1. A cord or tapelike tissue that connects or holds structures together.
SEE: bundle; SEE: ligament; SEE: tract
2. An appliance that encircles and applies pressure around a body part or structure.
3. A segment of a myofibril.
4. A metal strip or seamless band for attaching orthodontic appliances to teeth.
5. An immature, unsegmented neutrophil seen in some illnesses on a peripheral blood smear. An increase in bands indicates that all mature neutrophils have been released from the bone marrow, usually during severe inflammation or infection, and that the marrow is releasing immature cells.

A band

The darker of the two alternating stripes of the sarcomere. The A bands are regions in which the thin (actin) filaments overlap the thick (myosin) filaments. The alternating regions, lighter in color, are the I bands and contain only actin fibrils.
SYN: SEE: anisotropic band; SEE: anisotropic disk

anisotropic band

SEE: A band.

diagonal band

An axon tract in the basal forebrain region of the cerebral hemisphere. It interconnects the septal area and the substantia inominata.
SYN: SEE: diagonal band of Broca; SEE: tractus diagonalis

H band

A narrow band in the center of the A band of a sarcomere; it contains only thick (myosin) filaments and is bisected by the M line.
SYN: SEE: H zone

I band

In muscle fibers, the light band segment of a sarcomere, containing lateral ends of thin (actin) filaments. There is one to either side of the medial A band.
SYN: SEE: isotropic band

iliotibial band

A thick, wide fascial layer from the iliac crest along the lateral thigh to the fascia around the lateral aspect of the knee joint. Fibers from the tensor fascia lata and gluteus maximus muscles insert into the proximal band.

isotropic band

SEE: I band.

M band

SEE: M line.

oligoclonal bands

Immunoglobulins found in the cerebrospinal fluid of patients with multiple sclerosis (MS) and, occasionally, in other neurological conditions. They are used as a marker of MS when magnetic resonance imaging studies of the brain are not diagnostic.

Z band

SEE: Z line.