Anatomy Flashcards
1
Q
What are modalities are used to image the pelvis?
A
- MRI
- U/S
2
Q
What are the advantages and disadvantages of MRI?
A
- No Ionising radiation
- Better soft-tissue contrast
- useful for staging cancers/tumours
- Longer examination time (45 mins)
- More expensive
3
Q
When would a CT be used to image the pelvis?
A
- In an emergency or acute settings
- produces a lot of artefact due to the pelvic girdle
- also has poor soft-tissue contrast
4
Q
What key structures are in the male pelvis at this level?
A
- Prostate
- Rectum
- Ischio-rectal fossae
- cancers of the rectum erode into this area - looking for a clean line of fat (not present in this image)
- Obturator internus
- provides lateral rotation and the abduction of the hip
5
Q
What key structures are in the male pelvis at this level?
A
- rectus sheath at the front
- the bladder
- the seminal vesicles (bowtie)
6
Q
What key structures are in the female pelvis at this level?
A
- Uterus
- Endometrium (looks bright white in T2)
- Myometrium (same density as skeletal muscle)
- Junctional zone
- if this is narrowed or thickened –> suggest endometrial cancer
- Ovary- fluid-filled and bright on the T2 weighted image
- Bladder
- Cervix
7
Q
What can be seen in this Sagittal MRI of the female pelvis?
A
- Bladder
- Uterus (OM)
- (anteverted uterus in this image- no functional difference)
- Cervix
- Rectum
- the sacral space should have a clear line fo fat - sigmoid colon cancer can infiltrate into this space
8
Q
How are the ovaries imaged?
A
- HSG: Hysterosalpingogram
- very similar to a smear test
- you want to see a blurring from the contrast - shows the infundibulum is clear
- HSG: Hysterosalpingogram
9
Q
The Peritoneum in the female pelvis - sagittal MRI -
A
- The peritoneal reflections in the pelvis consist of the peritoneum wrapping around
- the bladder
- the uterus
- the rectum
- this creates two pouches/spaces
- vesicouterine pouch
- rectouterine pouch (pouch of Douglas)
- the pouches are a common site of infection/ abscess
10
Q
The peritoneum in the male pelvis - sagittal MRI -
A
- there is only the vesicorectal pouch - as the perineum wraps around the bladder and down the front of the rectum
- common site of abcist formation
11
Q
What types of Ultrasound imaging can be down to image the pelvis?
A
- Transabdominal
- Transvaginal
- Transrectal
12
Q
What is measured in an Ante-natal ultrasound?
A
- 12 week scan (dating scan)
- 20-week scan (looking for congenital abnormalities)
- growth rate: crown-rump length, head measurements etc.
13
Q
How is the vascular anatomy of the pelvis?
A
- Magnetic Resonance Angiography (using contrast (e.g gadolinium), similar to MRI)
- Duplex U/S (doppler effect)
- plots the wave form blood flow of the artery
- CT angiogram
- iodinated intra-venous contrast through the peripheral cannula with imaging
- Angiography (direct catheter angio)
14
Q
What type of imaging is this?
A
Duplex ultrasound of the right renal artery
15
Q
What type of imaging is this?
A
CT Angiogram
16
Q
What type of imaging is this?
A
Catheter angiogram
17
Q
At what level does the aorta and vena cava bifurcate?
A
- aorta is L4
- vena cava is L5:
- the right CIA crosses the origin of the Left CIV –> left iliac DVT
- May-Thurner syndrome
18
Q
Anatomy of the Internal Iliac artery
A
- Divides into the Anterior and posterior division
- the posterior division is iliolumbar
- lumbosacral and superior gluteal
19
Q
What pathology is this?
A
Unifying Pseudoaneurysm of the Right Common Femoral Artery
- the blood vessel isn’t dilating there is just a hole in it
20
Q
Labelled anatomy of the sagittal female pelvis
A
21
Q
What is the blood supply and nerve supply of the ovaries?
