Parathyroid glands are 4 small pea-sized glands of the endocrine system located in the throat just behind the butterfly-shaped thyroid gland which regulate and monitor the calcium levels in our blood and bones. All four parathyroid glands do the exact same thing, which is to produce Parathyroid hormone(PTH). You can easily live with one (or even half) parathyroid gland.
The thyroid gland controls much of your body’s metabolism, but the parathyroid glands control body calcium.
Parathyroid hormone (PTH) is the main hormone regulating calcium metabolism and is involved in both catabolic(Bone resorption) and anabolic(osteogenesis or ossification) actions on bone.
Normal parathyroid glands are the colour of spicy yellow mustard.
Physical exercise has frequently been shown to induce bone mass gain, particularly in load-bearing bone sites. Exercise may thus be an important factor in preventing osteoporosis by either increasing the peak bone mass during childhood growth or decreasing the rate of bone loss in the elderly.
The single major disease of parathyroid glands is over-activity of one or more of the parathyroids which make too much parathyroid hormone causing a potentially serious calcium imbalance (too high calcium in the blood). This is called hyperparathyroidism.
although Hypoparathyroidism is not common, muscle spasm, Numbness and tingling are signs of it.
If you have parathyroid disease, you very likely have 3 normal parathyroid glands the size of a grain of rice and one parathyroid tumour that is as big as an olive, grape, or even a walnut. If you have parathyroid disease (hyperparathyroidism) you will need an operation to remove the one parathyroid gland which has become a tumour.
The main target organs where parathyroid hormone exerts its effects are the bones and kidneys.
(Alfacalcidol is a type of vitamin D which helps your body absorb the calcium that you digest)
You can learn to build up your strength gradually as long as you take enough calcium and maintain good levels of alfacalcidol, magnesium and vitamin D3 to aid absorption.
Calcium is needed to make your muscles contract and also regulates the rate at which your heart contracts. Every action you make uses up the calcium in your blood. Normally, when this runs low the body will use the calcium stored in your bones(catabolic action of bones also called bone resorption) but without PTH, this mechanism is reduced so you need to replace your calcium you’ve used up with food or calcium supplements. calcium is the only mineral that has its own regulatory system.
Lactic acid or pH can also influence the PTH concentration.
parathyroid hormone vs calcitonin?
calcitonin counteracts parathyroid hormone(PTH) in order to help regulate both blood’s calcium level and blood’s phosphate level. Parathyroid hormone increases blood calcium levels, while calcitonin decreases blood calcium levels. This interaction between these two is crucial for bone remodeling. calcitonin hormone decreases osteoclasts activity which protects against the development of hypercalcemia, a condition in which the calcium level in your blood is above normal range.parathyroid hormone increases osteoclasts activity which protects against the development of hypocalcemia, a condition in which the calcium level in your blood is below normal range.
CT is an older hormone phylogenetically than PTH dating back to fish in the ocean with a need to protect against hypercalcemia while PTH developed in land-dwelling animals to protect against hypocalcemia. As such, this may be an explanation why salmon CT is more potent than CT from mammals.
in comparison to parathyroid hormone, the role of calcitonin in the regulation of serum calcium in humans is minor.
The adapting of PTH and CT secretion to the existing serum calcium concentration is an interesting phenomenon that may reflect a broader concept of physiologic adaptation. For example, adaptation to cold and hot weather as well as oxygen adaptation to high altitude in Himalayan mountain climbers is well known. However, adaptation of hormonal effects and secretion is less well appreciated. In type 1 diabetic patients, an unawareness of hypoglycemia is associated with prolonged insulin therapy and frequent episodes of hypoglycemia.
studies about parathyroid
before we go through researches, let’s describe what ventilatory threshold(VT1, VT2 andV̇O₂) is:
the ventilatory threshold refers to the point during exercise at which breathing starts to increase at a faster rate than VO₂.
VT1 is called the first ventilatory threshold. It is a marker of intensity that can be observed in a person’s breathing at a point where lactate begins to accumulate in the blood. in VT2 A person who is at VT1 can no longer talk comfortably,—but can still string together a few words—while exercising. It is a higher marker of intensity than VT1. At this rapid rate of breathing, the exerciser can no longer speak. VT2 can also be called the anaerobic threshold or lactate threshold. V̇O₂ max is the maximum rate of oxygen consumption measured during incremental exercise. It is the maximum capacity of the body to take in, transport, and use oxygen during exercise and reflects a person’s cardiorespiratory fitness.
we also need to mention the word Serum means The clear liquid that can be separated from clotted blood. Serum differs from plasma, the liquid portion of normal unclotted blood containing the red and white cells and platelets. It is the clot that makes the difference between serum and plasma.
