Muscle, ciliary
A circular muscle that relaxes or tightens the zonules to enable the lens to change shape for focusing.
The zonules are fibers that hold the lens suspended in position and enable it to change shape during accommodation.
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- Muscle, central core disease of
One of the conditions that produces ‘floppy baby’ syndrome. Central core disease of muscle causes hypotonia (low muscle tone) in a newborn baby, slowly progressive muscle weakness, and muscle cramps after exercise. Muscle biopsy shows a key diagnostic finding of absent mitochondria in the center of many muscle fibers. It is caused by an abnormal […]
- Muscle, heart
A type of muscle with unique features only found in the heart. The heart or cardiac muscle is medically called the myocardium (“myo-” being the prefix denoting muscle).
- Muscle, infraspinatus
The infraspinatus muscle; The teres minor muscle, which (like the infraspinatus muscle) helps in the outward turning (external rotation) of the arm; The supraspinatus muscle, which is responsible for elevating the arm and moving it away from the body; and The subscapularis muscle, which moves the arm by turning it inward (internal rotation). Damage to […]
- Muscle, papillary
A small muscle within the heart that anchors the heart valves. The anchor ropes are the chordae tendineae, thread-like bands of fibrous tissue that attach on one end to the edges of the tricuspid and mitral valves of the heart and on the other end to the papillary muscles.
- Muscle, piriformis
A muscle that begins at the front surface of the sacrum (the V-shaped bone between the buttocks, at the base of the spine) and passes through the greater sciatic notch to attach to the top of the thighbone (femur) at its bony prominence (the greater trochanter). The gluteus maximus muscle covers the piriformis muscle in […]