The Human Body

This site is all about human body. From basics to higher levels. It is equally useful to children as well as professionals.

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Neurons may be classified into three groups: sensory neurons, motor neurons, and interneurons.

Sensory neurons (or afferent neurons) carry impulses from receptors to the central nervous system. Receptors detect external or internal changes and send the information to the CNS in the form of impulses by way of the afferent neurons. The central nervous system interprets these impulses as a sensation. Sensory neurons from receptors in skin, skeletal muscles, and joints are called somatic; those from receptors in internal organs are called visceral sensory neurons.

Motor neurons (or efferent neurons) carry impulses from the central nervous system to effectors. The two types of effectors are muscles and glands. In response to impulses, muscles contract or relax and glands secrete. Motor neurons linked to skeletal muscle are called somatic; those to smooth muscle, cardiac muscle, and glands are called visceral. Sensory and motor neurons make up the peripheral nervous system. Visceral motor neurons form the autonomic nervous system, a specialized subdivision of the PNS that will be discussed later in this chapter.

Interneurons are found entirely within the central nervous system. They are arranged so as to carry only sensory or motor impulses, or to integrate these functions. Some interneurons in the brain are concerned with thinking, learning, and memory. A neuron carries impulses in only one direction. This is the result of the neuron’s structure and location, as well as its physical arrangement with other neurons and the resulting pattern of synapses. The functioning nervous system, therefore, is an enormous network of “one-way streets,” and there is no danger of impulses running into and canceling one another out.


1. Heredity—each person has a genetic potential for height, that is, a maximum height, with genes inherited from both parents. Many genes are involved, and their interactions are not well understood. Some of these genes are probably those for the enzymes involved in cartilage and bone production, for this is how bones grow.

2. Nutrition—nutrients are the raw materials of which bones are made. Calcium, phosphorus, and protein become part of the bone matrix itself. Vitamin D is needed for the efficient absorption of calcium and phosphorus by the small intestine. Vitamins A and C do not become part of bone but are necessary for the process of bone matrix formation (ossification). Without these and other nutrients, bones cannot grow properly. Children who are malnourished grow very slowly and may not reach their genetic potential for height.

3. Hormones—endocrine glands produce hormones that stimulate specific effects in certain cells. Several hormones make important contributions to bone growth and maintenance. These include growth hormone, thyroxine, parathyroid hormone, and insulin, which help regulate cell division, protein synthesis, calcium metabolism, and energy production. The sex hormones estrogen or testosterone help bring about the cessation of bone growth. The hormones and their specific functions are listed in Table.

4. Exercise or “stress”—for bones, exercise means bearing weight, which is just what bones are specialized to do. Without this stress (which is normal), bones will lose calcium faster than it is replaced. Exercise need not be strenuous; it can be as simple as the walking involved in everyday activities. Bones that do not get this exercise, such as those of patients confined to bed, will become thinner and more fragile.


During embryonic development, the skeleton is first made of cartilage and fibrous connective tissue, which are gradually replaced by bone. Bone matrix is produced by cells called osteoblasts (a blast cell is a “growing” or “producing” cell, and osteo means “bone”). In the embryonic model of the skeleton, osteoblasts differentiate from the fibroblasts that are present. The production of bone matrix, called ossification, begins in a center of ossification in each bone.

The cranial and facial bones are first made of fibrous connective tissue. In the third month of fetal development, fibroblasts (spindle-shaped connective tissue cells) become more specialized and differentiate into osteoblasts, which produce bone matrix. From each center of ossification, bone growth radiates outward as calcium salts are deposited in the collagen of the model of the bone. This process is not complete at birth; a baby has areas of fibrous connective tissue remaining between the bones of the skull. These are called fontanels, which permit compression of the baby’s head during birth without breaking the still thin cranial bones. The fontanels also permit the growth of the brain after birth. You may have heard fontanels referred to as “soft spots,” and indeed they are. A baby’s skull is quite fragile and must be protected from trauma. By the age of 2 years, all the fontanels have become ossified, and the skull becomes a more effective protective covering for the brain.

