cytology

Study of cells

cytoplasm

The fluid that fills a cell and holds the organelles

DNA

The genetic compound of the cell; makes up the genes. DNA stands for deoxyribonucleic acid.

Enzyme

An organic substance that speeds the rate of metabolic reactions

gene

A hereditary unit composed of DNA and combined with other genes to form the chromosomes

glucose

A simple sugar that circulates in the blood; the main energy source for metabolism (roots: gluc/o, glyc/o)

histology

Study of tissues

homeostasis

A steady state; a condition of internal stability and constancy

lipid

A category of organic compounds that includes fats (root lip/o)

metabolism

The sum of all the physical and chemical reactions that occur within an organism

mitosis

Cell division

mucus

A thick fluid secreted by cells in membranes and glands that lubricates and protects tissues (roots: muc/o, myx/o); the adjective is mucous.

nucleus

The cell's control center; directs all cell activities based on the information contained in its chromosomes (roots nucle/o, kary/o)

abdominal cavity

The larger ventral cavity below the diaphragm and above the pelvic cavity

abdominopelvic cavity

The larger ventral cavity between the diaphragm and pelvis that includes the abdominal and pelvic cavity

anatomic position

Standard position for anatomical studies, in which the body is erect and facing forward, the arms are at the sides with palms forward, and the feet are parallel

cranial cavity

The dorsal cavity that contains the brain

diaphragm

The muscle that separate the thoracic from the abdominal cavity

frontal (coronal) plane

Plane of section that separates the body into anterior (front) and posterior (back) portions

pelvic cavity

The ventral cavity that is below the abdominal cavity

peritoneum

The large serous membrane that lines the abdominopelvic cavity and cover the organs with it

sagittal plane

Plane that divides the body into right and left portions

spinal cavity (canal)

Dorsal cavity that contains the spinal cord

thoracic cavity

The ventral cavity above the diaphragm; the chest cavity

transverse (horizontal) plane

Plane that divides the body into superior (upper) and inferior (lower) portions

digit

A finger or toe (adjective, digital)

epigastrium

The epigastric region

fundus

The base or body of a hollow organ; the area of an organ farthest from its opening

hypochondrium

The hypochondriac region (left or right)

lumen

The central opening within a tube or hollow organ

meatus

A passage or opening

orifice

The opening of a cavity

os

Mouth; any body opening

septum

A wall dividing two cavities

sinus

A cavity, as within a bone

sphincter

A circular muscle that regulates an opening

LLQ

Left lower quadrant

LUQ

Left upper quadrant

RLQ

Right lower quadrant

RUQ

Right upper quadrant

atopic dermatitis

Hereditary, allergic, chronic inflammation of the skin with pruritus (itching); eczema

basal cell carcinoma

An epithelial tumor that rarely metastasizes and has a high cure rate with surgical removal

cicatrization

The process of scar formation; a scar is a cicatrix

debridement

Removal of dead or damaged tissue, as from a wound

dehiscence

Splitting or bursting, as when the layers of a wound separate

dermatitis

Inflammation of the skin, often associated with redness and itching; may be caused by allergy, irritants (contact dermatitis), or a variety of diseases

dermatology

Study of the skin and diseases of the skin

dermatome

Instrument for cutting thin sections of skin for skin grafting

eczema

A general term for an inflammation of the skin with redness, lesions, and itching; atopic dermatitis

erythema

Diffuse redness of the skin

escharotomy

Removal of scab tissue (eschar) resulting from burns or other skin injuries

evisceration

Protrusion of internal organs (viscera) through an opening, as through a wound

exudates

Material, which may include fluid, cells, pus, or blood, that escapes from damaged tissue

Kaposi sarcoma

Cancerous lesion of the skin and other tissues seen most often in patients with AIDS

keloid

A raised, thickened scar caused by tissue overgrowth during scar formation

lupus erythematosus (LE)

A chronic, inflammatory, autoimmune disease of connective tissue that often involves the skin; types include the more widespread systemic lupus erythematosus (SLE) and a discoid form (DLE) that involves only the skin

malignant melanoma

A metastasizing pigmented tumor of the skin

pemphigus

An autoimmune disease of the skin characterized by sudden, intermittent formation of bullae (blisters); may be fatal if untreated

pressure ulcer

An ulcer caused by pressure to an area of the body, as from a bed or chair; decubitus ulcer, bedsore, pressure sore

pruritus

Severe itching

psoriasis

A chronic hereditary dermatitis with red lesions covered by silvery scales

rule of nines

A method for estimating the extent of body surface area involved in a burn by assigning percentages in multiples of nine to various regions of the body

scleroderma

A chronic disease that is characterized by thickening and tightening of the skin and that often involves internal organs in a form called progressive systemic sclerosis (PSS)

squamous cell carcinoma

An epidermal cancer that may invade deeper tissues but tends not to metastasize

acne

An inflammatory disease of the sebaceous glands and hair follicles usually associated with excess secretion of sebum; acne vulgaris

actinic

Pertaining to the effects of radiant energy, such as sunlight, ultraviolet light, and x-rays

albinism

A hereditary lack of pigment in the skin, hair, and eyes

alopecia

Absence or loss of hair; baldness

Beau lines

White lines across the fingernails; usually a sign of systemic disease or injury

bromhidrosis

Sweat that has a foul odor because of bacterial decomposition; also called bromidrosis

carbuncle

A localized infection of the skin and subcutaneous tissue, usually caused by staphylococcus, and associated with pain and discharge of pus

comedo

A plug of sebum, often containing bacteria, in a hair follicle; a blackhead (plural: comedones)

dermatophytosis

Fungal infection of the skin, especially between the toes; athlete's foot (root: phyt/o means “plant”)

diaphoresis

Profuse sweating

dyskeratosis

Any abnormality in keratin formation in epithelial cells

ecchymosis

A collection of blood under the skin caused by leakage from small vessels

erysipelas

An acute infectious disease of the skin with localized redness and swelling and systemic symptoms

erythema nodosum

Inflammation of subcutaneous tissues resulting in tender, erythematous nodules; may be an abnormal immune response to a systemic disease, an infection, or a drug

exanthema

Any eruption of the skin that accompanies a disease, such as measles; a rash

excoriation

Lesion caused by scratching or abrasion

folliculitis

Inflammation of a hair follicle

furuncle

A painful skin nodule caused by staphylococci that enter through a hair follicle; a boil

