Nutrition
Adapted to the harsh Arctic environment, this group of people has a traditional diet that is primarily composed of fat and protein from marine mammals, fish, and caribou, with very limited plant matter.
Alaskan inuits
This wave-like muscular contraction in the esophagus propels a swallowed food downward toward the stomach.
Peristalsis
These are the body's smallest blood vessels, forming networks where oxygen, nutrients, and waste products are exchanged between blood and tissues.
This dome-shaped muscle located at the base of the chest cavity is the primary muscle responsible for breathing.
Diaphragm
This division of the peripheral nervous system controls voluntary movements of skeletal muscles and also carries sensory information from the body's receptors to the brain.
Somatic nervous system
This popular diet drastically limits carbohydrate intake, typically to under 50 grams per day, in order to shift the body's primary fuel source to fat.
In digestion, this term refers to the soft, chewed mass of food that is ready to be swallowed and passed onto the stomach.
Bolus
Often called the "natural pacemaker" of the heart, this specialized cluster of cells in the right atrium initiates the electrical impulses that cause the heart to beat.
Sinoatrial node
These tiny, balloon-like air sacs in the lungs are the primary sites where oxygen and carbon dioxide are exchanged between the air and the blood.
Alveoli
This almond-sized brain region is the body's main control center for regulating essential functions like body temperature, hunger, thirst, and sleep, linking the nervous and endocrine systems.
This is an autoimmune disorder where the ingestion of gluten leads to damage in the small intestine, requiring a strict, lifelong avoidance of wheat, barley, and rye.
Celiac disease
Often dubbed the "hunger hormone," this peptide is primarily produced by the stomach and signals the brain when it's time to eat.
Ghrelin
These enlarged, twisted veins, most commonly found in the legs and feet, occur when weakened valves allow blood to pool.
Varicose veins
Despite being a vein, this vessel is unique in that it carries oxygenated blood from the lungs back to the left atrium of the heart.
Pulmonary veins
Damage to this specific region in the left frontal lobe of the brain can lead to difficulty producing fluent speech, a condition known as expressive aphasia.
Broca
This genetic trait, prevalent in populations with a history of dairying, allows adults to continue digesting milk sugar, unlike most other mammals.
Lactase persistence
This hormone is released by the small intestine in response to fats and proteins, stimulating the gallbladder to contract and the pancreas to release digestive enzymes.
CCK (cholecystokinin)
This condition is characterized by the hardening and narrowing of arteries due to the buildup of plaque, which can restrict blood flow and lead to serious heart problems.
Atherosclerosis
Many diving mammals, like seals, have a large one of these organs, which contracts during a dive to release extra oxygen-rich red blood cells into circulation, acting as a natural SCUBA tank.
Spleen
Named for the quick eye movements that occur, this stage of sleep is characterized by vivid dreaming, muscle paralysis, and brain activity similar to wakefulness.
REM stage
Once used as a food dye with the E-number E125, this red additive is now banned in many regions, including the U.S. and E.U., due to concerns over its safety.
This fat-soluble vitamin is crucial for blood clotting and bone health, and can be found in leafy green vegetables and produced by gut bacteria.
This condition, also known as stress-induced cardiomyopathy, can mimic a heart attack but is typically triggered by extreme emotional distress, such as grief or shock, and usually resolves on its own.
Broken heart syndrome
This lowest part of the brainstem contains vital "respiratory" centers that control involuntary functions, including the rhythm and depth of breathing.
Medulla oblongata
These highly sensitive photoreceptors in the retina are responsible for vision in dim light and detecting movement, but they do not perceive color.
Rods