Anatomy Of Pelvic/Genital Organs

Question 1

What does the term vulva refer to?

Answer 1

The external female genitalia

Question 2

What are the three main functions of the vulva?

Answer 2

• Acts as sensory tissue during sexual intercourse
• Assists in micturition by directing the flow of urine
• Protects the internal female reproductive tract from infection

Question 3

What is the mons pubis?

Answer 3

A subcutaneous fat pad located anterior to the pubic symphysis, formed by the fusion of the labia majora

Question 4

What are the labia majora?

Answer 4

Two hair-bearing external skin folds extending from the mons pubis to the posterior commissure

They are embryologically derived from labioscrotal swellings.

Question 5

What are the labia minora?

Answer 5

Two hairless folds of skin lying within the labia majora, fusing anteriorly to form the hood of the clitoris and extend posteriorly on either side of the vaginal opening. Merge posteriorly to create the fourchette.

Embryologically derived from urethral folds

Question 6

What is the vestibule?

Answer 6

The area enclosed by the labia minora, containing the openings of the vagina and urethra

Question 7

What is the function of Bartholin’s glands?

Answer 7

To secrete lubricating mucus during sexual arousal. They’re found on either side of the vaginal orifice

Question 8

What are the two main sources of arterial supply to the vulva?

Answer 8

• Internal pudendal artery
• External pudendal artery

Question 9

What nerves provide sensory innervation to the vulva?

Answer 9

ANTERIOR
* Ilioinguinal nerve
* Genital branch of the genitofemoral nerve
POSTERIORLY
Pudendal nerves
Posterior cutaneous nerve of the thigh

Question 10

clitoris

Answer 10

Formed of erectile corpora cavernous a tissue which becomes engorged with blood during sexual stimulation. Embryologically derived from genital tubercle

Question 11

What is the primary function of the vagina?

Answer 11

Acts as a distensible muscular tube for sexual intercourse, childbirth, and menstruation

Question 12

What organs are located lateral, anterior and posterior to the vagina?

Answer 12

• Anterior: bladder and urethra
• Posterior: rectouterine pouch, rectum, and anal canal
  Lateral: ureters and levator ani m.

Question 13

Venous and lymphatic supply of vulva

Answer 13

Venous drainage is via pudendal veins
Lymph drains to nearby superficial inguinal lymph nodes

Question 14

What are the histological layers of the vagina?

Answer 14

• Stratified squamous epithelium: provides protection and is lubricated by cervical mucus
• Elastic lamina propria : dense connective tissue layer which projects papillae into the overlying epth. Contains larger veins also
• Fibromuscular layer: 2 layers of smooth muscle (inner circular and outer longitudinal )
• Adventitia : fibrous layer which provides additional strength to vagina while binding it to surrounding structures

Question 15

What is the blood supply to the vagina?

Answer 15

ARTERIAL
Uterine and vaginal arteries, both branches of the internal iliac artery
VENOUS
Vaginal venous plexus which drains into the internal iliac veins via the uterine vein

Question 16

What are the three sections of lymphatic drainage for the vagina?

Answer 16

• Superior: drains to external iliac nodes
• Middle: drains to internal iliac nodes
• Inferior: drains to superficial inguinal lymph nodes

Question 17

What is the cervix?

Answer 17

The lower portion of the uterus connecting the vagina with the main body of the uterus. It’s anatomically and histologically distinct from the uterus

Question 18

What are the two regions of the cervix?

Answer 18

• Ectocervix : projects into the vagina and is lined by stratified squamous non keratinized epth
• Endocervical canal : inner part lines by mucus secreting simple columnar epth

Question 19

What are the two main functions of the cervix?

Answer 19

• Facilitates passage of sperm into the uterine cavity
• Maintains sterility of the upper female reproductive tract

Question 20

Innervation of the vagina

Answer 20

ANS
nerves arose from uterovaginal nerve complex

Question 21

What are the three parts of the uterus?

Answer 21

• Fundus
• Body
• Cervix

Question 22

How is the uterus positioned in a normal adult?

Answer 22

Varies with degree of distension of the bladder.
Anteverted with respect to the vagina and anteflexed with respect to the cervix

Question 23

What are the tissue layers of the uterus?

Answer 23

• Peritoneum : double layered membrane continuous with the abd peritoneum
• Myometrium : thick smooth muscle layer.
• Endometrium : inner mucus membrane lining of the uterus further divided into
  1. Deep stratum basalis
  2. Superficial stratum functionalis which is shed during menstruation

Question 24

Ligaments of the uterus

Answer 24

Broad - a double layer of peritoneum attaching the sides of the uterus to the pelvis. Acts as mesentary for the uterus and contributes to maintaining it in position
Round - remnant of gubernaculum extending from uterine horns to labia majora via inguinal canal. Maintains the anteverted position of the uterus
Ovarian - joins ovaries to uterus
Cardinal - at base of broad ligament and extends from cervix to lateral pelvic walls.
Uterosacral- extends from cervix to sacrum

Question 25

What is the main function of the uterine tubes?

Answer 25

To assist in the transfer and transport of the ovum from the ovary to the uterus ## Footnote The ultrastructure of the uterine tubes, including ciliated cells and smooth muscle, facilitates this process.

