Doctor-Reviewed Health Guides: Conditions, Procedures & Health News

The ankle joint, medically called the tibiotalar or talocrural joint, is the synovial hinge joint connecting the foot and lower leg. Formed by the tibia, fibula and talus bones and supported by cartilage, ligaments and muscles, it allows plantar flexion and dorsiflexion. Common conditions include arthritis, sprains and fractures, and the RICE method helps manage pain and swelling.

The Adam's apple is the bump on the front of the throat formed by thyroid cartilage, which protects the voice box. Everyone has this cartilage, but it usually becomes more prominent in males during puberty, and its size has no bearing on health. Sudden changes, swelling or trouble swallowing or breathing should be checked by a provider.

The epiglottis is a cartilage flap in the throat that prevents food and fluids from entering the larynx and trachea during swallowing. By flipping backward to seal the airway, it routes everything you consume safely to the esophagus, hundreds of times daily. When it becomes inflamed or floppy, it can cause life-threatening airway obstruction and infections like pneumonia.

The amygdala is a small, almond-shaped brain structure in the temporal lobe that serves as a primary emotion-processing center. Part of the limbic system, it automatically detects danger and regulates the fight-or-flight response, and it also influences memory, learning and social communication. Dysfunction in this area is linked to anxiety, PTSD and epilepsy.

The gallbladder is a small, pear-shaped organ in the upper right abdomen that stores and concentrates bile made by the liver. When you eat, it contracts to release bile into the small intestine to help break down fats. It is not essential for survival, but its removal requires temporary dietary changes, such as limiting greasy foods.

Testicles, also called testes, are the main male reproductive organs. They sit in the scrotum, outside the body. There it is about 5°F (3°C) cooler than inside, which is better for making sperm. They also make testosterone, which drives the changes of puberty. Report any lump, swelling, or pain quickly to protect your health and fertility.

The temporal lobe is one of the four main lobes of the brain's outer layer, located on both sides of the head near the temples. It processes sound, helps you understand language through Wernicke's area and controls emotion through the amygdala. It also holds the hippocampus, which forms and recalls long-term memories.

Teeth are specialized organs in the mouth that begin digestion by cutting, tearing and grinding food. Most adults have 32 permanent teeth, including incisors, canines, premolars and molars. They are made of enamel, dentin, cementum and a pulp core with nerves and blood vessels. Unlike bones, teeth cannot regenerate, so consistent hygiene and professional care are essential.

Tears are a complex fluid made of water, electrolytes, lipids and antibacterial enzymes that lubricate the eye surface, flush away debris and help focus light for clear vision. The tear film is maintained by the lacrimal glands, meibomian glands and goblet cells. When this system is disrupted, it can cause discomfort ranging from gritty dry eyes to excessive tearing.

The sural nerve is a sensory nerve just below the skin in the back of the lower leg that lets you detect touch, foot position, temperature, pain and vibration. It is part of the peripheral nervous system. Because of its length and ability to regenerate, providers also use it for nerve biopsies and grafts to manage complex nerve problems.

The superior mesenteric vein is a blood vessel in the portal venous system that carries blood from the intestines toward the liver. It collects blood from many tributaries in the belly and feeds the portal vein, which delivers blood to the liver for processing before it returns to the heart. A clot in this vein can cause serious complications.

The superficial temporal artery is a blood vessel that supplies the scalp and face. A terminal branch of the external carotid artery, it runs vertically between the cheekbone and ear, with one on each side of the head. Providers often use it as a bypass route to restore blood flow to the brain and for certain minimally invasive procedures.

The subclavian vein is a deep vein just below the collarbone on each side of the body that returns oxygen-poor blood from the arms, head and neck to the heart. Providers also use it for central lines and pacemaker wires. A clot here can cause deep vein thrombosis with arm swelling or heaviness; call 911 right away.

The subclavian artery is a major blood vessel that carries oxygenated blood from the heart to the upper body, including the head, neck and arms. Located just below the collarbones, the right and left arteries follow different paths but serve the same function. Keeping them healthy helps prevent conditions like atherosclerosis and subclavian steal syndrome that impair circulation.

The stomach is a J-shaped muscular organ in the upper left abdomen and a primary site of food digestion. It temporarily stores food, mixes it with digestive acids and enzymes through rhythmic contractions and breaks it into a semi-liquid. It then regulates release of its contents into the small intestine for nutrient absorption, supporting gastrointestinal health.

Stem cells are the only cells in the body that can both copy themselves and become specialized cells such as muscle, bone or blood cells. They act as a natural repair system, maintaining and fixing tissues throughout life. Providers use stem cell therapy to treat blood cancers and orthopedic injuries, and researchers study them to understand disease.

The splenic vein is a large blood vessel that carries blood from the spleen, pancreas and stomach to the portal vein. Part of the hepatic portal system, it joins the superior mesenteric vein to route blood to the liver for filtering. Located behind the stomach, it helps recycle blood components, move infection-fighting cells and support nutrient processing.

Somatic and germline mutations are changes to the DNA sequence that occur during cell replication. Germline mutations are inherited through egg or sperm, affect every cell and can pass to future generations, causing conditions like cystic fibrosis. Somatic mutations arise after conception in non-reproductive cells, are not hereditary and often lead to cancers or sporadic syndromes.

Soft tissue is the flexible, non-hardened structures that surround and support bones and internal organs, including muscles, skin, fascia, fat, tendons and ligaments. These tissues are vital for movement, energy storage and sensory feedback. Though not a formal anatomical category, the term helps providers distinguish flexible structures from bone when diagnosing injuries and inflammation.

Skene's glands are small paraurethral structures on either side of the female urethral opening that secrete lubricating fluid during arousal and provide antimicrobial protection to the urinary tract. They are anatomically equivalent to the male prostate. Common problems include skenitis, an inflammation often caused by infection, which needs medical evaluation and typically responds well to antibiotics.

The sclera is the strong, white tissue that wraps around the eyeball from the cornea to the optic nerve. It is approximately one millimeter thick and made of tough collagen fibers that maintain the eye's shape and protect it, and it anchors the muscles that move the eye. Persistent redness or yellowing should be checked by an eye specialist.

Skull sutures are tough, flexible tissue joints that connect the 22 bones of the skull. They allow an infant's head to pass safely through the birth canal and give the brain room to expand during rapid growth. As the brain reaches full size, the sutures gradually fuse into solid bone, usually by early adulthood or middle age.

Semen is a thick, sticky, whitish-gray fluid released from the penis during ejaculation that carries sperm and helps protect and nourish them. It is mostly seminal vesicle and prostate fluid, with only a small share of sperm, plus nutrients such as fructose. See a provider for persistent changes in color, volume or smell, or blood in semen.

The skin is the body's largest organ, a protective shield against the environment and microorganisms, with three layers: the epidermis, dermis and hypodermis. It regulates temperature, senses touch and supports immune defense. Healthy skin care includes daily SPF 30+ sunscreen, gentle cleansing and avoiding tobacco. See a professional for severe burns, infection or changing moles.