Bio - Hormones affecting metabolism

3 glands affecting metabolism

Thyroid gland
Anterior pituitary
Parathyroid gland

Thyroid gland

2 lobes on either side of trachea connected by tissue in front of trachea
Secretes T3 and T4 (T3 is 4x stronger and only about 20% is made)
Lipid soluble but not steroid hormones
Hormones are vital to growth, development, maturation
Almost every cell relies on the hormones it produces
Thyroid hormone increases BMR and O2 consumption
Regulated by negative feedback

Hypothyroidism

Too less thyroid hormone
Slower metabolism
Lower body temp, weight gain, reduced appetite

Hyperthyroidism

Too much thyroid hormone
Faster metabolism
Higher body temp, elevated BP, weight gain

Goiter

Swelling of thyroid gland
Compresses blood vessels

Anterior pituitary

Growth hormone is secreted
Has direct and indirect effects

Direct affects of GH

Increase amino acid uptake and reduced muscle degradation
Spares protein and keeps glucose for brain

Indirect affects of GH

Lets liver secrete hormones for bones

How is growth hormone monitored and stimulated

Sleep, nutrition, exercise, stress
Stimulated by Ghrelin (stomach) and GHRH

Pituitary dwarfism

Lack of GH during childhood

Acromegaly

Excess secretion of GH in adults
Overgrowth of hands, jaws, feet

Calcatonin

A hormone that helps lower blood calcium levels

Parathyroid gland and PTH

Posterior part of each thyroid lobe
Releases PTH
Stimulated by low calcium in blood
Targets bones and kidneys
Acts like glucagon (insulin is calcatonin)
Underproduction of PTH could cause nerve disruptions, potentially fatal
Overproduction of PTH could cause lack of calcium in bones, leading to weakness and fragile