hemangioma

A benign tumor of blood vessels; in the skin, called birthmarks or port wine stains

herpes simplex

A group of acute infections caused by herpes simplex virus. Type I herpes simplex virus produces fluid-filled vesicles, usually on the lips, after fever, sun exposure, injury, or stress; cold sore, fever blister. Type II infections usually involve the genital organs

hirsutism

Excessive growth of hair

ichthyosis

A dry, scaly condition of the skin (from the root ichthy/o, meaning “fish”)

impetigo

A bacterial skin infection with pustules that rupture and form crusts; most commonly seen in children, usually on the face

keratosis

Any skin condition marked by thickened or horny growth. Seborrheic keratosis is a benign tumor, yellow or light brown in color, that appears in the elderly. Actinic keratosis is caused by exposure to sunlight and may lead to squamous cell carcinoma

lichenification

Thickened marks caused by chronic rubbing, as seen in atopic dermatitis (a lichen is a flat, branching type of plant that grows on rocks and bark)

mycosis fungoides

A rare malignant disease that originates in the skin and involves the internal organs and lymph nodes. There are large, painful, ulcerating tumors

nevus

A defined discoloration of the skin; a congenital vascular tumor of the skin; a mole, birthmark

paronychia

Infection around a nail. Caused by bacteria or fungi, and may affect multiple nails

pediculosis

Infestation with lice

petechiae

Flat, pinpoint, purplish red spots caused by bleeding within the skin or mucous membrane (singular, petechia)

photosensitization

Sensitization of the skin to light, usually from the action of drugs, plant products, or other substances

purpura

A condition characterized by hemorrhages into the skin and other tissues

rosacea

A condition of unknown cause involving redness of the skin, pustules, and overactivity of sebaceous glands, mainly on the face

scabies

A highly contagious skin disease caused by a mite

senile lentigines

Brown macules that appear on sun-exposed skin in adults; liver spots

shingles

An acute eruption of vesicles along the path of a nerve; herpes zoster (HER-pēz ZOS-ter); caused by the same virus that causes chickenpox

tinea

A fungal infection of the skin; ringworm

tinea versicolor

Superficial chronic fungal infection that causes varied pigmentation of the skin

urticaria

A skin reaction marked by temporary, smooth, raised areas (wheals) associated with itching; hives

venous stasis ulcer

Ulcer caused by venous insufficiency and stasis of venous blood; usually forms near the ankle

verruca

An epidermal tumor; a wart

vitiligo

Patchy disappearance of pigment in the skin; leukoderma

xeroderma pigmentosum

A fatal hereditary disease that begins in childhood with discolorations and ulcers of the skin and muscle atrophy. There is increased sensitivity to the sun and increased susceptibility to cancer

aloe

A gel from the leaves from the plant Aloe vera that is used in treatment of burns and minor skin irritations

antipruritic

Agent that prevents or relieves itching

cautery

Destruction of tissue by physical or chemical means; cauterization; also the instrument or chemical used for this purpose

dermabrasion

A plastic surgical procedure for removing scars or birthmarks by chemical or mechanical destruction of epidermal tissue

dermatoplasty

Transplantation of human skin; skin grafting

diascopy

Examination of skin lesions by pressing a glass plate against the skin

fulguration

Destruction of tissue by high frequency electric sparks

skin turgor

Resistance of the skin to deformation. Evidenced by the ability of the skin to return to position when pinched. Skin turgor is a measure of the skin’s elasticity and state of hydration. It typically declines with age and when decreased may also be a sign of poor nutrition

wood lamp

An ultraviolet light to diagnose fungal infections

acetabulum

The bony socket in the hip bone that holds the head of the femur (from the Latin word for vinegar because it resembles the base of a vinegar cruet)

articulation

A joint (adjective: articular)

atlas

The first cervical vertebra (root: atlant/o)

axis

The second cervical vertebra

bone

A calcified form of dense connective tissue; osseous tissue; also an individual unit of the skeleton made of such tissue (root: oste/o)

bone marrow

The soft material that fills the cavities of bones. Yellow marrow fills the central cavity of the long bones; blood cells are formed in red bone marrow, which is located in spongy bone tissue (root: myel/o)

bursa

A fluid-filled sac that reduces friction near a joint (root: burs/o)

cartilage

A type of dense connective tissue that is found in the skeleton, larynx, trachea, and bronchi. It is the precursor to most bone tissue (root: chondr/o)

diarthrosis

A freely movable joint; also called a synovial join; adjective: diarthrotic

diaphysis

The shaft of a long bone

epiphyseal plate

The growth region of a long bone; located in the metaphysis, between the diaphysis and epiphysis. When bone growth ceases, this area appears as the epiphyseal line

epiphysis

The irregularly shaped end of a long bone

Ilium

The large, flared, superior portion of the pelvic bone; adjective: iliac; (root: ili/o)

joint

The junction between two bones; articulation (root: arthr/o)

ligament

A strong band of connective tissue that joins one bone to another

metaphysis

The region of a long bone between the diaphysis (shaft) and epiphysis (end); during development, the growing region of a long bone

ossification

The formation of bone tissue (from Latin os, meaning “bone”)

osteoblast

A cell that produces bone tissue

osteoclast

A cell that destroys bone tissue

osteocyte

A mature bone cell that nourishes and maintains bone tissue

pelvis

The large ring of bone at the inferior trunk. Formed of the two hip bones (os coxae) joined to the sacrum and coccyx (plural: pelves). Each os coxae is formed of three bones, the superior, flared ilium, ischium, and pubis

periosteum

The fibrous membrane that covers the surface of a bone

resorption

Removal of bone by breakdown and absorption into the circulation

skeleton

The bony framework of the body, consisting of 206 bones. The axial portion (80 bones) is composed of the skull, spinal column, ribs, and sternum. The appendicular skeleton (126 bones) contains the bones of the arms and legs, shoulder girdle, and pelvis

suture

An immovable joint, such as the joints between the skull bones

symphysis

A slightly movable joint

synovial fluids

The fluid contained in a freely movable (diarthrotic) joint; synovia (root: synov/i)

synovial joint

A freely movable joint; has a joint cavity containing synovial fluid; a diarthrosis

tendon

A fibrous band of connective tissue that attaches a muscle to a bone

thorax

The upper part of the trunk between the neck and the abdomen; formed by the 12 pairs of ribs and sternum

ankylosing spondylitis

A chronic, progressive inflammatory disease involving the joints of the spine and surrounding soft tissue, most common in young males; also called rheumatoid spondylitis

ankylosis

Immobility and fixation of a joint

arthritis

Inflammation of a joint

chondrosarcoma

A malignant tumor of cartilage

curvature of the spine

An exaggerated spinal curve, such as scoliosis, lordosis, or kyphosis

degenerative joint disease (DJD)