A
- supplied by the ovarian artery and the vein within the suspensory ligament
- Nerve supply of the ovarian plexus
22
Q
Describe the structure of the uterine tube
- VAN
A
- Infandibulum
- Ampulla
- often the site of fertilization
- Isthmus
- Uterine
- VAN
- V: ovarian arteries pass laterally and drain into the left renal vein (on the left side), drain into the inferior vena cava (on right side)
- A: ovarian artery
- N: sympathetic supply from the ovarian nerve and parasympathetic from the pelvic splanchnic nerve
23
Q
Where is pain from the ovaries felt in which dermatome region?
A
- ischaemia and pain which is referred to the dermatome region of T10
24
Q
Describe the structure of the uterus
A
- made up of the fundus, body of the uterus and cervix
- Formed of 3 layered walls
- Perimetrium – outer serous wall covering the uterus
- Myometrium – thick muscular layer, responsible for the process of parturition
- Endometrium – inner mucous layer; site of implantation; thickness changes through menstrual cycle
25
What is this innervation and supply of the uterus?
* Innervation: symp from the hypogastric plexus (along uterine artery); parasymp via the pelvic splanchnic n.
* Arterial supply: uterine artery
* Venous drainage: via the uterine plexuses to the internal iliac veins
* Touch and Pain (birth): via somatic afferents to S2-S4
26
What are the key uterine ligaments?
* Ligament of ovary
* **Round ligament of uterus**
* remnants of the gubernaculum
* from the uterus to the labia majora- the route the process the ovaries would have taken if it was male and would have formed the scrotum
* women who are pregnant may report a pulling
* **Broad ligament**
* covers over the uterine body and ovaries
* forms the **mesosalpinx** when it pinches around the uterine tube
* forms the **mesovarium** when it pinches around the ovaries
* Transverse cervical ligament
* Uterosacral ligament
* **Peritoneal pouches**- trapped fluid where infection can take place
* Vesicouterine pouch
* Rectouterine pouch
27
Describe the structure of the vagina
- VAN
* musculomembranous tube 7-9cm long
* has to recesses superiorly
* Posterior fornix
* Anterior fornix
* VAN
* V: drainage though the vaginal plexus to the **internal iliac veins**
* A: by branches from the **internal iliac arteries**
* N: autonomic nerves, sensory nerves convey pain messages to an area of the abdomen supplied by **T12 and L1 spinal nerves**
28
Review the vasculature of the female reproductive tract organs
29
What structures make up the external female genitalia?
Consists of:
* **Mons pubis,**
* **Labia majoria,**
* **Bulb of vestibule**
* **Clitoris**- erectile organ consists of: root, body and glans
* **Bulb of vestibule**- erectile tissue over bulbospongiosus muscle
* **Vestibular glands**- secrete mucus
* **Labia minora** encloses the vestibule (openings for vagina and urethra) and the clitoris
* Blood supply/drainage: _pudendal artery (erectile) & vein_
* Innervation: branches of _genitofemoral and pudendal_ n (e.g. dorsal n of clitoris)
30
What changes happen to the female reproductive tract during pregnancy?
* Uterus expands from 50g to 950g.
* Uterus extends to the xiphisternum.
* Centre of gravity is altered-increased lumbar lordosis.
* Sacroiliac joint and pubic symphysis relaxes
* With uterine expansion the ovaries and uterine tubes are displaced laterally. The cervix becomes softer and swollen.
31
What is the VAN of the testis?
* V: form the pampiniform plexus
* forms around the testis that keep it cool
* A: supplied by the testicular artery
* N: spermatic plexus
32
Describe the structure of the testis
* The dorsolateral surface of each testis is overlain by the **epididymis** which has an expanded ‘head’ connected to the superior part of the testis.
* The **seminiferous tubules** in each testis drain, via a series of tubules, into the single duct of the epididymis at the head of the epididymis.
* In the epididymis, the duct of the epididymis is tightly coiled and it continues as the uncoiled **ductus (vas) deferens** at the inferior pole of the epididymis.
33
What are the three fascial layers of the testis?
these are continuous with the layers of the surrounding spermatic cord
* The outer layer, the **external spermatic fascia,** is derived from the _external oblique aponeurosis._
* The middle layer, the **cremaster muscle and fascia**, is derived from the _internal oblique and transversus abdominis_.
