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Medical Dictionary: s

Word	Definition
s-t segment	The segment on an EKG tracing that represents the interval between the end of ventricular depolarization and the beginning of ventricular repolarization.
s.o.s.	if necessary
S1	first heart sound
S2	second heart sound
S3	third heart sound
S4	fourth heart sound
SA	sinoatrial
sac	A bag-like structure.
saccades	An abrupt voluntary shift in ocular fixation from one point to another, as occurs in reading.
sacchar-	sugar
saccule	One of the two membranous sacs within the vestibule of the inner ear. It contains fluid, responses to gravity and provides the brain with information about head position.
sacr/o	sacrum (large bone at base of spine)
sacroiliitis	Inflammation of the sacroiliac joint, marked by lower back pain, fever, uveitis, psoriasis and decreased range of motion.
sacrum	The large, triangular bone at the dorsal part of the pelvis, between the two hip bones. The sacrum strengthens and stabilizes the pelvis.
SAD	seasonal affective disorder
sadism	A condition in which there is pleasure from inflicting pain, discomfort or humiliation on another person.
sagittal	A plane that extends down the long axis of the body, parallel to the median plane.
sagittal plane	separates the body's left and right sections
salicylism	Poisoning by salicylic acid or its compounds.
saliva	The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It serves to moisten the oral cavity, to initiate the digestion of starches, and to aid in the chewing and swallowing of food.
salivary ducts	Any of the ducts which transport saliva.
salivary glands	Glands that secrete saliva in the mouth. There are three pairs of salivary glands: parotid gland; sublingual gland and submandibular gland.
salmonella	A genus of gram-negative, rod-shaped bacteria. It causes food poisoning, enteric fevers, gastroenteritis, and bacteremia.
salping/o	fallopian tube
salpingitis	Inflammation of the fallopian or eustachian tube.
salpingostomy	Formation of an artificial opening in a fallopian tube.
salvage therapy	A therapeutic approach, involving chemotherapy, radiation therapy, or surgery, after initial regimens have failed to lead to improvement in a patient's condition. Salvage therapy is most often used for neoplastic diseases.
sanatorium	A facility for the treatment of chronic disorders.
sanguineous	Pertaining to blood.
sanit/a	health
sap/o	soap
sapro-	rotten
sarc/o	flesh, connective tissue
sarcocystosis	Infection of the striated muscle of mammals by parasites of the genus Sarcocystis. Often asymptomatic, but symptoms include vomiting, diarrhea, muscle weakness, and paralysis.
sarcoid	A fleshy tumor.
sarcoidosis	An disease that leads to inflammation, usually in the lungs, skin, or lymph nodes. Characterized by the formation of granulomas which contain giant cells.
sarcoma	A cancer of the bone, muscle, cartilage, fat, blood vessels or connective tissue.
-sarcoma	cancer of connective tissue
sarcopenia	A disease associated with aging resulting in loss of muscle mass and strength.
SARS	severe acute respiratory syndrome
sartorius	The thin, long, diagonal, strap-like anterior thigh muscle extending from the pelvis to the calf of the leg.
satiation	A fulfillment of a need or desire followed by a state of relative insensitivity to that particular need or desire.
saur/o	lizard
SB	small bowel
SBO	small bowel obstruction
SBP	systolic blood pressure
SC	subcutaneous
scabies	Itchy skin caused by a tiny burrowing mite. Symptoms worse at night.
scalp	The outer covering of the calvaria. It is composed of several layers: skin, subcutaneous connective tissue, the occipitofrontal muscle , loose connective tissue and the pericranium.
scaph/o	boat-shaped, scapha
scaphoid bone	The bone which is located most lateral in the proximal row of carpal bones.
scapul/o	scapula (shoulder blade)
scapula	The flat triangular bone in the back of the shoulder. Also called the shoulder blade.
scar	A permanent mark remaining after a wound heals.
scarlet fever	An acute contagious bacterial disease of childhood characterized by tonsillitis and pharyngitis as well as fever, chills, nausea, headache, abdominal pain, malaise and rash.
scat-	dung
-schisis	cleft, split
schisto-	split, cleft
schiz-	division
schizophrenia	A chronic, severe mental illness that interferes with the ability to think, manage emotions, make decisions and relate to others.
