Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Threshold Value of Different Larval Tissues
Threshold value of dissimilar larval tissues for the thyroid hormone concentration
One of the main problems of metamorphosis is the co-ordination of developmental events. The tail should not degenerate till some another means of locomotion, namely the limbs develop, and the gills should not regress till the animal can employ its newly developed lung muscles. Kollros (1961) illustrated the possibility of this coordination that displays that different larval tissues have diverse threshold value for thyroxine. In other words the different larval tissues are sensitive to dissimilar concentrations of thyroid hormone.
This model is termed as the threshold concept. It has been observed that structures in the tadpole that change early during metamorphosis are more sensitive to and have low threshold value to thyroxine, than those which go through transformation at a later stage. As metamorphosis commences the thyroid hormone level slowly builds up and different events occur at different concentrations of the hormone. Experimental studies have revealed that tadpole pans that have a low threshold respond earlier during metamorphoses than those parts comprising a high threshold response. In other words, the threshold value reflects the order where metamorphic changes occur in normal development. In urodeles the bulging of eyes reacts to the weakest dose of thyroid hormone (minimum threshold) and thus is the first event in metamorphosis. This is followed by reduction of fin fold and the shortening and disappearance of external gills. After which takes place the closure of gill clefts and transformation of skin.
Smooth muscles These muscles are beyond our control. That means these muscles are controlled by autonomic nervous system. They are non-voluntary muscles. They are found in thin
TESTE S (TESTICLES) - 2 in number (Diarchic). Pinkish in colour. Oval shaped. 4-5 cms long, 2.5 cm wide and 3 cm thick. Mesodermal. In embryonic stage attached to kid
Glucometer mainly for the following purpose. (i) In acute and chronic care facilities at the patient's bedside, in clinics or hospitals. (ii) In physician's clinics. (iii
Define cause of vitamin a deficiency - Infections? During acute infections, vitamin A intake in preschool children is reduced due to impaired appetite and impaired vitamin A ab
Q. Fats requirement in diabetes? Fats: The total fat recommended by WHO is less than 30% of the total calories. However in view of the widely prevalent Asian paradox in India,
Q. What is compensation point? What is the inference of the compensation point for the plant growth? The photic compensation point is the photic energy intensity under which ae
Q. What is R - Wave Amplitude? The R-wave amplitude in the lateral precordial leads usually decreases more in normal than in abnormal subjects and correlates with left ventr
Neutral fat & oils These are triglyceryde compounds. 1 molecule of neutral fat consists of 1 molecule of glycerole and 3 molecule of fatty acids. 3 ester bo
The first evidence of implants dates back to 600 A.D. in the Mayan population. There are reports that the ancient Egyptians attempted intra-osseous implantation of animal teeth or
Explain Food plan for an anaemic pregnant lady? Justification of the Plan: The plan is for an anaemic pregnant lady, from a lower socio-economic level and doing moderate lev
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd