Reproductive Anatomy Flashcards
Name the structures that define the superior pelvic aperture
- Sacral promontory
- Ala of the sacrum
- Arcurate line of the ilium
- Pecten pubis (ridge on the superior rams of the pubic bone)
- Pubic tubercle
- Pubic crest
- Pubic symphysis
What is the sexual diamorphism of the greater pelvis?
Females have a shallow greater pelvis
Males have a deep greater pelvis
What is the sexual diamorphism of the lesser pelvis?
Females have a wide lesser pelvis
Males have a narrow lesser pelvis
What shape is the pelvic inlet in both sexes?
Females have an oval/rounded shaped pelvic inlet
Males have a heart shaped one
What is the difference in relative size of the pelvic outlet between the two sexes?
Female relatively large
Male relatively smaller
What is the sexual diamorphism of the suprapubic angle?
Female - Obtuse: greater than 90 degrees
Male - Acute: less than 90 degrees
What is the difference in shape of the obturator foramen in men and women?
Female - oval
Male - round
What is the sexual diamorphism of the relative size of the acetabulum?
Female relatively small
Male relatively large
What are the two types of joints found in the pelvis?
Planar synovial e.g. sacroiliac joint
Pubic symphysis e.g. secondary cartilaginous
What is the pelvic brim?
The edge of the superior pelvic aperture - anything superior to this point is known as the greater (false) pelvis and inferior to this point, the lesser (true) pelvis
Why is the greater pelvis known as the false pelvis?
Contains the inferior part of the peritoneal cavity (i.e. intestines and other abdominal organs)
Why is the lesser pelvis known as the true pelvis?
Contains true pelvic organs (i.e. reproductive systems)
What walls does the pelvic cavity have?
Antero-inferior wall, two lateral walls and a posterior wall
What is the antero-inferior wall made of?
Bodies and rami of the pubic bones and the pubic symphysis
What is the lateral walls made of?
Obturator internus and the piriformis muscles
What is the posterior wall made of?
Coccygeus muscle
What is the pelvic floor?
Funnel-shaped ‘hammock’ of muscles and fascia that separates the pelvic cavity from the perineum, inferior to which the genitalia and anus sit
How does the pelvic floor allow for defaection and urination?
Hiatuses for the anal and urethral canal
Between anal and urethral hiatuses lies a fibrous node of connective tissue known as what?
Perineal body
What are the functions of the pelvic floor?
- Support of abdomen-pelvic viscera
- Resistance to increases in intra-pelvic/abdominal pressure
- Urinary and faecal incontinence
What are the muscles of the pelvic floor?
- Levator ani muscles
- Coccygeus muscle
- Fascia covering the muscles
What muscles form the elevator ani muscles?
Puborectalis, pubococcygeus and the iliococcygeus
How does the puborectalis maintain continence?
Originates at the pubic bone and form muscular slings around the anal canal and urethra respectively
What is the only true levator muscle of the levator ani muscles?
Iliococcygeus - elevating the pelvic floor and ano-rectal canal
How is the levator ani muscle innervated?
Pudendal nerve (roots S2, S3, S4)
Describe the course of the coccygeus muscle
Originates from the ischial spines and runs posteriorly attaching to the lateral aspect of the sacrum and coccyx along the sacrospinous ligament
What is the blood supply to the pelvis?
Branches of the internal iliac artery supply everything except for the testes/ovaries (gonadal artery) and the upper rectum (superior rectal artery from the Inferior Mesenteric Artery)
What structures do the superior and inferior vesicle arteries supply?
Bladder, seminal glands, prostate
What structures do the uterine arteries supply?
Uterus, ovaries, Fallopian tubes
From where do the gonadal arteries arise?
Abdomain aorta
From where do the middle and inferior rectal arteries arise?
Internal iliac a.
What structures does the vaginal artery supply?
Vagina/base of bladder
What is the vaginal artery a branch of?
Uterine artery
What is the main artery to the perineum?
Internal pudendal artery
What does the obturator artery supply?
Thigh adductors
Five different veins drain the pelvis; name them.
