Thyroid Flashcards
- Function: Controls apptetite, Temperature, Sex drive, Weight, mood, Sleep, Thurst
Hypothalamus Controls by ?
Controls **Pituary Hormones **by releasing Hormones :
* Thyrotropic - releasing hormone (TRH)
* Grownth Hormone- Releasing Hormone (GHRH)
* Corticotropin - releasing Hormone (CRH
* Gonadotropin- releasing Hormone(GRH)
Pituary Gland
Another Name
Master Gland
Pituitary Gland
Anterior Pituatary
TSH
Prolactin
GH
ACTH
LH
Pituatary Gland
Posterior Pituatary
ADH
Oxytocin
Thyrotropin -Releasing Hormone (TRH)
Stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary.
Growth Hormone-Releasing Hormone (GHRH):
Stimulates the secretion of growth hormone (GH) from the anterior pituitary.
Corticotropin-Releasing Hormone (CRH):
Adrenocorticotropic hormone (ACTH) from the anterior pituitary.
Gonadotropin-Releasing Hormone (GnRH):
Stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary.
Thyroid Gland
Function
Controller of metabolism
Energy use
Oxygen consumption
Heat Production
T4 another name
Thyroxine (another name )
Thyroxine (T4)
- **Major Thyroid Hormone secreted
- 4 Iodine Atoms
- T4 more occurate Hormone measure for clinical significant**s
- Iodine is element needed for production of hormone
- Iodine is not produce by body, must be ingensted with diet
- Thyroid has active mechanism that able to pick up iodine in blood stream
- T4 active in tissues they pick up iodine untile it’s converted T3
- T4 to T3
Triodothyronine
T3 ( anoter name )
T3 Triiodothyronine
T4 convereted to T 3 removal iodine atom in Liver
Thyroid Stimulating Hormone (TSH)
- Activated in Pituatary
- Less T4 more TSH
- More T4 less TSH
Somatrostatin
- Released from Hypothylamus
- Ability to inhibit (stop) TSH release
THyroid Function
Thyroid Hormone Uses
T3 and T4
- Facilitate normal growth and development
- Increases metabolism
- Increases catechlamine effects
TSH
- Most useful marker for thyroid function
- Follows a diurnal rhythms, peaks at midnight
Metablic Effects of T3
- Stimulates lipolysis and release of free fatty acids and glycerol
- Stimlates metabolism of chelesterol to bile acids
- Induces expression of lipogenic enzymes
- Facilatates rapid removal of LDL from plasma
- Effects chelsterol metabolism
- Stimulates aspect of carbohydrate metabolism and the pathway for protein degradation
Levels
- Normal TSH 0.3/0.5 to 3.0/5.0
- TSH level below 0.4 suggest Thyroid **overactive **
- TSH above 5.0 thyroid is underactive
Primary Hypothyroidism
-
U.S.A most common cause : Autoimmune
* World Wide: Iodine Dyfisiansy - **Second Most Common Cause **: Post-therapetic treatment
- Thyroid Destructtion
- Medacations : Amio, Lithium, Interferon Alpha
Secondary (central ) hypothyroidism
- Deficient TSH Secretion
- Rare
Tertiary (central ) hypothyroidism
- Deficient TRH secretion
- Even mroe rare
Hypothyroidism **Signs **
- Hypotension/Bradycardia
- Brittle nail
- Hair Loss
- Decrased DTR
- Dry course skin
- Myxedema in extremities
- Puffiness of eyes/face (periorbital edema )
- HYpglycemia
- Decreased bowel sound/constipation
- Goiter( not present in all pts )
Hypothyroidism** Symptoms**
- Weight gain; inability to lose weight
- Extreme fatigue
- Forgetfulness
- Prutitus
- Depression
- Cold intolerance
- Menstual irregulatiriet
- Muschle Cramps