The endocrine system Flashcards
What is the endocrine system?
A system of hormones that controls many aspects of physiology and that work with different organs and all have different functions.
What is the endocrine system responsible for?
Regulating growth and development
Regulating reproductive system
Regulating internal environments of the body
Give the meaning of the word ‘gland’
Group of cells that makes chemicals such as hormones or enzymes
Give the meaning of the word hormone
Chemical messenger released into blood by endocrine gland that acts on a target tissue
What will exocrine glands do?
Release anything they produce into ducts or onto body surface
Give the components of the endocrine system
Pineal gland
Parathyroid gland
Thymus
Adrenal glands
Hypothalamus
Pituitary gland
Thyroid gland
Pancreas
Give the role of the hypothalamus
Reponsible for body temp control and water balance. it contains most homeostaic mechanisms and controls pituitary and thyroid gland.
What two sections are the pituitary gland split into?
Posterior and anterior lobes
Give the role of the growth hormone
Stimulates muscle and bone cells to divide and stimulate intestines to absorb calcium and the pituitary gland is responsible for this
Give the role of the pineal gland
Produces melatonin that regulates sleep and body circadian rhythms
Give the meaning of the word ‘metabolism’
Describes all chemical reactions that take place in the body
What does metabolic rate mean?
Rate at which energy from food is transferred by metabolic reactions that take place in the body.
What 4 hormones are involved withinn thyroid function?
Thyrotropin-releasing-hormone (TRH)
Thyroid-stimulating hormone (TSH)
triiodothyronine & thryoxine (T3 & T4)
What does the parathyroid secrete?
PTH that increases concentraton of C02 ions in blood and targets bone and kidneys
Give the role of G cells
Gastrin is released into the stomach and targets it stimulating the hydrochloric acid, digestive enzymes, stomach muscle contraction.
Give the role of the adrenal glands
Adrenaline is produced in the adrenal medulla and preps body for fight or flight response
What does adrenaline do?
Works on sympathetic nervous system
Increases heart rate
Increases blood flow to the muscles and brain
Decreases blood flow to the gut and skin
Stimulates liver cells to convert glycogen to glucose
Dilates pupils
What is the pancreas endocrine function?
Islets of Langerhans that produces insulin and glucagon
What is the pancreas exocrine function?
Produces digestive enzymes that are taken to the duodenum via duct. The enzymes are inactive until they reach the small intestines.
Thyroxine storage and role
In the thyroid and regulates metabolic rate
Cortisol storage and role
Adrenal cortex
Response to stress and acts on the liver and muscle cells.
Oestrogen storage and role
Ovaries
Involved in menstruation cycle regulation
Testosterone storage and role
Testes
Sex organs
Gastrin storage and role
Stomach
Several actions in digestion involving stomach and small intestines
Growth hormone storage and role
Pituitary
Responsible for normal growth
FSH storage and role
Secreated by pituitary gland and acts on ovaries.
Stimulates growth and developments of egg follicles during the first half of the menstral cycle.
What are the kidneys in charge of doing?
Regulating water balance
What happens if there is low water potential?
It leads to dehydration
What happens if there is a high water potential?
The body becomes over-hydrated
What is the amount of water lost in urine controlled by?
The hypothalamus through ADH
What happens when water potential is low?
Hypothalamus stimulates release of ADH from posterior pituitary. ADH then causes more water to be absorbed by kidney and water potential returns to normal.
What happens when water potential is too high?
Hypothalamus inhibits release of ADH and less water is reabsorbed by the kidney and reduces water potential to normal level
What is the cause of type 1 diabetes?
Destruction of beta cells in the pancreas leading to insulin defiency caused by an autoimmune response.
What is the cause of type 2 diabetes?
Insulin resistance so liver and muscle cells no longer respomd to insulin
What are risk factors of type 2 diabetes?
Obesity
Lack of physical activity
Poor diet
Give the meaning of hyperglycaemia
Blood glucose rises above normal level
Give the meaning of hypoglycaemia
Blood glucose falls below normal
What can type 1 diabetes lead to?
Diabetic ketoacidosis
What can happen long-term caused by type 2 diabetes?
Hyperglycaemia can damage small blood vessels leading to long-term complications
Give complications of diabetes
Diabetic retinopathy - damage to capillaries in the retina
Diabetic neuropathy - damage to blood vessels supplying nerves
Diabetic kidney disease - damage to capillaries in the glomerulus
Increased risk of cardiovascular disease
How can type 1 diabetes be treated?
By replacing missing insulin via injections
How can type 2 and gestational diabetes be treated?
Lifestyle changes e.g. healthy eating and exercise
What is advised for those with gestational diabetes?
To keep consumption of sugar, fat and salt to a minimum
What does metformin do?
Treat high blood sugar levels and is taken as a tablet
In some cases, how can gestational diabetes be treated?
Insulin injections if needed and other medications if these do not work adequately.
