D3 homeostasis Flashcards
homeostasis
The ability of the body to seek and maintain equilibrium and maintain conditions optimal for survival.
what are examples of internal conditions which are monitored in body
body temp, ph glucose concentration, osmotic concentration
positive feedback
A mechanism by which a system responds to changes in its internal or external environment by amplifying the direction of the change, often leading to a cascade of events.
negative feedback
A mechanism by which a system responds to changes in its internal or external environment by reversing the direction of the change, thereby maintaining homeostasis.
exocrine tissue
The system for secreting substances through ducts onto surfaces of the body. Examples are sweat and digestive enzymes.
endocrine tissue
The system for secreting hormones from glands into the blood. These hormones help control body functions.
what are islets of langerhans
Clusters of cells in the pancreas that produce hormones insulin and glucagon.
pancreatic endocrine cells
insulin importance and secretion for regulation of glucose
Insulin is produced and secreted by the beta cells of the islets of Langerhans in response to rising blood glucose levels. It stimulates glucose uptake from the blood into the cells.
glucagon importance and secretion for regulation of glucose
Glucagon is produced and secreted by the alpha cells of the islets of Langerhans in response to decreasing glucose levels. It stimulates the liver to release stored glucose into the bloodstream.
what happens when the blood glucose level rises above the normal range:
-Beta cells of the islets of Langerhans release insulin into the bloodstream.
-Insulin promotes (mainly) cells of the liver, muscles and fat tissue to take up glucose from the blood to decrease the blood glucose level. The glucose is stored as glycogen in the cells of muscle and liver, or as fat in the cells of fat tissue, for later use.
-As the blood glucose levels decrease, the secretion of insulin also decreases.
what happens when If the blood glucose level falls below the normal rang
-Alpha cells of the islets of Langerhans release glucagon into the bloodstream.
-Glucagon promotes (mainly) the cells of liver and fat tissue to break down glycogen and lipids and release the glucose into the blood until the level of blood glucose increases to the normal range.
-As the blood glucose levels increase, the secretion of glucagon also decreases.
what causes hyperglacaemia
Insufficient insulin production or ineffective use of insulin will result in high levels of blood glucose. Continued high blood glucose concentration
hormonal disorder that causes hyperglycaemia is called diabetes.
what happens to individuals with diabetes
cells cannot obtain enough glucose from the blood. Cells start to burn the body’s supply of fats and proteins. Since the digestive system continues to absorb glucose, the glucose concentration in the blood can become extremely high.
The kidneys start filtering excess glucose from the blood. Kidneys also draw water from blood to dilute the urine which causes dehydration of the body. The person becomes unusually and continually thirsty
what are the 2 types of diabetes
type 1, type 2
type 1 diabetes
insulin-dependent or early onset diabetes
unable to produce insulin. Insufficient insulin production leads to chronically elevated levels of glucose in the bloodstream – hyperglycaemia.
no known cure, must manage their blood glucose levels through a combination of insulin therapy, dietary modifications and regular exercise.
what are risk factors of type 1 diabetes
family history, age (younger), race, poor nutrition
symptoms of type 1 diabetes
feeling more thirsty
unirantion increase
very hungry
blurred vision
weight loss
tired
related health problems of type 1 diabetes
loss of eye sights
foot problems
heart disease
high blood pressure
kidney disease
stroke
nerve damage
