Normal Anatomy & Physiology of Female Pelvis

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Questions and Answers

What is the primary function of the levator ani muscles?

Aid in abdominal compression

Assist in knee flexion

Support the pelvic floor (correct)

Facilitate hip rotation

Which muscle is located on the posterolateral wall of the true pelvis?

Obturator internus

Piriformis (correct)

Coccygeus

Iliacus

Where does the obturator internus muscle originate?

Sacrum

Arcuate line of innominate bones (correct)

Greater trochanter of femur

Lesser sciatic notch

Which of the following muscles travel in an anterolateral direction and cross over the obturator internus?

Piriformis Signup and view all the answers

What is the primary characteristic of the coccygeus muscle?

It is the most posterior pelvic floor muscle Signup and view all the answers

Which muscle narrows inferiorly as it passes through the lesser sciatic notch?

Obturator internus Signup and view all the answers

Which among the following is not part of the pelvic diaphragm?

Rectus abdominis Signup and view all the answers

What type of muscle is the obturator internus classified as?

Triangular muscle Signup and view all the answers

Which position describes a uterus that is tilted posteriorly?

Retroversion Signup and view all the answers

What does the term 'anteversion' describe in uterine positioning?

The fundus and body are bent forward towards the cervix Signup and view all the answers

What characterizes a retroflexed uterus?

Fundus and body bent backward towards the cervix Signup and view all the answers

In which uterine position is the body and cervix nearly in the same axis?

Retroverted Signup and view all the answers

What defines the normal variant of uterine position where the uterus is angled to the right?

Dextroversion Signup and view all the answers

What is the primary role of the round ligaments in nulliparous females?

To hold the uterus in an anteverted, anteflexed position Signup and view all the answers

How long are the fallopian tubes approximately?

10-12 cm Signup and view all the answers

What is the diameter range of the fallopian tubes?

1-4 mm Signup and view all the answers

What structure carries urine from the kidneys to the bladder?

Ureters Signup and view all the answers

Where do the ureters enter the bladder?

Posteriorly at the trigone Signup and view all the answers

What happens to the bladder as it fills with urine?

Its superior surface distends and rises Signup and view all the answers

What is the normal thickness of the bladder wall when distended?

Less than 5mm, with a mean of 1.5mm Signup and view all the answers

What anatomical position does the bladder occupy when it is empty or slightly filled?

Entirely within the true pelvis Signup and view all the answers

Which of the following statements about the bladder when empty is correct?

Its wall may appear thicker but should not exceed 5mm Signup and view all the answers

What is the primary anatomical structure impacted by the bladder as it fills?

Small bowel and peritoneum Signup and view all the answers

What is the location of ureters in relation to the psoas major muscles?

Anteriorly and medially Signup and view all the answers

What hormone primarily stimulates the growth of ovarian follicles?

Follicle-stimulating hormone (FSH) Signup and view all the answers

During which phase of the ovarian cycle does ovulation occur?

Ovulation Phase Signup and view all the answers

How many primordial follicles begin development at puberty in each ovary?

200,000 Signup and view all the answers

What structure forms when a primary follicle fills with fluid during the follicular phase?

Secondary follicle Signup and view all the answers

Which hormone increase contributes to increased LH production?

Estrogen Signup and view all the answers

What happens to the follicles that do not mature during the ovarian cycle?

They degenerate. Signup and view all the answers

What is the estimated size of the graafian follicle when fully matured?

2.0 - 2.5 cm Signup and view all the answers

What hormone is primarily responsible for endometrial repair and growth?

Estrogen Signup and view all the answers

Which muscle joins with the iliacus to form the iliopsoas muscle in the false pelvis?

Psoas major Signup and view all the answers

What is the primary insertion point of the iliopsoas muscle?

Lesser trochanter of the femur Signup and view all the answers

Which ligament supports the ovary?

Ovarian ligament Signup and view all the answers

Where does the psoas major muscle arise from?

Lumbar spine Signup and view all the answers

Which of the following is NOT a ligament that supports the uterus?

Infundibulopelvic ligament Signup and view all the answers

What is the course of the iliopsoas muscles along the pelvic sidewalls?

Laterally and anteriorly Signup and view all the answers

Which muscle is considered part of the false pelvis?

Iliopsoas Signup and view all the answers

Which structure do the iliopsoas muscles travel over to reach their insertion?

Pelvic brim Signup and view all the answers

What physiological change occurs during the follicular phase that leads to ovulation?

Increase of estrogen production Signup and view all the answers

What marks the peak of LH levels in the blood before ovulation?

LH surge occurring 10-12 hours before ovulation Signup and view all the answers

What is the term used to describe the pain some women feel during ovulation?

Middleschmerz Signup and view all the answers

Which event happens on day 14 of the ovarian cycle?

The rupture of the graafian follicle Signup and view all the answers

What effect does the LH surge have in the ovarian cycle?

Triggers ovulation Signup and view all the answers

What is the outcome of the rupture of the graafian follicle?

Release of the ovum into the fallopian tube Signup and view all the answers

What condition is associated with fluid in the posterior-cul-de-sac during ovulation?

Normal physiological response Signup and view all the answers

Which hormone's production is stimulated by increased estrogen levels during the follicular phase?