The rest of the embryonic skeleton is first made of cartilage, and ossification begins in the third month of gestation in the long bones. Osteoblasts produce bone matrix in the center of the diaphyses of the long bones and in the center of short, flat, and irregular bones. Bone matrix gradually replaces the original cartilage.

The long bones also develop centers of ossification in their epiphyses. At birth, ossification is not yet complete and continues throughout childhood. In long bones, growth occurs in the epiphyseal discs at the junction of the diaphysis with each epiphysis. An epiphyseal disc is still cartilage, and the bone grows in length as more cartilage is produced on the epiphysis side. On the diaphysis side, osteoblasts produce bone matrix to replace the cartilage. Between the ages of 16 and 25 years (influenced by estrogen or testosterone), all of the cartilage of the epiphyseal discs is replaced by bone. This is called closure of the epiphyseal discs (or we say the discs are closed), and the bone lengthening process stops.

Also in bones are specialized cells called osteoclasts (a clast cell is a “destroying” cell), which are able to dissolve and reabsorb the minerals of bone matrix, a process called resorption. Osteoclasts are very active in embryonic long bones, and they reabsorb bone matrix in the center of the diaphysis to form the marrow canal. Blood vessels grow into the marrow canals of embryonic long bones, and red bone marrow is established. After birth, the red bone marrow is replaced by yellow bone marrow. Red bone marrow remains in the spongy bone of short, flat, and irregular bones. For other functions of osteoclasts and osteoblasts, 


There are more than 200 different types of cancer, all of which are characterized by abnormal cellular functioning. Normally, our cells undergo mitosis only when necessary and stop when appropriate. A cut in the skin, for example, is repaired by mitosis, usually without formation of excess tissue. The new cells fill in the damaged area, and mitosis slows when the cells make contact with surrounding cells. This is called contact inhibition, which limits the new tissue to just what is needed. Malignant (cancer) cells, however, are characterized by uncontrolled cell division. Our cells are genetically programmed to have particular life spans and to divide or die. One gene is known to act as a brake on cell division; another gene enables cells to live indefinitely, beyond their normal life span, and to keep dividing. Any imbalance in the activity of these genes may lead to abnormal cell division. Such cells are not inhibited by contact with other cells, keep dividing, and tend to spread.

A malignant tumor begins in a primary site such as the colon, then may spread or metastasize. Often the malignant cells are carried by the lymph or blood to other organs such as the liver, where secondary tumors develop. Metastasis is characteristic only of malignant cells; benign tumors do not metastasize but remain localized in their primary site.

What causes normal cells to become malignant? At present, we have only partial answers. A malignant cell is created by a mutation, a genetic change that brings about abnormal cell functions or responses and often leads to a series of mutations. Environmental substances that cause mutations are called carcinogens. One example is the tar found in cigarette smoke, which is definitely a cause of lung cancer. Ultraviolet light may also cause mutations, especially in skin that is overexposed to sunlight. For a few specific kinds of cancer, the trigger is believed to be infection with certain viruses that cause cellular mutations. Carriers of hepatitis B virus, for example, are more likely to develop primary liver cancer than are people who have never been exposed to this virus. Research has discovered two genes, one on chromosome 2 and the other on chromosome 3, that contribute to a certain form of colon cancer. Both of these genes are the codes for proteins that correct the “mistakes” that may occur when the new DNA is synthesized. When these repair proteins do not function properly, the mistakes (mutations) in the DNA lead to the synthesis of yet other faulty proteins that impair the functioning of the cell and predispose it to becoming malignant.

Once cells have become malignant, their functioning cannot return to normal, and though the immune system will often destroy such cells, sometimes it does not, especially as we get older. Therefore, the treatments for cancer are directed at removing or destroying the abnormal cells. Surgery to remove tumors, radiation to destroy cells, and chemotherapy to stop cell division or interfere with other aspects of cell metabolism are all aspects of cancer treatment.