sciatic nerve	A nerve which originates in the lumbar and sacral spinal cord and supplies motor and sensory innervation to the lower extremity. The sciatic nerve is the largest nerve in the body.
sciatica	Pain radiating along the sciatic nerve from the lower back down the leg.
scint/i	spark
scirrh/o	hard, hard tumor
scler-	hard
scler/o	white of eye, hard
sclera	The white, opaque, fibrous, outer envelope of the eyeball, covering it entirely except the cornea.
scleritis	A severe, vision-threatening inflammation of the white part of the eye.
scleroderma	An autoimmune, chronic disease that affects the body by hardening connective tissue.
sclerosis	A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve.
-sclerosis	abnormal hardening
scoli/o	curved, crooked
scoliosis	A sideways curvature of the spine that occurs most often during the growth spurt just before puberty.
-scope	instrument used to view
-scopy	process of viewing
scot/o	darkness
scotoma	An area of diminished vision within the visual field.
scotopic	Pertaining to the adjustment of the eye to low illumination.
scrofula	Tuberculosis affecting the lymph nodes, particularly the neck.
scrot/o	scrotum
scrotum	A pouch of skin containing the testicles and spermatic cords.
scurvy	An acquired blood vessel disorder caused by severe deficiency of vitamin C, characterized by spongy, bleeding gums, bleeding under the skin, and extreme weakness.
SDAT	standard deviation
seb/o	sebum, oil, fatty
sebaceous glands	Small, sacculated organs found within the dermis. Each gland has a single duct that opens into a hair follicle or onto the general surface of the skin. These glands secrete sebum, an oily lubricating substance.
seborrhea	A common skin problem that causes a red, itchy rash and white scales. On the scalp, it is called dandruff.
sebum	The oily substance secreted by sebaceous glands. It is composed of keratin, fat, and cellular debris.
sect-	dissect, cut
sedation	The reduction of anxiety, stress or excitement by administration of a sedative drug.
sedative	A drug that calms and relieves anxiety.
sedentary lifestyle	Usual level of physical activity that is less than 30 minutes of moderate-intensity activity on most days of the week.
seizure	A sudden surge of the brain’s electrical activity affecting movement and awareness for a short time.
seizures	A sudden attack, spasm, or convulsion.
semantics	Study of the meanings of words (or symbols) and the rules of their use.
semen	The thick, yellowish-white, viscid fluid secretion of male reproductive organs discharged upon ejaculation. It contains spermatozoa and their nutrient plasma and secretions from the prostate and bulbourethral glands.
semi-	half
semicircular canals	Three long canals (anterior, posterior, and lateral) of the bony labyrinth. They are set at right angles to each other and are concerned with balance.
semih.	half an hour
semilunar valve	Either the aortic valve or the pulmonary valve, each consisting of crescent-shaped cusps.
semin/i	semen
seminoma	A malignant neoplasm of the testis.
senescence	The process of growing old.
sensation	A perception produced by afferent nerve impulses conveyed to the sensorium.
sensitivity	The probability that a person having a disease will be correctly identified by a clinical test.
sensor/i	sensory
sensorineural hearing loss	Loss of hearing resulting from problems in the inner ear. A common hearing impairment.
sepsis	A serious medical condition caused by an overwhelming immune response to infection that triggers widespread inflammation. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock.
-sepsis	decay caused by
sept/o	septum, seven
septal defect	A hole in the septum of the heart, usually congenital.
septi-	seven
septicemia	A serious bacterial bloodstream infection. It’s also known as bacteremia, or blood poisoning.
sequela	Any disorder that results from a preceding disease or accident.
ser/o	blood serum
seroma	Tumor-like sterile accumulation of serum in a tissue, organ, or cavity. It most commonly occurs following mastectomy.
seropus	Pus diluted with serum.
serositis	Inflammation of a serous membrane.
serotonin	A compound widely distributed in the tissues that mediates important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity.
serous membrane	A thin layer of tissue that covers a surface, cavity or divides a space. It consists of a single layer of squamous epithelial cells (mesothelium) resting on a thin layer of connective tissue, and covered with secreted clear fluid from blood and lymph vessels. Major serous membranes in the body include pericardium; peritoneum; and pleura.
serratia	A genus of gram-negative, rod-shaped bacteria that occurs in soil, water and plant surfaces or as an opportunistic human pathogen.
serum	Blood plasma after the removal of clotting proteins.
sesamoid	Denoting a small nodular bone embedded in a tendon or joint capsule and that slides over another bony surface. The patella is a sesamoid bone.
sesqui-	one and one-half
sex	The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism.
sex-	six
sexuality	The sexual functions, activities, attitudes, and orientations of an individual. Sexuality, male or female, becomes evident at puberty under the influence of gonadal steroids (testosterone or estradiol) and social effects.
