L8 (T1): Calcium homeostasis, hyper and hypocalcaemia

ProlificSynergy avatar
ProlificSynergy
·
·
Download

Start Quiz

Study Flashcards

54 Questions

What percentage of normals have Chvostek’s Sign present?

10%

What percentage of calcium is protein-bound in the blood?

40%

What percentage of calcium is ionized (free) in the blood?

50%

What is the normal range for blood calcium level?

2.0 - 2.5 mmoles/l

What determines the release of Parathyroid hormone (PTH)?

Serum Calcium concentration

Where are the PTH1 receptors located?

Bone

What is the biological effect of PTH on bone?

Stimulation of osteoblasts

What is the primary action of PTH in the kidney?

Suppression of calcium excretion

Which of the following is a complication of primary hyperparathyroidism?

Osteoporosis

What is the common cause of secondary hyperparathyroidism?

Low serum 25 OH vitamin D

What is a cause of hypoparathyroidism?

Autoimmune disorder

What is the effect of vitamin D deficiency in the elderly?

Reduced bone mineral density

What is the primary purpose of the presentation mentioned in the text?

To be used for private study only

What may happen if the presenter disregards the instructions for the use of the presentation?

Breach of copyright

Which medical condition can destabilize neurons due to low calcium levels?

Hypocalcaemia

What is the physical sign of hypocalcaemia described as 'Trousseau’s sign'?

Carpopedal spasm

What is the role of calcium in blood clotting as mentioned in the text?

It is involved in blood clotting

Which medical professional is presenting in the mentioned presentation?

Dr. Trevor Wheatley

Where is the Princess Royal Hospital located?

Sussex, UK

What is the specialty of Dr. Trevor Wheatley as mentioned in the text?

Endocrinologist

What is the effect of hypocalcaemia on neurons?

Destabilizes neurons

What is the recommended action if someone has a first fit according to the text?

Check the serum calcium

What is the significance of calcium in exocytosis as mentioned in the text?

It is involved in neurotransmitter secretion

What is the primary biochemical process mentioned in relation to calcium in the text?

Many biochemical processes

What is the primary focus of the presentation mentioned in the text?

Endocrinology and the regulation of hormones

What is the suggested action if someone has a single nodule that autonomously produces excessive hormones?

Immediate removal of the affected gland

What was the specialty of Dr. Trevor Wheatley mentioned in the text?

Endocrinology

What is the effect of having an excess of hormones, as mentioned in the text?

Mechanisms for hormone removal are activated

What was the humorous perspective shared by the infectious diseases doctor about endocrinology?

Endocrinology is essentially very simple and easy to comprehend

What is the primary problem associated with having an excess of hormones?

Mechanisms for hormone removal are activated

What may be a consequence of an enlarged thyroid gland?

Breathing difficulties due to pressure on the trachea

What is the consequence of hypercalcemia on kidney function?

Increased urinary calcium excretion

What are Chvostek's sign and Trousseau's sign indicators of?

Neuromuscular irritability due to calcium imbalance

What is the effect of hypocalcemia on the body?

Seizures

What is the primary cause of osteoporosis?

Calcium imbalance

What can result from surgeons damaging the parathyroid glands during thyroid surgery?

Low calcium levels and neuromuscular symptoms

What is the main consequence of hypercalcemia mentioned in the text?

Increased risk of kidney stones and worsened osteoporosis

What is the role of parathyroid glands in response to low calcium levels?

Secrete parathyroid hormone

What is the function of the calcium-sensing receptor in the chief cells of the parathyroid glands?

Detect low calcium levels and trigger parathyroid hormone secretion

How does the body adjust total calcium levels for albumin levels?

To closely align with ionized calcium

What is the primary response of the body to low calcium levels?

Increased parathyroid hormone secretion

What is the significance of the parathyroid glands in calcium control?

They play a crucial role due to their production of parathyroid hormone

What is the primary site of action for parathyroid hormone (PTH) in the body?

Bone and kidney

How does parathyroid hormone (PTH) affect calcium levels in the bloodstream?

It increases calcium absorption in the kidneys

What is the consequence of low magnesium levels in relation to parathyroid hormone (PTH)?

Hypercalcemia and related health issues

How does parathyroid hormone (PTH) influence phosphate levels in the kidneys?

It decreases phosphate absorption in the kidneys

What is the role of the kidney in response to parathyroid hormone (PTH) activity?

Activation of vitamin D to enhance calcium absorption

What is the primary effect of parathyroid hormone (PTH) on bone cells?

It stimulates bone breakdown cells to increase serum calcium levels

What triggers the production of vitamin D in the body?

Ultraviolet light hitting the skin

What is the primary role of the kidney in vitamin D processing?

Stimulating the production of active vitamin D

What can lead to extremely low phosphate levels and related health issues?

Excessive parathyroid hormone production

What inhibits the production of active vitamin D in the body?

Fibroblast growth factor 23

What is a consequence of excessive parathyroid hormone production?

Increased serum calcium levels

How does the body's endocrine system regulate vitamin D production?

Through a negative feedback loop

Study Notes

Vitamin D and Calcium Regulation in the Body

  • Ultraviolet light hitting the skin triggers the production of vitamin D, which is effective in younger people but requires initial stores of the vitamin.
  • Vitamin D levels in the United Kingdom's population are generally low due to limited sun exposure and diet.
  • Vitamin D can also be obtained from the diet, but its sources may not be sufficient to meet the body's needs.
  • Elderly individuals with poor diets and limited sun exposure can have very low vitamin D levels, leading to health issues.
  • Vitamin D is hydroxylated in the liver and then undergoes further processing in the kidney under the influence of parathyroid hormone (PTH).
  • The kidney's role in vitamin D processing includes increasing calcium reabsorption and stimulating the production of active vitamin D, which enhances calcium absorption in the gut.
  • The body's endocrine system regulates vitamin D production through a negative feedback loop to maintain balance.
  • Fibroblast growth factor 23, produced by bone cells, can inhibit the production of active vitamin D, contributing to the regulation of calcium and phosphate levels.
  • Excessive production of fibroblast growth factor 23 can lead to extremely low phosphate levels and related health issues.
  • Excessive parathyroid hormone production, often due to a single nodule behaving autonomously, can lead to increased serum calcium levels and phosphate excretion.
  • The diagnosis of excessive parathyroid hormone production is relatively straightforward, as it is associated with increased serum calcium levels.
  • High levels of parathyroid hormone increase phosphate excretion by the kidneys.

Test your knowledge of endocrine control of calcium homeostasis with this quiz designed for medical students. Covering topics such as parathyroid hormone, calcitonin, and vitamin D, this quiz will help you understand the intricate regulation of calcium levels in the body.

Make Your Own Quizzes and Flashcards

Convert your notes into interactive study material.

Get started for free

More Quizzes Like This

Vitamin D Regulation and Mechanism
10 questions
Calcium and Vitamin D Sources
13 questions

Calcium and Vitamin D Sources

ThriftyDramaticIrony avatar
ThriftyDramaticIrony
Vitamin D: Sources and Functions
30 questions
Use Quizgecko on...
Browser
Browser