New chemotherapy drugs are becoming more specific, with very precise targets. For example, the cells of several types of solid-tumor cancers have been found to have mutations in the gene for the cell membrane receptor for a natural growth factor (epidermal growth factor receptor, or EGFR). These altered receptors, when triggered by their usual growth factor, then cause the cell to divide uncontrollably, an abnormal response. Medications that target only these altered receptors have already been developed for some forms of lung cancer and breast cancer. Not only do they show promise in treating the cancer, they do not have the side effects of other forms of chemotherapy.


Multicellular organisms, including people, age and eventually die; our cells do not have infinite life spans. It has been proposed that some cells capable of mitosis are limited to a certain number of divisions; that is, every division is sort of a tick-tock off a biological clock. We do not yet know exactly what this cellular biological clock is. There is evidence that the ends of chromosomes, called telomeres, may be an aspect of it. With each cell division, part of the telomeres is lost (rather like a piece of rope fraying at both ends), and eventually the telomeres are gone. With the next division, the ends of the chromosomes, actual genes, begin to be lost. This may be one signal that a cell’s life span has come to an end (there are probably many different kinds of signals).

Cellular aging also involves the inevitable deterioration of membranes and cell organelles. Just as the parts of a car break down in time, so too will cells. Unlike cars or machines, however, cells can often repair themselves, but they do  have limits. As cells  age, structural proteins  break down  and  are not
replaced, or necessary enzymes are not synthesized. Proteins called chaperones, which are responsible for the  proper folding of many other proteins and for the repair or disposal of damaged  proteins, no
longer function as well as cells age. Without chaperones, damaged proteins accumulate within cells and
disrupt normal cellular processes. Clinical manifestations of impaired chaperones include cataracts and neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease.

Much about the chemistry of the aging process remains a mystery, though we can describe what happens to organs and to the body as a whole. Keep in mind that a system is the sum of its cells, in tissues and organs, and that all aging is ultimately at the cellular level.


Anemia is a deficiency of red blood cells, or insufficient hemoglobin within the red blood cells. There are many different types of anemia.

 Iron-deficiency anemia is caused by a lack of dietary iron, and there is not enough of this mineral to form sufficient hemoglobin. A person with this type of anemia may have a normal RBC count and a normal hematocrit, but the hemoglobin level will be below normal.

A deficiency of vitamin B12, which is found only in animal foods, leads to pernicious anemia, in which the RBCs are large, misshapen, and fragile. Another cause of this form of anemia is lack of the intrinsic factor due to autoimmune destruction of the parietal cells of the stomach lining.

Sickle-cell anemia has already been discussed in previous post. It is a genetic disorder of hemoglobin, which causes RBCs to sickle, clog capillaries, and rupture.

Aplastic anemia is suppression of the red bone marrow, with decreased production of RBCs, WBCs, and platelets. This is a very serious disorder that may be caused by exposure to radiation, certain chemicals such as benzene, or some medications. There are several antibiotics that must be used with caution since they may have this potentially fatal side effect.

Hemolytic anemia is any disorder that causes rupture of RBCs before the end of their normal life span. Sickle-cell anemia and Rh disease of the newborn are examples. Another example is malaria, in which a protozoan parasite reproduces in RBCs and destroys them. Hemolytic anemias are often characterized by jaundice because of the increased production of bilirubin.


Apart from the above mentioned anemias, there are few others like megaloblastic anemia, sideroblastic anemia etc. These are somehow related to the above mentioned anemias. No matter whatever the cause of anemia be its signs and symptoms are similar. Cause is basically needed for the proper treatment of the disease.


A genetic disease is a hereditary disorder, one that may be passed from generation to generation. Although there are hundreds of genetic diseases, they all have the same basis: a mistake in DNA. Because DNA makes up the chromosomes that are found in eggs and sperm, this mistake may be passed from parents to children. Sickle-cell anemia is the most common genetic disorder among people of African descent and affects the hemoglobin in red blood cells. Normal hemoglobin, called hemoglobin A (HbA), is a protein made of two alpha chains (141 amino acids each) and two beta chains (146 amino acids each). In sickle-cell hemoglobin (HbS), the sixth amino acid in each beta chain is incorrect; valine instead of the glutamic acid found in HbA. This difference seems minor—only 2 incorrect amino acids out of more than 500—but the consequences for the person are very serious.