Osteoarthritis

fracture

A break in a bone. In a closed or simple fracture, the broken bone does not penetrate the skin; in an open fracture, there is an accompanying wound in the skin

gout

A form of acute arthritis, usually beginning in the knee or foot, caused by deposit of uric acid salts in the joints

herniated disk

Protrusion of the center (nucleus pulposus) of an intervertebral disk into the spinal canal; ruptured or “slipped” disk

kyphosis

An exaggerated curve of the spine in the thoracic region; hunchback, humpback

lordosis

An exaggerated curve of the spine in the lumbar region; swayback

osteoarthritis (OA)

Progressive deterioration of joint cartilage with growth of new bone and soft tissue in and around the joint; the most common form of arthritis; results from wear and tear, injury, or disease; also called degenerative joint disease (DJD)

osteogenic sarcoma

A malignant bone tumor; osteosarcoma

osteomalacia

A softening and weakening of the bones due to vitamin D deficiency or other disease

osteomyelitis

Inflammation of bone and bone marrow caused by infection, usually bacterial

osteopenia

A lower than average bone density, which may foreshadow osteoporosis

osteoporosis

A condition characterized by reduction in bone density, most common in white women past menopause; predisposing factors include poor diet, inactivity, and low estrogen levels

Paget disease

Skeletal disease of the elderly characterized by bone thickening and distortion with bowing of long bones; osteitis deformans

Pott disease

Inflammation of the vertebrae, usually caused by tuberculosis

rheumatoid arthritis

A chronic autoimmune disease of unknown origin resulting in inflammation of peripheral joints and related structures; more common in women than in men

rheumatoid factor

A group of antibodies found in the blood in cases of rheumatoid arthritis and other systemic diseases

rickets

Faulty bone formation in children, usually caused by a deficiency of vitamin D

sciatica

Severe pain in the leg along the course of the sciatic nerve, usually related to spinal nerve root irritation

scoliosis

A sideways curvature of the spine in any region

spondylolisthesis

A forward displacement of one vertebra over another (-listhesis means “a slipping”)

spondylolysis

Degeneration of the articulating portions of a vertebra allowing for spinal distortion, specifically in the lumbar region

alkaline phosphatase

An enzyme needed in the formation of bone; serum activity of this enzyme is useful in diagnosis

arthrocentesis

Aspiration of fluid from a joint by needle puncture

arthrodesis

Surgical immobilization (fusion) of a joint; artificial ankylosis

arthroplasty

Partial or total replacement of a joint with a prosthesis

arthroscopy

Use of an endoscope to examine the interior of a joint or to perform surgery on the joint; the instrument used is an arthroscope

diskectomy

Surgical removal of a herniated intervertebral disk; also spelled discectomy

orthopedics

The study and treatment of disorders of the skeleton, muscles, and associated structures; literally “straight” (ortho) “child” (ped); also spelled orthopaedics

reduction of a fracture

Return of a fractured bone to a normal position; may be closed (not requiring surgery) or open (requiring surgery)

traction

The process of drawing or pulling, such as traction of the head in the treatment of injuries to the cervical vertebrae

antiinflammatory agent

Drug that reduces inflammation; includes steroids, such as cortisone, and nonsteroidal antiinflammatory drugs (NSAIDs)

bisphosphonate

Agent used to prevent and treat osteoporosis; increases bone mass by decreasing bone turnover. Examples are alendronate (Fosamax) and risedronate (Actonel)

nonsteroidal antiinflammatory drug (NSAID)

Drug that reduces inflammation but is not a steroid; examples include aspirin and ibuprofen and other inhibitors of prostaglandins, naturally produced substances that promote inflammation

selective estrogen receptor modulator (SERM)

Drug that acts on estrogen receptors. Raloxifene (Avista) is used to prevent bone loss after menopause. Other SERMs are used to prevent and treat estrogen-sensitive breast cancer

annulus fibrosus

The outer ring-like portion of an intervertebral disk

calvaria

The dome-like upper portion of the skull

coxa

Hip

cruciate ligaments

Ligaments that cross in the knee joint to connect the tibia and fibula. They are the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL). Cruciate means “shaped like a cross”

genu

The knee

glenoid cavity

The bony socket in the scapula that articulates with the head of the humerus

hallux

The great toe

malleolus

The projection of the tibia or fibula on either side of the ankle

meniscus

Crescent-shaped disk of cartilage found in certain joints, such as the knee joint. In the knee, the medial meniscus and the lateral meniscus separate the tibia and femur. (plural: menisci (me-NIS-kī); meniscus means “crescent”)

nucleus pulposus

The central mass of an intervertebral disk

olecranon

The process of the ulna that forms the elbow

os

Bone (plural: ossa)

osseous

Pertaining to bone

symphysis pubis

The anterior pelvic joint, formed by the union of the two pubic bones; also called pubic symphysis

achondroplasia

Decreased growth of cartilage in the growth plate of long bones resulting in dwarfism; a genetic disorder

Baker cyst

Mass formed at the knee joint by distention of a bursa with excess synovial fluid resulting from chronic irritation

bunion

Inflammation and enlargement of the metatarsal joint of the great toe, usually with displacement of the great toe toward the other toes

bursitis

Inflammation of a bursa, a small fluid-filled sac near a joint; causes include injury, irritation, and joint disease; the shoulder, hip, elbow, and knee are common sites

carpal tunnel syndrome

Numbness and weakness of the hand caused by pressure on the median nerve as it passes through a tunnel formed by carpal bones

chondroma

A benign tumor of cartilage

Ewing tumor

A bone tumor that usually appears in children 5 to 15 years of age. It begins in the shaft of a bone and spreads readily to other bones. It may respond to radiation therapy, but then returns. Also called Ewing sarcoma

exostosis

A bony outgrowth from the surface of a bone

giant cell tumor

A bone tumor that usually appears in children and young adults. The ends of the bones are destroyed, commonly at the knee, by a large mass that does not metastasize

hammertoe

Change in position of the toe joints so that the toe takes on a claw-like appearance and the first joint protrudes upward, causing irritation and pain on walking

hallux valgus

Painful condition involving lateral displacement of the great toe at the metatarsal joint. There is also enlargement of the metatarsal head and bunion formation