* the cremaster muscle lifts the testis back into the abdomen when it isunder threat or if it's cold
* The inner layer, the **internal spermatic fascia**, is derived from _transversalis fascia_.
34
What is the microscopic structure of the seminiferous tubules?
* Each testis is subdivided into approx. 250 pyramid-shaped lobules contain seminiferous tubules
* Function- production of spermatozoa (spermatogenesis)
* Structure- highly tortuous, lined by seminiferous epithelium
* Tunica propria-loose C.T, fibroblasts and myoid cells
* Stroma-surrounds seminiferous tubules, loose C.T, vascular and houses small clusters of large interstitial cells of Leydig
* _Sertoli Cells_
* Stretch from basal lamina to the lumen, linked by tight junctions
* perform many roles in the testis
35
What is the role of Sertoli Cells?
* Stretch from basal lamina to the lumen, linked by tight junctions
* Enfold developing spermatozoa-acting to
* Protect them from antibodies in the blood
* Provide nutrients
* Phagocytose excess cytoplasm
* Secrete androgen binding protein
* Secrete inhibin
* Add fluid to the lumen
36
What is the VAN of the Ductus Deferens?
* Arteries: those that primarily supply the lower bladder – inferior vesical– and rectum – middle rectal.
* Venous: blood follows the arteries and so have the same name.
37
What is the function of eh vas deferens and where is it found?
* the tube continuous with epididymis that is joined by duct seminal gland =\> ejaculatory duct
* The ductus deferens (vas deferens) ascends on the medial side of the epididymis,
* enters the spermatic cord and then passes through the inguinal canal on its way to the urethra.
* Spermatozoa, with their accompanying fluid (from the seminal vesicles and prostate), are then discharged by a closed duct system
38
What are the accessory glands of the Ductus deferens?
- what are their roles?
* **Seminal vesicles** – just inferior to rectovesical pouch, _secretes alkaline fluid + fructose + coagulate_
* **Prostate** – secretes prostatic fluid (20% total volume)
* **Bulbourethral glands** – pea sized glands; a.k.a. Cowpers glands; located inferior to prostate; _secretion assists lubrication of ducts and removes any urine that would have been in the tract_
39
What is the VAN of the Prostate?
* Supplied by prostatic arteries and veins,
* Innervated by sympathetic from _inferior hypogastric_ and parasympathetic from _pelvic splanchnic nerves_
40
What is the VAN of the Seminal Vesicles?
* Wall of sac contains smooth muscle, which when stimulated by sympathetic nerves expels fluid out-ejaculation.
* Blood: Inf vesicle + prostatic vessels (int iliac a)
41
What is the VAN of the bulbourethral gland?
* inferior vesicles + prostatic vessels and the internal iliac arteries
42
What is the VAN of the penis?
* A: Internal pudendal arteries
* V: External pudendal veins.
* N: by S2/4 Pudendal nerve, dorsal nerve to penis, ilioinguinal nerve
43
Describe the gross anatomy of the penis
* Consists of
* root,
* body and glands,
* the body contains 3 cylindrical bodies
* Paired corpora cavernosa and 1 corpus spongiosum
44
What are the various parts of the male Urethra?
* Prostatic
* Membranous
* Penile
45
Explain the stages of Erection Emission and Ejaculation in males during sexual stimulation
* **Erection-** Deep arteries-supply the corpora-in flaccid state A/V shunts
* Increased parasympathetic nerve supply, increases blood flow- diverted to vascular spaces
* this causes increased pressure in erectile tissue thus decreasing venous return
* **Emission-** semen is delivered to the prostatic urethra, prostatic fluid added.
* Emission results from sympathetic activity.
* **Ejaculation**-semen expelled through the urethra
* Inhibition of sympathetic supply-return to flaccid state
46
What clinical pathologies arise from the male reproductive tract?
* Testicular Torsion
* Cryptorchidism
* Patent processus vaginalis
* Hydrocele
* Hematocele