- Internal iliac veins
- Superior rectal veins
- Median sacral veins
- Gonadal veins
- Internal vertebral arteries (Batson’s plexus)
What veins do the rectal veins drain into? Think about types of venous drainage
Superior - portal circulation
Middle and inferior - systemic circulation
What is the clinical significance of the rectal veins?
Suppositories bypass portal circulation, potentially giving better bioavailability
What is the significance of the prostatic venous plexus?
Freely communicates with Batson’s plexus; significant in metastasis of cancers
What are the four components of innervation to he pelvis?
- Ilioinguinal nerve
- Genitofemoral nerve
- Pudendal nerve
- Autonomic components
Describe the ilioinguinal nerve
Originate from L1 and enters the inguinal canal at the superficial ring to supply the skin at the root of the penis and labia
Describe the genitofemoral nerve
Originates from L1-L2 and enters at the deep inguinal ring, supplying the cremaster muscle and is tested via the cremasteric reflex
Describe the pudendal nerve
Arises form the sacral plexus (L4-S4) and follows the course of the pudendal artery to innervate the sin and the muscles of the perineum
What bony landmark is used to locate the pudendal nerve or nerve block during forceps delivery?
Ischial spine
What effect do symapthetic fibres have in the pelvis?
From L1-L2, via the hypogastric plexus supply the vas deferens, vesicles and epididymis
Fibres from the pelvic and ovarian plexuses and parasympathetic nerve fibres from the pelvic splanchnic (S2-S4) nerve supply the female genital tract
What effect doe parasymptahtic fibres have in the pelvis?
Fibres from S2-S4 form the hypogastric plexus innervate the erectile tissue
How many lymph node groups are there in the pelvis
Four primary
What are the groups of lymph nodes in the pelvis called?
Extrernal iliac
Internal iliac
Sacral
Common iliac
What structures are drained by the external iliac nodes?
External genitalia, rectal viscera, abdominal wall (inferior to umbilicus)
What structures are drained by the internal iliac nodes?
Gluteal region, deep perineum and inferior pelvic viscera
What structures are drained by the sacral nodes?
Pelvic, perineal nad gluteal regions
What structures are drained by the common iliac nodes?
Receive drainage from the other groups of lymph nodes in the pelvis and lower limbs
Reproductive organs can be classified into four categories in males; what are they?
- External genitalia
- Gonads
- Tubal systems
- Accessory glands
What are the male reproductive organs?
Testes, ductus deferens/vas deferens, seminal glands, prostate, epididymis, bulbourethral glands
What is the function of the counter-current heat exchange system in the testes?
Testes optimal temperature is two degrees below core body temperature. the testicular artery is surrounded by the pampiniferous venous network to draw out heat
What are the fascial coverings of the testes?
- Skin
- Dartos muscles and superficial fascia
- External spermatic fascia
- Cremasteric fascia
- Internal spermatic fascia
Describe the structure of the testes
Tough fibrous outer layer called tunica albugeniea
Tunica vaginalis is a peritoneal sac covering the testes. It has two layers: visceral and parietal and between them exists serous fluid
What spinal level do the testicular arteries arise?
L1/L2
What is the peritonisation fo the testicular arteries?
Retroperitoneal
What structures do the testicular arteries cross before entering the inguinal canal?
Psoas major and IVC
What is the pampiniferous venous plexus?
A network of 8-12 anastomosing veins surrounding the testicular artery in the scrotum that are important in the heat transfer
Where do the testicular veins drain into?
Left - Left Renal Vein
Right - Inferior Vena Cava
What two groups of lymph nodes drain the testes?
Para-aortic and inguinal nodes
What is the vas deferens?
Muscular tube which arises from the caudal epididymis and enters the pelvis over the external iliac vessels
Where does the vas deferens terminate?
Joining the duct of the seminal gland to forth ejaculatory process
What are seminal glands?
Paired structures on the posterior aspect of the bladder
What is the funciton of the seminal glands?
Secrete a thick, yellow, alkaline fluid which comprises of protein, sugar and semen
Where is the prostate anchored?
