ARD Module 1

The linea terminalis is a bony ridge that separates the true pelvis from the false pelvis.

The false pelvis supports the growing uterus during pregnancy. It is bounded by the lumbar vertebrae posteriorly, the iliac fossae laterally, and the anterior abdominal wall anteriorly.

The pelvic inlet marks the entrance to the true pelvis. It is bounded by the pubic crest and spine anteriorly, the iliopectineal lines laterally, and the sacral promontory posteriorly.

The pelvic cavity, also called the midpelvis, is a curved canal. It has a straight and shallow anterior wall, a deep and concave posterior wall, and is bordered by the ischium and ilium laterally.

The pelvic outlet marks the exit from the true pelvis. It is bounded by the arcuate pubic ligament and the pubic arch anteriorly, the ischial tuberosity and sacrotuberous ligament laterally, and the tip of the sacrum posteriorly.

The anatomical conjugate is the distance between the sacral promontory and the superior aspect of the pubic symphysis. It measures approximately 11.5 cm and is not clinically significant in obstetrics.

The obstetric conjugate (the shortest distance between the sacral promontory and the symphysis pubis) is the most important anteroposterior diameter of the pelvis because it determines whether the fetus can pass through the birth canal. It measures 11 cm on average, but it is the minimum measurement that is important.

The diagonal conjugate can be measured clinically and is used to estimate the obstetric conjugate. It measures 12.5 cm on average and is clinically important.

The Caldwell Malloy Classification categorizes pelvic shapes based on the dimensions of the inlet, midpelvis, and outlet. This classification helps determine the suitability of the pelvis for vaginal birth.

The pelvic floor muscles support pelvic organs, help generate pressure during activities like coughing or lifting, and guide the baby during birth.

The endopelvic fascia provides support to the vagina and visceral organs, the pelvic diaphragm separates the pelvic cavity from the perineal space, the perineal diaphragm separates levator muscles from superficial perineal muscles, and superficial perineal muscles support the urethra and contribute to sphincter function.

The pubococcygeus muscle is the muscles that can be torn during a second-degree laceration or episiotomy during childbirth. It stretches from the pubis to the coccyx.

The Levator Ani is composed of three muscles: Pubococcygeus, Iliococcygeus and Ischiococcygeus.

The Pubovaginalis muscle is the primary support of the female pelvic organs, acting as a sling for the vagina.

The Caldwell Malloy Classification helps determine the pelvic size and shape. It uses measurements of the pelvic inlet, midpelvis, and outlet, to classify the pelvis into four types: Gynecoid, Anthropoid, Android, and Platypelloid.

Pelvic shape is one factor that can influence the course of labor and the delivery method. A physician or midwife will assess the pelvis during pregnancy to determine if it is adequate for vaginal delivery.

The perineum's muscles, including the transverse perineal, bulbocavernosus, and potentially the external anal sphincter, can tear during childbirth, impacting the anus' control.

The pudendal nerve, arising from the S2, S3, and S4 vertebrae, innervates the perineum, levator ani, rectal sphincter, vulva skin, urogenital diaphragm, and lower birth canal.

The pudendal artery branches provide blood supply to the perineum.

The fetal skull bones are: frontal, parietal, occipital, temporal, and the sagittal suture.

The anterior fontanel, or 'soft spot,' helps the skull mold during birth, allowing for the passage through the birth canal. It facilitates brain growth and closes by 18 months.

Sutures in the fetal skull, including the sagittal, coronal, and lambdoidal sutures, allow for skull flexibility during labor, facilitating passage through the birth canal.

Fontanels and sutures are crucial for molding during birth as the fetal skull adapts to the birth canal's size and shape.

Landmarks like anterior fontanel and diameters like biparietal diameter help determine fetal head size and position during labor.

The relationship between the long axis of the fetus and the long axis of the mother. It describes how the baby is lying in the uterus.

The part of the fetus that enters the pelvic inlet first and presents towards the birth canal.

The specific fetal structure that is closest to the cervix and felt by the examiner during a vaginal exam.

The relationship of the fetal head to the fetal body. It describes how the baby's head is positioned relative to its spine.

The specific fetal bone used to describe fetal position. This is usually a landmark on the presenting part.

The relationship of the denominator to the mother's pelvis. It describes the position of the baby in the pelvis during labor.