SGA	small for gestational age
shaken baby syndrome	Brain injuries resulted from vigorous shaking of an infant or young child held by the chest, shoulders, or extremities causing extreme cranial acceleration. It is characterized by the intracranial and intraocular hemorrhages with no evident external trauma. Serious cases may result in death.
sheath	A tubular casing that envelops structures such as arteries, nerves, tendons and muscles.
shin splint	Inflammation of the muscles, tendons, and bone tissue around the tibia.
shivering	Involuntary contraction or twitching of the muscles due to cold or fear.
shock	An emergency pathological condition manifested by failure to perfuse or oxygenate vital organs and tissues.
shoulder	The junction of the clavicle, scapula, and humerus where the arm connects to the trunk.
shoulder dislocation	Displacement of the humerus from the scapula.
shunt	A passage connecting two anatomical sites or channels.
SI	international system of units
SIADH	syndrome of inappropriate diuretic hormone
sial/o	saliva
sialaden/o	salivary gland
sialadenitis	Inflammation of a salivary gland.
sialomucins	A subcategory of mucins that contain sialic acid.
sialorrhea	Excessive salivary flow.
sibilant	A high pitched hissing or whistling sound heard while auscultating.
sicc-	dry
sickle cell anemia	An inherited form of anemia where red blood cells become rigid, sticky and shaped like sickles. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow to parts of the body.
SICU	surgical intensive care unit
sider/o	iron
siderosis	A form of pneumoconiosis resulting from inhalation of iron in mining dust or welding fumes.
SIDS	sudden infant death syndrome
Sig	write on label
sigmoid	The distal part of the colon from the level of the iliac crest to the rectum.
sigmold/o	sigmoid colon
sign	Objective evidence of a disease.
sign language	A system of hand gestures used for communication by the deaf or by people speaking different languages.
signs and symptoms	Clinical manifestations that can be either objective when observed by a physician, or subjective when perceived by the patient.
silic/o	silica, quartz
silicosis	A form of pneumoconiosis resulting from prolonged inhalation of silica dust.
simplexvirus	A genus of the family herpesviridae, consisting of herpes simplex-like viruses.
simvastatin	A statin used to treat high blood cholesterol levels.
singultus	Hiccups.
sinistr/o	left
sinoatrial block	The electrical impulse from the sinoatrial node is inhibited or completely blocked before it reaches the atrium.
sinoatrial node	The small mass of modified cardiac muscle fibers located in the upper part of the right atrium. Contraction impulses are generated at the SA node and spread over the atrium, then transmitted by the Bundle of HIS to the ventricles.
sinus rhythm	A normal heart rhythm as indicated on an EKG tracing.
sinus/o	sinus
sinusitis	Inflammation of the sinuses.
-sis	condition
sito-	bread, food
skeleto-	skeleton
skeleton	The rigid framework of connected bones that gives form to the body, protects and supports its soft organs and tissues and provides attachments for muscles.
skin	The tough, supple, outer covering of the body that protects it from the environment. It is the largest organ of the body and is composed of the dermis and the epidermis.
skull	The skeleton of the head including the facial bones and the bones enclosing the brain.
SLE	systemic lupus erythematosus
sleep	Physiologic state of rest, relative unconsciousness and inaction of voluntary muscles.
sleep apnea	Sleep disorder characterized by multiple starts and stops of breathing, interfering with normal sleeping patterns. Measurable decrease in blood oxygen levels.
sling	A bandage that supports an injured limb.
slough	Necrotic tissue separated from living tissue.
smallpox	An acute, highly contagious, often fatal infectious viral disease characterized by fever and skin eruptions. It has been eradicated by vaccination programs worldwide.
smear	A tissue specimen smeared on a microscopic slide.
smell	The ability to detect scents or odors, such as the function of olfactory receptor neurons.
