Human Endocrine System Practice Flashcards

A complete set of practice flashcards covering the Human Endocrine System, including glands, hormones, disorders, and homeostatic mechanisms as described in the lecture notes.

Which gland is known as the "master gland" and where is it located?

The pituitary gland (also called the hypophysis); it hangs from the hypothalamus by a stalk in the brain.

Where is ADH (anti-diuretic hormone) produced and where is it stored?

ADH is produced in the hypothalamus and stored in the posterior pituitary gland.

What is the function of ADH in the kidneys?

It increases the permeability of the collecting ducts of the nephrons, leading to increased reabsorption of water, more concentrated urine, and lower urine volume (osmoregulation).

What are the two hormones released by the posterior lobe of the pituitary?

ADH (anti-diuretic hormone) and Oxytocin.

What are the two functions of Oxytocin?

It causes uterine contractions in labour and stimulates milk ejection from the mammary glands (breasts).

Which gland targets the thyroid to cause the release of thyroxin?

The anterior lobe of the pituitary gland via Thyroid-stimulating hormone (TSH).

What element is required for thyroxin to become active?

Iodine.

What are the symptoms of hyperthyroidism?

Restlessness, weight loss, increased appetite, excessive sweating, anxiety, hyperactivity, diarrhoea, enlarged thyroid gland (goitre), and exophthalmos (protruding eyeballs).

What is the difference between Myxoedema and Cretinism?

Myxoedema occurs in adults due to hypothyroidism (low metabolic rate, tiredness, weight gain), while Cretinism occurs in children (stunted growth, mental retardation, lack of sexual maturity).

What is the effect of growth hormone (GH) on the body?

It promotes increase in cell size and mitosis, and increases the rate of protein synthesis, especially in bone and muscle.

What is acromegaly?

A condition caused by too much growth hormone in adults, leading to thicker bones (enlarged hands, feet, jaw, and tongue) because bone epiphyses have already fused.

What is rBST or rBGH?

Genetically engineered Bovine Somatotropin or Bovine Growth Hormone used to improve milk production in cows.

Which cells in the testes are stimulated by Follicle Stimulating Hormone (FSH)?

The Sertoli cells, which then stimulate sperm production (spermatogenesis).

What is the role of Luteinising Hormone (LH) in females?

It causes ovulation (release of the egg) and stimulates the formation of the corpus luteum.

Which hormones are produced by the alpha and beta cells of the Islets of Langerhans?

Alpha cells produce glucagon and beta cells produce insulin.

How does insulin lower blood glucose levels?

It helps cells take in glucose for cellular respiration and causes the liver and muscles to convert blood glucose into glycogen for storage.

What is the normal blood glucose concentration range?

Between $3,5 \, \text{--} \, 5,5 \, mmol/litre$ of blood.

What is the difference between Type 1 and Type 2 diabetes?

Type 1 is an autoimmune disease where the immune system destroys beta cells (lack of insulin); Type 2 is a lifestyle disease where body cells resist or don't respond properly to insulin.

From which part of the adrenal gland is adrenalin secreted?

The adrenal medulla.

What are the primary functions of cortisol?

To increase blood sugar through gluconeogenesis, suppress the immune system, and aid with fat, protein, and carbohydrate metabolism.

What are the three components of a negative feedback system?

1. A receptor (detects change), 2. A control centre (activates corrective mechanism), 3. An effector (corrects the change back to the set point).

What are the anabolic effects of testosterone?

It helps build and grow muscle, promotes bone density, and helps a person recover quicker from injury.

Define homeostasis.

The maintenance of a constant internal environment (tissue fluid and blood) in the body.

What are the causes of infertility in males?

Low sperm count, poor sperm quality, ejaculatory problems, testicular problems, or hormonal imbalances.