Welcome to Dr. Kate Brilakis' Learning Portal

potassium is absorbed from food in your small intestine. 
if your potassium levels are too low, your body may make less insulin which
​may lead to an increase in blood glucose and type 2 diabetes.

The depolarization of their membranes of the beta cells of your pancreas triggers these cells to release insulin. This depolarization involves the movement of K+ across the membrane. So there needs to be a gradient of potassium across the membrane. Low K+ levels prevent this gradient from being maintained. We'll learn about how membranes propagate electric charges via ion transfer later this semester. Where can you get dietary potassium?
As with all things healthy...eat right ;)
ideas...greens, berries, potatoes, citrus, peanuts, bananas, avocados and wheat germ 

homeostatic mechanisms follow one of two patterns: 
1. ​
negative feedback loop
2. positive feedback loop

​1. receptors detect change =stimulus
2. coordination center interprets change
3. effectors carry out response to change


2. blood pressure:
a healthy blood pressure is maintained via a homeostatic mechanism. the hypothalamu.
can raise or lower blood pressure by adjusting the sympathetic nervous system.
a bp increase results in greater resistance in arterial walls which is detected by receptors.

3. blood calcium level:
Calcium concentration must be regulated via a homeostatic mechanism that relies on the release of hormones. Hormones are circulating ligands that bind to specific receptors and trigger a response within the cells that exhibit those receptors.  
Thyroid hormones increase the uptake of calcium by bones tissue if blood calcium levels are elevated, lowering blood calcium levels. Parathyroid hormones (PTH) trigger the release of calcium from bones if blood calcium levels are low. 

7. blood pH:
Ph is regulated by a 
 chemical buffer system tied CO2 concentrations and your
 respiratory system

examples of homeostatic mechanisms

while positive
feedback loops
are less common

can you think of an example of an effector?

1. body temperature:
core body temperature is set and monitored by the the thermoregulatory center of the hypothalamus, which functions as a thermostat receiving
information from peripheral nerve receptors stimulated by external cold/heat and internal receptors that monitor the temp of the blood circulating about the hypothalamus.
The maximum body temperature a human can survive is 108°F. 

6. Potassium (K) concentration:
Potassium homeostasis is maintained primarily by your kidneys with the help of your adrenal gland and, less understood, your pancreas. The adrenal gland produces a hormone called aldosterone.
In your kidneys, there are aldosterone receptors. Aldosterone increases sodium and water reabsorption, to bring blood pressure back up but this also causes an increase in potassium excretion. Potassium (+) is excreted to balance the sodium (+) being absorbed.

most systems rely on
negative feedback loops

4. Osmoregulation:
the regulation of water concentrations in the bloodstream is controlled by osmoreceptors in the hypothalamus which send info to the pituitary which responds by secreting a hormone called ADH = anti-diuretic hormone. ADH targets kidney tubules, regulating their permeability. ADH is made by the hypothalamus and stored in the pituitary gland. Higher water concentration increases the volume and pressure of your blood. Osmotic sensors and baroreceptors work with ADH to maintain water metabolism by evaluating the concentration of solutes (Na, K, Cl, CO2) in your blood. When solute concentration isn’t isotonic, the sensors stimulate your kidneys to reabsorb or release water. 
They also regulate thirst.

is a self-regulating, dynamic process by which an organism strives to maintain internal equilibrium while adjusting to changing external conditions.

calcium (CaSR) receptors detect changes in blood calcium concentration. 

big picture...

5. blood glucose concentration:
Insulin and glucagon work antagonistically to maintain  blood glucose levels.
When your blood sugar level is elevated, the beta cells of your pancreas respond by secreting more insulin which permits cells to increase glucose uptake and stimulates your liver to convert glucose to glycogen.  
When your blood sugar level drops, the alpha cells of your pancreas respond by releasing glucagon to raise it. Glucagon accomplishes this by:
a. stimulating the conversion of glycogen to glucose = glycogenolysis. Livers store glycogen.
 b. accelerating the synthesis of glucose from amino acid molecules = gluconeogenesis.
c. stimulating adipose tissue to release stored fat into the bloodstream so they can be converted to glucose. Fats are broken down into glycerol and fatty acids which are then converted to glucose.

your hypothalamus is an area in your brain that regulates your  autonomic nervous system and
your pituitary gland. it is "in change" of body temperature, thirst, hunger, sleep and an array of behavioral/emotional  activities.