To the inferior neck of the bladder and surrounds the prostatic urethra
What does the prostate secrete?
A thick milky and slightly acidic fluid
What are the bulbourethral glands (also known as Cowper’s glands)?
Small, paired structures located in the urogenital diaphragm which empty in to the penile/spongy urethra
What lymph node group drains the prostate?
Internal iliac and sacral
What lymph node group drains the seminal glands?
Internal and eternal iliac nodes
What lymph node group drains the scrotum?
Superficial inguinal nodes
What lymph node group drains the penis?
Superficial inguinal nodes
What are the histological features of a testis sample?
Convoluted tubules in various planes
4-8 layers of celss
Spermatozoa in the lumen
Leydig cells in the interstitium
What are the histological features of a prostate sample?
Serous alveoli with infolding epithelium
Trabeculae of muscular stroma
Amorphous eosinophilic masses called corpora amylacae in the alveoli in older men
What are the histological features of a seminal vesicle sample?
No sperm in lumen
Highly recessed and irregular lumen forming crypts and cavities giving a honey-combed appearance
Well-developed muscular externa
What are the histological features of a ductus deferens sample?
Lumen stellate in shape
A thick walled muscular tube
Epithelial lining and its supporting lamina propriety are thrown into longitudinal folds
What reproductive organs comprise the female reproductive system?
Uterus, ovaries, fallopian tubes, vagina
What comprises the birth canal?
Vagina, cervix and vulva
What are the three layers f the uterus?
Perimetrium, myometrium, endometrium
As pregnancy advances, the uterus has what two sections?
Upper and a lower
What is the normal position of the uterus?
Anteverted and antiflexed
What is anteversion?
Refers to the positions of the uterus in which its long axis is bent forward on the long axis of the vagina
What is anteflexion?
Refers to the position in which the long axis of the body of the uterus is bent forward along the axis of the vagina at the internal os
What are the fornices of the vagina?
Superior portions of the vagia extending into recesses
Why is the posterior fornix clinically relevant?
It is an important surgical route into the rectouterine pouch and can be a common site of metastasis
What is the main ligamentous support of the uterus?
Cardinal ligament (lateral cervical ligament)
Apart from the pelvic fascia, what other structure provides important support of the uterus?
Bladder
What are the sections of the Fallopian tube called?
Starting at the ovarian end:
Fimbriae
Infundibulum
Ampulla
Isthmus
The ovary is held in place by which two ligaments?
Suspensory ligament - from ovary to pelvic wall
Ovarian ligament - from uterus to ovary
The ovarian ligament is covered by what flat ligament?
Broad ligament
What two major branches of the abdominal aorta supply the gonads and genitalia?
Internal iliac and Gonadal arteries
Where do the gonadal arteries originate?
L2 level
In females, the ovarian artery descends within what structure and freely communicates with what other major pelvic artery?
Suspensory ligament; uterine artery
Where does the uterine artery cross over the ureter?
Lower level of the ischial spine at the junction of the cervix and lateral part of the fornix of the vagina
Lymph from the labia and distal vagina drain into which nodes?
Deep inguinal and external iliac nodes
Lymphatic drainage of the ovaries is achieved by what nodes?
Para-aortic
Describe the lymphatic drainage of the uterus
Fundus and upper part - para-aortic
Body - internal iliac
Uterine cervix - internal iliac and sacral
Describe the structure of the breast
Each breast contains 15-25 lobes with tubule-acinar glands (parenchyma) and stroma (connective tissue)
Describe the position of the breasts anatomically
Extend vertically from the 1st to the 6/7th rib and horizontally from the lateral border of the sternum to the mid-axillary line
What are the deep surface relations of the breast?
Pec. major, serrates ant., intercostal muscles, rectus abdomens, external oblique
What arteries supply the breast?
Branches of the subclavian/axillary (internal and lateral thoracic arteries)
What lymph groups drain the breast?
