Endocrine System
Blood sugar too high
Glucose sensing neurons in the hypothalamus stimulates beta cells in pancreas to release insulin into the blood.
Liver takes up glucose and stores it as glycogen. Body cells take up glucose and stores it as fat. Blood glucose level declines, release of insulin is stopped.
Blood sugar too low
Glucose sensing neurons in the hypothalamus stimulates the alpha cells in the pancreas to release glucagon.
The liver breaks down glucagon and releases glucose. Once the blood sugar is restored to its set point the release of glucagon is stopped.
Temperature too hot
When temperature is higher than the hypothalamic set-point, the hypothalamus will activate its heat-loss center
Blood vessels dilate to allow heat to release from the surface of the skin. Sweat glands activated to secrete perspiration.
When body temperature decreases, the hypothalamus heat loss center will "shut off"
Temperature too cold
When temperature is cooler than hypothalamic set-point, it activates the heat promoting center in the hypothalamus
Blood vessels constricted to conserve heat, less heat loss from the skins surface. Skeletal muscles activated to shiver to produce more heat.
Body temperature rises, Hypothalamus heat promoting center "shuts off"
Hormones secreted by thyroid gland ?
-Thyroxine (T4)
-Triiodothyronine (T3)
Goiter disorder
disorder related to throid gland
-swelling/tumor in the neck due to iodine insufficiency
2 ways to scan Goiter disorder ?
-ultrasound
-radioactive iodine fluroscopy
Acromegaly disorder
- increase in the hands/facial bones and facial features
- due to increase in growth hormone production from the pituitary gland
-pituatary abnormality- secreting an over production of growth hormone
Cretinism disorder
-results from thyroid hormone insufficiency in infants
-needs to be detected in early stages
-thryoid hormones is crucial for the brains development
-doesnt kill but leads to mental disability
-disturbance of the bones aswell
Cushing's Syndrome
-increased production of cortisone
-accumulations of adipose tissue in cheeks and base of neck
-can be exogenous(from cortisone intake) or endogenous (from glands)