The distance between two specific points on the fetal head. It helps determine if the head size is suitable for vaginal delivery.

The diameters are clinically significant for recognizing the attitude and presentation of the fetus to determine success for vaginal delivery. They help predict the likelihood of a successful vaginal birth.

The part of the fetus that is nearest to the cervix, and what the provider touches first during a vaginal exam.

The relationship of the fetal parts to each other, focusing on flexion and extension.

The relationship of the denomiator to the front, back, or sides of the maternal pelvis, described with a three-letter code. For example, LOP (left occiput posterior) indicates the denominator is in the posterior segment of the pelvis and 45 degrees left of the midline.

The largest transverse diameter of the fetal head is the biparietal diameter.

The largest anterior-posterior diameter of the fetal skull is the verticomental diameter.

The smallest diameter of the fetal skull is the suboccipitobregmatic diameter.

The sutures and fontanelles of the fetal skull serve as landmarks during vaginal exam to help determine the position and descent of the baby's head.

A description of the presenting part that designates the specific landmark of the fetus.

The denominator is the presenting part of the fetus that is lowest in the pelvis. It's the landmark used to describe the baby's position.

Back of the head, used as a landmark for fetal positioning.

When the back of the baby's head is facing the front of the mother's pelvis.

The sacrum, as it's the presenting part in a breech position.

The area between the two fontanelles (soft spots) on top of the skull.

The anterior fontanelle (soft spot) on the top of the baby's head, usually diamond-shaped.

The posterior fontanelle (soft spot) at the back of the baby's head, often triangular or Y-shaped.

Location on the fetal skull, the region between the glabella and the bregma.

The sacroiliac joint is a synovial joint that connects the sacrum to the ilium and allows for limited movement. It helps transfer weight from the upper body to the pelvis and lower limbs.

The symphysis pubis is a cartilaginous joint between the two pubic bones. It permits a small degree of movement and is essential for flexibility during childbirth.

The sacrococcygeal joint is a synovial hinge joint that connects the sacrum to the coccyx. It allows for flexion and extension and helps widen the pelvic outlet to facilitate childbirth.

The iliac crest is the superior border of the ilium and forms the upper part of the hip bone. It is a landmark used in obstetrics to assess pelvic size and shape.

The ischial spine is a bony projection on the inner surface of the ischium. It is a landmark used to assess the size and shape of the pelvic outlet during labor.

The sacrospinous ligament is a strong ligament that extends from the ischial spine to the sacrum. It plays a role in supporting the pelvic organs and helps stabilize the pelvic outlet.

The sacrotuberous ligament is a strong ligament that connects the sacrum to the ischial tuberosity. Along with the sacrospinous ligament, it helps stabilize the pelvic outlet and support the pelvic organs.

The greater sciatic notch is a large opening in the pelvis located between the sacrum and the ilium. It allows for the passage of blood vessels, nerves, and muscles.

The strong ligaments on the front of the pelvis, which are strengthened by the tendons of the abdominal muscles.

The strong ligaments on the bottom of the pelvis, forming the pubic arch.

The muscles that make up the floor of the pelvis, supporting internal organs and playing a role in childbirth.

The muscles that make up the deepest layer of the pelvic floor, including the levator ani, coccygeus, and deep transverse perineal muscles.

The muscles that make up the superficial layer of the pelvic floor, including the bulbospongiosus, ischiocavernosus, and superficial transverse perineal muscles.

The bony structure that supports the internal female reproductive organs, the bladder, and the intestine. It also plays a key role in childbirth by resisting the descent of the fetus.

The three important landmarks on the ischium that the fetus must navigate during birth.

The anatomical structure that marks the transition between the false pelvis and the true pelvis.

The true pelvis is the bony canal that the fetus passes through during birth. It's below the pelvic brim and includes the inlet, cavity, and outlet.

The false pelvis supports the pregnant uterus. It's above the true pelvis and extends from the lumbar vertebrae to the anterior abdominal wall.

The obstetric conjugate is the shortest distance between the sacral promontory and the symphysis pubis. It's the most crucial anteroposterior diameter for determining if the fetus can pass through the birth canal.

The diagonal conjugate measures the distance from the sacral promontory to the subpubic angle. It's measured manually and helps estimate the obstetric conjugate.

The plane of least dimensions is the narrowest part of the pelvis. It usually lies at the level of the ischial spines and is the most common area for labor arrest.