Luteinizing hormone (LH) Signup and view all the answers

Study Notes

Normal Anatomy and Physiology of the Female Pelvis

This chapter covers the female pelvis's anatomy and physiology.
Sonography techniques are a crucial tool for evaluating the female pelvis.
An in-depth knowledge of normal anatomy and physiology is essential for a proper assessment of pelvic organs and structures.
The pelvic organs and structures include the uterus, vagina, ovaries, fallopian tubes, urinary bladder, and pelvic colon.
Transabdominal sonography requires a full bladder for acoustic visualization, usually with a 3.5-5 MHz transducer.
Endovaginal sonography uses an empty bladder and a higher frequency transducer (7.5-10 MHz).
The pelvic skeleton, composed of bones, muscles, and ligaments, forms the outer boundaries and inner margins of the pelvis.

Key Structures of the Pelvis

Bones:
- Two innominate (coxal) bones
- Sacrum
- Coccyx
Muscles:
- Psoas major
- Iliacus
- Piriformis
- Obturator internus
- Levator ani
- Coccygeus
Ligaments:
- Broad ligaments
- Round ligaments
- Uterosacral ligaments
- Cardinal ligaments
- Infundibulopelvic ligament
- Ovarian ligament
Spaces:
- Vesicouterine pouch
- Pouch of Douglas
- Space of Retzius

Functions of the Pelvic Skeleton

Weight-bearing bridge connecting spine and legs.
Childbirth pathway - protecting the fetal head.
Protecting pelvic organs.

The Bony Pelvis

Consists of four bones: two innominate (coxal) bones, sacrum, and coccyx.
Divided into two compartments: true and false pelvis, separated by an oblique plane running through the pelvic brim.

The Pelvic Cavity and Perineum

True pelvis is the area inferior to the parietal peritoneum, considered the pelvic cavity.
True pelvis has the pelvic organs like the bladder, uterus, and ovaries
False pelvis is the area above the linea terminalis
False pelvis is the area above the pelvic brim, containing mostly bowel.

Pelvic Muscles

The skeletal muscles of the pelvis support and stabilize pelvic organs.
The pelvic diaphragm is crucial for supporting pelvic organs.
It is comprised of pubococcygeus, iliococcygeus, and coccygeus muscles.

Pelvic Ligaments

The various ligaments support the pelvic organs in position.
They hold the uterus, ovaries, and vagina in their correct anatomical place.
Broad ligaments: Support and contain pelvic organs like ovaries and fallopian tubes
Round ligaments: Support the uterus.
Uterosacral ligaments: Support the cervix.
Cardinal ligaments: Support the cervix.
Other ligaments support the ovaries and vaginal structures

Pelvic Organ Anatomy

Urinary bladder and urethra.
External genitalia (mons pubis, labia majora, labia minora, clitoris, urethral opening, vestibule of vagina).
Uterus, two fallopian tubes, and vagina.
Two ovaries.
Colon and rectum.

Bladder Anatomy

Located in the anterior segment of the pelvis, anterior to the uterus and vagina, posterior to the pubic symphysis.
Anchored by the pubovesical ligament.
Function: Collect and store urine until it empties through the urethra.
Has three sections: apex, base, and neck.
The apex is located posterior to the pubic bone.

Bladder and other pelvic organ Anatomy cont.

Ureters run from kidneys, pass anterior to the major muscles, and enter bladder at the trigone.
The bladder expands and recedes with filling.
When the bladder is empty, it is entirely within the true pelvis. As the bladder fills, its superior surface pushes bowel and peritoneum to the false pelvis.

Ovarian Anatomy

Almond-shaped structure in the adnexa of the true pelvis.
Supported by the ovarian ligaments, suspensory ligaments (infundibulopelvic), and the mesovarium.
Anterior to the iliac artery and vein.
Consists of Cortex and Medulla
The cortex has varying stages of follicles.
The medulla has connective tissue, including blood, nerves, lymphatic vessels, and some smooth muscle.

Physiology of the Female Pelvis

Gynecologic physiology explores how the hormones regulate the menstrual, ovarian, and uterine cycles.
Cycles are controlled by endocrine glands.
Hormones influence the maturation and release of ovum, establishing and maintaining the structures of the reproductive organs.
Sonographic interpretation will reveal characteristics and changes within the organs, aiding diagnoses when needed.

Menstrual Cycle

Reproductive lifespan: 11 - 50.
Average cycle: 28 days.
Cycle begins with menstrual bleeding (Day 1).
Different phases influence the process:
- Preovulatory (Days 1-13): Hormones prepare uterus for possible fertilization
- Ovulation (Day 14): Release of the egg
- Postovulatory (Days 15-28): Fertilized egg implants in the uterus, or not

Ovarian Cycle

Ovarian cycle focuses on the phases of follicular development, ovulation, and corpus luteum formation.

Endometrial Cycle

The endometrial cycle correlates with the ovarian cycle causing changes in the lining of the uterus
There are three phases of the endometrial cycle
- Menstrual Phase
- Proliferative Phase
- Secretory Phase

Menopause/Postmenopause

Menopause is the cessation of menstrual cycles, generally around age 50.
Perimenopause is the transition period before menopause, characterized by fluctuating hormone levels.

Pelvic Spaces (Adjacent to Uterus)

Vesicouterine pouch: Space between the bladder and the uterus.
Pouch of Douglas: Space between the rectum and the uterus.
Space of Retzius: Space separating the anterior bladder wall from the pubic symphysis, containing extraperitoneal fat.

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Description

This quiz covers the essential aspects of normal anatomy and physiology of the female pelvis, focusing on key structures, organs, and sonography techniques. An understanding of these concepts is crucial for evaluating pelvic health using transabdominal and endovaginal sonography. Test your knowledge on the bones, muscles, and organs that form the female pelvis.