[M6] Part 2: Thyroid & Parathyroid gland Flashcards
Butterfly-shaped glands found in the lower anterior neck
THYROID GLAND
THYROID GLAND is a Butterfly-shaped glands found in the ____
lower anterior neck
T/F: Thyroid gland is Bilobed
T
thyroid tissue that connects the two lobes
Isthmus
Thyroid gland functions:
- Controls ____ and release of ____ from ____
- Regulates ___ , ____ and ____
- Acts on ___
- Stimulates the ____
- Physical ___ and ____
- ___ body temperature
- ____ consumption
-biosynthesis ; thyroid hormones ; thyroglobulin
-carbohydrates ; proteins ; lipid metabolism
-CNS
-heart
-growth ; development
-Basal
-Oxygen
Thyroid gland acts on CNS by ____ and ____ of the ____
By maturation and development of the brain
Thyroid gland Function:
Basal body temperature:
_____ TH = ____ body temperature
↑ TH = ↑ body temperature
Thyroid gland Function:
Oxygen consumption
___ TH = ____ O2 demand
↑ TH = ↑ O2 demand
The thyroid gland is composed of hollow spheres called ____
colloid follicles
Colloid fills the ____
follicle cavities
Follicle cells produce ___
thyroglobulin
HISTOLOGY OF THYROID GLAND:
composed of Cuboidal cells called ___ or ____
Follicular cells ;
thyroid follicular cells
Where T3 and T4 are produced/synthesized
follicular cells or thyroid follicular cells
Arranged in spheres
follicular cells or thyroid follicular cells
a gel-like matrix retained within the spherical structures of the follicular cells
Colloid
found within the colloids
Thyroglobulin
Major component of the colloid itself
Thyroglobulin
Thyroglobulin has 2 ____
Has 2 tyrosine backbone
Has 2 tyrosine backbone
Thyroglobulin
Each tyrosine backbone has_____, therefore, each thyroglobulin has _____
1 iodine-binding site ;
2 iodine-binding sites
Important substance in the synthesis of thyroid hormones
Thyroglobulin
Produces calcitonin
Parafollicular C cells
important element in the synthesis of thyroid hormones
Iodine
Iodine deficiency =____
thyroid hormone deficient
_____ = thyroid hormone deficient
Iodine deficiency
What are the 2 biologically active thyroid hormones:
T3, T4
What is T3
triiodothyronine
What is T4
tetraiodothyronine
More active thyroid hormones
T3 (triiodothyronine)
Not that biologically active thyroid hormones
T4 (tetraiodothyronine)
What are the 5 steps in Thyroid Hormone Synthesis
- Iodide uptake
- Iodide → iodine
- Iodine uptake
- Iodination of tyrosine (thyroglobulin)
- Coupling of iodinated tyrosine
____ from ___ will enter the ____
Iodide
diet
follicular cells
Inside the ___, it will be ____ to form ____
follicular cells;
oxidized ;
iodine
Iodine in the ___ will attach to the ____ of the ____
colloid ;
tyrosine backbone;
thyroglobulin
For each ____, pwedeng ____ ang mag attach pero ____ all the time
thyroglobulin;
2 iodine;
not
1 iodine attached
Monoiodothyronine (MIT)
2 iodine attached
Diiodothyronine (DIT)
Coupling reaction:
DIT + MIT = ____
triiodothyronine
____ + ___ = triiodothyronine
DIT
MIT
Coupling reaction:
DIT + DIT = ____
tetraiodothyronine
____+ ____= tetraiodothyronine
DIT
DIT
For T4 to be biologically active, ____ should be
____ (para maging T3)
1 iodine;
removed
removal of iodine by the enzyme_____
Deiodination
monodeiodinase
more specific term since 1 iodine lang ang tinatanggal
Monodeiodination
Pag nagtanggal ng iodine, dapat yung nasa ____ ang tatanggalin
outer ring
Pag yung nasa ___ ang natanggal, the T4 will become ___ or ____ which is ____
inner ring;
rT3;
reverse T3;
biologically inactive
The REGULATION OF THYROID GLAND follows the ___
hypothalamic-pituitary-thyroidal axis
hypothalamic-pituitary-thyroidal axis:
- The hypothalamus secretes the ____
thyrotropin releasing hormone (TRH)
