Use the drop-down menus to indicate which endocrine structure is being described in each case.

1. Adrenal gland:

This structure secretes adrenaline, noradrenaline, cortisol, and aldosterone.

The adrenal gland is located above each kidney. It has two parts:

Adrenal Cortex - secretes cortisol and aldosterone.  

Adrenal Medulla - secretes adrenaline and noradrenaline.  

2. Pineal gland/Pineal body:  

This structure regulates the sleep cycle and other biological rhythms.

The pineal gland is located in the middle of the brain. It secretes the hormone melatonin, which regulates the wake and sleep cycle.  

3. Thyroid gland:  

This structure is located at the throat and regulates metabolism.  

The thyroid gland is found in the neck. It produces thyroid hormones that regulate metabolism. It also helps maintain blood pressure, heart rate, digestion, muscle tone and other reproductive functions.  

4. Pancreas:

This structure secretes glucagon and insulin.

The pancreas is located in the abdominal cavity, behind the lower part of the stomach. It secretes glucagon and insulin to regulate the glucose level in the blood.  

5. Thymus gland

This structure regulates the development and differentiation of T lymphocytes.

The thymus gland can be found in the thoracic cavity, in the mediastinum to be exact. T-lymphocytes are produced in the bone marrow, but they develop in the thymus.  

6. Parathyroid glands

This structure regulates blood calcium levels.

They come in two pairs and are embedded on they thyroid gland. It releases parathyroid hormone. This hormone helps regulate the calcium levels in the blood.  

answer: dinosaur

explanation

their extinction was caused by massive asteroid that fell on earth

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