Endocrine System Flashcards
What is the endocrine system?
The endocrine system is a group of glands that produce hormones, which are chemical messengers transported by the blood to target areas in the body.
What is the difference between endocrine and exocrine glands?
• Endocrine gland: Produces hormones and releases them directly into the blood (e.g., the thyroid gland).
• Exocrine gland: Produces substances that are released into ducts (e.g., the salivary gland releases saliva into the mouth).
What is a hormone?
A hormone is a chemical messenger produced by an endocrine gland, transported by the blood, and many are protein in nature.
What hormones are produced by the pituitary gland, and what are their functions?
• FSH (Follicle Stimulating Hormone): Stimulates the production and maturation of eggs in the ovary.
• LH (Luteinizing Hormone): Triggers ovulation in females.
• Oxytocin: Stimulates uterine contractions during childbirth.
• Prolactin: Promotes milk production in breastfeeding.
• ADH: Stimulates water reabsorption in the kidneys.
• TSH: Stimulates the thyroid gland to release thyroxine.
What hormone does the thyroid gland produce, and what is its function?
• Hormone: Thyroxine.
• Function: Controls the metabolic rate.
Name the hormone produced by the adrenal gland and its function.
• Hormone: Adrenaline.
• Function: Helps the body cope with stress; it is the “fight or flight” hormone.
What hormones do the ovaries produce, and what are their functions?
• Oestrogen and Progesterone: Regulate the menstrual cycle and prepare the body for pregnancy.
What hormone is produced by the testes, and what is its role?
• Hormone: Testosterone.
• Function: Triggers sperm production and influences secondary sexual characteristics.
Why is the pancreas considered both an endocrine and exocrine gland?
• Endocrine: Produces insulin to control blood sugar levels.
• Exocrine: Produces digestive enzymes released into ducts.
How does the hypothalamus and pituitary gland control hormone activity?
The hypothalamus monitors internal conditions and directs the pituitary gland, which produces hormones that regulate other glands and organs.
What are the symptoms and treatments for thyroxine deficiency (hypothyroidism)?
• Symptoms: Lack of energy, weight gain, Myxedema in adults, Cretinism in children, and goitre.
• Treatment: Taking thyroxine tablets or iodine supplements.
What are the symptoms and treatments for thyroxine excess (hyperthyroidism)?
• Symptoms: Anxiety, weight loss, bulging eyes, and Graves’ disease.
• Treatment: Surgery to remove part of the thyroid or taking radioactive iodine.
Describe the negative feedback loop for thyroxine regulation.
- Low thyroxine: Hypothalamus signals the pituitary to release TSH, stimulating the thyroid to produce thyroxine.
- High thyroxine: Hypothalamus signals the pituitary to stop releasing TSH, reducing thyroxine production.
What is the function of insulin, and where is it produced?
• Function: Stimulates cells to absorb glucose from the blood and store it as glycogen.
• Produced by: The pancreas.
What is the function of the contraceptive pill, and which hormones does it contain?
• Function: Prevents egg release and implantation.
• Hormones: Oestrogen and progesterone.