Heberden nodes

Small, hard nodules formed in the cartilage of the distal joints of the fingers in osteoarthritis

hemarthrosis

Bleeding into a joint cavity

Legg–Calvé–Perthes disease

Degeneration (osteochondrosis) of the proximal growth center of the femur. The bone is eventually restored, but there may be deformity and weakness. Most common in young boys. Also called coxa plana

multiple myeloma

A cancer of blood-forming cells in bone marrow (see Chapter 10)

neurogenic arthropathy

Degenerative disease of joints caused by impaired nervous stimulation; most common cause is diabetes mellitus; Charcot arthropathy

Osgood-Schlatter disease

Degeneration (osteochondrosis) of the proximal growth center of the tibia causing pain and tendinitis at the knee

osteochondroma

A benign tumor consisting of cartilage and bone

osteochondrosis

Disease of a bone's growth center in children; degeneration of the tissue is followed by recalcification

osteodystrophy

Abnormal bone development

osteogenesis imperfecta (OI)

A hereditary disease resulting in the formation of brittle bones that fracture easily. There is faulty synthesis of collagen, the main structural protein in connective tissue.

osteoma

A benign bone tumor that usually remains small and localized

Reiter syndrome

Chronic polyarthritis that usually affects young men; occurs after a bacterial infection and is common in those infected with HIV; may also involve the eyes and genitourinary tract

spondylosis

Degeneration and ankylosis of the vertebrae resulting in pressure on the spinal cord and nerve roots; often applied to any degenerative lesion of the spine

subluxation

A partial dislocation

talipes

A deformity of the foot, especially one occurring congenitally; clubfoot

valgus

Bent outward

varus

Bent inward

von Recklinghausen disease

Loss of bone tissue caused by increased parathyroid hormone; bones become decalcified and deformed, and fracture easily

allograft

Graft of tissue between individuals of the same species but different genetic makeup; homograft, allogenic graft (see autograft)

arthroclasia

Surgical breaking of an ankylosed joint to provide movement

aspiration

Removal by suction, as removal of fluid from a body cavity; also inhalation, such as accidental inhalation of material into the respiratory tract

autograft

Graft of tissue taken from a site on or in the body of the person receiving the graft; autologous graft (see allograft)

calcitonin

A hormone from the thyroid gland that decreases resorption (loss) of bone tissue; used in the treatment of Paget disease and osteoporosis; also called thyrocalcitonin

chondroitin

A complex polysaccharide found in connective tissue; used as a dietary supplement, usually with glucosamine, for treatment of joint pain

glucosamine

A dietary supplement used in the treatment of joint pain

goniometer

A device used to measure joint angles and movements (root goni/o means “angle”)

iontophoresis

Introduction into the tissue by means of electric current, using the ions of a given drug; used in the treatment of musculoskeletal disorders

laminectomy

Excision of the posterior arch (lamina) of a vertebra

meniscectomy

Removal of the crescent-shaped cartilage (meniscus) of the knee joint

myelogram

Radiograph of the spinal canal after injection of a radiopaque dye; used to evaluate a herniated disk

osteoplasty

Scraping and removal of damaged bone from a joint

prosthesis

An artificial organ or part, such as an artificial limb

acetylcholine (ACh)

A neurotransmitter that stimulates contraction of skeletal muscles

actin

One of the two contractile proteins in muscle cells; the other is myosin

agonist

The muscle that carries out a given movement; prime mover

antagonist

The muscle that opposes an agonist (prime mover); it must relax when the agonist contracts

cardiac muscle

Involuntary muscle that makes up the wall of the heart

fascia

The fibrous sheath of connective tissue that covers a muscle; called deep fascia to differentiate it from the superficial fascia that underlies the skin (root: fasci/o); plural: fasciae

fascicle

A small bundle, as of muscle or nerve fibers

insertion

In a given movement, the point where a muscle is attached to a moving part of the skeleton

muscle

An organ that produces movement by contracting; also the tissue that composes such organs (root: my/o, muscul/o)

myosin

One of the two contractile proteins in muscle cells; the other is actin

neuromuscular junction (NMJ)

The point of contact, or synapse, between a branch of a motor neuron and a muscle cell

origin

In a given movement, the point where a muscle is attached to a stable part of the skeleton

skeletal muscle

Voluntary muscle that moves the skeleton and maintains posture

smooth muscle

Involuntary muscle that makes up the wall of the hollow organs, vessels, and ducts; visceral muscle

synergist

A muscle that assists an agonist to produce a given movement

tendon

A fibrous band of connective tissue that attaches a muscle to a bone (root: ten/o, tendin/o)

tonus

A state of steady, partial contraction of muscle that maintains firmness; muscle tone (root: ton/o)

amyotrophic lateral sclerosis (ALS)

A disease caused by degeneration of motor neurons resulting in muscular weakness and atrophy; Lou Gehrig disease

chronic fatigue syndrome (CFS)

A disease of unknown cause that involves persistent fatigue, along with muscle and joint pain and other symptoms; may be virally induced

dermatomyositis

A disease of unknown origin involving inflammation of muscles as well as dermatitis and skin rashes

fibromyalgia syndrome (FMS)

A disorder associated with widespread muscular aches and stiffness and having no known cause

muscular dystrophy

A group of hereditary muscular disorders marked by progressive weakness and atrophy of muscles

myasthenia gravis (MG)

A disease characterized by progressive muscular weakness; an autoimmune disease affecting the neuromuscular junction

polymyositis

A disease of unknown cause involving muscle inflammation and weakness

repetitive strain injury

Tissue damage caused by repeated motion, usually overuse of the arm or hand in occupational activities such as writing, typing, painting, or using hand tools; also called repetitive motion injury, cumulative trauma injury, overuse syndrome

sprain

Injury to a ligament caused by abnormal or excessive force at a joint, but without bone dislocation or fracture

strain

Trauma to a muscle because of overuse or excessive stretch; if severe, may involve tearing of muscle, bleeding, or separation of muscle from its tendon or separation of a tendon from bone

tendinitis

Inflammation of a tendon, usually caused by injury or overuse; the shoulder, elbow, and hip are common sites; also spelled tendonitis

tenosynovitis

Inflammation of a tendon sheath

creatine kinase (CK)

