602 Introduction to Anatomy and Physiology
sprain injuries caused by abnormal motion of the
articulating bones that result in overstretching or tearing
of ligaments, tendons, or other connective tissues
crossing a joint
squamous cell carcinoma (KAR-si-NOH-ma) a type of
rapidly growing cancer that appears as a scaly, reddened
patch of skin
squamous epithelia almost–fl at epithelia
SRY gene on the Y chromosome that acts as a switch to
cause development of male sex organs; sex-determining
region Y
stapes see stirrup
static lung volume lung volume that measures volume
only
statistical inference the practice of generalizing the
fi ndings of a research study to a large population
statistical signifi cance an interpretation of statistical
data indicating that the results of a study can legitimately
be generalized to the population represented in the study
sample
stent a circular, hollow, wire mesh tube
sternoclavicular joint (STER-noh-kla-VIK-yoo-lar) joint
between the sternum (breast bone) and clavicle (collar
bone)
sternum (STER-num) breastbone
steroid hormones lipid (fat-based) hormones
steroids a class of lipids with a structure that is different
from other lipids; cholesterol, testosterone, and estrogen
are three well-known steroids
stirrup tiny bone in the middle ear that attaches to the
anvil on one side and the oval window on the other
stomach the reservoir in which food is broken down
mechanically and chemically before it enters the small
intestine
strabismus (strah-BIZ-mus) a condition that causes
one eye to drift in different directions due to the
malfunctioning of the extrinsic muscles of the eye
stratifi ed epithelia epithelium with multiple layers of cells
stratifi ed squamous epithelia epithelium with multiple
layers of cells, the outermost layer of which are fl attened;
found where chemical and mechanical protection are
most needed
stratum basale the deepest layer of the epidermis
stratum corneum the outer layer of the epidermis
stratum granulosum a layer of somewhat fl attened cells
lying just superfi cial to the stratum spinosum and inferior
to the stratum lucidum
stratum lucidum the clear layer of thick skin found only
on the palms of the hands, fi ngers, soles of the feet, and
toes
stratum spinosum the layer of cells in the epidermis
superior to the stratum basale and inferior to the
stratum granulosum
stress force distribution inside a structure
stress fracture tiny, painful crack in bone that results
from overuse
stretch receptors mechanoreceptors in the bronchioles
and alveoli that are sensitive to stretching and prevent
over infl ation of the alveolar sacs and stimulate expiration
stroke a sudden blockage of blood fl ow, or rupture of an
artery in the brain, that causes brain cells to die from lack
of oxygen
stroke volume the volume of blood pumped from the
heart per beat
styloid process (STIGH-loyd) bony projection on the
distal lateral end of each radius and ulna; easy to see
and feel
subcutaneous fascia (sub-kyoo-TAY-nee-us
FASH-a) see hypodermis
submucosa (SUB-myoo-KOH-sa) a layer of irregular,
dense connective tissue containing blood vessels,
lymphatic vessels, and nerves
sudoriferous glands (SOO-doh-RIF-er-us) sweat glands
that are distributed in the dermis over the entire body
sulcus (SUL-kus) a groove between adjacent gyri on the
outer surface of the brain
superior above or over
superior articular processes indentations on the top
side of each vertebra that form a facet joint with the
above vertebra
superior vena cava second largest vein in the body that
returns deoxygenated blood to the right atrium of the
heart from the upper half of the body
supination (SOO-pi-NAY-shun) lateral rotation of the
forearm (palm up)
suppressor T cell T lymphocyte that prevents the
cellular immune response from being too strong or too
long-lasting
surfactant a phospholipid that reduces the surface
tension in the alveoli and prevents them from collapsing
suspensory ligaments tiny structures that attach the
lens of the eye to the ciliary body
sutures joints in which irregularly grooved, articulating
bone sheets join closely and are tightly connected by
fi brous tissues
sweet one of the fi ve basic tastes
swelling a sign of infl ammation
swimmer’s ear a bacterial or fungal infection of the
auditory canal caused by immersion in contaminated
water
symphysis (SIM-fi -sis) type of amphiarthrosis joint in
which a thin plate of hyaline cartilage separates a disc of
fi brocartilage from the bones
synapse (SIN-aps) the intersection between a neuron
and another neuron, a muscle, a gland, or a sensory
receptor
synaptic cleft (si-NAP-tik) a microscopic gap that
separates axon terminals from other neurons or
muscle fi ber
synarthrosis (SIN-ar-THROH-sis) fi brous joint that can
absorb shock, but permits little or no movement of the
articulating bones
synchondrosis (SIN-kahn-DROH-sis) type of
amphiarthrosis joint in which the articulating bones are
held together by a thin layer of hyaline cartilage
syndesmosis (SIN-dehz-MOH-sis) joint at which dense
fi brous tissue binds the bones together, permitting
extremely limited movement
synovial fl uid (si-NOH-vee-al) a clear liquid secreted by
synovial membranes that provides cushioning for and
reduces friction in synovial joints
synovial joint (si-NOH-vee-al) a diarthrodial joint
synovial membrane (si-NOH-vee-al) the lining of the
synoival joint cavity that produces synovial fl uid
systemic circulation circulation of oxygenated blood
through the arteries, capillaries, and veins of the
circulatory system, from the left ventricle to the right
atrium
systole (SIS-toh-lee) a period of contraction when the
chambers are pumping blood out of the heart