chap 13 Flashcards
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what is homeostasis
the regulation of physical and chemical factors of the internal environment within normal ranges
what is the function of homeostasis
for cell to function in optimum condition
list physical factors that need to be regulated
temperature, osmotic blood pressure and blood pressure.
what are chemical factors that need to be regulated
pH value, the concentration of minerals and blood sugar concentrations.
what does any change (deviation) from normal range trigger
homeostatic mechanism
maintain through
- negative feedback mechanism (process to return back any changes)
what happens when a factor exceeds normal range
it is brought back to the normal range
List organ systems involved in maintaining body temperature
the integumentary system, nervous system, circulatory system, muscle system and endocrine system
list organ systems involved in maintaining blood sugar levels
endocrine gland, circulatory system, digestive system
list organ systems involved in maintaining the partial pressure of carbon dioxide
respiratory system
circulatory system
nervous system
list organ systems involved in maintaining blood pressure
circulatory system and nervous system
why is it important to maintain body temperature
enzyme reaction occur at optimum level
too high - enzyme denature
too low - slow down of metabolic activity of cell
how are the changes in body temperature detected
with thermoreceptors in the skin and the hypothalamus (brain)
how is blood sugar regulated when it is low
PANCREAS
alpha cells in pancreatic langerhans cells are stimulated to secrete glucagon into the blood
TO
LIVER
glucagon stimulates liver cells to convert glycogen to glucose
glucagon also promotes the breakdown of fat to release fatty acids that can be metabolised to produce energy
then, blood sugar level returns to normal
how is blood sugar regulated when it is high
PANCREAS
beta cells in pancreatic langerhans are stimulated to secrete insulin into the blood
TO
ADIPOSE CELLS
insulin stimulates the muscle cells to use glucose in the process of cell respiration
insulin stimulates the conversion of excess glucose into glycogen to be stored in the liver and muscle cells
in adipose cells, insulin concerts excess glucose to fat
then it turns back to normal
