The thyroid is very important endocrine gland that secretes three hormones.
Two of the hormones are iodinated ( have iodine attached to them ) and are called iodothyronines.
The three hormones are
Triodothyronine ( T3)
Tetraiodothyronine(T4) also called thyroxine calcitonin (CT)
When studied under the microscope the thyroid gland is composed of follicles . these follicles are filled with a substance known as colloid where the iodothyoronines are stored surrounding these cells are para follicular cells . these cells produce the hormones calcitonin that is involved in calcium metabolism . the general scheme of the hormones Biosynthesis is as follows Iodide which is ingested in food and water is actively concentrated by the Thyroid gland converted to organic iodine by thyroid peroxidase and in corporate tyrosine in intra follicular thyroglobulin with in the colloid at the basal cell surface of the thyroid follicular cell . the thyrosines are iodinated at one (monoiodotyrocine ) or two (diodotyrosine) diiodotyrosine triiodothyronine (Thyroxine,T4) ) diioddotyrosinet monoidotyrosine triodothyronine(T3) another source of T3 with the thyroid gland is the result of the outer ring deiodination of T4 by a selenoenzyme type 1.5 deiodinase (_5-D-1) thyroglobulin a glycoprotein containing T3 and T4 with in its matrix is taken of up from the follicle as colloid droplets by the thyroid cells .Lysosomes containing proteases cleave T3and T4 from thyroglobulin resulting in release of free T3 and T4 the iodotyrosines (monoiodtyrosine and dilodotyrosine) are also released from thyroglobulin . but only very small amount reach the blood stream . iodine is removed from by intracellular deiodinases and this iodine is used by the thyroid gland
The T4 and T3 released from the thyroid by proteolysis reach the blood stream .where there are bound to thyroid hormone binding serum proteins for transport . the major thyroid hormone binding protein is thyroxine binding globulin (TBG) which has high vicinity affinity but low capacity for T$ and T# TBG normally accounts for about75% of the bound hormones others thyroid hormone binding proteins primarily thyroxine binding PREALBUMIN , also called trams thy retin , which has high affinity but low capacity for T4 and albumin which has low affinity but high capacity for T4 and T3 account for remainder of the bound serum thyroid hormones about 0.03% of the total serum T$ and 0.3% of the total serum T3 are free and in equllibrium with bound hormones only free T4 and T3 are available to the peripheral peripheral tissues for thyroid hormone action . all reaction necessary for the formation of T3 and T4 are influenced and controlled by pitiutary thyroid stimulating hormone (TSH) also called thyrotropin, which stimulates follicular cells in the thyroid gland TSH binds to its thyroid plasma membrane receptor on the external follicular cell surface and activates the enzyme adenylate
Cyclase . thus increasing the formation of adenosine 3.5 cyclic phosphate (camp)
The nucleotide that mediates the intracellular affects TSH pituitary TSH secretion is controlled by a negative feedback mechanism modulated by the circulating level of free T4 and free T3 and by conversion of T4 and T3 in the pituitary thyrotropin cells . T3 is the metabolically active iodothyronine increased levels of free thyroid hormones (T4 and T3) in TSH secretion from the pituitary , where as decreased levels of T4 and T3result in an increased TSH release from the pituitary .TSH secretion is also influenced by thyrotropin releasing hormone (TRH) a3
Amino acid peptide synthesized in the hypothalamus .
TRH, released in to the portal system between the hypothalamus TRH, released in to the portal system between the hypothalamus and pituitary binds to a specific TRH receptor on the thyrotropic cells of the anterior pituitary and causes the subsequent release of TSH the precise regulation of TRH synthesis and release is not clear ,although thyroid hormones do play a role.
Symptoms and signs of hypothyroidism
1. weight gain and change in appearance with a deep voice
2. cold intolerance
3. Goitre
4. mental changes -ranging from depression to madness (myxaedena madnesss 0
5. Coma
6. Constipation
7. menstrual Irregularly
8. poor libido
9. hair loss
10. Coarse dry with puffy eyes
11. joint pains
12. carpel tunnel syndrome
13. Hypothermia in winter
14. muscle weakness
SYMPTOMS AND SIGNS HYPERTHYROIDISM
- Palpitation
- Nervousness
- Heart intolerance
- Breathlessness
- Insomnia
- Irregular periods
- Fast heart rate
- Fatigue
- Hairless
- Muscle weakness
- Trembling hands
- Weight loss
- Increased bowel movements
- Warm most skin
Case history
A Female of aged 48 years house wife following complaints weakness , tremors of both hands pain right hypochondrium no modalities
Cold and cough associated with head ache -full noon , damp weather and she had suffered in the past with nasal polyp
Left side legs pain , weight sensation left side arms pain , hands pain , pulling pain
Lifting ( pain severe)
She was obese, attained menarche at the age for 14, and menstruated irregularly , 45, 90 days interval pain full during , scanty and heavy flow reported randomly she had been immunized for all , communicable disease during child hood had tonsillitis at the age of 12
MENTAL GENERALS
Calm, impulsive , intelligent worries about complaints affectionate .
PHYSICAL GENERALS
Appetite normal , thirst normal urine normal , stool normal , sleep normal mental intellectual state of mind is very calm , anxious , weeps easily frightened easily , depressed easily
GENERAL E XAMINATION S
B.P . 130/80mm.hg pulse 75min CVS and RS NAD
INVESTIGATIONS
I advised thyroid profile
Mallya hospital department of laboratory
Name: Anitha pai.
Age: 48 years
Date – 16 February 2009
Thyroid profile T3 T4 TSH
T3 – 1.0 ng/ml (0.7-1.7 reference range)
T4 7.7 ng/ml 5.12
TSH 9.16 ul/ml C4 -4.0
She was put on 1 Calcarea carb 200 T.D.S
2. Thyroidinum 30 from 16-feb -2009 to 26-05-2009
She was clinically a symptomatic after one month of treatment no pain
Repeat thyroid profile
Date 26-5-2009 special biochemistry report
Free T4 (CLIA) results 1.01 ng / dl reference range 0.8 -2.0 ng /dl
FREE T3 by (ELISA) results 3.2 pg/ ml reference range 1.2 -4.2 pg/ ml
THYROID STIMULATING HARMONE 3.01 ulU/ml reference range adults ; 0.3 -6.0ulU/ml
TSH(CLIA)
1-30 days ; 0.5 -16.0 uiU/ml
1mth -5yrs ; 0.4-8.1 uiU/ml
6-18years ; 0.3 -6ulU /ml
She was given on thyroidinum 30 from
26-5-2009 to 8-9-2009
A thyroid profile was repeated 8-9-2009
T3 ng / ml observed values 0.85 ng /ml reference range adults 0.7 -2.0
60 years 0.4 – 1.8 ng/ml
T4 observed values 6.41 mcg/dl
Reference range adults 4.5 – 11.0
60 years 5.0 – 10.7 mcg/dl
TSH THOROID STIMULATING HARMONE observed values 2.55 mclU/ml
Reference range adults 0.4 – 4.2
60 years 0.5 – 8.9 mclU/ml
She symptomatically free and normal one can not always elicit a clinical picture or a mass of symptoms in spite of detailed interrogation . this prescription was purely clinical knowing the affinity of these drugs to this spare of pathology . but the gratifying results justify at least the cause and effect relationship of our remedies if not an explanation of cure