The transverse diameter at the level of the ischial spines is the narrowest dimension the fetus needs to pass through. A typical measurement is around 10cm.

The obstetric conjugate, diagonal conjugate, transverse diameter at the level of the ischial spines, anterior sagittal diameter of the outlet, and posterior sagittal diameter of the outlet are the most important measurements for assessing the obstetric capacity of the pelvis.

The Caldwell-Malloy classification helps categorize pelvic shapes based on the dimensions of the inlet, midpelvis, and outlet. This classification can help predict the likelihood of a successful vaginal delivery.

The muscle that is torn during a second-degree laceration or with an episiotomy, and is perforated by the urethra, vagina, and rectum.

It separates the pelvic cavity from the perineal space and supports the abdominal, pelvic, and visceral organs.

The three main muscles of the Levator Ani, which work together to support the pelvic organs.

They are involved in urethral support and sphincter mechanics. Not part of the Levator Ani

The muscles of the perineum, specifically the transverse perineal muscles, bulbocavernosus muscles, and depending on the severity of the tear, the external anal sphincter which controls the anus.

The pudendal nerve, originating from S2, S3, and S4 vertebrae, innervates the perineum, levator ani, rectal sphincter, vulva skin, urogenital diaphragm, and lower portion of the birth canal.

The fetal skull consists of the frontal bone, parietal bones, occipital bone, and temporal bones. These bones are joined by sutures that allow for flexibility during birth.

Sutures, including the sagittal, coronal, and lambdoidal sutures, provide flexibility to the fetal skull during labor.

Fontanels and sutures help the fetal skull mold during birth as the baby's head passes through the birth canal.

Landmarks like the anterior fontanel and diameters such as the biparietal diameter aid in determining the fetal head size and position during labor.

The urogenital triangle is a region of tissue located at the base of the pelvis. It's bordered by the subpubic angle in the front, the ischial rami and tuberosities on the sides, and the transverse perineal muscle and urogenital diaphragm in the back.

The vestibule is an area between the labia minora that extends from the clitoris to the fourchette. It contains the openings of the urethra and vagina, and the openings of the greater vestibular glands and paraurethral glands.

The pubococcygeus muscle, also called the pubovisceral muscle, is a crucial muscle in the pelvic floor. Its insertion creates functional sphincters that help maintain fecal and urinary continence.

The perineal body serves as a central point of support for several muscles in the pelvic floor. It's formed by the sphincter ani externus, two levator ani muscles, superficial and deep transverse perineal muscles, and the bulbocavernosus muscle.

The superficial transverse perineal muscle, the bulbocavernosus muscle, and the ischiocavernosus muscle all contribute to supporting the delicate structures of the perineum.

The muscles involved in tearing during childbirth include the transverse perineal, bulbocavernosus, and, sometimes, the external anal sphincter. These tears are categorized as first-degree, second-degree, third-degree, and fourth-degree, depending on the extent and involvement.

The opening of the vagina, terminal part of the urethra, crura of the clitoris, vestibular bulbs, Bartholin's glands, urogenital diaphragm, perineal body, perineal pouches, and associated blood vessels, nerves, and lymphatics are all components of the urogenital triangle.

The urogenital diaphragm plays a significant role in supporting the pelvic floor and its associated structures. It is a muscular sheet that separates the pelvic cavity from the perineum, contributing to urinary continence and overall pelvic stability.

The bony canal that the fetus passes through during childbirth.

The area above the true pelvis that supports the pregnant uterus.

The shortest distance between the sacral promontory and the symphysis pubis, crucial for determining if the fetus can pass through the birth canal.

The distance from the sacral promontory to the subpubic angle, helping estimate the obstetric conjugate by manual measurement.

The narrowest part of the pelvis, usually at the level of the ischial spines, where labor arrest is most common.

The narrowest dimension the fetus needs to pass through, usually at the level of the ischial spines, typically around 10cm.

This is the narrowest diameter the baby's head must pass through during labor.

This is the most common pelvic type in women. This pelvis helps the baby rotate and have a vaginal birth.

This pelvis is similar to males and often creates difficult births that may require forceps.

This pelvis is long and narrow. It often leads to easy deliveries and birthing face-to-pubis.

This flat pelvis can lead to a cesarean section because the outlet is too narrow for the baby.

