A reactant on which an enzyme acts to cause a chemical action
er-us) Epidermal gland that produces
kus) A furrow on the brain, less deep than a ﬁssure.
Accumulation of eﬀects, especially those of muscular, sen-
sory, or mental stimuli.
Located close to or on the body surface.
Toward the head or upper body regions.
Superior vena cava
Vein that returns blood from body regions superior
to the diaphragm.
shun) ±e outward rotation of the forearm caus-
ing palms to face anteriorly.
tant) Secretion produced by certain cells of the al-
veoli that reduces the surface tension of water molecules, thus preventing
the collapse of the alveoli aFer each expiration.
Heterogeneous mixtures with large, oFen visible solutes that
tend to settle out.
cher) An immovable ﬁbrous joint; with one exception, all
bones of the skull are united by sutures.
±e division of the autonomic nervous system
that prepares the body for activity or to cope with some stressor (danger,
excitement, etc.); the ﬁght, fright, and ﬂight subdivision.
Sympathetic (vasomotor) tone
State of partial vasoconstriction of the
blood vessels maintained by sympathetic ﬁbers.
ﬁh-sis) A joint in which the bones are connected by
aps) ²unctional junction or point of close contact between
two neurons or between a neuron and an eﬀector cell.
sis) Pairing of homologous chromosomes during the
ﬁrst meiotic division.
tik) ²luid-ﬁlled space at a synapse.
Time required for a signal to cross a synapse between
Small membranous sacs containing neurotransmitter.
sis) Immovable joint.
sis) A joint in which the bones are united
by hyaline cartilage.
sis) A joint in which the bones are united by a
ligament or a sheet of ﬁbrous tissue.
er-jist) (1) Muscle that aids the action of a prime mover
by eﬀecting the same movement or by stabilizing joints across which the
prime mover acts, preventing undesirable movements. (2) Hormone that
ampliﬁes the eﬀect of another hormone at a target cell.
sis) A completely ossiﬁed joint; a fused joint.
²luid secreted by the synovial membrane; lubricates joint
surfaces and nourishes articular cartilages.
²reely movable joint exhibiting a joint cavity; also called
Synthesis (combination) reaction
A chemical reaction in which larger,
more complex atoms or molecules are formed from simpler ones.
ik) Pertaining to the whole body.
System of blood vessels that serves gas exchange in the
yoot) ±e substance that is dissolved in a solution.
Enzyme-like protein carrier that mediates active transport
of solutes such as amino acids and ions uphill against their concentration
Somatic nervous system
tik) Division of the peripheral nervous
system that provides the motor innervation of skeletal muscles; also
called the voluntary nervous system.
Reﬂexes that activate skeletal muscle.
±at part of the sensory system dealing with
reception in the body wall and limbs; receives inputs from exteroceptors,
proprioceptors, and interoceptors.
mīt) A mesodermal segment of the body of an embryo that
contributes to the formation of skeletal muscles, vertebrae, and dermis of
±e ability of neurons to identify the site or pat-
tern of stimulation.
±e senses of taste, smell, vision, hearing, and equilib-
Term used to compare the weight of a substance to the
weight of an equal volume of distilled water.
ĕ-sis) ±e process of sperm (male
gamete) formation; involves meiosis.
ter) A circular muscle surrounding an opening; acts as
±e bundle of nervous tissue that runs from the brain to the
ﬁrst to third lumbar vertebrae and provides a conduction pathway to and
from the brain.
±e 31 nerve pairs that arise from the spinal cord.
nik) ±e blood vessels serving the di-
Largest lymphoid organ; provides for lymphocyte proliferation,
immune surveillance and response, and blood-cleansing functions.
Internal layer of skeletal bone. Also called cancellous bone.
Ligaments reinforcing a joint are stretched or torn.
Sense of head position in space with respect to gravity.
sis) Abnormal constriction or narrowing.
roidz) Group of chemical substances including certain hor-
mones and cholesterol; they are fat soluble and contain little oxygen.
u-lus) An excitant or irritant; a change in the environ-
ment that evokes a response.
Temporary reservoir in the gastrointestinal tract where chemi-
cal breakdown of proteins begins and food is converted into chyme.
Any stimulus that directly or indirectly causes the hypothalamus to
initiate stress-reducing responses, such as the ﬁght-or-ﬂight response.
Stroke volume (SV)
Amount of blood pumped out of a ventricle during
mah) ±e basic internal structural framework of an organ.
Structural (ﬁbrous) proteins
Consist of extended, strandlike polypep-
tide chains forming a strong, ropelike structure that is linear, insoluble in
water, and very stable; e.g., collagen.
ne-us) Beneath the skin.
Subendocardial conducting network
Modiﬁed ventricular muscle ﬁ-
bers of the conduction system of the heart. Also called Purkinje ﬁbers.