THYROID GLAND

located at _________________________________ two important thyroid hormones (which

regulate body metabolism, growth, and differentiation of tissues)____________________________________________________________________________________

HORMONES THAT AFFECT METABOLISM Three different glands affect metabolism ____________________________________________

helps regulate body metabolism (glucose oxidation rate)

produces three hormones triiodothyronine, thyroxine, calcitonin

______________________________________________ produces parathyroid hormone helps regulate calcium levels in blood and

lower phosphate levels _______________________________________________

produces growth hormones and regulatory hormones

HORMONES THAT AFFECT METABOLISM

Gland Hormone Action

Thyroid

Parathyroid

Anterior Pituitary Gland

THYROID GLAND

individuals who secrete higher levels of thyroxine oxidize sugars and other nutrients _____________

__________________________________________ When glycogen stores are filled, excess sugar

is converted to ___________________________ control of thyroid hormones is accomplished

by ____________________

FEEDBACK LOOP... receptors in hypothalamus are activated if the

metabolic rate __________________________ nerve cells secrete ______ (thyroid releasing

hormone) this stimulates pituitary to release _________(thyroid

stimulating hormone) carried by blood to thyroid gland which then

releases ___________________________which raises metabolism by _______________________________

____________________________________by cells high levels of thyroxine cause pathway to be

turned ________________, inhibiting release of TRH Thyroid gland also contains ________________________

hormone acting on _________________cells to lower level of __________________________found in blood

OH NO!

when inadequate amounts of iodine are obtained from the diet, thyroid enlarges, producing a _________.

If thyroxine levels ↓’s, TSH ↑’s, and thyroid is stimulated more and more

Thyroid cells continue to develop and thyroid _________________

PARATHYROID GLANDS

____________________parathyroid glands hidden within larger thyroid gland

Usually nerves or other hormones regulate the endocrine glands with the parathyroid glands being the ________________________________These maintain homeostasis by responding

__________________________________in their immediate surroundings (low calcium levels)

PTH raises _______________levels in the blood

 PTH (parathyroid hormone) also help activate vitamin D. (Low levels of vit D cause rickets!)

RICKETS AND GOITERS...

REGULATION OF BLOOD CALCIUM

blood calcium level(10 mg/100mL)

calcitonin

parathyroid hormone (PTH)

Ca++ uptakein intestines

high

low

FeedbackEndocrine System Control

kidney reabsorption of Ca++

bones release Ca++

kidney reabsorption of Ca++

Ca++ depositedin bones

activated Vitamin D

thyroid

parathyroid

HUMAN GROWTH HORMONE (AKA SOMATOTROPIN)

Too little = __________ Too much = __________ Released by Ant. Pit. GH increases cell

__________in muscle cell and connective tissue by promoting Protein Synthesis (increasing Amino Acid uptake)

Promotes fat burning Dec. Levels of GH with

age

HGH AND CONTROVERSY...

Should you take it?

GH affects all body cells BUT mainly ____________cells

_____________________________bones of jaw, forehead, fingers and toes increase in width, once other bones can no longer increase in length (growth plates fused)