HbS has a great tendency to crystallize when oxygen levels are low, as is true in capillaries. When HbS crystallizes, the red blood cells are deformed into crescents (sickles) and other irregular shapes. These irregular, rigid red blood cells clog and rupture capillaries, causing internal bleeding and severe pain. These cells are also fragile and break up easily, leading to anemia and hypoxia (lack of oxygen). Treatment of this disease has improved greatly, but it is still incurable. What has happened to cause the formation of HbS rather than HbA? Hemoglobin is a protein; the gene for its beta chain is in DNA (chromosome 11). One amino acid in the beta chains is incorrect, therefore, one triplet in its DNA gene must be, and is, incorrect. This mistake is copied by mRNA in the cells of the red bone marrow, and HbS is synthesized in red blood cells.

Sickle-cell anemia is a recessive genetic disease, which means that a person with one gene for HbS and one gene for HbA will have “sickle-cell trait.” Such a person usually will not have the severe effects of sickle-cell anemia, but may pass the gene for HbS to children. It is estimated that 9% of African-Americans have sickle-cell trait and about 1% have sickle-cell anemia.


An eponym is a person for whom something is named, and an eponymous term is a term that uses that name or eponym. For example, fallopian tube is named for Gabriele Fallopio, an Italian anatomist of the 16th century. In recent years it has been suggested that eponymous terms be avoided because they are not descriptive and that they be replaced with more informative terms. Such changes, however, occur slowly, because the older terms are so familiar to those of us who teach. Some of us may even use them as opportunities to impart a little history, also known as “telling stories.”

In this post, the most familiar eponymous terms have been retained, with the newer term in parentheses
after the first usages. The list below is provided to show the extent of reclassification of eponymous terms as related to basic anatomy and physiology.


