1. Urethra
   Pancreas
2. Pituitary gland
   Thyroid gland

Your pancreas has several functions. The first is to produce insulin, which lowers your blood sugar when it becomes high. It also produces somatostatin, which is a hormone that plays a role in tissue growth.

1. Kidneys
   Adrenal glands
2. Thyroid
   Testes

Your adrenal glands also produce the hormone adrenal, but if we told you that in the question, it would have made the question too easy. You may have heard of the condition 'adrenal fatigue,' which is thought to occur when your adrenal glands can't produce enough cortisol to counteract your stress levels. However, there's no evidence to support that this disorder exists.

1. Thyroid
   Thymus
2. Pancreas
   Adrenal glands

Your thyroid is located at the front of your throat. Besides controlling your metabolism, it also produces the hormone calcitonin, which helps regulate your body's calcium balance.

1. Heart
   Brain
2. Pancreas
   Adrenal glands

Hopefully, this was one of the more obvious questions in this quiz. Unlike some essential organs, like your lungs and kidneys, you only have one heart, so if it stops working, you'll die within minutes.

1. Tonsils
   Spleen
2. Thymus
   Bone marrow

Your thymus is located in the middle of your chest. It trains T-cells, which help your body adapt to foreign bodies. By your teenage years, it atrophies into a clump of fatty tissue.

1. Temporal lobe
   Cortex
2. Occipital lobe
   Pons

Your pons is located at the top of your brainstem and is responsible for controlling several involuntary actions. It's also called the 'Bridge of Varolius' since it connects your brainstem to your thalamus.

1. Cornea
   Outer ear
2. Retina
   Olfactory epithelium

Your ear is perfectly shaped to direct sound waves from your environment into your ear canal. Once sound waves enter your ear, they cause your eardrum to vibrate. These vibrations are then sent to your inner ear for processing.

1. Retina
   Skin
2. Olfactory epithelium
   Cochlea

If you didn't have a retina, you wouldn't be able to see the world around you. Your retina senses light and sends that sensory information to your brain via your optic nerve. Your optic lobe in the back of you brain then processes this information.

1. Stomach
   Medulla Oblongata
2. Pancreas
   Parathyroid gland

Your parathyroid gland is located below your thyroid gland at the front of your neck. Its primary function is to help regulate your calcium levels. The number of parathyroid glands can vary from three to eight.

1. Pituitary gland
   Pancreas
2. Prostate
   Parathyroid gland

Your pituitary gland secretes hormones that affect almost every part of your body. People who have gigantism often have tumors on their pituitary glands. These tumors cause an overproduction of growth hormone.

1. Mammary glands
   Pineal gland
2. Pituitary gland
   Parathyroid gland

Your pineal gland is located deep in you brain. It produces melatonin and is shaped like a pine cone. It's present in almost all vertebrates — animals with a spinal column — except for a few species, such as the hagfish.

1. Mammary glands
   Salivary glands
2. Pineal gland
   Pituitary gland

The ability to produce milk is a trait unique to mammals. Most mammals only produce milk shortly after having a baby. In humans, milk production usually starts somewhere around the midpoint of pregnancy.

1. Cerebellum
   Cerebrum
2. Medulla oblongata
   Diencephalon

Your cerebellum is located in your hindbrain. A few functions of the cerebellum include, controlling attention, language ability, fear regulation, pleasure and coordination. Damage to the cerebellum causes problems with posture, fine movement and motor learning.

1. Taste buds
   Corneas
2. Cranial nerves
   Lymph nodes

It's a common misconception that certain regions of your tongue are responsible for tasting different flavors. In reality, your taste buds that sense sour, sweet, umami, bitter, and salty are spread all over your tongue.

1. Diencephalon
   Cochlea
2. Skin
   Mammary glands

You may not think of your skin as an organ, but by surface area, it's the largest organ in your body. It's thought that over 1,000 types of bacteria live on the human skin, so don't forget to wash your hands!

1. Tongue
   Gallbladder
2. Liver
   Esophagus

Your gallbladder is located next to your liver and holds bile. You can live without your gallbladder. In people who've had a cholecystectomy (gallbladder removed), the liver releases bile directly into the intestines.

1. Bladder
   Kidney
2. Diaphragm
   Larynx

Your larynx is more commonly referred to as your voice box. You can manipulate the pitch of your voice by changing the tension in your vocal cords, which are flaps of skin that vibrate as air passes by them.

1. Kidneys
   Ovaries
2. Intestines
   Testes

Your kidneys are one of the most important organs in your body. Kidney failure can often be fatal and is most often caused by high blood pressure and diabetes. Some autoimmune diseases, like lupus, can also cause kidney failure.

1. Teeth
   Pharynx
2. Tongue
   Sublingual gland

If you still have all your teeth, you probably have 32 in total. If you've had your wisdom teeth extracted, as many people do, you likely only have 28. Some animals, like sharks, constantly regrow their teeth. Unfortunately, humans aren't so lucky.

1. Pharynx
   Stomach
2. Epiglottis
   Mesentery

Your pharynx is essentially the part of your mouth behind your tongue. When you breath through your nose, air passes from your nasal cavity to this part of your mouth. Your pharynx leads to your trachea and esophagus.

