Follicular cells of thyroid gland : summary

Follicular cells of thyroid gland : summary 

Topics	Follicular cells
Secretion	T3 and T4
Shape and size of cell	It is smaller than the parafollicular cell. The shape of the cell vary according to functional state of gland: from simple squamous to low columnar epithelium
Staining	It takes more staining
Exposure to luminal surface	It is exposed to luminal surface
Nuclei	It contains comparatively dark nuclei with two or three prominent nucleoli
Golgi complex	Golgi complex are supranuclear in position
Secretory vesicles	Few and Present in apical region
rER	Present basally
Lysosome	Abundant
Endocytotic vesicles or colloidal resorption droplets	Present in the apical region of cell
Microvilli	Present
Development	Thyroglossal duct
Derived from	Endoderm

Corpora arenacea / brain sand of pineal gland

Brain sand or corpora arenacea

Definition:  The intercellular spaces of pineal gland contain calcified granular material known as brain sand or corpora arenacea

Locations of corpora arenacea:

Pineal gland

Brain sand also found in other brain area such as choroid plexus

In the leptomeninges,

In the habenular commissure

Composition:

1. calcium phosphate,
2. calcium carbonate,
3. magnesium phosphate, and
4. ammonium phosphate

How these calcifications are produce?

These calcifications are derived from precipitation of calcium phosphates and carbonates on carrier proteins that are released into the cytoplasm pinealocytes (the chief cells of pineal gland). These precipitation of calcium is release into intercellular spaced of pineal gland during secretion of pineal gland by exocytosis .

              They are the result of caclification of dead cells (e.g. erythrocytes or glial cells).

Factors increases the calcification :  
This calcification process is caused by constant exposure to substances like fluoride which build up in the body over time. Toothpaste, public water systems, hormones, food additives, excess sugar and sweeteners in your diet or even regular exposure to cell phones has been linked to the phenomenon of calcifying the pineal gland.

Clinical importance

It is appear as opaque structure in x-ray and located in the midline of the brain .

These concretions are conspicuous with imaging techniques and provide a useful landmark for orientation in the diagnosis of intracranial diseases.

Age changes :

 Calcification of the pineal gland is unfortunately typical in adults, and has been observed in children as young as 2 with estimates of 40% of population experiencing symptoms of heavy calcification of the pineal gland by the time they are 17. The degree of calcification was associated to various diseases.

Benefits of Decalcification

·         Improved Sleep & Mental Health 

·         Improved Immune System 

·         Weight Maintenance

·         Reduction in heart disease, diabetes and osteoporosis

·         Migraine Reduction 

·         Cancer Fighting

Trendelenburg sign

The trendelenburg sign 

It is found when superior gluteal nerve is damage due to surgery, hip dislocation or poliomyelitis.

It caused by weakness of the hip abductors, mostly the gluteal medius and minimus.

This condition makes it difficult to support the body’s weight on the affected side.

In a normal gait situation, both legs bear half of the body weight.

When the left leg is lifted, the right leg takes the entire weight, abductors of left side contract and prevent dropping of pelvis. But due to superior gluteal nerve lesion, the pelvis drops instead of rising on the unsupported side.