Endocrine/Exocrine System Flashcards
endocrine system
The endocrine system is a complex network of glands and organs. It uses hormones to control and coordinate your body’s metabolism, energy level, reproduction, growth and development, and response to injury, stress, and mood.
exocrine system
the exocrine system is a series of glands that secrete chemicals into a ductal system to an epithelial surface (e.g. Sweat, saliva)
hormone
Chemical mediators released by endocrine glands into the bloodstream where they travel to target tissue and generate a response.
hypothalamus
located in the Diencephalon, regulates secretions of all glands
pineal gland
Short stalk (pinecone) within the brain, not fully understood, is thought to regulate hormones such as melatonin
thyroid gland
Gland responsible for producing hormones such as triiodothyronine t3 and thyroxine t4 to help regulate the body’s metabolism
metabolism
the chemical processes that occur within a living organism to maintain life - food breakdown to form energy
pituitary gland
The master gland, that plays a major role in regulating vital body functions, it controls the function of most other hormone-secreting glands (such as the thyroid, adrenal, testes/ovaries etc)
adrenal gland
The adrenal medulla is found in the centre of the adrenal gland. This is responsible for synthesising adrenaline & noradrenaline.
cortisone
reduces inflammation
cortisol
acts upon adipose tissue and stimulates gluconeogenesis
increases sugars (glucose) in the bloodstream, enhances your brain’s use of glucose and increases the availability of substances that repair tissues
4 cells of islet of langerhans
percentages and secretory functions
20% alpha cells secrete glucagon
70% beta cells secrete insulin
5% delta cells secrete somatostatin
5% F cells secrete pancreatic polypeptide
treatment for diabetes
3
Metformin = stops stored glycogen turning into glucose, inhibition of hepatic gluconeogenesis
Sulphonylurea = a class of medications used to treat type 2, they usually act on beta cells to secrete more insulin
Sulphonylurea Gliclazide = stimulates beta cells to secrete insulin
diabetes mellitus type 1
aetiology
the body does not produce enough insulin
Macrophages phagocytose beta cells (no key for lock and key model) - beta cells are required for insulin secretions
caused by genetics, environmental, and auto-immune factors
cannot be prevented
diabetes mellitus type 2
aetiology
either the body does not produce enough insulin or the body does not react to insulin
caused by lifestyle, genetics, aging
can be prevented by adopting a healthy lifestyle, including sensible eating and exercise
gestational diabetes
Gestational diabetes is high blood sugar (glucose) that develops during pregnancy and usually disappears after giving birth. Happens as a result of the extra demands placed on the body during pregnancy.
(as a result of diabetes) hyperglycaemia
increased glucose in bloodstream due to lack of insulin or insulin receptors
(as a result of diabetes) polyuria
excessive waste products that cause over-urination, excessive glucose promotes diffusion of water across membrane via osmosis OSMOTIC PULL
(as a result of diabetes) polydipsia
knock on effect of polyuria
(as a result of diabetes) polyphagia
glucose unable to reach cells so stimulates ghrelin release. It is caused by the metabolism of fat and protein. Brain thinks its starving, signals for more fuel, but the body is unable to metabolise it. This creates a viscous circle by increasing blood glucose levels.
(as a result of diabetes) glucosuria
glucose unable to enter cells via lock and key model, remains in blood and is excreted
(as a result of diabetes) anorexia
a lack of glucose within body cells causes metabolism of adipose tissue, this causes gluconeogenesis
(as a result of diabetes) ketosis/acidosis
fat hydrolysis takes place when glucose cannot reach the cells, causing the release of ketones which make the blood acidic
effects of hyperglycaemia
4
hypertension - large volumes of blood glucose cause an increase in Osmosis. Water leaves the cell and enters the blood, increasing blood volume, thus, increasing BP
polyuria - as a result of high BP, less ADH is produced, thus more urine is produced
polydipsia - caused by large volumes of urine being produced
anorexia - caused by a lack of glucose in the cells, energy cannot be produced, cell function becomes impaired, starvation mode occurs, cortisol is released (acts on adipose tissue, stimulates gluconeogenesis)
ADH
anti-diuretic hormone
what happens when the blood glucose levels in the blood rise?
beta cells of pancreas release insulin into the blood
liver takes up glucose and stores it as glycogen
body cells take up more glucose
BM levels decline
what happens when the glucose levels in the blood drop?
Alpha cells of pancreas release glucagon
liver breaks down glycogen and releases glucose
BM levels increase