The distance between the sacral promontory and the superior aspect of the pubic symphysis. It's not crucial for childbirth.

The vestibule is the area between the labia minora, extending from the clitoris to the fourchette. It contains the openings to the urethra and vagina, and the openings of the greater vestibular glands and the paraurethral glands. It is like a special entryway for the vagina and urethra.

The pubococcygeus muscle, also known as the pubovisceral muscle, plays a vital role in maintaining fecal and urinary continence. This muscle acts like a sphincter to control the flow of these fluids.

The back of the head, specifically the occipital bone, used as a landmark to describe fetal positioning in the pelvis during labor.

The denominator is the specific landmark on the presenting part used to describe the fetal position in the pelvis. It tells you which part of the baby is leading the way.

In ROA fetal presentation, the 'A' means Anterior. This signifies that the back of the baby's head (occiput) is facing the front of the mother's pelvis.

In ROA, the 'R' means Right. The denominator (occiput) is positioned 45 degrees to the right of the midline of the mother's pelvis.

The vertex is the area located on top of the fetal skull, between the two fontanelles (the soft spots) - think of this as the top of the head that's coming first.

The anterior fontanelle is a diamond-shaped space on the top of the baby's head, also called the 'soft spot.' It's important for the baby's head to mold during labor.

The suboccipitobregmatic diameter measures from the junction of the occipital bone and neck to the center of the bregma. It is seen when the fetal head is well flexed. This diameter is approximately 9.5cm and is ideal for vaginal delivery because this position allows the smallest cephalic diameter to pass through the maternal pelvis.

Begins at the lower jaw and extends to the center of the bregma. Seen in face presentations.

The posterior fontanelle is a smaller, triangular-shaped space located at the back of the baby's head. It is usually a 'Y' or 'triangular' shape.

The occipitofrontal diameter measures from the external occipital protuberance to the glabella. It is seen in military attitude and is approximately 11cm long. This diameter is similar clinically to a brow presentation because it does not typically fit through the maternal pelvis.

The Verticomental diameter, measured from the chin to the vertex, is the largest fetal head diameter. This diameter may not fit through the maternal pelvis, leading to concerns for vaginal delivery. It is seen in brow presentations.

Fetal presentation refers to the part of the fetus that enters the pelvic inlet first and presents towards the birth canal, meaning the part that is closest to the cervix.

The presenting part is the fetal structure that is closest to the cervix and felt by the examiner during a vaginal exam.

Fetal attitude describes the relationship of the fetal head to the fetal body, specifically how the baby's head is positioned relative to its spine.

The perineum is the area between the anus and the vulva. It's made up of muscles and other tissue that helps support the pelvic organs and the baby during birth. The perineum can tear during childbirth, which is why it's important that health care providers know how to assess and manage perineal tears.

The deep pelvic floor muscles, also known as the levator ani, are essential for supporting the bladder, uterus, and rectum. These muscles are important for keeping these organs in place and for helping to control urine and stool. The levator ani also plays a crucial role in childbirth, helping to guide the baby down the birth canal.

The pudendal nerve is a vital nerve that supplies sensation and motor control to the perineum, including the vulva, anus, and the muscles surrounding the vagina. During childbirth, it's crucial to ensure the pudendal nerve isn't injured as it supports the vulva, anus, and pelvic floor muscles.

The fetal skull has several bones, including the frontal, parietal, temporal, and occipital bones. The bones are connected by sutures, which are flexible areas that allow the skull to change shape during labor. This adaptability is crucial for helping the baby's head navigate the birth canal.

The fontanels are soft spots on the fetal skull that are formed where bones meet. The anterior fontanel is the largest and is located at the top of the head. The posterior fontanel is smaller and is located at the back of the head. These soft spots allow the fetal skull to mold through the birth canal.

Sutures and fontanels are crucial for molding during delivery. The baby's skull must adapt to the shape of the birth canal to pass through. This flexibility is essential for a safe and successful vaginal birth.

The fetal skull landmarks, such as the fontanels, and diameters, such as the biparietal diameter, allow healthcare providers to understand the baby's head size and position in the pelvis. This information is essential for determining how labor will progress and for deciding the best delivery approach.

The urogenital diaphragm, a muscular sheet, supports the pelvic floor, separating the pelvic cavity from the perineum. It's vital for urinary continence, helps stability and overall structure of the pelvis.