Two Very Different Things The Thymus and the Thyroid

When starting an anatomy and physiology training course for the first time, the task can be challenging. Particularly when you come across organ names that sound similar, but are in fact, not connected at all.

Take the thymus gland and the thyroid gland as an example.

They have similar-sounding names, but bear no similarity in their anatomy, physiology or pathology.

Look at the differences

Thymus Gland

Anatomy

Its shape looks similar to a thyme leaf (hence its name)

It consists of two lobes. Each lobe has a central medulla and an outer cortex

The gland is located behind the sternum, in front of the heart and between the two lungs

Physiology

It is primarily a lymphoid organ of the immune system, but does produce hormones to support the immune response

T-lymphocytes (T-cells) are produced in the outer cortex of the gland lobes

The T-cells then mature in the central medulla of the gland lobes

This maturation is supported by hormones, such as thymosin, which are specifically produced by the thymus

The gland is active from birth and through puberty. It then gradually atrophies (shrinks).

Pathology

Myasthenia gravis (MG) is a condition whereby the thymus gland is abnormally large and manufactures antibodies that destroy receptor sites in muscles, causing them  to become weak.

Thyroid Gland

Anatomy

It is butterfly-shaped

It has two lobes joined by an isthmus or bridge

It is located in front of the trachea, just below the Adam?s apple

Physiology

A gland of the endocrine system

On receipt of signals from the pituitary gland, the thyroid produces thyroxin, triiodothyronine and calcitonin to regulate the body?s metabolic rate

Thus it controls heart, muscle and digestive function

It also controls brain development and bone health

Pathology

Hyperthyroidism: too much hormone produced, causing weight loss, increased heart rate and muscle weakness, amongst other symptoms

Hypothyroidism: too little hormone produced. The body uses energy at a slower pace, thus symptoms include weight gain, slower heart rate  and fatigue.

Want to know more?

To find out more about the immune and endocrine systems, join our Anatomy and Physiology online course. Here you?ll work towards the internationally recognised ITEC Level 3 Diploma in Anatomy, Physiology and Pathology:

https://www.anatomyandphysiologyonline.com

If you work in complementary therapies and need a revision aid or simply a refresher, why not sign up for our Anatomy and Physiology Revision E-Course?

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