An enzyme found in muscle tissue; the serum level of CK increases in cases of muscle damage; creatine phosphokinase (CPK)

electromyography (EMG)

Study of the electrical activity of muscles during contraction

aponeurosis

A flat, white, sheetlike tendon that connects a muscle with the part that it moves

creatine

A substance in muscle cells that stores energy for contraction

glycogen

A complex sugar that is stored for energy in muscles and in the liver

isometric

Pertaining to a muscle action in which the muscle tenses but does not shorten (literally: same measurement)

isotonic

Pertaining to a muscle action in which the muscle shortens to accomplish movement (literally: same tone)

kinesthesia

Awareness of movement; perception of the weight, direction, and degree of movement (-esthesia means “sensation”)

lactic acid

An acid produced in muscle cells that accumulates in muscle cells functioning without enough oxygen (anaerobically), as in times of great physical exertion

motor unit

A single motor neuron and all of the muscle cells that its branches stimulate

myoglobin

A pigment similar to hemoglobin that stores oxygen in muscle cells

asterixis

Rapid, jerky movements, especially in the hands, caused by intermittent loss of muscle tone

asthenia

Weakness (prefix a- meaning “without” with root sthen/o meaning “strength”)

ataxia

Lack of muscle coordination (from root tax/o meaning “order, arrangement”); adjective: ataxic

athetosis

A condition marked by slow, irregular, twisting movements, especially in the hands and fingers; adjective: athetotic

atrophy

A wasting away; a decrease in the size of a tissue or organ, such as the wasting of muscle from disuse

avulsion

Forcible tearing away of a part

clonus

Alternating spasmodic contraction and relaxation in a muscle; adjective: clonic

contracture

Permanent contraction of a muscle

fasciculation

Involuntary small contractions or twitching of muscle fiber groups (fasciculi)

fibromyositis

A nonspecific term for pain, tenderness, and stiffness in muscles and joints

fibrositis

Inflammation of fibrous connective tissue, especially the muscle fasciae; marked by pain and stiffness

restless legs syndrome (RLS)

Uneasiness, twitching, or restlessness in the legs that occurs after going to bed and often leading to insomnia; may be caused by poor circulation or drug side effects

rhabdomyolysis

An acute disease involving diffuse destruction of skeletal muscle cells (root rhabd/o means “rod,” referring to the long, rodlike muscle cells)

rhabdomyoma

A benign tumor of skeletal muscle

rhabdomyosarcoma

A highly malignant tumor of skeletal muscle

rheumatism

A general term for inflammation, soreness, and stiffness of muscles associated with pain in joints (adjective: rheumatic, rheumatoid)

spasm

A sudden, involuntary muscle contraction; may be clonic (contraction alternating with relaxation) or tonic (sustained); a strong and painful spasm may be called a cramp (adjectives, spastic, spasmodic)

spasticity

Increased tone or contractions of muscles causing stiff and awkward movements

tetanus

An acute infectious disease caused by the anaerobic bacillus Clostridium tetani. It is marked by persistent painful spasms of voluntary muscles; lockjaw

tetany

A condition marked by spasms, cramps, and muscle twitching caused by a metabolic imbalance, such as low blood calcium caused by underactivity of the parathyroid glands

torticollis

Spasmodic contraction of the neck muscles causing stiffness and twisting of the neck; wryneck

Chvostek sign

Spasm of facial muscles after a tap over the facial nerve; evidence of tetany

occupational therapy

Health profession concerned with increasing function and preventing disability through work and play activities. The goal of occupational therapy is to increase the patient's independence and quality of daily life

physical therapy

Health profession concerned with physical rehabilitation and prevention of disability. Exercise, massage, and other therapeutic methods are used to restore proper movement

rheumatology

The study and treatment of rheumatic diseases

Trousseau sign

Spasmodic contractions caused by pressing the nerve supplying a muscle; seen in tetany

antiinflammatory agent

Drug that reduces inflammation; includes steroids, such as cortisone, and nonsteroidal antiinflammatory drugs

COX-2 inhibitor

Nonsteroidal antiinflammatory drug that does not cause the stomach problems associated with other NSAIDs. Inhibits the cyclooxygenase (COX)-2 enzyme without affecting the COX-1 enzyme, a lack of which can cause stomach ulcers. Some of these drugs have been withdrawn from the market because of cardiac risk. Example is celecoxib (Celebrex)

muscle relaxant

A drug that reduces muscle tension; different forms may be used to relax muscles during surgery, to control spasticity, or to relieve musculoskeletal pain

nonsteroidal antiinflammatory drug (NSAID)

Drug that reduces inflammation but is not a steroid; examples include aspirin, ibuprofen, naproxen, and other inhibitors of prostaglandins, naturally produced substances that promote inflammation

afferent

Carrying toward a given point, such as the sensory neurons and nerves that carry impulses toward the CNS (root fer means “to carry”)

arachnoid mater

The middle layer of the meninges (from the Greek word for spider, because this tissue resembles a spider web)

autonomic nervous system (ANS)

The division of the nervous system that regulates involuntary activities, controlling smooth muscles, cardiac muscle, and glands; the visceral nervous system

axon

The fiber of a neuron that conducts impulses away from the cell body

brain

The nervous tissue contained within the cranium; consists of the cerebrum, diencephalon, brainstem, and cerebellum (root: encephal/o)

brainstem

The part of the brain that consists of the midbrain, pons, and medulla oblongata

central nervous system (CNS)

The brain and spinal cord

cerebellum

The posterior portion of the brain dorsal to the pons and medulla; helps to coordinate movement and to maintain balance and posture (cerebellum means “little brain”) (root: cerebell/o)

cerebral cortex

The cerebrum's thin surface layer of gray matter (the cortex is the outer region of an organ) (root: cortic/o)

cerebrum

The large upper portion of the brain; it is divided into two hemispheres by the longitudinal fissure (root: cerebr/o)

cerebrospinal fluid (CSF)