hypothalamic-pituitary-thyroidal axis:
- TRH stimulates the___ to secrete ____
pituitary gland;
thyroid-stimulating hormones (TSH)
hypothalamic-pituitary-thyroidal axis:
- TSH stimulates the ___ to produce ____ (___ , ____)
thyroid gland;
thyroid hormones;
T3, T4
hypothalamic-pituitary-thyroidal axis:
- TSH stimulates the ___ to produce ____ (___ , ____)
thyroid gland;
thyroid hormones;
T3, T4
hypothalamic-pituitary-thyroidal axis:
- ___ and ___ will then act on its ____ which contain the ____ specific to them
T3 ;
T4 ;
peripheral tissues;
receptors
hypothalamic-pituitary-thyroidal axis:
- If enough ___ and ____ are produced, the ____ will send signals to the ____ to stop production of ____, hence, the ____ will no longer produce ____, hence, no hormone will stimulate the____ to secrete ___ and ___
T3;
T4 ;
thyroid gland;
hypothalamus ;
TRH;
pituitary gland;
TSH;
thyroid gland;
T3;
T4
hypothalamic-pituitary-thyroidal axis:
- On the other hand, when T3 and T4 levels are ___, the thyroid gland will send signals to the ___ to secrete ___
low;
hypothalamus;
TRH
3 classifications of thyroid hormone disorders
Primary ;
Secondary;
Tertiary
the affected gland is the thyroid gland
Primary
Primary Hypothyroidism
↓ T3, T4
Primary Hyperthyroidism
↑ T3, T4
the problem is the pituitary gland
Secondary
Secondary Hypothyroidism
↓ TSH, T3, T4
Secondary Hyperthyroidism
↑ TSH, T3, T4
the problem is the hypothalamus
Tertiary
Tertiary Hypothyroidism
↓ TRH, TSH, T3, T4
Tertiary Hyperthyroidism
↑ TRH, TSH, T3, T4
What are the 2 Major Thyroid Hormones
Triiodothyronine (T3)
Tetraiodothyronine (T4)
Triiodothyronine (T3) is Chemically known as ___
3, 5, 3’-triiodothyronine
With Most active hormonal activity
Triiodothyronine (T3)
More biologically active than T4
Triiodothyronine (T3)
Metabolic rate of every cell of the body
Triiodothyronine (T3)
Encourages cellular differentiation
Triiodothyronine (T3)
Tissue growth and development
Triiodothyronine (T3)
Triiodothyronine (T3) ____ oxygen consumption
Increased
Increased oxygen consumption
Triiodothyronine (T3)
Calorie and Vitamin/Mineral metabolism
Triiodothyronine (T3)
Triiodothyronine (T3) is an indicator of ___
hyperthyroidism recovery
Involved in brain maturation
Triiodothyronine (T3)
It can cause increase in heat production
Triiodothyronine (T3)
Accounts for 20% of the total thyroid hormone synthesized
Triiodothyronine (T3)
Triiodothyronine (T3) Accounts for ____ of the ____ synthesized
20%;
total thyroid hormone
Triiodothyronine (T3)
Reference Ranges:
ADULT: ___
60 – 160 μg/dL
Triiodothyronine (T3)
Reference Ranges:
Children (1-14 y.o): ___
105 – 245 ng/dL
Mas mataas ang reference range ng T3 sa mga bata kasi involved sila sa ____ and ___
tissue growth and development
Tetraiodothyronine (T4) is Chemically known as ___
3, 5, 3’, 5’-tetraiodothyronine
Also known as thyroxine
Tetraiodothyronine (T4)
Tetraiodothyronine (T4) is AKA
thyroxine
Pre-hormone for T3
Tetraiodothyronine (T4)
_____ level of Tetraiodothyronine (T4)
will inhibit ____, ___ level will stimulate ____
Increased ; TSH production
decreased ; TSH production
Tetraiodothyronine (T4)
Accounts for ____ of the ____ synthesized
80% ;
total thyroid hormone
Accounts for 80% of the total thyroid hormone synthesized
Tetraiodothyronine (T4)
Tetraiodothyronine (T4)
Reference Ranges:
Adult:_____
5.5 – 12.5 μg/dL
Tetraiodothyronine (T4)
Reference Ranges:
Neonates:_____
11.8 – 22.6 ng/dL
T/F: Thyroid hormones may be bound or free
T
Thyroid hormones may be ____ or ____
bound ;
free
How many % of thyroid hormones are protein bound
99.9%
How many % of T4 is unbound/free (FT4)
0.04%
How many % of T3 is unbound/free (FT3)