Lateral quadrants - axillary nodes
Medial quadrants - parasternal nodes
Superior quadrants - supraclavicular nodes
What is the clinical significance about lymph drainage of the breast?
Lymph from the medial side of one breast can drain into nodes on the medial side of the contralateral breast - thus providing a route for infection/cancer
What are the three distinct phases of uterine histology?
Proliferative and secretory and menses
What hormone facilitates the proliferative phase of the uterus; what are its features histologically?
Follicle Stimulating Hormone (oestrogen for vascularisation)
Thick endometrium, renewed connective tissue, glandular structure and ehlicrine arteries
What hormone facilities the secretory phage and what are its features?
Luteinising Hormone
Cork-screw endometrial glands, filled with glycogen
What hormones are responsible for the beginning of menses?
Decreasing levels of Luteinising Hormone and progesterone
What feature are histologically recognisable in menses?
Lumen, degeneration of the endometrium and ears of blood leakage as spiral arterioles degenerate
What ype of organ is the placenta?
Foetomaternal (common to both the foetus and the mother)
What embryological structure does the placenta develop from?
The placenta develops from the trophoblast following implantation of the blastocyst
What are the features of the maternal side of the placenta?
Rough and spongy
What are the features of the foetal side of the placenta?
Smooth and bears the attachment of the umbilical cord
What are the four main functions of the placenta?
Gaseous exchange
Excretion of waste
Immunity
Endocrine
Describe the structure of the umbilical cord
Two umbilical arteires, one vein, one allantoic duct and surrounded by Wharton’s jelly
What type of blood do the umbilical arteries and vein transmit?
Vein - oxygenated
Arteries - deoxygenated
Where does the perineum lie?
Inferior to the pelvic diaphragm
What are the structures of the perineum?
Exrtenal genitalia, perineal muscles, anal canal
The perineum is divided into what two triangles? What demarcates these?
Urogenital triangle and the anal triangle; the imaginary line between the two ischial tuberosities
What are the four main muscles of the perineum?
External anal sphincter
Transverse perineal muscles
Bulbospongiosus
Ischiocavernosus
What are the action and innervation of the external anal sphincter?
Continence (faecal); branch of the pedundal nerve
What are the action and innervation of the bulbospongiosus?
Males: empties urethra
Female: clenches vagina; pudendal nerve
What are the action and innervation of the ischiocavernosus?
Assists bulbospongiosus; pudendal nerve
What are the action and innervation of the superficial and deep transverse perineal muscle
Fixation of the perineal body; pudendal nerve
What are the action and innervation of the external urethral sphincter?
Continence (urinary); pudendal nerve
What is the perineal body?
The raphe of fibromuscle which denotes the boundary between the anal and urogenital triangle
Which muscles converge towards the perineal body?
External anal sphincter, bulbospongiosus, elevator ani, transverse perineal
What are the perineal pouches?
Superficial and deep perineal pouches are fascia-limited, potential spaces traversed by the urethra
What is the clinical significance of the perineal pouches?
They can become infiltrated following traumatic surgical injury of the urethra
What urethral sphincter is found in the deep perineal pouch?
Internal
What urethral sphincter is found in the superficial perineal pouch?
External
How does the superficial perineal pouch relate to the urogenital membrane?
Antero-inferior and surround the external genitalia
How does the deep perineal pouch relate to the perineal muscle?
Surrounds it
What are the three main parts of the urethra?
Prostatic, membranous, spongy
Which is the widest part of the urethra? Which is the narrowest?
Prostatic; membranous
What is the function of the ischio-anal fossa?
Allows room for the anal canal to expand during defaecation
What characteristic of the ischia-anal fossa makes it susceptible to pathology? What lifestyle can predispose you to this?
Fatty tissue is susceptible to abscess and can result in fistulae; sedentary lifestyle
What neurovascular bundle enters the ischio-anal fossa?
The pudendal nerve and vessels (artery and vein)
What foramen does the pudendal bundle enter the ischia-anal fossa through?
Lesser sciatic foramen
What structures do the pudendal neurovasculature supply?
Sensory external genitals and motor supply to the pelvic muscles
