thyroid hormones

Hypothalamus releases thyrotropin releasing hormone, This hormones binds to the anterior pituitary “thyrotrophs” - cells, This hormone releases and binds to thyroid gland, Blood stream goes back up the system as a way to terminate the signaling

hypothalamic pituitary thyroid (HPT) axis

wraps around the trachea anteriorly, If there is an enlargement, sometimes this is palpable, Show up as a butterfly shape in screening

thyroid gland

helps create T3 hormones and thyroid hormones, can happen once the thyroid stimulating hormone binds to its receptor

iodine

creates T4 hormones, can happen once the thyroid stimulating hormone binds to its receptor

tyrosine

The thyroid gland is made up of numerous

follicles

(kind of follicle) is a protein-rich center where thyroid hormone is synthesized and stored, Human diets do not contain a lot of iodine, so this also serves as a store of iodine, protein rich jelly

colloid

surround the colloid and participate in almost all phases of thyroid hormone synthesis and secretion

follicular epithelial cells

An Anatomical Term = A Small (Often Spherical) Secretory Cavity, surround colloids

follicles

Transport Hormones, Nutrients to and from Thyroid Gland

blood vessels

A Protein Enriched in the Thyroid Gland, Source of Tyrosines for Thyroid Hormone, Acts as a physical support for the tyrosines so that other things can come in and help with thyroid hormone synthesis

thyroglobulin

is inactive, Can be converted into T3, Inactive form of the thyroid hormones - precursor in a way

T4

active form of thyroid hormones

T3

1.Iodide is Cotransported with —- Ion

sodium

2.Iodide Diffuses Toward the —- (middle of follicle)

follicle lumen

3.Iodide Transported to Colloid & Combines with —— on Thyroglobulin

tyrosines

The Iodinated Ring of One MIT/DIT is Added to a —- at Another Spot

DIT

5.—— of Thyroglobulin-Containing T3 and T4 Molecules

endocytosis

6.—— Cleave and Release T3 and T4 from Thyroglobulin

lysosomal enzymes

is exclusively located in the thyroid colloid, adds the iodines onto the thyroid colloid, how iodine binds tyrosine to thryoglobulin

thyroid peroxidase

if you find thyroid peroxide (TPO) in the blood it could be —-

autoimmune destruction

increased metabolism, growth and metabolism, increased catecholamine effect

release of T3 and T4 hormones

most of T3 and T4 stay

bound to the thyroglobulin

hormones are —— as long as they are bound to binding proteins

inactive

(iodized salt, shrimp, seaweed) is necessary for thyroid hormone production

iodine

is the biologically active form

T3

action of thyroid hormones

metabolic actions, permissive actions, growth and development

Thyroid Hormone Receptors are Present in the Nuclei of Most Cells of the Body, and Critically Impact the Following Organs:

brain and pituitary, heart, bone, adipose tissue, liver

High-affinity —— are present in most cells of the body

T3 receptors

Increases overall metabolic rate, Increases oxygen consumption and ATP hydrolysis, Leads to increased thermogenesis. (production of body heat)

T3 stimulation

Keep in mind that most target cells in your body tend to have receptors for ——

more than one hormone

dramatically increases the effectiveness of epinephrine at a target cell, due in large part to its ability to increase the number of cell surface receptors for epinephrine

thryoid hormone

thyroid hormone signaling acts on TH receptor to influence

target gene expression

altered protein levels =

altered cellular physiology

TH is —— on epinephrine’s cellular actions

permissive

little or no fatty acids released

thyroid hormone by itself

small amounts of fatty acids released

epinephrine by itself

large amounts of fatty acids released

epinephrine and thyroid hormone

Thyroid hormone acts closely with —- for body growth and development, A particularly important role in early brain structure development

growth hormone

Binds to its receptor in the thyroid gland, Stimulates all steps involved in thyroid hormone synthesis & release

TSH

Stores iodine and thyroid hormone in colloid,Produces more T4 (inactive) than T3 (active)

thyroid gland

Synthesis and release are under negative feedback regulation by the HPT axis, T4 (prohormone) is converted to T3 (hormone), Binds to nuclear receptors and modulates gene expression

thyroid hormone