1. The brain and nerves
   The kidneys
2. The liver
   Skin

Remember "n for nerves" and you've got this one covered. The nervous system is one of two systems by which the body sends messages from one part to another, usually from the brain to outlying areas. The other is the endocrine system, which uses hormones as messengers.

1. Blood cells
   Hormones
2. Immune cells
   Urine

Hormones get a bad rap. In popular culture, they're considered the thing that makes men get in fights (testosterone) or women binge on Haagen-Dazs (estrogen). In truth, these two hormones are far more subtle and complex in their functioning. Others, like insulin, are essential for survival.

1. Cerebral
   Intellectual
2. Hepatic
   Planar

"Cerebral" relates to the brain. It has been adopted into everyday English as a synonym for "intellectual," but the former term still has a medical meaning, whereas "intellectual" does not. An "intellectual" injury might be the embarrassment of thinking you just quoted Socrates, only to be told the words were from a Hallmark card instead.

1. Cranial
   Frontal
2. Medullar
   Tibular

We remember this one thanks to the late Ann Landers. The advice columnist liked to say that kooky people had "a geranium in his/her cranium." It refers to the skull or "braincase," not the brain itself.

1. Cancer
   Disease
2. Fever
   Cell growth

This is a fairly broad term. Often, though, we think of pathogens as being microbial, because they often are. An example is E. coli, a bacterium which causes nasty food poisoning.

1. Humerus
   Patella
2. Metacarpal
   Metatarsal

The humerus is the long bone that runs from your shoulder to your elbow. From the elbow to the hand, two bones make the connection: the radius and ulna, which are parallel to each other.

1. White blood cells
   Red blood cells
2. The liquid, non-cellular part of blood
   White matter in the brain

Generally speaking, this refers to plasma, minus cells called "fibrinogens." When you have a blood test to check whether medication is getting into your bloodstream properly, the test results will refer to your "serum levels" of the drug (or its metabolites).

1. Pituocyte
   Neuron
2. Synapse
   Vertebra

This one was probably easy, because of a previous question about the prefix "neuro-". A "synapse" is a related term, meaning the connection between neurons.

1. Blocks a substance, or prevents an effect
   Bonds to cell receptors
2. Rapidly breaks down in the bloodstream
   All of the above

This term is also common in describing precursor hormones (ones that influence other hormones). For example, dopamine is also known as "prolactin-inhibiting hormone," meaning that dopamine prevents the creation of prolactin, a hormone that stimulates production of breast milk.

1. Immune failure
   Inflammation
2. Cell death
   Subnormal temperature

Inflammation is a common medical problem and can be anything from a minor annoyance to a life-threatening condition. In the latter category, consider "pancreatitis," a dangerous inflammation of the pancreas.

1. Eyes
   Liver
2. Stomach
   Teeth

You might be familiar with "hepatitis," or inflammation of the liver. There are five varieties of hepatitis, A through E. (Or six, if you watched "True Blood" and learned about hepatitis V, the kind that affected vampires).

1. Medial
   Ulnar
2. Posterior
   Radial

This is another pair of terms that helps medical professionals find their way around the body. "Anterior" is front and "posterior" is rear. For example, the pituitary gland is divided into an anterior and posterior lobe, each of which has a different set of functions.

1. Proximal
   Medial
2. Planar
   Ventral

There are more than a dozen general terms that let medical people "navigate" the body (often in sketches or at autopsy), and often these terms are paired up as opposites. "Dorsal" and "ventral" are "back" and "stomach," respectively.

1. Glands
   Kidneys
2. Stomach
   Zygote

Our public-service announcement of the day: If you're having back pain and pain with urination, it can be easy to dismiss these symptoms as "getting older disease." However, these are two signs of pyelonephritis, or kidney infection. If they persist, have these symptoms checked out.

1. Adrenalin
   Estrogen
2. Ghrelin
   Leptin

This hormone is named for its position in the body. The partial word "-nephri" refers to the kidneys, while "epi-" means "over." The adrenal gland, therefore, sits atop the kidneys. Sidebar: It's good to have a backup name for this hormone, as "adrenalin" has been almost completely taken over by car buffs talking about muscle cars.

1. Femur
   Tarsal
2. Patella
   The elbow is not a bone.

The elbow is the name for the joint, not a bone. If you must have a formal name for this, you could use the Latin term "cubitus," though it only turns up in medical terminology in its adjective form, "cubital."

1. Ductal
   Subductal
2. Venous
   Vascular

"Venous" refers only to veins and is usually used in relation to the blood that flows through the veins. If you need a word that covers *all* the blood vessels, "vascular" is the right choice.

1. Cervical spine
   Femur
2. Radius
   Tibia

The femur is casually called the "thigh bone," and runs from the pelvis to the knee. The femoral artery is named for it, a large-bore artery that is very dangerous to accidentally cut into (but, fortunately, is well-protected by a layer of thick muscle.)

1. Gamete
   Joint
2. Muscle
   Quadricep

"Musculus" is "little mouse in Latin (the suffix "-ulus" or "-culus" is a diminutive, making a word smaller). So our muscles, which we think of as making us big and strong, actually have a rather humbling name!

