons, then through blood to the pituitary Pituitary: Located below brain Controls other glands - PowerPoint PPT PresentationTRANSCRIPT
HYPOTHALAMUS AND PITUITARY
Hypothalamus and PituitaryHypothalamus: Part of the brain, below the thalamusProduces neurohormones, which travel along length of neurons, then through blood to the pituitary
Pituitary:Located below brainControls other glandsTwo lobes (anterior and posterior)
THYROID HORMONES
Thyroid Gland
• Located in front of the throat
• Shaped like a bow tie, or butterfly
• Secretes thyroxine (T4) and triiodothyronine (T3)
Thyroid Hormones
Thyroxine (T4) Triiodothyronine (T3)
Where do you get your iodine?
Can you spot the difference?
TRH
TSH
T4
Thyroid hormone feedback loop1. TRH released by hypothalamus, stimules release
of TSH in pituitary2. TSH stimulates thyroid, inhibits release of TRH3. Thyroxine (T4) from thyroid inhibits release of TSH
What happens if you don’t get enough iodine?
TRH
TSH
T4
Iodine deficient goiter1. TRH released by hypothalamus, stimules release
of TSH in pituitary2. TSH stimulates thyroid, inhibits release of TRH3. Thyroxine (T4) from thyroid inhibits release of TSH4. Lack of iodine prevents T4 formation, loss of
negative feedback on TSH5. TSH continues to stimulate thyroid
Iodine Deficient Goiter
Calcitonin
• Thyroid gland also produces calcitonin, which is involved in calcium balance
• Calcitonin is released in response to rising blood Ca2+ levels
PARATHYROID HORMONES
Parathyroid Glands
• 4 small glands on posterior side of thyroid gland
• Produce parathyroid hormone (PTH)
• Involved in calcium balance
• Released in response to low blood Ca2+ levels
PINEAL GLAND
Pineal Gland
• Regulates several biological rhythms
• Secretes melatonin• When eyes see light,
melatonin secretion is inhibited
LED Screens and Melatonin
• What affect do you think LED screens on phones and tablets have on melatonin levels in the brain?