inertia

1. The tendency of a physical body to oppose any force tending to move it from a position of rest or to change its uniform motion. 2. Denoting inactivity or lack of force, lack of mental or physical vigor, or sluggishness of thought or action. [L. want of skill, laziness]

- magnetic i. SYN: hysteresis (2).

- psychic i. a psychiatric term denoting resistance to any change in ideas or to progress; fixation of an idea.

- uterine i. absence of effective uterine contractions during labor; primary uterine i., true uterine i., uterine i. that occurs when the uterus fails to contract with sufficient force to effect continuous dilation or effacement of the cervix or descent or rotation of the fetal head, and when the uterus is easily indentable at the acme of contraction; secondary uterine i., uterine i. that occurs when the uterine contractions are initially vigorous but then decrease in vigor, and the progress of labor ceases.

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in·er·tia in-'ər-shə, -shē-ə n

1 a) a property of matter by which it remains at rest or in uniform motion in the same straight line unless acted upon by some external force

b) an analogous property of other physical quantities (as electricity)

2) lack of activity or movement used esp. of the uterus in labor when its contractions are weak or irregular

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n.

(in physiology) sluggishness or absence of activity in certain smooth muscles. In uterine inertia the muscular wall of the uterus fails to contract adequately during labour, making the process excessively long. This inertia may be present from the start of labour or it may develop because of exhaustion following strong contractions.

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in·er·tia (in-urґshə) [L.] inactivity; inability to move spontaneously.