Overview Of The Endocrine System Flashcards by Ashleigh Davies

What is a hormone

A hormone is a substance secreted directly into the blood by specialised cells which bind to specific receptors in target cells to influence a cellular response

How well did you know this?

Not at all

Perfectly

What are the endocrine glands found within the body

Hypothalamus
Pituitary
Thyroid
Parathyroid
Adrenals
Pancreas
Ovaries
Testes

How well did you know this?

Not at all

Perfectly

What else within our bodies can be classed as an endocrine organs

Heart
Liver
Intestines
Fat
Kidneys
Skin

How well did you know this?

Not at all

Perfectly

What are the 3 different types of hormones

Steroid
Peptides
Thyroid hormones

How well did you know this?

Not at all

Perfectly

What are steroid hormones synthesised from

Cholesterol

How well did you know this?

Not at all

Perfectly

What are catecholamines synthesised from

Tyrosine

How well did you know this?

Not at all

Perfectly

How do hormones exert their effect

They bind to cell surface and intracellular receptors

How well did you know this?

Not at all

Perfectly

What is the basic action of a thyroid hromone

Basal metabolic rate and growth

How well did you know this?

Not at all

Perfectly

What is the basic action of the parathyroid hormone

Ca2+ regulation

How well did you know this?

Not at all

Perfectly

What is the basic action of cortisol

Glucose regulation and inflammation

How well did you know this?

Not at all

Perfectly

What is the basic action of aldosterone

Blood pressure and Na+ regulation

How well did you know this?

Not at all

Perfectly

What is the basic action of catecholamines

Blood pressure and stress

How well did you know this?

Not at all

Perfectly

What is the basic action of oestradiol

Menstruation and femininity

How well did you know this?

Not at all

Perfectly

What is the basic action of testosterone

Sexual function and masculinity

How well did you know this?

Not at all

Perfectly

What is the basic action of insulin

Glucose regulation

How well did you know this?

Not at all

Perfectly

What is the basic action of ANP

Na+ regulation

How well did you know this?

Not at all

Perfectly

What is the basic function of vitamin D

Ca2+ Regulation

How well did you know this?

Not at all

Perfectly

How are hormone levels measured

Bioassays
Immunoassays
Mass spectrometry

How well did you know this?

Not at all

Perfectly

What is the most important endocrine organ

The pituitary gland

How well did you know this?

Not at all

Perfectly

What hormones are secreted by the anterior pituitary

ACTH - regulation of adrenal cortex
TSH - thyroid hormone regulation
GH - growth hormone
LH/FSH - reproductive control
PRL - Breast milk production

How well did you know this?

Not at all

Perfectly

What hormones are secreted by the posterior pituitary

ADH - water regulation
Oxytocin - breast milk expression

How well did you know this?

Not at all

Perfectly

What are example of endocrinological disorders

Thyrotoxicosis
Cushing’s disease
Acromegaly

How well did you know this?

Not at all

Perfectly

What are Avaliable treatments for thyrotoxicosis

Destruction of thyroid tissue using radioiodine
Anti thyroid drugs to stop hormone synthesis
Partial surgical ablation of thyroid

How well did you know this?

Not at all

Perfectly

What drugs can be used to treat functioning pituitary tumours

Somatostatin analogues
Dopamine agonists
GH receptor antagonists

What is a type of steroid hormone

Cortisol

What is an example of a peptide hormone

Insulin

Hat is an example of a thyroid hormone

Thyroxine

Which endocrine gland is the main regulator for metabolism

Thyroid gland

What does high levels of thyroid hormones such as T3 and T4 cause

They cause metabolic pathways and metabolic processes to occur more frequently and faster

What metabolic processes are increased by thyroid hormones

Basal metabolic rate Gluconeogenesis Glycogenolysis Lipogenesis Thermogenesis

What are the 6 steps involved in the synthesis of thyroid hormones

Active transport of iodide into the follicular cells via a sodium-iodide symporter Thyroglobulin is a large protein rich in thyrosine is formed in the follicular ribosome Exocytosis of the thyroglobulin into the follicle lumen where it is stored as colloid Iodination of the thyroglobulin to produce MIT and DIT Coupling of MIT and DIT = T3 hormone and coupling of DIT and DIT = T4 hormone Endocytosis of iodinated thyroglobulin back into follicular cell and free T3 and T4 released

How are Thyroid hormones carried

They are carried by plasma proteins

How are T3 and T4 deactivated and where does this happen

They are deactivated by removing the iodine and is done in the liver and kidneys

Why are thyroid hormones released

Thyroid hormones are released due to the hypothalamus detecting low plasma concentration if thyroid hormones which stimulates the release of TRH into the hypophyseal portal system. TRH binds to cells in the anterior pituitary gland stimulating the release of TSH into the systemic circulation. TSH then binds to cells off the membrane of the thyroid follicular cells inducing the synthesis of thyroid hormones

What is goitre

Enlarged thyroid

What is hyperthyroidism

The thyroid is overactive

What can caused hyperthyroidism

Graves’ disease- an autoimmune disease where antibodies are produced that stimulate TSH receptors

What is hypothyroidism

They thyroid is under active

What can cause hypothyroidism

Hashimotos disease- an autoimmune disease where thyroid follicles are destroyed

What are the main 3 actions of parathyroid hormone

All 3 actions act to increase the calcium levels in the body Increased bone resorption Increased reabsorption in the kidneys Vitamin D synthesis

How is parathyroid hormone regulated

It is controlled by a negative feedback loop Chief cells have a unique G-protein calcium receptor on their cut face which can regulate the hormone When calcium is elevated PTH production must stop to prevent further elevation of calcium which could lead to hypercalcaemia, to do this calcium binds to the G protein and stimulated the production of phosphoinositide which prevents any more secretion of PTH and so calcium is deposited into the bones When calcium is reduced the reverse happens

What are the different types of hyperparathyroidism

Primary - direct alterations to the parathyroid gland like a benign tumour Secondary - elevated PTH due to reduced calcium levels due to chronic renal failure or decreased vit D intake Tertiary - prolonged secondary Malignant - caused by some tumours such as bronchial squamous cell carcinomas

What cells are responsible for producing glucagon

Alpha cells in the pancreas

What cells are responsible for producing insulin and amylin

Beta cells of the pancreas

What cells are responsible for productions somatostatin

Delta cells in the pancreas

What cells are responsible for producing pancreatic polypeptide

Gamma cells in the pancreas

What cells are responsible for producing ghrelin

Epsilon cells in the pancreas

What type of hormones do the pancreas produce

Polypeptide hormones

What is the function of insulin

Decrease blood glucose

What is the function of amylin

Slows gastric emptying to prevent spikes in blood glucose

What is the function of glucagon

Increase blood glucose

What is the function of somatostatin

Regulates islet cells secretion of other hromones

What is the function of pancreatic polypeptide

GI function

What is the function of Ghrelin

Increase in appetite

Where is oxytocin released from

Posterior pituitary gland

What is the main function of oxytocin

Regulation of lactation and control of the uterine contractions in labour

What are the 2 posterior pituitary hormones

Oxytocin and ADH

What is the main function of ADH

Increases plasma osmolarity