Sn	tin
sneezing	The sudden, forceful, involuntary expulsion of air from the nasal cavities and mouth due to irritation to the mucous membranes of the upper respiratory tract.
SNF	skilled nursing facility
snoring	Noisy breathing during sleep, due to vibration of the soft palate and other soft tissue in the upper airway.
snow blindness	A painful eye condition caused by exposure of insufficiently protected eyes to ultraviolet (UV) rays. Also called photokeratitis.
SOAP	subjective, objective, assessment, plan
SOB	shortness of breath
socio-	social, society
sol	solution
soleus	A flat, broad muscle in the calf of the leg.
solution	A homogeneous mixture formed by the mixing of a solid, liquid, or gaseous substance with a liquid (the solvent) in which the substances are completely dispersed.
solvent	A liquid that dissolves other substances (solutes), generally solids.
soma	The body as distinguished from the mind or germ cells.
somat/o	body
somatic	Pertaining to the body.
somatotrophs	Anterior pituitary cells which produce growth hormone.
somatotypes	Categories of body build determined on the basis of certain physical characteristics. The three basic body types are ectomorph (thin physique), endomorph (rounded physique), and mesomorph (athletic physique).
-some	body
somn/o	sleep
somnambulism	A parasomnia characterized by a partial arousal that occurs during stage IV of non-REM sleep. Also called sleep-walking.
son/o	sound
souffle	A soft blowing sound heard with a stethoscope.
-spadia	to tear, cut
span/o	scarce
spasm	An involuntary contraction of a muscle or group of muscles.
-spasm	sudden, involuntary muscle contraction
spasmo-	spasm
spasmodic torticollis	A very painful condition in which neck muscles contract involuntarily causing the head to twist, bend or rotate to one side.
specific gravity	The ratio of the density of a material to water at 4 degrees C.
specificity	The probability that a person who does not have a disease will be correctly identified by a clinical test.
spectr-	image
spectrometry	Measurement of the wavelengths of electromagnetic emissions.
speech	Use of vocal sounds to communicate.
sperm	The male gamete or sex cell that contains the genetic information to be transmitted by the male. Also called spermatozoon.
sperm/o	sperm cells
sperma-	sperm, seed
spermatids	Immature sperm cells developed in the testicle.
spermatozoa	Mature male germ cells derived from spermatids.
SPF	skin protection factor
sphen/o	wedge, wedge-shaped
sphenoid bone	An irregular unpaired bone situated at the skull base and wedged between the frontal, temporal, and occipital bones.
sphenoid/o	sphenoid (compound bone at base of skull)
spher/o	sphere, round
spherocytes	Small, abnormal spherical red blood cells with more than the normal amount of hemoglobin.
spherocytosis	A blood disorder characterized by the presence of small, sphere like red blood cells.
sphincter	A ring-link muscle that constrictions a natural body passage or orifice and which relaxes as needed. Present in the rectum and urinary tract.
sphygmo-	pulse
sphygmomanometer	Device for measuring arterial blood pressure. Includes an inflatable cuff, inflating bulb and a gauge showing the blood pressure.
spica	A figure-eight bandage.
spin/o	spine
spina bifida	A spinal birth defect.
spinal cord	The section of the central nervous system enclosed in the vertebral column.
spinal nerves	The 31 paired peripheral nerves formed by the union of the dorsal and ventral spinal roots from each spinal cord segment. The spinal nerve plexuses and the spinal roots are also included.
spinal puncture	Tapping fluid from the subarachnoid space in the lumbar region, usually between the third and fourth lumbar vertebrae.
spinal stenosis	Narrowing of the spinal canal.
spine	The spinal or vertebral column.
spir/o	to breath
spirometer	Device that measures inhaled or exhaled air volume.
splanchn/o	viscera
splanchnic	Pertaining to the viscera.
spleen	An encapsulated lymphatic organ through which venous blood filters.
splen/o	spleen
splenectomy	Surgical procedure involving either partial or entire removal of the spleen.
splenic artery	The largest branch of the celiac trunk with distribution to the spleen, pancreas, stomach and greater omentum.
splenitis	Inflammation of the spleen.
splenomegaly	Enlargement of the spleen.