prefix

a-, an- absent, without (amenorrhea: absence of menstruation)
ab- away from (abduct: move away from the midline)
abdomin/o- abdomen (abdominal aorta: the portion of the aorta in the abdomen)
acou- hearing (acoustic nerve: the cranial nerve for hearing)
ad- toward, near, to (adduct: move toward the midline)
aden/o- gland (adenohypophysis: the glandular part of the pituitary gland)
af- to, toward (afferent: toward a center)
alba- white (albino: an animal lacking coloration)
alg- pain (myalgia: muscle pain)
ana- up, back (anabolism: the constructive phase of metabolism)
angi/o- vessel (angiogram: imaging of blood vessels, as in the heart)
ante- before (antenatal: before birth)
anti- against (antiemetic: an agent that prevents vomiting)
arthr/o- joint (arthritis: inflammation of a joint)
atel- imperfect, incomplete (atelectasis: incomplete expansion of a lung)
auto- self (autoimmune disease: a disease in which immune reactions are directed against part of one’s own body)
bi- two, twice (biconcave: concave on each side, as a red blood cell)
bio- life (biochemistry: the chemistry of living organisms)
blasto- growth, budding (blastocyst: a rapidly growing embryonic stage)
brachi/o- arm (brachial artery: the artery that passes through the upper arm)
brachy- short (brachydactyly: abnormally short fingers or toes)
brady- slow (bradycardia: slow heart rate)
bronch- air passage (bronchioles: small air passages in the lungs)
carcin/o- cancer (carcinogen: cancer-causing substance)
cardi/o- heart (cardiopathy: heart disease)
carp/o- wrist (carpals: bones of the wrist)
cata- down (catabolism: the breaking down phase of metabolism)
caud- tail (cauda equina: the spinal nerves that hang below the end of the spinal cord and resemble a horse’s tail)
celi/o- abdomen (celiac artery: a large artery that supplies abdominal organs)
cephal/o- head (cephaledema: swelling of the head)
cerebr/o- brain (cerebrum: the largest part of the human brain)
cervic- neck (cervical nerves: the spinal nerves from the neck portion of the spinal cord)
chem/o- chemical (chemotherapy: the use of chemicals to treat disease)
chondr/o- cartilage (chondrocyte: cartilage cell)
circum- around (circumoral: around the mouth)
co-, com-, with, together (congenital: born with)
con-, contra- opposite, against (contraception: the prevention of conception)
cost/o- ribs (intercostal muscles: muscles between the ribs)
crani/o- skull, head (cranial nerves: the nerves that arise from the brain)
cut- skin (cutaneous: pertaining to the skin)
cyan/o- blue (cyanosis: bluish discoloration of the skin due to lack of oxygen)
cyst- bladder, sac (cystic duct: duct of the gallbladder)
cyt/o- cell (hepatocyte: cell of the liver)
dactyl/o- digits, fingers or toes (polydactyly: more than five fingers or toes)
de- down, from (dehydration: loss of water)
derm- skin (dermatologist: a specialist in diseases of the skin)
di- two, twice (disaccharide: a sugar made of two monosaccharides)
diplo- double (diplopia: double vision)
dis- apart, away from (dissect: to cut apart)
duct- lead, conduct (ductus arteriosus: a fetal artery)
dys- difficult, diseased (dyspnea: difficult breathing)
ecto- outside (ectoparasite: a parasite that lives on the body surface)
edem- swelling (edematous: affected with swelling)
endo- within (endocardium: the innermost layer of the heart wall)
enter/o- intestine (enterotoxin: a toxin that affects the intestine and causes diarrhea)
epi- on, over, upon (epidermis: the outer layer of the skin)
erythr/o- red (erythrocyte: red blood cell)
eu- normal, good (eupnea: normal breathing)
ex- out of (excise: to cut out or remove surgically)
exo- without, outside of (exophthalmia: protrusion of the eyeballs)
extra- outside of, in addition to, beyond (extraembryonic membranes: the membranes that surround the embryofetus)
fasci- band (fascia: a fibrous connective tissue membrane)
fore- before, in front (forehead: the front of the head)
gastro/o- stomach (gastric juice: the digestive secretions of the stomach lining)
gluco-, glyco- sugar (glycosuria: glucose in the urine)
gyn/o-, gyne/co- woman, female (gynecology: study of the female reproductive organs)
haplo- single, simple (haploid: a single set, as of chromosomes)
hema-, hemato-, hemo- blood (hemoglobin: the protein of red blood cells)
hemi- half (cerebral hemisphere: the right or left half of the cerebrum)
hepat/o- liver (hepatic duct: the duct that takes bile out of the liver)
hetero- different (heterozygous: having two different genes for a trait)
hist/o- tissue (histology: the study of tissues)
