endocrine system Flashcards
what is the endocrine system
complex network of glands and organs that produce and release hormones into the bloodstream to regulate various bodily functions.
they act as chemical messengers to travel around the body ad target cells and organs.
what are the main glands and organs involved in the endocrine system
-hypothalamus
-pituitary gland
-thyroid gland
-parathyroid gland
-adrenal gland
-pancreas
-gonads (ovaries and testes)
nocioception (for pain/stimulus response)
proprioception (movement)
what does the hypothalamus do and where is it situated
located in the rain, links the nervous system to the endocrine system via pituitary gland.
produces, releases and inhibits hormones that control the secretion of hormones from the pituitary gland.
what does the pituitary gland do and where is it situated
back of the brain, often known as the master gland.
regulates other endocrine glands.
divided into:
-anterior pituitary gland- produces hormones.
-posterior pituitary- stores and releases hormone produced by hypothalamus.
what does the thyroid gland do and where is it situated
located in the neck.
produces thyroid hormones that regulate metabolism, growth, and development.
also produces calcitonin, which helps regulate calcium levels.
what does the adrenal glands do and where is it situated
situated on top of the kidneys
-adrenal cortex- produces corticosteroids (cortisol, aldosterone, and adrenal androgens)
-adrenal medulla produces catecholamines (adrenaline and noradrenaline)
what does the pancreas do and where is it situated
has both endocrine and exocrine functions.
endocrine function involves producing insulin (lowers blood sugar), glucagon (raises blood sugar) and somatostatin (regulates other pancreatic hormones)
exocrine function involves production and secretion of digestive enzymes into gastrointestinal tract.
what does the gonads do and where is it situated
-ovaries- produce oestrogen and progesterone, regulate female reproductive function.
-testes- produces testosterone, which regulates male reproductive functions.
what are the three main types of hormones
-peptid hormones
-steroid hormones
-amine hormones
what are peptide hormones
-made up of amino acids
-e.g: insulin, glucagon, growth hormone and more
-they act on cell membrane receptors.
what are steroid hormones
-derived from cholesterol
-e.g: cortisol, aldosterone, oestrogen, progesterone and testosterone
-act on intracellular receptors and affect gene transcription.
what are amine hormones
-derived from amino acids
-include thyroid hormones and catecholamines (adrenaline and noradrenaline)
-act on both cell membrane and intracellular receptors.
explain the lock and key model
enzyme –> enzyme-substrate complex –> enzyme- products complex –> enzyme + products.
how do hormones work
-Hormones bind to specific receptors on target cells.
-A target cell responds to a hormone because it bears receptors for the hormone
-trigger intracellular signally cascades that regulate: gene expression, protein synthesis, or other cellular activities.
what do feedback mechanisms do
maintain homeostasis by regulating hormone production
what does negative feedback do
inhibit further hormone release when levels are adequate
what does positive feedback do
amplify hormone secretion in response to specific stimuli
what is endocrine shock
A broad category of shock caused by hormonal imbalances, leading to metabolic disturbances.
what is hypoglycaemia
A specific type of metabolic shock caused by an excessively low blood glucose level, often due to an overdose (excess) of insulin or inadequate food intake.
what is hyperglycaemia
A specific type of metabolic shock caused by excessive high blood sugar levels, commonly caused by missed medications , medications or illness
what is diabetic ketoacidosis
DKA is a condition in which high blood sugar and acid buildup in the blood occur because the body lacks enough insulin, producing ketones. High levels of ketones make your blood acidic.
what is adrenal crisis
lack of cortisol
(it can also occur if existing cortisol replacement does not meet body’s needs)
what does insulin do
plays a crucial role in maintaining blood glucose levels by helping cells to absorb glucose.
-helps store glucose (as glycogen)
-promotes fat storage
-prevents fat breakdown
-regulates protein synthesis
cellular effects of DKA.
what is homeostasis
process by which living organisms maintain a stable internal environment despite changes in external conditions.
-balance and stability
-feedback mechanisms
-negative feedback
-positive feedback
-dynamic equilibrium
how does homeostasis maintain balance and stability
regulating temperature, pH levels, glucose concentration and other vital conditions.
what are feedback mechanisms
detect changes and respond accordingly.
-sensors
-control centre
-effectors
what is negative feedback
When a change is detected, negative feedback works to counteract the change and bring conditions back to their normal range.
e.g: if body temp rises, sweating and increased blood flow to akin are activated to cool the body.