1. Hair follicles
   A joint
2. The stomach
   The uterus

Synovial fluid is said to resemble egg whites (and we're sure it does; we're just glad we've never had an accident bad enough to confirm this in person!) Its purpose is to lubricate the inside of a joint, protecting it from regular friction.

1. Bones
   The cerebral cortex
2. Muscles
   The kidneys

The prefix "osteo-" comes from the Latin word "os," which, confusingly, can mean either "bone" or "mouth." Osteoblasts and osteoclasts are types of cells, encouraging the creation and the breakdown of bone material, respectively.

1. Coniferous
   Deciduous
2. Angiosperm
   Monocot

"Deciduous teeth" are better known as baby teeth or milk teeth. In forests, a deciduous tree is one that sheds leaves in autumn and regrows them in the spring, as opposed to evergreens, which have leaves or needles year-round.

1. Anaphylaxis
   Hypothermia
2. Demyelination
   Tetanus

Anaphylaxis is a life-threatening swelling of tissues, especially those in the airway, which can lead to suffocation. Patients sometimes have anaphylactic reactions to bee stings (among other triggers), and carry epinephrine auto-injectors in case of emergency.

1. Brainpan
   Kneecap
2. Pinky
   Thumb

The patella is a flat triangular bone that protects the knee joint from injury. Well, it does so until we injure the knee anyway, by playing pickup basketball, or rugby, or taking up snowboarding at 50 ... any of the unwise things humans are prone to doing.

1. The bones
   The nose
2. The stomach
   The uterus

You likely learned in third- or fourth-grade health science that bone marrow is where new blood cells are created. It's also where certain immune cells are formed. (The thymus is the other part of the body involved in making immune cells).

1. The smallest region of the brain
   A gland controlling body temperature
2. The staff-and-snakes symbol of the medical profession
   A discreet tunnel leading from the morgue to the outside world

Technically, a caduceus has a staff, two snakes and two wings. People with extensive knowledge of ancient symbols will tell you that the caduceus is a flawed choice to represent the medical profession. It was a common symbol of a tribune or messenger of the gods, but the symbol of the healer was the Rod of Asclepius, a single staff with only one snake.

1. Cell
   Gland
2. Organ
   Both a gland and an organ

The confusion here comes from the definition of "gland." Some people say it's a type of organ, others not. In fact, there's no exact consensus on how many organs the human body has. At any rate, the ovaries are glands that create egg cells, allowing reproduction of the species (human or otherwise).

1. A cortex
   A lobe
2. A fold
   A span

The brain has six lobes. While they are generally defined as "regions," certain functions do tend to cluster in certain lobes. For example, religious ideation or feelings of spirituality tend to arise from the temporal lobe.

1. The atrium
   The cervix
2. The retina
   The thalamus

The thalamus is a region of the brain responsible for sleep and waking, alertness, and the release or inhibition of a number of important hormones. Other, similar functions are taken on by the hypothalamus, so named because it is located below the thalamus.

1. Ankle
   Ring finger
2. Funny bone
   Shinbone

There are two bones that run from your knee to your ankle, the tibia and the fibula. The tibia is the one in front, which means that when an angry little kid kicks you, the tibia is the bone that takes the hit.

1. Brain
   Egg
2. Lung
   Stem

It's a funny little word, isn't it? If you like, you can use its variant, "ovocyte" (which makes the connection to "egg" and "ovary" etymologically clearer). In essence, we're talking about the cells that travel from the ovaries to the uterus to be fertilized.

1. Fluid
   Solid
2. Not very severe
   In-between

You'll find the word "interstitial" in usages far afield of medicine; it's used to describe things that exist in the gaps between almost anything. In medicine, it often refers to the space between tissues in the organs, e.g. interstitial cystitis in the lungs.

1. Hearing
   SIght
2. Smell
   Touch

This term refers to the sense of smell or to the nose. Fun fact: Did you know that it's a myth that you only have five senses? Other senses include "proprioception," the awareness of one's body in space, which is rooted in far more than touch, and the awareness of the passage of time, sometimes called the "body clock."

1. Pharmaceuticals derived from herbs in the Western or desert states
   Basic emergency care practiced by cowboys and ranch hands
2. A tradition of medicine rooted in European values going back for millennia
   A 20th-century term creating an artificial distinction between European and Asian medicine

Don't @ us! Linguistic research bears out that the term "Western medicine" was virtually unheard of before about 1920, and began a rapid ascent around 1960. The truth is that premodern medicine looked the same all over the world -- herbs, bloodletting, prayers -- just as today, evidence-based medicine looks the same all over the world. Chinese and Indian medical researchers lead the way in stem-cell therapy and other cutting-edge, lifesaving procedures.

1. Bees
   Birds
2. Reptiles
   Mammals

Herpetology is the study of reptiles; the word comes from the Greek "herpetos," meaning "crawling." Labial herpes appears as fever blisters on the rips or, more rarely, inside the mouth. It is not serious or life-threatening, but can be quite stigmatizing.