Endocrinology Flashcards
What is the Endocrine System Responsible for?
Responsible for the chemical co-ordination of Hormones in the body.
What is a Endocrine Gland?
> A gland that pours its hormones directly into the blood stream.
What is a Exocrine Gland?
> A Gland which has its secretions/hormones transported by means of ducts.
What is a Hormone?
> Chemical messengers which are Protein in nature, secreted by Endocrine Glands.
What are the Endocrine Glands?
> Hypothalamus
Pituitary Gland/ Hypophysis
Thyroid Gland
Andrenal Gland
Pancreas (Islets of Langerhans)
Ovaries
Testes
What is the Function of the Hypothalamus?
> Produces the Anti-Diuretic Hormone (ADH).
What is the Location and Function of ADH?
> Found and released from the Pituitary Gland
> Function is to help in the Concentration of Urine.
What is the Function of the Pituitary Gland?
° Produce many important hormones. That control other Endocrine Glands. It’s also called the Master Gland.
What are the Hormones that the Pituitary Gland produces?
> Growth Hormone
Thyroid Stimulated Hormone (TSH)
> Follicle Stimulating Hormone (FSH)
Luteinising Hormone (LH) in females
Prolactin
What is the Function of the Growth Hormone?
> Essential for the growth and development of the skeleton and muscles and thus the body as a whole.
What is Hypersecretion of Growth Hormone?
> When the secretion of Growth Hormone is too much. This is also known as Gigantism.
What is Hyposecrection of Growth Hormone?
> The secretion of too Little Growth Hormone. This is also known as Dwarfism.
What is the Function of (TSH)?
> Simulates the Thyroid Gland to secrete the Hormone Thyroxin.
What is the Function of (FSH)?
> In the Female, this Hormone controls the production of ova (eggs) in the Graafian Follicles of the ovary.
> In Males, it controls the development of sperm.
Negative Feedback: Control of Thyroxine levels
> Thyroxine Levels increase above normal levels
> Pituitary Gland is Stimulated
> Pituitary Gland produces less TSH
> Low TSH level stimulates the Thyroid Gland
> The Thyroid Gland secretes less Thyroxin
> The Thyroxin level thus decreases
> Thyroxin level returns to normal
Glucose Levels increase:
> Glucose levels in the blood increase above normal levels.
> The Pancreas is Stimulated to secrete insulin into the blood.
> Insulin travels in the blood to the liver, where it stimulates the conversion of excess glucose to glycogen which is then stored.
> The Glucose level in the blood now decreases and returns to normal.
When the Blood has more water than usual.
> The Hypothalamus is Stimulated and sends signals to the Pituitary Gland to produce more ADH.
> ADH travels in the blood into the Kidneys.
> ADH increases the permeability of the of the collecting Duct and the distal Convoluted tubules of the Kidney.
> More water is absorbed and passed into the surrounding blood vessels.
> The Water level in the blood returns to normal.
When Salt levels increase:
> Receptor cells in the efferent and afferent arterioles of the Kidney detect the high salt level.
> The Adrenal Gland is Stimulated to secrete less aldosterone.
> This decreases the re-absorption of sodium ions from the renal tubules in the Kidney to the surrounding blood vessels.
> The Salt level in the blood returns to normal.
What is the purpose of the Thyroid Gland?
> Controls the basic metabolism rate
> Affects growth by maintaining the GH content of the Pituitary.
> Affects the functioning of the heart and nervous system.
What is Hyperthyroidism?
> Overproduction of Thyroxine
> Symptoms include:
• increased metabolic rate which leads to hyperactivity and nervous tension.
• Development of Goitre (bug eyes)
What is the purpose of the Adrenal Gland?
> Secretes the Hormone Adrenalin and Aldosterone.
What are the results of the Adrenal Glands secreting Adrenalin?
• Increases the heartbeat
• Raises blood pressure
• Speeds up the conversion from glycogen to glucose
• Causes pupils to dilate
• Increases the blood supply to the cardiac and skeletal muscles, ect..
