D3.3 Homeostasis Flashcards
Homeostasis
Ability to maintain a constant internal environment
regulator
An animal that can maintain a constant internal environment, enabling it to continue normal activities, regardless of external conditions
negative feedback loops
Conditions are brought back to a set value as soon as it detected deviation
examples of negative feedback
Regulation of body temperature
Blood sugar level
Amounts of water and ion and blood and tissue fluid
order of negative feedback
Input - receptor - coordinator - effector - output
normal level of blood glucose
90 MG of glucose in every 100 cm^3 of blood
What is glucose needed for?
Respiration because it is quickly absorbed across the cell membrane
Main respiratory substance
Glycogen gets used up very quickly
hypoglycemia
Condition my blood sugar levels are too low below 60 MG
cant faint and coma
hyperglycemia
When blood sugar levels are too high
Water goes back into blood because of lower water potential
Body becomes dehydrated
what happens if glucose is too high
Withdrawn from blood and stored as glycogen
islets of Langerhans
Groups of endocrine cells located in the pancreas
Become hormone secreting glands
Rich capillary network, but no ducts
Alpha cell
Glucose cell of the islets of Langhan and pancreas
beta cell
Insulin greeting cells of the islets of Langerhans in the pancreas
Stimulated by raised blood glucose levels
glycogenesis
Conversion of glucose to glycogen and cells and glucose to fatty acids and fat
Deposition of fatter around the body
what happens when blood glucose level falls below normal
A cells of pancreas, secrete glucagon
glucagon
Made in pantry that promote background of glycogen to glucose and the muscle cells
diabetes
Failure to regulate blood glucose levels
type 1 diabetes
The result of failure of insulin production by beta cells
type 2 diabetes
Fear of the influence receptor proteins on the cell membrane of target cells
what can type two diabetes lead to?
Increase risk of circulatory disorders, renal failure, blindness, strokes, or heart attacks
risk factors for type two
Overweight, obese, age 40 or older, family history, high BP low HDL or high triglycerides, inactivity
type 1
genes and environmental factors like viruses
what can type 2 be controlled by?
diet, reduction in weight
what can type 1 be controlled by?
insulin rejections, and insulin pumps
physiological controls
Regulation of loss of heat through skin
Thermal regulation is called endotherm
Can also regulate their body temperature by modifying their behavior
vasoconstruction
The narrowing of blood vessels by small muscles in the walls, restricting blood flow
vasodilation
The widening of blood vessels by small muscles in the walls increasing blood flow
increase in temperature
Vasodilation
Hair is life, flat allowing variation of heat from body
increased sweat to cool body
Decrease in temperature
Vasoconstriction
Had to be wrecked to trapped heat
Decreased sweat production
Skeletal muscles contracting, causing shivering
Metabolic activity in liver increases heating body
adipose tissue roll in heat
To maintain temperature of newly born babies
Memorize his triglycerides for heat
uncoupled respiration
Energy stored in ATP to release heat to maintain body temperature
