Webster's New World Medical Dictionary

TIA
Transient ischemic attack.
tibia
The larger of the two long bones in the
lower leg. The tibia is familiarly known as the shin-
bone.
tibia vara
A condition that is characterized by
disturbance of normal growth in the inner part of
the upper tibia. Tibia vara causes a bowlegged gait
and can impair the knees significantly. It is most
common in children of African descent. Treatment
usually involves surgery, although a knee-ankle-foot
orthosis brace may be used. Also known as Blount
disease.
tibial bowing
Improper growth of the tibia in the
leg that causes bowlegs or other leg problems. The
tibia may bow anteriorly (in the front) or posteri-
orly (in the back). See also 
tibia vara.
tic
A repetitive movement that is difficult, if not
impossible, to control. Tics can affect any group of
muscles. The most common are facial tics, such as
eye-blinking, nose-twitching, and grimacing. Tics
that affect the muscles used to produce speech are
known as vocal tics and can range from grunts or
whistles to the repetition of complete words or
phrases. Complex motor tics involve multiple
sequenced movements and can include behaviors
such as twirling in place, tapping a certain number
of times, or stooping to touch the ground. Tics are
believed to arise in differences in or damage to the
basal ganglia, a structure deep within the brain that
controls automatic movements and that also affects
impulsivity. See also 
coprolalia; echolalia;
palilalia; tic disorder; Tourette’s syndrome.
tic disorder
A disorder that is characterized by
the presence of tics. If both motor and vocal tics are
present for more than 6 months, the diagnosis of
Tourette’s syndrome may be made. Diagnosis is
made via observation. Treatment can involve med-
ications but is not usually recommended for minor
tics that are not bothersome to the patient. See also
tic; Tourette’s syndrome.
tick bite
A bite from a bloodsucking parasitic
insect that punctures the skin with a sharp beak and
burrows into the skin with its head. Tick bites can
carry serious illness, including Rocky Mountain
spotted fever, other forms of tick typhus, and Lyme
disease. See also 
tick-borne disease.