What are glands?
Glands are sac like tissue made of secretory cells. They are situated in safe yet prominent location inside the body.
There are various types of glands characterised by their locations, their type of secretions, and the organ systems they control. Each type of gland is in charge of regulating different physiological functions and activities by releasing certain secretions. These secretions can be hormones, enzymes or just fluid yet all of them have important functions.
Without sufficient release of secretions, enzyme and hormone deficiency diseases can arise.
Different types of glands in human body and their functions
There are two types of glands in human body.
Exocrine glands release secretion into region of the body through a duct. Their secretions are often called enzymes although some of them are non enzymes.
Examples of glands in the exocrine glands are:
- Salivary gland: It is located in the mouth cavity, in and around the mouth and throat. Salivary gland secrete saliva that helps moisten the mouth, initiates digestion, and protects the teeth from decay.
- Pancreas: The pancreas is situated in the abdomen. Their function is secreting enzyme amylase, trypsin and lipase used to digest carbohydrates, proteins and fats respectively.
- Sweat glands: They are located in the skin. When the body temperature is too hot, these glands secrete sweat through which the body is cooled down.
- Sebaceous gland: It is situated in the skin. It works by producing sebum that helps to lubricate and waterproof the skin and hair.
- Lacrimal glands: Their location is in eye, just above the upper, outer corner. They secrete tear containing proteins, electrolytes and water that help to moisten, nourish and protect the ocular surface.
Endocrine glands release their secretion into blood that flow through them, allowing the secretion to function at parts of the body that are far away from the gland. Endocrine glands are ductless glands and their secretion are called hormones.
Endocrine glands consist of:
- Pituitary gland (of hypothalamus): This gland is located in the brain, below the hypothalamus.
The gland includes anterior and posterior gland; each of which has definite secretions.
- a) Anterior pituitary gland: Lies in the front part of pituitary. It secretes:
- Prolactin: Calls for milk production in breastfeeding moms.
- Somatotrophin: Regulates the body and tissue growth.
- Leutinising hormone: Triggers ovulation in females and testosterone production in males.
- Thyroid stimulating hormone: Stimulates thyroid gland to produce thyroxine (T4), and then triiodothyronine (T3) hormone that promotes the metabolism of almost every tissue in the body.
- Adreno corticotrophic hormone: Promotes secretion of glucocoticoids and mineralo corticoid hormones.
- Follicle stimulating hormone: Control the formation of estrogen and progesterone by female reproductive system.
b)Posterior pituitary: lies behind the front part of pituitary. It secretes:
- Vasopressin (anti-diuretic hormone): Controls the amount of water the kidneys conserve. It minimizes urine formation and helps to save water in the body.
- Oxytocin: Signals uterus for delivery in pregnant women. It stimulates milk production in mothers as well.
- Thyroid gland: It presents in the neck and secretes thyroid hormones T3 & T4.
- Parathyroid gland: It presents in the neck and secretes parathormone.
- Adrenal gland: This gland lies on the two kidneys. It consists of two regions: outer cortex and inner medulla.
- Cortex: produces gluco-corticoids and mineralo-corticoids.
- Medulla: produces nor-adrenalin, which is one of the neurotransmitters (flight or fight hormone)
- Pancreas: Pancreatic gland has both exocrine and endocrine functions. It produces a number of hormones that control body glucose metabolism. With endocrine functions, the pancreas secrete insulin, glucagon, somatostatin.
- Kidneys: produce Renin angiotensin that helps to control blood pressure.
- Pineal gland: This gland is located inside the brain and and works as the body natural clock. Pineal gland secretes melatonin, a hormone affecting the modulation of wake/sleep patterns and seasonal functions.
Glands that release sex hormones
- Testes: produces the male hormone testosterone that signals male characters like beard, muscles etc. Testosterone is secreted in large extent in males and in small extent in females.
- Ovaries: secretes estrogen and progesterone. Those hormones are produced only in women and they regulate the reproduction cycle.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: October 16, 2017 | Last Modified: September 11, 2019