1. Trachea
   Ureter
2. Bronchi
   Esophagus

Your esophagus is nearly a foot long and creates a passageway for food to pass to your stomach. At the top of your esophagus, a flap of skin called the epiglottis covers your windpipe when you swallow so that food doesn't get into your lungs.

1. Trachea
   Mesentery
2. Diaphragm
   Lungs

Your diaphragm is a muscle at the base of your thoracic cavity. When you inhale, it contracts and creates a vacuum in your lunges. Singers have to learn to engage their diaphragm to project their voice.

1. Small intestines
   Mesentery
2. Duodenum
   Liver

Your liver is the workhorse of your organs. Besides the functions we already mentioned, it also produces insulin-like growth factor 1, which is vital for synthesizing new muscle and connective tissue.

1. Mesentery
   Esophagus
2. Duodenum
   Ileum

Even though the presence of the mesentery has been known for more than 1,000 years, it wasn't clear if people had multiple mesenteries or one large mesentery. Surgeon Sir Frederick Treves dissected hundreds of cadavers to find that there is only one mesentery.

1. Large intestines
   Small intestines
2. Liver
   Mesentery

Your large intestines are shorter than your small intestines but get their name from their wider diameter. Your large intestines is your food's last stop before it passes through your body.

1. Small intestines
   Large intestines
2. Liver
   Rectum

Despite the name small intestines, they're actually the longest organ in your body. If you unraveled your small intestines they would reach a length of up to 35 feet. For most people, they're 10 to 16 feet.

1. Stomach
   Liver
2. Bone marrow
   Arteries

Your bones have many functions, such as acting as a place for your body to deposit calcium and supporting your movement. However, the marrow inside your bones has the important role of creating new blood cells.

1. Capillaries
   Tonsils
2. Pharynx
   Lymphatic vessel

Many people get this non-essential organ removed when they have a history of becoming inflamed. Even though they aren't essential, they help your body fight against pathogens that enter your body through your mouth.

1. Seminal vesicle
   Testes
2. Scrotum
   Bulbourethral gland

The testes are the site of sperm production in men. After sperm is formed, other substances are added by organs such as the prostate to give it better mobility in the vagina. Once these substances are added, it's called semen.

1. Urethra
   Bronchi
2. Trachea
   Tongue

The average person's tongue is about four inches long. In the animal kingdom, the title of largest tongue in relation to its body belongs to the tube-lipped nectar bat. Its tongue can reach 3.3 inches long which is about 50% longer than its body.

1. Thymus
   Spleen
2. Tonsils
   Arteries

Your spleen may not be the most well-known organ, but it does play an important role in your overall health. Your blood constantly flows through your spleen, and cells that are old or damaged are removed by the spleen and broken down into their individual molecules to be recycled.

1. Skeletal muscle
   Smooth muscle
2. Bone
   Cardiac muscle

If it wasn't for your skeletal muscles, you wouldn't be able to move. Your muscle can contract to produce force or resist external forces by elongating. Unlike smooth and cardiac muscle, skeletal muscle is under your conscious control.

1. Lymphatic vessels
   Lymph nodes
2. Thymus
   Capillaries

Lymphatic vessels carry lymph fluid around your entire body. They work in synergy with your cardiovascular system to transport nutrients around your body. Your blood and lymph vessels can exchange nutrients at the level of capillaries.

1. Brain stem
   Cortex
2. Medulla oblongata
   Choroid plexus

You have a choroid plexus in each ventricle of your brain. They produce the fluid that your brain floats in that protects it from impact. Your cerebral spinal fluid also circulates along your spinal cord.

1. Medulla oblongata
   Choroid plexus
2. Cerebellum
   Diencephalon

Your medulla oblongata plays a role in connecting the higher level parts of your brain, such as your cortex, to the functions of the spinal cord. The medulla also controls many of your reflexes, like gagging and swallowing.

1. Iris
   Semicircle canals
2. Eardrum
   Retina

Your semicircle canals are three rings in your inner ear filled with crystals that signal to your brain when your body is moving in the X, Y, or Z axises. Movement in these planes is call pitch, roll, and yaw.

1. Vas deferens
   Prostate
2. Thymus
   Thyroid

The prostate is a common site of cancer in men. In fact, about one in nine men will be diagnosed with prostate cancer at some point during their life. African American men are at the highest risk.

1. Ovaries
   Vulva
2. Fallopian tubes
   Urethra

Women have two ovaries that take turns releasing an egg each month. The ovaries are also the site of estrogen production, which is the primary female hormone that gives women secondary sex characteristics, like breast tissue and a higher voice.

1. Vulva
   Urethra
2. Trachea
   Ureter

Both men and women have a urethra. Women have a shorter urethra than men, which leads to a higher incidence of bladder infections since bacteria have a shorter distance to travel.

1. Trachea
   Bronchi
2. Vas deferens
   Scrotum

Your trachea is often referred to as your windpipe. Children's toys will often have a warning if they have the potential to be choking hazards, since these can block airflow. The epiglottis covers the top of your windpipe when you swallow.