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What is the endocrine system?
The endocrine system provides hormones that act as messengers. Hormones target specific glands and tissues and bring about change. 
What are the 6 main glands in the body?
1. Pituitary gland : located in the head (anterior/posterior gland)
2. Thyroid gland : Located in the throat
3. Pancreas
4. Adrenal glands : sit on top of the kidneys
5. Gonads/ovaries : in females
6. Testes : in males
Define the following terms:
1. Endocrine
2. Autocrine
3. Paracrine
1. Endocrine: Hormones are released into the bloodstream.
2. Autocrine: Hormone acts on the same cell that released it.
3. Paracrine: Hormone is released into the surrounding tissue rather than the bloodstream.
Name some of the different substances that make up hormones.
Amines : Catecholamines (adrenaline and dopamine) and thyroid hormones
Proteins and peptides: Insulin, calcitonin, oxytocin, growth hormine (GH)
Steroids: Mineralcorticoids, glucocorticoids (anti-inflammatory) and gonoadocorticoids (sex hormones)
Name some general stimuli that result in the secretion of hormones.
- a level of constituent in the blood (e.g. blood sugar)
- Signalling hormones that cause secretion of other hormones (e.g. trophic hormones that are secreted by the pituitary gland to stimulate the adrenal gland to secrete hormones)
-Direct nerve stimulation to cause glands to secrete hormones
- 'stretch' - may be involved in the release of a number of hormones related to blood pressure regulation.
Describe the process of the endocrine system when a drop in blood pressure occurs in terms of cardiac function
1. Stimulus :  A drop in BP signals the brain to stimulate the adrenal gland to secrete adrenaline.
2. First Messenger NT/Hormone : Adrenaline released by the adrenal gland acts as the first messenger and travels by the bloodstream to the target (heart) where it binds.
3. Target: Hormines target receptors on the heart. Adrenaline binds to an adrenergic cell in the heart.
4. Intracellular Secondary Messenger: receptors mediate their effects directly by secondary messengers that may be intracellular enzymes, lipids or calcium. Adrenergic receptors cause an increase in heart rate by modulating calcium ion channels.
5. Response : the cell response aims to modulate the original stimulus that was initiated. An increase in hr increases BP thus correcting the initial stimulus.
Name some characteristics of the hypothalamus.
The hypothalamus is located in the brain, responsible for:
1. Secreting regulatory hormones which control the release of several hormones from the pituitary gland.
2.  Exerts neuronal control over the endocrine cells of the adrenal glands through the SNS
3. Acts as an endocrine gland by secreting oxytocin and ADH.
What is Cushings Disease?
Adrenal gland disorder:
Cushings Disease:
Excessive levels of hormone ACTH This can be a result of high medication doses of corticosteroids ot a tumour causing a gland to procduce excessive amounts.

What is Addisons Disease?
Adrenal Gland Disorder:
Addisons Disease (Hypoadrenocorticocism) : A rare disorder where the adrenal gland is damaged and doesn't produce enough aldosterone.
In the medulla of the adrenal gland, is it largely stimulatory or relaxed in terms of its stimulation?
Stimulatory. It is strongly innervated by the SNS via the splanchic nerve which stimulates chromaffin cells to secrete catecholamines adrenaline (80%) and noradrenaline (20%)
What is the main mineralcorticosteroid secreted by the adrenal gland?
Aldosterone.
What is the main bodily response when the aldosterone hormone is secreted by the adrenal gland?
Aldosterone increases the reabsorption of sodium, keeping sodium levels normal in the body. This will increase the reabsorption of water by osmosis and increase renal excretion of pottasium.
What are the two significant regulators/stimuli of aldosterone secretion?
1. Concentration of K+ in the extracellular fluid. Too much potassium will cause aldosterone to be released.
2. Activation of the renin angiotensin system as a result of decreased renal blood flow.
What hormones are released by the anterior pituitary?
1. Thyroid Stimulating Hormone (TSH): triggers the release of thyroid hormones from the thyroid gland
2.  Adrencorticotrophic Hormone (ACTH): stimulates the release of steroid hormones from the adrenal glands.
3. Gonadotrophins: Follicle stimulating Hormone (FSH) and Luteinising Hormone (LH)
What is the function of the follicle stimulating hormone?
FSH: stimulates follicle development in femals and sperm production in males.

What is the function of the Luteinizing Hormone?
LH: Induces ovulation in females and androgen production in males.
Describe the compartmentalisation of the adrenal cortex, and what each zone functions for.
The adrenal cortex is divided into different zones, where each zone produces different hormones.

Zona glomerulosa: secretes aldosterone for sodium retention.
Zona fasciculata secretes hydrocortisone for anti-inflammation. 
Zona reticularis secretes androgens and oestrogens for development of male and female features.

