What are exocrine and endocrine glands?


Exocrine and endocrine glands are important for the body. They both play a role in releasing hormones, but they do it in different ways. Both glands release substances into the bloodstream, but exocrine glands release mucus or sweat, while endocrine glands release hormones. Their main difference is that they release their products at different rates and locations throughout the body.

Endocrine Glands

Endocrine glands are small glands that secrete hormones directly into the bloodstream. They include the pituitary, thyroid, parathyroid, adrenal cortex, and medulla. Most endocrine glands are made of two types of cells: epithelial cells and chromaffin cells.

Endocrine glands can be found throughout your body, but they’re most abundant in areas that need communication with other organs or tissues (like your brain). Some examples include the pancreas, liver, and testes.

What are exocrine and endocrine glands?

Image source: VectorStock

Different types of endocrine glands

First, let’s review the different types of endocrine glands. These include:

  • Pituitary gland
  • Pineal gland
  • Thalamus
  • Hypothalamus
  • Adrenal glands (adrenaline-producing)
  • Pancreas (producer of insulin and glucagon)
  • Testes (male gonads)
  • Ovaries (female gonads)

Finally, parathyroid glands produce parathyroid hormone but are not considered endocrine glands since they have no duct system.

What are common conditions that affect endocrine glands?

  • Hyperthyroidism (overactive thyroid gland)
  • Hypothyroidism (underactive thyroid gland)
  • Diabetes mellitus (sugar diabetes)
  • Cushing’s syndrome (excess hormone production by the adrenal gland)
  • Addison’s disease (hypoadrenalism—low levels of adrenal hormones)
  • Pituitary dwarfism, gigantism, acromegaly, and hyperparathyroidism

Exocrine Glands

Exocrine glands secrete substances into ducts, then transport them to the body’s surface. These ducts may be visible along the skin’s surface or internal organs.

Exocrine glands are found in most body parts, including your lungs, throat, digestive tract, and kidneys. They’re part of the immune system because they produce antibodies that fight infections.

Exocrine glands can be classified as either holocrine or merocrine based on how many cells they produce: Holocrine glands produce one cell at a time through an unbroken wall (like our sebaceous glands), while merocrine glands produce many cells at once after breaking through their outer walls (like our sweat or oil glands).

Different types of exocrine glands

Exocrine glands are the ones that secrete products on the body’s surface through ducts. The products of these glands are other than hormones, ranging from watery to waxy. Examples include:

  • Sweat glands (found in the skin)
  • Sebaceous glands (found in the skin)
  • Salivary glands (found in your mouth)
  • Lacrimal glands (found near your eye)
  • Mammary gland (in women’s breasts)
  • Milk-producing tissue for feeding offspring after birth or adoption
  • Parathyroid glands (found near the thyroid gland)
  • The pineal gland
  • The thymus gland (found behind the sternum and below the lungs)
  • Appendix (small tube attached to the large intestine)

What are common conditions that affect exocrine glands?

You may have heard of diseases that affect endocrine glands, but what about exocrine glands? Many health issues can indeed affect your body’s exocrine glands. For example:

  • Dry eyes – This occurs when the eye doesn’t produce enough tears to keep the surface moist and comfortable.
  • Acne – Acne is a skin condition caused by excess sebum (oil) in hair follicles on your face or back. People with acne typically have blackheads and whiteheads (pimples).
  • Hives – Hives are raised patches of skin that appear anywhere on your body. They’re often itchy and painful, but they’re not usually serious.
  • Seborrheic dermatitis – It is a common skin condition that causes flaking, itching, and redness on your scalp. It’s often mistaken for dandruff or psoriasis.
  • Canker sores These are small ulcers that form inside the mouth. They’re usually red, painful, and surrounded by a yellowish-white area. Your lips may be cracked and sore as well.


The endocrine and exocrine glands are important to the body’s function but have very different roles. They play an important role in helping us maintain good health! Endocrine glands secrete hormones into the bloodstream, while exocrine glands release their contents from a duct or tube, which is then excreted from the body.