Question 26

What are the four parts of the fallopian tube?

Answer 26

* Fimbriae * Infundibulum * Ampulla * Isthmus

Question 27

What are the main functions of the ovaries?

Answer 27

* To produce oocytes in preparation of fertilization * To produce sex steroid hormones (oestrogen and progesterone)

Question 28

What are the three main histological features of the ovary?

Answer 28

* Surface (germinal epithelium) : formed by simple cuboidal epth * Cortex (connective tissue stroma and ovarian follicles) * Medulla (loose connective tissue and neurovascular network)

Question 29

What are the two peritoneal ligaments that attach to the ovary?

Answer 29

* Suspensory ligament of ovary * Ligament of ovary

Question 30

What is the blood supply to the ovary?

Answer 30

Paired ovarian arteries from the abdominal aorta. There is also a contribution from the uterine arteries. Venous drainage is achieved by paired ovarian veins. The left ovarian vein drains into the left renal vein, and the right ovarian vein drains directly into the inferior vena cava. The ovaries receive sympathetic and parasympathetic innervation from the ovarian and uterine (pelvic) plexuses, respectively. The nerves reach the ovaries via the suspensory ligament of the ovary, to enter the ovary at the hilum. ## Footnote There is also contribution from uterine arteries.

Question 31

What is the lymphatic drainage pattern for the ovaries?

Answer 31

Drains into the para-aortic nodes

Question 32

What is the anatomical structure of the breast?

Answer 32

Composed of mammary glands surrounded by connective tissue stroma Mammary Glands The mammary glands are modified sweat glands. They consist of a series of ducts and secretory lobules (15-20). Each lobule consists of many alveoli drained by a single lactiferous duct. These ducts converge at the nipple like spokes of a wheel. Connective Tissue Stroma The connective tissue stroma is a supporting structure which surrounds the mammary glands. It has a fibrous and a fatty component. The fibrous stroma condenses to form suspensory ligaments (of Cooper). These ligaments have two main functions: • Attach and secure the breast to the dermis and underlying pectoral fascia. • Separate the secretory lobules of the breast. Pectoral Fascia The base of the breast lies on the pectoral fascia – a flat sheet of connective tissue associated with the pectoralis major muscle. It acts as an attachment point for the suspensory ligaments. There is a layer of loose connective tissue between the breast and pectoral fascia – known as the retromammary space. This is a potential space, often used in reconstructive plastic surgery.

Question 33

Outline the vasculature of the breast

Answer 33

Arterial supply to the medial aspect of the breast is via the internal thoracic artery (also known as internal mammary artery) – a branch of the subclavian artery. The lateral part of the breast receives blood from four vessels: • Lateral thoracic and thoracoacromial branches – originate from the axillary artery. • Lateral mammary branches – originate from the posterior intercostal arteries (derived from the aorta). They supply the lateral aspect of the breast in the 2nd 3rd and 4th intercostal spaces. • Mammary branch – originates from the anterior intercostal artery. The veins of the breast correspond with the arteries, draining into the axillary and internal thoracic veins.

Question 34

What nerves innervate the breast?

Answer 34

Anterior and lateral cutaneous branches of the 4th to 6th intercostal nerves ## Footnote These nerves contain both sensory and autonomic nerve fibers.

Question 35

What is the triple assessment for suspected breast cancer?

Answer 35

* Clinical examination * Imaging (mammogram and ultrasound) * Biopsy

Question 36

Lymphatic drainage of the breast

Answer 36

The lymphatic drainage of the breast is of great clinical importance due to its role in the metastasis of breast cancer cells. There are three groups of lymph nodes that receive lymph from breast tissue – the axillary nodes (75%), parasternal nodes (20%) and posterior intercostal nodes (5%). The skin of the breast also receives lymphatic drainage: • Skin – drains to the axillary, inferior deep cervical and infraclavicular nodes. • Nipple and areola – drains to the subareolar lymphatic plexus.

Question 37

Surface anatomy of the breast

Answer 37

The breast is located on the anterior thoracic wall. It extends horizontally from the lateral border of the sternum to the mid-axillary line. Vertically, it spans between the 2nd and 6th costal cartilages. It lies superficially to the pectoralis major and serratus anterior muscles. The breast can be considered to be composed of two regions: • Circular body – largest and most prominent part of the breast. • Axillary tail – smaller part, runs along the inferior lateral edge of the pectoralis major towards the axillary fossa. At the centre of the breast is the nipple, composed mostly of smooth muscle fibres. Surrounding the nipple is a pigmented area of skin termed the areolae. There are numerous sebaceous glands within the areolae – these enlarge during pregnancy, secreting an oily substance that acts as a protective lubricant for the nipple.

Question 38

Describe the pelvic floor

Answer 38

Pelvic floor  Is a muscular partition which separates the pelvic cavity from the anatomical perineum.  Consists of 3 sets of muscles on either side- pubococcygeus, iliococcygeus and ischiococcygeus and these are collectively called levator ani.  Muscle with the covering fascia is called the pelvic diaphragm.  Formed by the two levator ani muscles which, with their fascia, form a musculofascial gutter during second stage of labour