NM704 - Mechanism of Labor – BBB: Questions With
Insightful Solutions (A+)
Mechanism of Labor is also known as: Right Ans - Cardinal Movements.
Cardinal movements: Right Ans - The way in which the fetus adapts itself
to and passes through the maternal pelvis.
Movements generally occur as a result of force from above and resistance
from below.
Force from above can be: Right Ans - Contractions.
Gravity.
Bearing down.
Resistance from below: Right Ans - Non-dilated cervix.
Pelvic floor muscle.
Force from above and resistance from below cause fetus to: Right Ans -
Twist and turn in order to fit through maternal pelvis.
Force from above and resistance from below: Reason fetus does not fit
through the pelvis without twisting and turning is because: Right Ans - The
fetal ovals and maternal ovals line up with each other.
Fetal ovals: Right Ans - Head and shoulde. The longer part of the oval goes
into different directions.
Longest part of the head: front to back.
Longest part of shoulders: side to side.
Maternal ovals: Right Ans - Inlet, midplane, outlet (3 planes of pelvis).
The configuration of the oval, the different planes, and thus requires
movement from the fetus in order to fit through pelvis.
Diameters: Right Ans - Antero-posterior (AP) [front to back] vs transverse
(side to side).
, The longer part of the fetus needs to line up with the: Right Ans - Longer
diameter of the pelvis.
Long axis is another term for: Right Ans - Long diameter.
The pelvic planes: Right Ans - Inlet.
Midplane.
Outlet.
As you learn the mechanisms of labor, think about in which plane each
mechanism occurs.
*Mechanism of labor for birth in OA position:* Right Ans -
If you can feel anterior fontanel during vaginal exam, position is most likely:
Right Ans - Posterior.
Anterior fontanel is in the anterior portion of the woman - position is
posterior.
1st mechanism of labor is Right Ans - Descent.
Descent: Right Ans - The downward passage of the presenting part through
the bony pelvis.
Occurs throughout labor; often begins before labor.
Results from downward pressure caused by contractions and maternal
bearing down efforts and gravity.
Some descent at end of pregnancy, even before labor begins and is the result
of a combination of the pelvic structure relaxing as hormones of late
pregnancy are excreted and this in combination with gravity and just mild
contractions in end of pregnancy often results in descent even before labor
begins
2nd mechanism of labor is" Right Ans - Flexion.
Insightful Solutions (A+)
Mechanism of Labor is also known as: Right Ans - Cardinal Movements.
Cardinal movements: Right Ans - The way in which the fetus adapts itself
to and passes through the maternal pelvis.
Movements generally occur as a result of force from above and resistance
from below.
Force from above can be: Right Ans - Contractions.
Gravity.
Bearing down.
Resistance from below: Right Ans - Non-dilated cervix.
Pelvic floor muscle.
Force from above and resistance from below cause fetus to: Right Ans -
Twist and turn in order to fit through maternal pelvis.
Force from above and resistance from below: Reason fetus does not fit
through the pelvis without twisting and turning is because: Right Ans - The
fetal ovals and maternal ovals line up with each other.
Fetal ovals: Right Ans - Head and shoulde. The longer part of the oval goes
into different directions.
Longest part of the head: front to back.
Longest part of shoulders: side to side.
Maternal ovals: Right Ans - Inlet, midplane, outlet (3 planes of pelvis).
The configuration of the oval, the different planes, and thus requires
movement from the fetus in order to fit through pelvis.
Diameters: Right Ans - Antero-posterior (AP) [front to back] vs transverse
(side to side).
, The longer part of the fetus needs to line up with the: Right Ans - Longer
diameter of the pelvis.
Long axis is another term for: Right Ans - Long diameter.
The pelvic planes: Right Ans - Inlet.
Midplane.
Outlet.
As you learn the mechanisms of labor, think about in which plane each
mechanism occurs.
*Mechanism of labor for birth in OA position:* Right Ans -
If you can feel anterior fontanel during vaginal exam, position is most likely:
Right Ans - Posterior.
Anterior fontanel is in the anterior portion of the woman - position is
posterior.
1st mechanism of labor is Right Ans - Descent.
Descent: Right Ans - The downward passage of the presenting part through
the bony pelvis.
Occurs throughout labor; often begins before labor.
Results from downward pressure caused by contractions and maternal
bearing down efforts and gravity.
Some descent at end of pregnancy, even before labor begins and is the result
of a combination of the pelvic structure relaxing as hormones of late
pregnancy are excreted and this in combination with gravity and just mild
contractions in end of pregnancy often results in descent even before labor
begins
2nd mechanism of labor is" Right Ans - Flexion.
