Human endocrine system: thyroid

The idea

The thyroid is one of the glands in the human endocrine system. It lies at the front of the neck, just below the larynx, and is often drawn as two lobes joined across the trachea. For this specification statement, the examinable skill is recognising and locating the gland on a diagram alongside the pituitary, pancreas, adrenal glands, ovaries and testes. Use position rather than size or colour: find the neck, identify the trachea, then choose the gland wrapped around its upper part. The thyroid is an endocrine gland, so it releases hormones into the bloodstream; detailed thyroid-hormone control is outside this statement.

What earns the marks

• Identifies the thyroid as a gland in the human endocrine system.
• Locates the thyroid at the front of the neck, below the larynx and around the upper trachea.
• Uses anatomical position to distinguish it from the pituitary in the brain and adrenal glands above the kidneys.
• States that, as an endocrine gland, it releases hormones directly into the bloodstream.

Common mistakes and how to put them right

• Placing the thyroid in the brain.

  Put it right by locating it in the neck; the pituitary is the gland in the brain.

• Choosing the adrenal glands near the kidneys.

  Put it right by finding the upper trachea at the front of the neck.

• Calling the thyroid an exocrine gland with a duct.

  Put it right by remembering that endocrine glands release hormones into the blood.

Exam tips

• On an unlabelled body diagram, find the neck and trachea before selecting the thyroid.
• Use the gland’s position, not the colour or drawing size, because diagrams may use different styles.