Thyroid-Stimulating Hormone (TSH)

Thyroid-Stimulating

Hormone (TSH)

By: Kajal Grover

Jayasri Vijay

Neal Shah

What is TSH?

• Thyroid-Stimulating Hormone (TSH or

thyrotropin)

• Stimulates thyroid gland to produce

Triidotheronine (T3) and Thyroxine

(T4), which in turn stimulates

oxidative respiration

How is TSH created?

• Hypothalamus produces Thyrotropin-

Releasing Hormone (TRH)

• Triggers the anterior pituitary gland

to release TSH (Thyroid-Stimulating

Hormone)

Hypothalamus and Pituitary Glands

Thyroid Gland

General Overview of Glands

TSH = Peptide-Based

Overview

• TSH (which is released from the pituitary

gland) binds to the TSH receptor on the

thyroid cells, activating adenylyl cyclase

and cAMP. This stimulates thyroid growth

and causes synthesis and the release of

thyroid hormones T3 and T4 which

stimulates our metabolic rates and are

crucial for normal growth and development.

TSH Signaling Pathway

TSH Signaling Pathway

Negative Feedback

• T3 and T4 concentrations in blood decrease

• Hypothalamus secrets TRH, stimulating TSH

secretion from pituitary, which stimulates

thyroid gland to release thyroxine

• Thyroxine acts on hypothalamus and anterior

pituitary gland to inhibit TRH and TSH

secretion

• Allows homeostasis: keeps thyroxine levels

fairly constant to control body’s metabolism

Negative Feedback Loop Diagram

Negative Feedback Loop Diagram

Negative Feedback Example• Example of person lacking iodine in diet:

– Thyroid gland can’t produce thyroxine (which contains 4

iodines per molecule)

– Thyroxine concentration in blood decreases

– Reduced inhibition received by hypothalamus and

anterior pituitary gland

– Causes elevated secretion of TRH and TSH

– High levels of TSH stimulates thyroid gland, which swells

with products of thyroxine metabolic pathway

– Still can’t produce thyroxine without iodine

– Consequence: enlarged thyroid gland (goiter)

TSH Receptor

• Too much TSH binding to the TSH

receptor on the thyroid cells will lead

to hyperthyroid diseases

• Too little TSH binding to these thyroid

cells will lead to hypothyroid

diseases

Diseases

• High TSH HYPERTHYROIDISM

– Hair loss, coarse texture of the hair, core body

temperature increases, sweating, heart beats

faster , oily skin, diarrhea , slows down mental

development

• Graves’ Disease: goiter, nervousness, heat

sensitivity, hand tremors, weight loss, fatigue

Goiter

Diseases

• Low TSH Hypothyroidism

– Weight gain, faster aging, lower core body

temperature, tiredness , hair loss, dry skin, dry

constipations, heart beats slower, memory

impairment, blood pressure can drop

– Myxedema (swelling) of the legs in adults

– Cretinism in children: stunted growth and

severe mental retardation

Myxedema in Legs

Diseases

How Pathway is Disrupted

Works Cited

• http://www.jpgmonline.com/article.asp?issn=0022-3859;year=2011;volume=57;issue

=2;spage=141;epage=142;aulast=Hari

• http://www.nature.com/nrc/journal/v6/n4/images/nrc1836-f3.jpg

• http://www.nature.com/nrendo/journal/v6/n1/images/nrendo.2009.225-f2.jpg

• http://www.taytan.com/goiter.htm

• http://www.webmd.com/a-to-z-guides/thyroid-stimulating-hormone-tsh

• http://classes.midlandstech.edu/carterp/Courses/bio211/chap16/chap16.htm

• http://bcs.whfreeman.com/thelifewire/content/chp42/4202s.swf

• http://wps.aw.com/wps/media/objects/443/454188/st1003.html

• http://www.google.com/url?sa=i&rct=j&q=pituitary+gland&source=images&cd=&ca

d=rja&docid=3IVjW2zxjUhfZM&tbnid=3o237C9_Z4sglM:&ved=0CAQQjB0&url=http%

3A%2F%2Fthebiologyzone.wordpress.com%2F&ei=vBlPUbSBEqS22gWnzYG4DA&bvm

=bv.44158598,d.aWc&psig=AFQjCNFQaKiAHTJuSklgJp5UphG55QIu3g&ust=

1364224753952394

Works Cited

• http://www.google.com/url?sa=i&rct=j&q=regulation+of+thyroxine+secretion&source=images&cd=&docid=P5L9BMWcR4lBgM&tbnid=apUFgtFBZBbbQM:&ved=0CAQQjB0&url=http%3A%2F%2Fmoodle.rockyview.ab.ca%2Fmod%2Fbook%2Fprint.php%3Fid%3D58094%26chapterid%3D20881&ei=6VhPUYyNHouE9QTVg4DgBQ&bvm=bv.44158598,d.eWU&psig=AFQjCNGjId4dgKu-xWywEkXUj4ZhKlQGug&ust=

1364240916336685

• http://www.google.com/url?sa=i&rct=j&q=thyroid+gland&source=images&cd=&cad=rja&docid=0zy0sNlJNGWLoM&tbnid=MB90rcicKw2mIM:&ved=0CAQQjB0&url=http%3A%2F%2Fwww.mayoclinic.com%2Fhealth%2Fmedical%2FIM01872&ei=aF1PUffmGo-w8QSh4IFo&bvm=bv.44158598,d.eWU&psig=AFQjCNHSlalZFMlac5twCu0QxJ4ltrETvQ&ust=

1364242142231717

• http://www.thyroidologists.com/images/Rich/TSH_Medium.png

• http://classes.midlandstech.edu/carterp/Courses/bio211/chap16/chap16.htm

• http://antranik.org/thyroid-stimulating-hormone-thyrotropin/

• http://drugline.org/img/ail/3153_3176_1.jpg