- in a study conducted in 2006 by ‘Int J Sports Med’, scientists measured PTH concentrations in young male cyclists during and after two 50-min cycling tests performed at 15% below the ventilatory threshold (VT) (-VT) and 15% above (+VT) and reported a significant increase in PTH concentrations at the end and during the recovery only in the exercise performed at +VT. This increase of PTH concentrations during these tests was accompanied by a decrease of the ionized calcium concentrations.
there was another study in 1997 by Brahm H, Piehl-Aulin K, Ljunghall S named ‘Calcif Tissue Int‘ which also found an increase in PTH concentration after a maximal exercise (10 minutes at 30% of VO2max followed by work periods of 10 minutes each at increased work loads corresponding to 47% and 76% of VO2max and at final maximal effort until exhaustion for 4-5 minutes, with a total work time of about 35 minutes) in 10 men and 10 women. During this study, PTH concentration rose in proportion to the intensity of exercise and remained elevated during the 24 hours recovery. - A study undertaken in rats also showed that acute acidosis causes, in the absence of hypocalcemia, an increase in the concentration of circulating PTH.
- in another 1994 study, The PTH concentration was increased during prolonged exercise at constant intensity (50 minutes at 4.2 m·sec-1) and progressive intensity (5 steps of 8 minutes with an increase of 0.25 m·sec-1 per step) performed by long distance runners.
- another study done by ‘Med Sci Sports Exerc‘ in 1988 also demonstrated a significant increase in PTH and stability in total serum calcium concentration after a prolonged physical exercise (7 days of military service: field exercise manoeuvre with intense physical activity) in 17 young men. These authors noted a significant relationship between the increase of serum myoglobin and the PTH concentration after the prolonged exercise indicating that the subjects who performed the largest amount of work also experienced the greatest stimulus of PTH.
what this means is The marked rise in PTH concentration was noted only during high-intensity (15% above VT) and long-duration (>50 minutes) or low-intensity (50% of VO2max) and very long-duration (5 hours) exercise suggests that a minimal intensity and duration is needed to induce a modification in PTH concentration.
PTH regulation is also influenced by the initial bone mineral content, age, gender, training state, and other hormonal and metabolic factors (catecholamines, lactic acid and calcium concentrations).
When parathyroid glands go bad, it is just one gland that goes bad about 91% of the time–it just grows big (develops a benign tumour) and makes too much hormone. About 8% of the time people with hyperparathyroidism will have two bad glands. It is quite uncommon for 3 or 4 glands to go bad.
Too much calcium in the urine can also cause calcium stones in the kidney. as we said, When calcium levels are low, parathyroid hormone is released by the parathyroid glands into the blood and causes the bones to release calcium and increase levels in the bloodstream. this causes the kidneys to stop excreting calcium in urine as well as stimulating the kidneys to increase vitamin D metabolism.
If someone does not take in enough calcium through their diet or does not have enough vitamin D, circulating calcium levels fall and the parathyroid glands produce more parathyroid hormone. This brings calcium levels in the bloodstream back up to normal.
If the high level of parathyroid hormone remains undetected for a long time, it can cause calcium from the bones to be lost into blood and subsequently the urine. This can eventually cause osteoporosis.
as mentioned, Calcium is what the nervous system of our body uses to conduct electricity. This is why the most common symptoms of parathyroid disease and high calcium levels are related to the nervous system (depression, weakness, tiredness, etc). parathyroid disease is not just about osteoporosis and kidney stones, it is primarily about us feeling “normal” and enjoying life. other Symptoms may include increased thirst, Difficulty speaking or swallowing, Loss of appetite, Hypertension, Muscle weakness, Constipation, increased urine production, abdominal pain and hypercalcemia(Sudden increase in blood calcium levels).
When one of your parathyroid glands go bad and makes too much hormone, the excess hormone goes to the bones and takes calcium out of the bones and puts it in your blood. It’s the high calcium in the blood that makes you feel bad.
Everybody with a bad parathyroid gland will eventually develop bad osteoporosis–unless the bad gland is removed.
our muscles use changes in calcium levels inside the cells to provide the energy to contract. When the calcium levels are not correct, people can feel weak and have muscle cramps.