In the medulla of the adrenal cortex, is this largely controlled by SNS or PSNS function?
The medulla is largely innervated by the SNS via the splanchic nerve, which stimulates chromaffin cells to secrete catecholamines adrenaline and noradrenaline.  These are primary mediators of the fight or flight response.
is noradrenaline a hormone or neurotransmitter?
neurotransmitter.
What is the function of chromaffin cells?
to secrete catecholamines adrenaline and noradrenaline.
what hormones does the anterior pituitary secrete?
all apart from oxytocin and ADH. these include ACTH, gonadotrophic, thyroid stimulating Hormone, GH
What is a pheochromocytoma?
Tumour of chromaffin cells causing persistant or episodic high blood pressure.
What is the function of the pancreas?
The pancreas has two main functions:
- To secrete gastric enzymes and a large volume of bicarbonate that neutralises gastric acid, causing a more alkaline environment in the intestine. 
- It is highly vascularised to allow hormones to enter the bloodstream. These hormones are secreted by cells in the pancreas.
What area in the pancreas is responsible for secreting hormones?
islet of langerhans
In the pancreas, the islet of langerhans, which cells produce and secrete what hormones?
alpha cells : secrete hormone glucagon (when blood sugar is low)
beta cells : secrete hormone insulin (when blood sugar is too high)
gama cells : produce pancreatic peptide
Delta cells : produce somatostatin (which can inhibit insulin and glucagon hormones)
What is the function of insulin?

  • Reduces blood glucose levels

  • Helps to absorb nutrients like amino acids

  • Insulin secretion of maximal after food intake when blood is laden with glucose.

How does insulin reduce blood sugars?
Glucose cannot penetrate cell membranes. Glucose transport proteins are required to transport insulin into cells. Insulin reduces blood sugars by facilitating glucose transport into cells. Insulin will bind to the cell receptor membrane, causing a series of events that leds transport proteins being inserted into the membrane.
Where is excess glucose stored in the body?
Excess glucose in the blood is converted into glycogen, which is then stored in the liver and muscle cells.
What body mechanisms will occur when blood sugars are low?
Stored glycogen in the liver and muscle cells will be broken down by hormone glucagon to liberate glucose into the blood.
Do negative or positive feedback mechanisms regulate glucose levels in the blood?
negative feedback mechanisms.
What are some characteristics of type 1 diabetes?
Type 1 diabetes: T1DM
No secretion of insulin.

Treatment: Hormone replacement therapy (HRT) in the form of natural or synthetic insulin.
What are some characteristics of type 2 diabetes?
Diabetes type 2: Insufficient insulin or resistance to secreted insulin.

Treatment: drugs that:
1. Stimulate beta cells to produce insulin (Sulphonylureas)
2. modulate glucose metabolism, but do not increase insulin secretion (Metformin, Biguanides)
Name the drugs that:
1. Stimulate the beta cells in the pancreas to produce insulin? (T2DM)
2.  Regulate blood glucose metabolism, but do not increase insulin secretion (TD2M)
1.Sulphonylureas (sulph-phon-ol-ureas)
2. Biguanides - Metformin. Metformin helps the cells respond naturally to insulin.
What are some nursing considerations or symptoms or hypoglycaemic patients?
Low blood sugars can cause:
- agitation
- confusion
- fatality
What are some nursing considerations for patients who are hyperglycaemic?
High blood sugars:
- Glucose in rine
- can cause fatal fluid loss
- In the absence of insulin, energy can't be derived from gluose efficiently, leading to the production of ketones (DKA)
- Can inhibit the bodys ability to heal, so patients may develop chronic wounds that may become gangrenous, particularly at extremities
- high risk of wounds becoming infected.
Where can you find the thyroid gland? and briefly outline its structure.
Found in the neck, below the larygnx. It is made of 2 lobes and 4 smaller glands known as parathyroid glands.
What are the functions of the thyroid hormones? Name the two main hormones secreted by the thyroid gland.
Hormones thyroxine and tri-iodothyroxine increase metabolism. They stimulate body and growth by:
- ATP production
- Activate genes that stimulate energy use
- Lipolysis (fat breakdown)
- stimlate protein synthesis
-Enhance the actions of catecholamines.
Outline the pathway in which thyroxine hormones are released.
1. The hypothalamus releases Thyrotropin releasing hormone (TR). This hormone signals
2. The pituitary gland to release thyroid stimulating hormone (TSH) which stimulates the
3. Thyroid gland to release thyroxine and tri-iodothyroxine into the blood. These hormones bind to thyroid binding proteins.
Outline how the release of thyroxine hormones are stopped.
The amount of free unbound hormone in the blood will inhibit further TSH secretion from the pituitary gland once hormone levels have normalised.
What is hyperthyroidism? and hypothyroidism?
Hyperthryoidism: over function of thyroid
Hypothyroidism: under function of thyroid
What are some signs and symptoms of hypothyroidism?
How can you treat hypothyroidism?
- lethargy, depression, weightgain 

Treatment: Hormone replacement therapy (HRT) by oral thyroxine
Safe treatment but overdose may cause restlessness, anxiety, insomnia, arrhythmia
What are some signs and symptoms of hyperthyroidism? How can you treat hyperthyroidism?
Hyperthyroidism: 
-restlessess, anxiety, insomnia, arrhythmias. Caused by a section of the thyroid producing too much hormone. 

Treatment: radioactive iodine leading to the destruction of defective tissue.
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