homeo- unchanged (homeostasis: the state of body stability)
homo- same (homozygous: having two similar genes for a trait)
hydr/o- water (hydrophobia: fear of water)
hyper- excessive, above (hyperglycemia: high blood glucose level)
hypo- beneath, under, deficient (hypodermic: below the skin)
idio- distinct, peculiar to the individual (idiopathic: of unknown cause, as a disease)
inter- between, among (interventricular septum: the wall between the ventricles of the heart)
intra- within (intracellular: within cells)
is/o- equal, the same (isothermal: having the same temperature)
kinesi/o- movement (kinesthetic sense: muscle sense)
labi- lip (herpes labialis: cold sores of the lips)
lacri- tears (lacrimal glands: tear-producing glands)
lact/o- milk (lactation: milk production)
leuc/o, leuk/o- white (leukocyte: white blood cell)
lip/o- fat (liposuction: removal of fat with a suctioning instrument)
macr/o- large (macromolecule: a large molecule such as a protein)
mal- poor, bad (malnutrition: poor nutrition)
medi- middle (mediastinum: a middle cavity, as in the chest)
mega- large (megacolon: abnormally dilated colon)
meta- next to, beyond (metatarsal: bone of the foot next to the ankle)
micr/o- small (microcephaly: small head)
mon/o- one (monozygotic twins: identical twins, from one egg)
morph/o- shape, form (amorphous: without definite shape)
multi- many (multicellular: made of many cells)
my/o- muscle (myocardium: heart muscle)
narco- sleep (narcotic: a drug that produces sleep)
nat/a- birth (neonate: a newborn infant)
neo- new (neoplasty: surgical restoration of parts)
nephr/o- kidney (nephrectomy: removal of a kidney)
neur/o- nerve (neuron: nerve cell)
non- not (non-communicable: unable to spread)
ocul/o- eye (oculomotor nerve: a cranial nerve for eye movement)
olig/o- few, scanty (oliguria: diminished amount of urine)
oo- egg (oogenesis: production of an egg cell)
ophthalmo- eye (ophthalmoscope: instrument to examine the eye)
orth/o- straight, normal, correct (orthostatic: related to standing upright)
oste/o- bone (osteocyte: bone cell)
ot/o- ear (otitis media: inflammation of the middle ear)
ovi-, ovo- egg (oviduct: duct for passage of an egg cell, fallopian tube)
path/o- disease (pathology: the study of disease)
ped/ia- child (pediatric: concerning the care of children)
per- through (permeate: to pass through)
peri- around (pericardium: membranes that surround the heart)
phag/o- eat (phagocyte: a cell that engulfs pariculate matter)
phleb/o- vein (phlebitis: inflammation of a vein)
pleuro-, pleura- rib (pleurisy: inflammation of the pleural membranes of the chest cavity)
pneumo- lung (pneumonia: lung infection)
pod- foot (pseudopod: false foot, as in ameboid movement)
poly- many (polysaccharide: a carbohydrate made of many monosaccharides)
post- after (postpartum: after delivery of a baby)
pre- before (precancerous: a growth that probably will become malignant)
pro- before, in front of (progeria: premature old age, before its time)
pseudo- false (pseudomembrane: false membrane)
py/o- pus (pyogenic: pus producing)
pyel/o- renal pelvis (pyelogram: an x-ray of the renal pelvis and ureter)
quadr/i- four (quadriceps femoris: a thigh muscle with four parts)
retro- behind, backward (retroperitoneal: located behind the peritoneum)
rhin/o- nose (rhinoviruses that cause the common cold)
salping/o- fallopian tube (salpingitis: inflammation of a fallopian tube)
sarc/o- flesh, muscle (sarcolemma: membrane of a muscle cell)
sclero- hard (sclerosis: deterioration of tissue with loss of function)
semi- half (semilunar valve: a valve shaped like a half-moon)
steno- narrow (aortic stenosis: narrowing of the aorta)
sub- below, beneath (subcutaneous: below the skin)
supra- above (suprarenal gland: gland above the kidney, the adrenal gland)
sym- together (symphysis: a joint where two bones meet)
syn- together (synapse: the space between two nerve cells)
tachy- fast (tachycardia: rapid heart rate)
thorac/o- chest (thoracic cavity: chest cavity)
thromb/o- clot (thrombosis: formation of a blood clot)
tox- poison (toxicology: the study of poisons)
trans- across (transmural: across the wall of an organ)
tri- three (trigone: a three-sided area on the floor of the urinary bladder)
ultra- excessive, extreme (ultrasonic: sound waves beyond the normal hearing range)
un/i- one (unicellular: made of one cell)
uria-, uro- urine (urinary calculi: stones in the urine)
vas/o- vessel (vasodilation: dilation of a blood vessel)
viscera-, viscero- organ (visceral pleura: the pleural membrane that covers the lungs)