splint	An appliance used to prevent movement of a joint or to fixate displaced or movable parts.
spondyl/o	vertebra, backbone
spondylitis	Inflammation of the synovial joints of the backbone.
spondylolisthesis	Forward displacement of a superior vertebral body over the vertebral body below.
spondylolysis	The degeneration of a vertebra.
spondylosis	A degenerative spinal disease that can involve any part of the vertebra, the intervertebral disk, and the surrounding soft tissue.
spongi/o	sponge-like
spor/o	spore, seed
spores	The reproductive elements of lower organisms such as bacteria and fungi.
sprain	An injury caused by tearing of the fibers of a ligament.
spt	spirit
sputum	Material coughed up from the lungs.
sq	squamous
squam/o	scaly
squamous cell carcinoma	Most squamous cell cancers occur on skin that is regularly exposed to sunlight or other ultraviolet radiation. It is the second most common type of cancer in the United States.
ss	a half
SSS	sick sinus syndrome
-stabile	stable, fixed
-stalsis	contraction
staped/o	stapes (a middle ear bone)
stapedectomy	Surgical removal of the stapes.
stapes	One of the three ossicles of the middle ear. It transmits sound vibrations from the incus to the internal ear.
staphylo-	bunch of grapes
staphylococci	Gram-positive bacteria. Natural populations of Staphylococcus are found on the skin and mucous membranes.
staphylococcus	Any of various spherical gram-positive parasitic bacteria, causing skin and other infections.
stasis	A cessation or diminution of flow of blood or other fluids.
-stasis	maintenance of level, prevent increase
-stat	agent or device for keeping something from changing
STAT	immediately
STD	sexually transmitted disease
steat/o	fat
steatoma	A cyst or tumor of the sebaceous gland.
stem cells	An unspecialized cell that can give rise to one or more different types of specialized cells, such as blood cells and nerve cells. Stem cells are present in embryos and in various tissues of adult organisms
stenosis	The abnormal narrowing of a passage or opening.
-stenosis	abnormal narrowing
stents	A small mesh tube used to treat narrow or weak arteries.
sterc-	feces
stere/o	three dimensional
stereognosis	Perception of shape and form of objects by the sense of touch.
sterile	Unable to produce offspring.
sterilization	The destroying of microorganisms by heat, chemicals, irradiation or other means.
stern/o	sternum (breastbone)
sternoclavicular joint	A double gliding joint formed by the clavicle, superior and lateral parts of the manubrium sternum at the clavicular notch and the cartilage of the first rib.
sternum	A long, narrow, and flat bone commonly known as breastbone occurring in the midsection of the anterior thoracic segment or chest region, which stabilizes the rib cage and serves as the point of origin for several muscles that move the arms, head and neck.
steroids	A hormone produced by the body. Also a drug used for treating swelling or to (illegally) improve athletic performance.
steth/o	chest
stethoscope	Instrument for listening to body sounds (auscultation).
STH	somatotropic hormone
sthen/o	strength
stich/o	rows
stom/o	mouth
stoma-	mouth
stomach	A saclike digestive organ situated in the left upper quadrant of the abdomen between the termination of the esophagus and the beginning of the duodenum.
stomach ulcer	Ulceration of the gastric mucosa due to contact with gastric juice.
stomatitis	Inflammation of the soft tissues of the mouth. Canker sores are an example.
-stomy	new opening
stool	Feces discharged from the anus.
strabismus	A condition that causes crossed eyes.
strain	Overstretching or overexertion of a part of the musculature.
strat/i	layer
strept/o	twisted
stress	The unfavorable effect of environmental factors on the physiological functions.
stress test	A test to evaluate heart function by monitoring heart rate, breathing, blood pressure and EKG while the patient exercises with a treadmill or exercise bike.
stridor	A very loud, wheezing breath sound heard when the trachea or larynx is obstructed.
stroke	A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to brain ischemia or intracranial hemorrhages. It is both common and deadly.
stroke volume	The amount of blood pumped out of one ventricle of the heart in one beat.