The watery fluid that circulates in and around the brain and spinal cord as a protection

cranial nerves

The 12 pairs of nerves that are connected to the brain

dendrite

A fiber of a neuron that conducts impulses toward the cell body

diencephalons

The part of the brain that contains the thalamus, hypothalamus, and pituitary gland; located between the cerebrum and the brainstem

dura mater

The strong, fibrous outermost layer of the meninges

efferent

Carrying away from a given point, such as the motor neurons and nerves that carry impulses away from the CNS (root fer means “to carry”)

ganglion

A collection of nerve cell bodies outside the CNS (plural: ganglia) (root: gangli/o, ganglion/o)

gray matter

Unmyelinated tissue of the nervous system

gyrus

A raised convolution of the surface of the cerebrum (plural: gyri)

hypothalamus

The part of the brain that controls the pituitary gland and maintains homeostasis

interneuron

Any neuron located between a sensory and a motor neuron in a neural pathway, such as the neurons that transmit impulses within the CNS

medulla oblongata

The portion of the brain that connects with the spinal cord. It has vital centers for control of respiration, heart rate, and blood pressure (root: medull/o). Often called simply medulla

meninges

The three membranes that cover the brain and spinal cord (singular: meninx) (root: mening/o, meninge/o)

midbrain

The part of the brainstem between the diencephalon and the pons; contains centers for coordination of reflexes for vision and hearing

motor

Producing movement; describes neurons that carry impulses away from the CNS

myelin

A whitish, fatty substance that surrounds certain axons of the nervous system

neuroglia

The supportive cells of the nervous system; also called glial cells (from glia meaning “glue;” root: gli/o)

neuron

The basic unit of the nervous system; a nerve cell

neurotransmitter

A chemical that transmits energy across a synapse. Examples are epinephrine, acetylcholine (a-sē-til-KŌ-lēn), serotonin (ser-ō-TŌ-nin), and dopamine (DŌ-pa-mēn)

nerve

A bundle of nerve cell fibers outside the CNS (root: neur/o)

parasympathetic nervous system

The part of the automatic nervous system that reverses the response to stress and restores homeostasis. It slows heart rate and respiration rate and stimulates activity of the digestive, urinary, and reproductive systems.

peripheral nervous system (PNS)

The portion of the nervous system outside the CNS

pia mater

The innermost layer of the meninges

pons

A rounded area on the ventral surface of the brainstem; contains fibers that connect regions of the brain; adjective: pontine (PON-tēn)

reflex

A simple, rapid, and automatic response to a stimulus

root

A branch of a spinal nerve that connects with the spinal cord; the dorsal (posterior) root joins the dorsal gray horn of the spinal cord; the ventral (anterior) root joins the ventral gray horn of the spinal cord (root: radicul/o)

sensory

Describing neurons that carry impulses toward the CNS

somatic nervous system

The division of the nervous system that controls skeletal (voluntary) muscles

spinal cord

The nervous tissue contained within the spinal column; extends from the medulla oblongata to the second lumbar vertebra (root: myel/o)

spinal nerves

The 31 pairs of nerves that connect with the spinal cord

sulcus

A shallow furrow or groove, as on the surface of the cerebrum (plural: sulci)

sympathetic nervous system

The part of the autonomic nervous system that mobilizes a response to stress; increases heart rate and respiration rate and delivers more blood to skeletal muscles

synapse

The junction between two neurons; also the junction between a motor neuron and a muscle or gland

thalamus

The part of the brain that receives all sensory impulses, except those for the sense of smell, and directs them to the proper portion of the cerebral cortex (root: thalam/o)

tract

A bundle of nerve cell fibers within the CNS

ventricle

A small cavity, such as one of the cavities in the brain in which CSF is produced (root: ventricul/o)

visceral nervous system

The autonomic nervous system

white matter

Myelinated tissue of the nervous system

Alzheimer disease (AD)

A form of dementia caused by atrophy of the cerebral cortex; presenile dementia

amyloid

A starchlike substance of unknown composition that accumulates in the brain in Alzheimer and other diseases

aneurysm

A localized abnormal dilation of a blood vessel that results from weakness of the vessel wall; an aneurysm may eventually burst

aphasia

Specifically, loss or defect in speech communication (from Greek phasis, meaning “speech”). In practice, the term is applied more broadly to a range of language disorders, both spoken and written. May affect ability to understand speech (receptive aphasia) or the ability to produce speech (expressive aphasia). Both forms are combined in global aphasia

astrocytoma

A neuroglial tumor composed of astrocytes

cerebral contusion

A bruise to the surface of the brain following a blow to the head

cerebrovascular accident (CVA)

Sudden damage to the brain resulting from reduction of cerebral blood flow; possible causes are atherosclerosis, thrombosis, or a ruptured aneurysm; commonly called stroke

coma

State of deep unconsciousness from which one cannot be roused

concussion

Injury resulting from a violent blow or shock; a concussion of the brain usually results in loss of consciousness

confusion

A state of reduced comprehension, coherence, and reasoning ability resulting in inappropriate responses to environmental stimuli

contrecoup injury

Damage to the brain on the side opposite the point of a blow as a result of the brain's hitting the skull (from French, meaning “counterblow”)

convulsion

A series of violent, involuntary muscle contractions. A tonic convulsion involves prolonged contraction of the muscles; in a clonic convulsion there is alternation of contraction and relaxation. Both forms appear in grand mal epilepsy

dementia

A gradual and usually irreversible loss of intellectual function

embolism

Obstruction of a blood vessel by a blood clot or other material carried in the circulation

encephalitis

Inflammation of the brain

epidural hematoma

Accumulation of blood in the epidural space (between the dura mater and the skull)

epilepsy

A chronic disease involving periodic sudden bursts of electric activity from the brain, resulting in seizures

glioma

A tumor of neuroglia cells

hemiparesis

Partial paralysis or weakness of one side of the body

hemiplegia

Paralysis of one side of the body

hydrocephalus

Increased accumulation of CSF in or around the brain as a result of obstruction to flow. May be caused by tumor, inflammation, hemorrhage, or congenital abnormality

insomnia

Insufficient or nonrestorative sleep despite ample opportunity to sleep

meningioma

Tumor of the meninges

meningitis

Inflammation of the meninges

multiinfarct dementia (MID)

Dementia caused by chronic cerebral ischemia (lack of blood supply to the tissues) as a result of multiple small strokes. There is progressive loss of cognitive function, memory, and judgment as well as altered motor and sensory function

multiple sclerosis (MS)

