MCN 2F Flashcards
Series of events by which uterine contractions and abdominal pressure expel a fetus and placenta
Labor
First Stage of Labor
Dilatation
Cervix dilates fully to a diameter of 10cm (2 inches)
Before 37-42 weeks
Preterm
Beyond 42 weeks
Post term
Exact mechanism that triggers onset of labor
Unknown
Combination of Occurrences as Responsible of Labor
Uterine Stretching
Changes in Estrogen and Progesterone balance
Cervical Pressure
Prostaglandins production by the fetus
Aging of the placenta
Increased Fetal Cortisol Level
Components of Labor
Passage
Passenger
Power
Psyche
Passage
Refers to maternal pelvis
Route that the fetus must travel from uterus through the cervix and vagina to the external perineum
Bony ring formed by four united bones:
2 innominate bones
Coccyx
Sacrum
Support and protect pelvic organs
Pelvis
Provide stability to the pelvis
Symphysis Pubis
Right Sacroiliac Joint
Left Sacroiliac Joint
Sacrococcygeal Joint
Four Pelvic Joints
Innominate bones: ilium (upper and lateral), ischium (inferior) and pubis
Hip - crest of ilium
Ischial tuberosities - markers used to determine lower pelvic width
Symphysis pubis
Sacrum - upper posterior
Coccyx - below sacrum
Parts and Functions of the Pelvis
Located in the superior half of the pelvis
Upper portion of the pelvic inlet
False Pelvis
Located in the inferior half of the pelvis
Includes pelvic inlet, pelvic outlet, and pelvic cavity
True Pelvis
Entrance to the true pelvis
also termed as Pelvic brim
Pelvic Inlet
Inferior portion of the true pelvis
Pelvic outlet
Space between the inlet and the outlet
Pelvic Cavity
Imaginary line that separates the true pelvis and the false pelvis
Linea Terminalis
Ideal type for childbirth
Most common type of pelvis for women
Easy passage of the fetal skull and shoulders
Female pelvis
Has inlet that is well-rounded forward and backward
Has a wide pubic arch
“Child bearing hips “
Coca-cola body
Gynecoid-shaped Pelvis
Pubic arch forms an acute angle; pelvis extremely narrow
Fetus may have difficulty exiting
could lead to Cesarean/Forceps/Vacuum
Male pelvis
Android-shaped Pelvis
Transverse diameter is narrow
Anteroposterior diameter of the inlet is larger than usual
Oval with longer anteroposterior diameter
Shaped as a monkey
Anthropoid-shaped Pelvis
Has a smoothly curved oval inlet, but the anteroposterior diameter is shallow.
Pelvis is super wide and super big that it causes difficulty delivering the baby because of flattened oval shape
obese have flattened pelvis
Platypelloid-shaped Pelvis
Pelvic Inlet: 11cm
Anteroposterior Diameter
Pelvic Inlet: 13cm
Transverse Diameter
Pelvic Inlet: 12cm
Oblique Diameter
Pelvic Inlet: 11cm
True Conjugate
Pelvic Inlet: 10.5-11cm
Diagonal Conjugate
Pelvic Inlet: 10cm
Obstetric Conjugate
Pelvic Outlet: 11.7cm from sacrum/symphysis pubis to coccyx
Anteroposterior Diameter
Pelvic Outlet: 10cm-13.5cm from left ischial tuberosity to the right side of ischial tuberosity
Transverse/Intertuberous Diameter
Pelvic Outlet: 9cm from this part to the sacral iliac joint
Posterior Sagittal Diameter
Lower segment of the uterus expands to accommodate the intrauterine contents
Cervix is drawn up and over the presenting part as it descends
Vaginal Canal distends to accommodate passage of fetus
Play a role in labor and delivery
Soft Tissues
Refers to the fetus and its ability to move
Passenger
Fetal Features as Passenger
Presentation
Attitude
Station
Lie
Position
Very important because this is significant during labor and delivery and is used to check for any disabilities
Fetal Skull
Compressible and made mainly of thin pliable tubular flat bones
Fetal Skull
8 bones of the Fetal Skull
2 fused Frontal Bones
2 Parietal Bones
1 Occipital Bone
Anchored to the rigid and incompressible bones at the base of the skull
T/F: you can determine specific condition by the use of suture lines
TRUE
Seams between the bones of the skull
Sutures
Coronal
Frontal and Parietal
Lambdoid
Occipital & Parietal
Sagittal
2 Parietal Bones