-stroma	connective or supportive tissue of an organ
stromal	Relating to the foundation-supporting tissues of an organ.
stupor	A state of diminished responsiveness to stimuli. The person is still conscious and can make voluntary movements.
stuttering	A disturbance in the normal fluency characterized by frequent repetitions, pauses or prolongations of syllables.
stye	Acute bacterial inflammation of a gland at the base of an eyelash.
sub-	under, below
subclavian	Below the clavicle.
subcutaneous	Beneath the skin.
subdural	Below the dura mater.
subdural effusion	Leakage and accumulation of cerebrospinal fluid in the subdural space which may be associated with an infection, craniocerebral trauma, brain neoplasms, intracranial hypotension and other conditions.
sublimation	A defense mechanism through which unacceptable impulses are diverted into socially acceptable channels.
sublingual	Below the tongue.
sublingual gland	A salivary gland located under the tongue in the floor of the oral cavity.
subretinal fluid	An exudate between the retina and choroid from various sources including the vitreous cavity, subarachnoid space or abnormal vessels.
subtalar joint	Formed by the articulation of the talus with the calcaneus.
sucrose	Cane or beet sugar.
suction	The removal of secretions, gas or fluid from hollow or tubular organs or cavities by means of a tube and a device that acts on negative pressure.
sud/o	sweat
sudden cardiac arrest	A sudden and unexpected cessation of cardiac function due to electrical malfunction. Reversible if immediately treated.
sudden cardiac death	Sudden, unexpected death caused by loss of cardiac function.
sudden infant death syndrome	The abrupt and unexplained death of an apparently healthy infant under one year of age. Positioning infants for sleep on their backs or sides has reduced SIDS incidence.
sunburn	An injury to the skin due to excessive sun exposure, causing erythema, tenderness, and sometimes blistering.
sunstroke	Heat stroke caused by exposure to the sun. It is characterized by dangerously high body temperature, red skin, delusions, convulsions or coma. It can be a life-threatening emergency and is most common in infants and the elderly.
sup.	superior
super-	above, beyond
superego	The component of the personality associated with ethics, standards, and self-criticism.
superficial	near the surface
superior	above
supf.	superficial
supination	The condition of being supine. Alternatively, the act of turning the hand so that the palm is up.
supine	lying face up
suppository	Medicated dosage that is designed to be inserted into the rectal, vaginal, or urethral orifice of the body for absorption.
suppuration	A pathologic process consisting in the formation of pus.
supra-	above, upward
supraglottitis	Inflammation of the of the laryngeal tissue above the glottis, particularly the epiglottis.
sural nerve	A branch of the tibial nerve which supplies sensory innervation to parts of the lower leg and foot.
surface tension	The force acting on the surface of a liquid, tending to minimize the area of the surface.
susceptibility	Vulnerable to a disease.
susp	suspension
suspension	A preparation of an undissolved substance dispersed in a liquid.
sutures	A stitch or stitches used to close a wound.
SVT	supraventricular tachycardia
Sx	symptoms
sycosis	Inflammation of hair follicles.
symbiosis	A Relationship between different species where both of the organisms in question benefit from the presence of the other.
symptom	Subjective evidence of disease. For example, a patient's complaints.
syn-	together
synaps/o	point of contact
synapse	The junctional area between two connected nerves or between a nerve and the effector organ.
syncope	Fainting. Loss of consciousness due to diminished blood flow to the brain.
syndactyly	A congenital anomaly of the hand or foot, marked by the webbing between adjacent fingers or toes.
syndesm/o	ligament
syndrome	A characteristic set of signs and symptoms of a particular disorder.
synovectomy	Removal of part or all of the synovial membrane of a joint
synovi/o	synovial membrane, synovial joint
synovitis	Inflammation of a synovial membrane.
syphil/o	syphilis
syphilis	A sexually transmitted disease. A bacterial infection.
syr	syrup
syring/o	tube, pipe, fistula
syringe	An instrument used for injecting or withdrawing fluids.
systemic	Affecting the body as a whole.
systemic circulation	The circulation of the blood to all parts of the body except the lungs.
systemic lupus erythematosus	An autoimmune disease in which the immune system mistakenly attacks healthy tissue.
systol/o	contraction
systole	Period of heart contraction when blood is surging from the heart into the systemic circulatory system and the lungs.
systolic blood pressure	Arterial blood pressure during heart contraction. In blood pressure readings, it is the first number.
systolic murmurs	Heart murmurs which occur during systole. They are heard between the first and the second heart sounds.
Sz	seizure