A chronic, progressive disease involving loss of myelin in the CNS

narcolepsy

Brief, uncontrollable episodes of sleep during the day

neurilemoma

A tumor of the sheath (neurilemma) of a peripheral nerve; schwannoma

paralysis

Temporary or permanent loss of function. Flaccid paralysis involves loss of muscle tone and reflexes and degeneration of muscles. Spastic paralysis involves excess muscle tone and reflexes but no degeneration

parkinsonism

A disorder originating in the basal ganglia and characterized by slow movements, tremor, rigidity, and masklike face. Also called Parkinson disease

seizure

A sudden attack, as seen in epilepsy. The most common forms of seizure are tonic–clonic, or grand mal (gran mal) (from French, meaning “great illness”); absence seizure, or petit mal (pet-Ē mal), meaning “small illness;” and psychomotor seizure

shingles

An acute viral infection that follows nerve pathways causing small lesions on the skin. Caused by reactivation of the virus that also causes chickenpox (varicella–zoster virus). Also called herpes zoster (HER-pēz ZOS-ter)

sleep apnea

Brief periods of breathing cessation during sleep

stroke

Sudden interference with blood flow in one or more cerebral vessels leading to oxygen deprivation and necrosis of brain tissue; caused by a blood clot in a vessel (ischemic stroke) or rupture of a vessel (hemorrhagic stroke). Cerebrovascular accident (CVA)

subdural hematoma

Accumulation of blood beneath the dura mater

thrombosis

Development of a blood clot within a vessel

tremor

A shaking or involuntary movement

carotid endarterectomy

Surgical removal of the lining of the carotid artery, the large artery in the neck that supplies blood to the brain

cerebral angiography

Radiographic study of the blood vessels of the brain after injection of a contrast medium

electroencephalography (EEG)

Amplification, recording, and interpretation of the brain’s electric activity

L-dopa

A drug used in the treatment of parkinsonism; levodopa

lumbar puncture

Puncture of the subarachnoid space in the lumbar region of the spinal cord to remove spinal fluid for diagnosis or to inject anesthesia; spinal tap

polysomnography

Simultaneous monitoring of a variety of physiologic functions during sleep to diagnose sleep disorders

anxiety

A feeling of fear, worry, uneasiness, or dread

Asperger syndrome

A behavioral condition on a continuum with autism that may include difficulty with social interactions and understanding, strong specific interests, and repetitive behaviors

attention-deficit hyperactivity disorder (ADHD)

A condition that begins in childhood and is characterized by attention problems, easy boredom, impulsive behavior, and hyperactivity

autism

A disorder of unknown cause consisting of self-absorption, lack of response to social contact and affection, preoccupations, stereotyped behavior, and resistance to change (from auto-, “self” and -ism, “condition of”)

bipolar disorder

A form of depression with episodes of mania (a state of elation); manic depressive illness

delusion

A false belief inconsistent with knowledge and experience

depression

A mental state characterized by profound feelings of sadness, emptiness, hopelessness, and lack of interest or pleasure in activities

dysthymia

A mild form of depression that usually develops in response to a serious life event (from dys- and Greek thymos, meaning “mind, emotion”)

hallucination

A false perception unrelated to reality or external stimuli

mania

A state of elation, which may include agitation, hyperexcitability, or hyperactivity (adjective: manic)

obsessive-compulsive disorder (OCD)

A condition associated with recurrent and intrusive thoughts, images, and repetitive behaviors performed to relieve anxiety

panic disorder

A form of anxiety disorder marked by episodes of intense fear

paranoia

A mental state characterized by jealousy, delusions of persecution, or perceptions of threat or harm

phobia

An extreme, persistent fear of a specific object or situation

posttraumatic stress disorder (PTSD)

Persistent emotional disturbances that follow exposure to life-threatening, catastrophic events, such as trauma, abuse, natural disasters, and warfare

psychosis

A mental disorder extreme enough to cause gross misperception of reality with delusions and hallucinations

schizophrenia

A poorly understood group of severe mental disorders with features of psychosis, delusions, hallucinations, and withdrawn or bizarre behavior (schizo means “split” and phren means “mind”)

acetylcholine

A neurotransmitter; activity involving acetylcholine is described as cholinergic

basal ganglia

Four masses of gray matter in the cerebrum and upper brainstem that are involved in movement and coordination

blood–brain barrier

A special membrane between circulating blood and the brain that prevents certain damaging substances from reaching brain tissue

Broca area

An area in the left frontal lobe of the cerebrum that controls speech production

circle of Willis

An interconnection (anastomosis) of several arteries supplying the brain, located at the base of the cerebrum; cerebral arterial circle

contralateral

Affecting the opposite side of the body

corpus callosum

A large band of connecting fibers between the cerebral hemispheres

dermatome

The area of the skin supplied by a spinal nerve; term also refers to an instrument used to cut skin for grafting (see Chapter 21)

ipsilateral

On the same side; unilateral

leptomeninges

The pia mater and arachnoid together

norepinephrine

A neurotransmitter very similar in chemical composition and function to the hormone epinephrine; also called noradrenalin

nucleus

A collection of nerve cells within the central nervous system

plexus

A network, as of nerves or blood vessels

pyramidal tracts

A group of motor tracts involved in fine coordination. Most of the fibers in these tracts cross in the medulla to the opposite side of the spinal cord and affect the opposite side of the body. Fibers not included in the pyramidal tracts are described as extrapyramidal.

reticular activating system (RAS)

A widespread system in the brain that maintains wakefulness

Schwann cells

Cells that produce the myelin sheath around peripheral axons

Wernicke area

An area in the temporal lobe concerned with speech comprehension

amyotrophic lateral sclerosis (ALS)

A disorder marked by muscular weakness, spasticity, and exaggerated reflexes caused by degeneration of motor neurons; Lou Gehrig disease

amnesia

Loss of memory

apraxia

Inability to move with purpose or to use objects properly

ataxia

Lack of muscle coordination; dyssynergia

athetosis

Involuntary, slow, twisting movements in the arms, especially the hands and fingers

Bell palsy

Paralysis of the facial nerve

berry aneurysm

A small saclike aneurysm of a cerebral artery

catatonia

A phase of schizophrenia in which the patient is unresponsive; there is a tendency to remain in a fixed position without moving or talking

cerebral palsy

A nonprogressive neuromuscular disorder usually caused by damage to the CNS near the time of birth. May include spasticity, involuntary movements, or ataxia

chorea

A nervous condition marked by involuntary twitching of the limbs or facial muscles

claustrophobia

Fear of being shut in or enclosed (from Latin claudere, “to shut”)

compulsion

A repetitive, stereotyped act performed to relieve tension

Creutzfeldt–Jakob disease (CJD)