0.4%
WHAT ARE THE 3 THYROID BINDING PROTEINS
Thyroxine Binding Globulin (TBG)
Thyroxine Binding Prealbumin
Albumin
Major transporter for T3
Thyroxine Binding Globulin
Also binds 70% to 75% of T4
Thyroxine Binding Globulin
Thyroxine Binding Globulin Also binds ___ to ____ of ____
70%
75%
T4
Binds 15% to 20% of T4
Thyroxine Binding Prealbumin
Thyroxine Binding Prealbumin
Binds ___ to ____ of ____
15%
20%
T4
Transport protein for T3
Albumin
Binds 10% of T4
Albumin
Albumin Binds ___ of ____
10%
T4
T/F: Only free thyroid hormones are biologically active
T
Only ___ thyroid hormones are biologically active
free
Binding of thyroid hormones to binding proteins is affected by _____
Example: ____ estrogen = ____ thyroid-binding proteins = ____concentration of bound thyroid hormones
several factors;
↑ estrogen = ↑ thyroid-binding proteins = ↑ concentration of bound thyroid hormones
Kapag ang pinapatest ng patient is T3 and T4, it refers to the ____ of T3 and T4
total population
T/F: There is a separate test for FT3 and FT4 which measures free T3 and T4
T
There is a separate test for FT3 and FT4 which measures _____
free T3 and T4
What are the 11 Laboratory Analysis in Thyroid Gland
- Thyroid Stimulating Hormone (TSH)
- Serum T3 And T4
- Thyrotropin-Releasing Hormone (TRH)
- Thyroglobulin
- T3 Resin Uptake
- Free Thyroxine Index (FT4I)
- Thyroid Antibody Screen
- TRH Stimulation Test
- Radioactive Iodine Uptake (RAIU)
- Thyroid Ultrasound
- Thyroid Needle Biopsy
Also known as thyrotropin
Thyroid Stimulating Hormone (TSH)
Thyroid Stimulating Hormone (TSH) is AKA
thyrotropin
Most useful test for assessing thyroid function
Thyroid Stimulating Hormone (TSH)
Used to differentiate primary hypothyroidism from secondary hypothyroidism
Thyroid Stimulating Hormone (TSH)
Thyroid Stimulating Hormone (TSH) is used to differentiate ____ from ____
primary hypothyroidism
secondary hypothyroidism
Primary hypothyroidism
TSH LEVEL ___
N – ↑
Primary hypothyroidism
T3 and T4 LEVEL ___
↓
Secondary hypothyroidism
TSH LEVEL ___
↓
Secondary hypothyroidism
T3 and T4 LEVELS ___
↓
Used to monitor and adjust thyroid hormone replacement therapy
Thyroid Stimulating Hormone (TSH)
3 Generation Test in Thyroid Stimulating Hormone (TSH)
Second Generation
Third Generation
Fourth generation
0.1 mU/L detection limit
Second Generation
Second Generation: ____
0.1 mU/L detection limit
0.01 mU/L detection limit
Third Generation:
Third Generation: _____
0.01 mU/L detection limit
More sensitive generation test
Third Generation:
Generation test that Monitor and adjust thyroid hormone therapy
Third Generation
for research purposes only, not used for diagnosis
Fourth generation
Serum T3 And T4 measures:
________
_________
Total T3 and T4
Free T3 and T4 (FT3, FT4)
Serum T3 And T4 methods: (3)
Radioimmunoassay
Chemiluminometric assay
Immunometric technique
Measures relationship between TSH and TRH secretions
Thyrotropin-Releasing Hormone (TRH)
Thyrotropin-Releasing Hormone (TRH) Measures relationship between ____ and ____ secretions
TSH
TRH
Used to confirm euthyroid Grave’s disease
Thyrotropin-Releasing Hormone (TRH)
Thyrotropin-Releasing Hormone (TRH) is used t o confirm ____
euthyroid Grave’s disease
euthyroid Grave’s disease is a type of __ (hypothyroidism/hyperthyroidism)
hyperthyroidism
Thyrotropin-Releasing Hormone (TRH) is INCREASED in ___
primary hypothyroidism
Thyrotropin-Releasing Hormone (TRH) is DECREASED in ___
hyperthyroidism
Glycoprotein synthesized and secreted only by the thyroid follicular cells
Thyroglobulin
Proof of presence of thyroid tissues
Thyroglobulin
Ideal tumor marker for thyroid cancer patients
Thyroglobulin