suffix

-ac pertaining to (cardiac: pertaining to the heart)
-al pertaining to (intestinal: pertaining to the intestine)
-an, -ian characteristic of, pertaining to, belonging to (ovarian cyst: a cyst of the ovary)
-ar relating to (muscular: relating to muscles)
-ary relating to, connected with (salivary: relating to saliva)
-ase enzyme (sucrase: an enzyme that digests sucrose)
-atresia abnormal closure (biliary atresia: closure or absence of bile ducts)
-blast grow, produce (osteoblast: a bone-producing cell)
-cele swelling, tumor (meningocele: a hernia of the meninges)
-centesis puncture of a cavity (thoracocentesis: puncture of the chest cavity to remove fluid)
-cide kill (bactericide: a chemical that kills bacteria)
-clast destroy, break down (osteoclast: a bone-reabsorbing cell)
-desis binding, stabilizing, fusion (arthrodesis: the surgical immobilization of a joint)
-dipsia thirst (polydipsia: excessive thirst)
-dynia pain (gastrodynia: stomach pain)
-ectasia, -ectasis expansion (atelectasis: without expansion)
-ectomy excision, cutting out (thyroidectomy: removal of the thyroid)
-emia pertaining to blood (hypokalemia: low blood potassium level)
-form structure (spongiform: resembling a sponge)
-gen producting (carcinogen: a substance that produces cancer)
-genesis production of, origin of (spermatogenesis: production of sperm)
-globin protein (myoglobin: a muscle protein)
-gram record, writing (electroencephalogram: a record of the electrical activity of the brain)
-graph an instrument for making records (ultrasonography: the use of ultrasound to produce an image)
-ia condition (pneumonia: condition of inflammation of the lungs)
-iasis diseased condition (cholelithiasis: gallstones)
-ic pertaining to (atomic: pertaining to atoms)
-ile having qualities of (febrile: feverish)
-ism condition, process (alcoholism: condition of being dependent on alcohol)
-ist practitioner, specialist (neurologist: a specialist in diseases of the nervous system)
-itis inflammation (hepatitis: inflammation of the liver)
-lepsy seizure (narcolepsy: a sudden onset of sleep)
-lith stone, crystal (otoliths: stones in the inner ear)
-logy study of (virology: the study of viruses)
-lysis break down (hemolysis: rupture of red blood cells)
-megaly enlargement (splenomegaly: enlargement of the spleen)
-meter a measuring instrument (spirometer: an instrument to measure pulmonary volumes)
-ness state of, quality (illness: state of being ill)
-oid the appearance of (ovoid: resembling an oval or egg)
-ole small, little (arteriole: small artery)
-oma tumor (carcinoma: malignant tumor)
-opia eye (hyperopia: farsightedness)
-ory pertaining to (regulatory: pertaining to regulation)
-ose having qualities of (comatose: having qualities of a coma)
-osis state, condition, action, process (keratosis: abnormal growth of the skin)
-ostomy creation of an opening (colostomy: creation of an opening between the intestine and the abdominal wall)
-otomy cut into (tracheotomy: cut into the trachea)
-ous pertaining to (nervous: pertaining to nerves)
-pathy disease (retinopathy: disease of the retina)
-penia lack of, deficiency (leukopenia: lack of white blood cells)
-philia love of, tendency (hemophilia: a clotting disorder; “love of blood”)
-phobia an abnormal fear (acrophobia: fear of heights)
-plasia growth (hyperplasia: excessive growth)
-plasty formation, repair (rhinoplasty: plastic surgery on the nose)
-plegia paralysis (hemiplegia: paralysis of the right or left half of the body)
-poiesis production (erythropoiesis: production of red blood cells)
-ptosis dropping, falling (hysteroptosis: falling of the uterus)
-rrhage burst forth (hemorrhage: loss of blood from blood vessels)
-rrhea discharge, flow (diarrhea: frequent discharge of feces)
-scope instrument to examine (microscope: instrument to examine small objects)
-spasm involuntary contraction (blepharospasm: twitch of the eyelid)
-stasis to be still, control, stop (hemostasis: to stop loss of blood)
-sthenia strength (myasthenia: loss of muscle strength)
-stomy surgical opening (colostomy: a surgical opening in the colon)
-taxia muscle coordination (ataxia: loss of coordination)
-tension pressure (hypertension: high blood pressure)
-tic pertaining to (paralytic: pertaining to paralysis)
-tomy incision, cut into (phlebotomy: incision into a vein)
-tripsy crush (lithotripsy: crushing of stone such as gallstones)
-trophic related to nutrition or growth (autotrophic: capable of making its own food, such as a green plant)
-tropic turning toward (chemotropic: turning toward a chemical)
-ula, -ule small, little (venule: small vein)
-uria urine (hematuria: blood in the urine)
-y condition, process (healthy: condition of health)