A slow-growing degenerative brain disease caused by a prion (PRĪ-on), an infectious protein. Related to bovine spongiform encephalopathy (BSE, “mad cow disease”) in cattle

delirium

A sudden and temporary state of confusion marked by excitement, physical restlessness, and incoherence

dysarthria

Defect in speech articulation caused by lack of control over the required muscles

dysmetria

Disturbance in the path or placement of a limb during active movement. In hypometria, the limb falls short; in hypermetria, the limb extends beyond the target

euphoria

An exaggerated feeling of well-being; elation

glioblastoma

A malignant astrocytoma

Guillain–Barré syndrome

An acute polyneuritis with progressive muscular weakness that usually occurs after a viral infection; in most cases recovery is complete, but may take several months to years

hematomyelia

Hemorrhage of blood into the spinal cord, as from an injury

hemiballism

Jerking, twitching movements of one side of the body

Huntington disease

A hereditary disease of the CNS that usually appears between ages 30 and 50. The patient shows progressive dementia and chorea, and death occurs within 10 to 15 years

hypochondriasis

Abnormal anxiety about one's health

ictus

A blow or sudden attack, such as an epileptic seizure

lethargy

A state of sluggishness or stupor

migraine

Chronic intense, throbbing headache that may result from vascular changes in cerebral arteries. Possible causes include genetic factors, stress, trauma, and hormonal fluctuations. Headache might be signaled by visual disturbances, nausea, photophobia, and tingling sensations

neurofibromatosis

A condition involving multiple tumors of peripheral nerves

neurosis

An emotional disorder caused by unresolved conflicts, with anxiety as a main characteristic

paraplegia

Paralysis of the legs and lower part of the body

parasomnia

Condition of having undesirable phenomena, such as nightmares, occur during sleep or become worse during sleep

quadriplegia

Paralysis of all four limbs; tetraplegia

Reye syndrome

A rare acute encephalopathy occurring in children after viral infections. The liver, kidney, and heart may be involved. Linked to administration of aspirin during a viral illness

sciatica

Neuritis characterized by severe pain along the sciatic nerve and its branches

somatoform disorders

Conditions associated with symptoms of physical disease, such as pain, hypertension, or chronic fatigue, with no physical basis

somnambulism

Walking or performing other motor functions while asleep and out of bed; sleepwalking

stupor

A state of unconsciousness or lethargy with loss of responsiveness

syringomyelia

A progressive disease marked by formation of fluid-filled cavities in the spinal cord

tic

Involuntary, spasmodic, recurrent, and purposeless motor movements or vocalizations

tic douloureux

Episodes of extreme pain in the area supplied by the trigeminal nerve; also called trigeminal neuralgia

tabes dorsalis

Destruction of the dorsal (posterior) portion of the spinal cord with loss of sensation and awareness of body position, as seen in advanced cases of syphilis

Tourette syndrome

A tic disorder with intermittent motor and vocal manifestations that begins in childhood. There also may be obsessive and compulsive behavior, hyperactivity, and distractibility

transient ischemic attack

A sudden, brief, and temporary cerebral dysfunction usually caused by interruption of blood flow to the brain

Wallerian degeneration

Degeneration of a nerve distal to an injury

whiplash

Cervical injury caused by rapid acceleration and deceleration resulting in damage to muscles, ligaments, disks, and nerves

Babinski reflex

A spreading of the outer toes and extension of the big toe over the others when the sole of the foot is stroked. This response is normal in infants but indicates a lesion of specific motor tracts in adults

evoked potentials

Record of the electric activity of the brain after sensory stimulation. Included are visual evoked potentials (VEPs), brainstem auditory evoked potentials (BAEPs), and somatosensory evoked potentials (SSEPs), obtained by stimulating the hand or leg. These tests are used to evaluate CNS function

Glasgow coma scale

A system for assessing level of consciousness by assigning a score to each of three responses: eye opening, motor responses, and verbal responses

positron emission tomography (PET)

Use of radioactive glucose or other metabolically active substances to produce images of biochemical activity in tissues. Used for study of the living brain, both healthy and diseased, and also in cardiology

Romberg sign

Inability to maintain balance when the eyes are shut and the feet are close together

sympathectomy

Interruption of sympathetic nerve transmission either surgically or chemically

trephination

Cutting a piece of bone out of the skull; the instrument used is a trepan (tre-PAN) or trephine (tre-FIN)

antianxiety agent

Relieves anxiety by means of a calming, sedative effect on the CNS; for example, chlordiazepoxide (Librium), diazepam (Valium), alprazolam (Xanax); anxiolytic

antidepressants (other than those listed in separate categories below)

Block the reuptake of neurotransmitters such as serotonin, norepinephrine, dopamine, alone or in combination; for example, bupropion (Wellbutrin, Zyban), mirtazapine (Remeron), nefazodone (Serzone), venlafaxine (Effexor XR), atomoxetine (Strattera)

monoamine oxidase inhibitors (MAOI)

Block an enzyme that breaks down norepinephrine and serotonin, thus prolonging their action; for example, phenelzine (Nardil), tranylcypromine (Parnate), isocarboxazid (Marplan)

neuroleptics

Drugs used to treat psychosis, including schizophrenia; for example, clozapine (Clozaril), haloperidol (Haldol), risperidone (Risperdal), olanzapine (Zyprexa); antipsychotic. Action mechanism unknown, but may interfere with neurotransmitters

selective serotonin reuptake inhibitors (SSRIs)

Block the reuptake of serotonin in the brain, thus increasing levels; for example, fluoxetine (Prozac), citalopram (Celexa), paroxetine (Paxil), sertraline (Zoloft)

stimulants

Promote activity and a sense of well-being; for example, methylphenidate (Ritalin), dextroamphetamine (Dexedrine), amphetamine + dextroamphetamine (Adderall)

tricyclic antidepressants (TCA)

Block the reuptake of norepinephrine, serotonin, or both; for example, amitriptyline (Elavil), clomipramine (Anafril), imipramine (Tofranil), doxepin (Sinequan), trimipramine (Surmontil)

equilibrium

The sense of balance