Histology Flashcards
After the descent of the ovary, the gubernaculum becomes the ___________________.
Ovarian ligament and round ligament
The round ligament attaches to which structures?
Labia majora (through inguinal canal) and uterus
True or false: The suspensory ligaments of the ovary are parts of the gubernaculum.
False.
They are peritoneal folds that contain the ovarian vessels
What is the surface of the ovary called and what is it composed of?
Tunica albuginea
- composed of connective tissue fibres and fusiform cells between
What is the function of the ovarian stroma?
1) Structural support
2) Microenvironment for development and function of ovarian follicles
What are the 5 components of an ovary?
Superficial to deep:
1) Tunica albuginea
- connective tissue + fusiform cells
2) Hilum
- entry/exit of vessels
3) Cortex
- ovarian follicles
4) Stroma
- in outer cortex and inner medulla
- structural support + ovarian follicle microenvironment
5) Medulla
- loose connective tissue, abundant vasculature, lymphatics and innervation
The primordial germ cells are precursors to the gametes that originate in the _____________ then migrate to the _________________ where they undergo multiple mitotic divisions.
Yolk sac wall near allantois → through dorsal mesentery → genital ridge → undergo mitotic divisions
The tunica albuginea of the ovaries are covered by _________________ which is composed of ________ cells.
Germinal epithelium
- simple squamous layer
- visceral peritoneum that covers ovaries
True or false: The germinal epithelium of the ovaries give rise to germ cell.
False.
What is the histological appearance of a primordial follicle?
Primary oocyte surrounded by single layer of flattened cells
What is the histological appearance of a primary follicle?
Deep to superficial:
1) Primary oocyte
2) Zona pellucida
- thick homogenous layer of glycoprotein and acid proteoglycans
3) Multiple layers of Follicular cells
4) Theca cells
- outermost stromal cells
- synthesises androgens
What is the most common site for ovarian cancers?
Germinal epithelium (90%)
Which layer of the ovary contain species-specific receptors for spermatozoa?
Zona pellucida
What is the histological appearance of a secondary follicle?
Superficial to deep:
1) Primary oocyte
2) Antrum
- fluid-filled follicular lumen
3) Inner granulosa cells
4) Outer theca cells
What is the histological appearance of a graafian/mature follicle?
1) Primary oocyte off-center
2) Zona pellucida
3) Corona radiata
4) Cumulus oophorus (crowded granulosa cells)
5) Follicular antrum
6) Outer granulosa cells
What is the histological appearance of a Corpus albicans?
White scar tissue on the surface of the ovary
What is the appearance of the corpus albicans on ultrasound?
Small, lobulated, hyperechogenic intra-ovarian lesion
What is the largest and longest part of the fallopian tube?
Ampulla
What is the histological appearance of the fallopian tube?
Lumen to basal:
1) Mucosa lined by simple columnar epithelium
- mucosa have multiple longitudinal folds
2) Well defined inner circular, outer longitudinal muscular layer
3) Outer serosa layer
The oviduct epithelium consists of 2 important cell types:
i) _______________________
ii) _______________________
i) Ciliated cells
- ciliary movement aids in movement of ovum toward uterus
ii) Secretory (peg) cells
- non-ciliated often dark stained cells
- secretes glycoproteins for the ovum’s nutrition
What are the 3 layers of the uterine wall?
1) Endometrium
- inner most
- lined by simple columnar epithelium
- numerous tubular glands
2) Myometrium
- middle layer
- highly vascularised, thick, smooth muscular layer in poorly-defined layers w bundles of fibres interwoven in varying directions
- induces uterine contractions
3) Perimetrium
- outer connective tissue
- some parts adventitial, others serosal
What are the layers of the endometrium?
1) Stratum functionale
- proliferates, secretes then sheds during menstrual cycle
2) Stratum basale
- closer to myometrium
- does not shed, regenerates endometrium for next menstrual cycle
True or false. The layers of the endometrium are separated by a basal membrane.
False.
There is no discrete border between the 2 layers, but can be differentiated as stromal tissue is more cellular than basal layer
Describe the arterial supply of the endometrium.
Bilateral uterine arteries penetrate myometrium
→ Circumferential arcuate arteries → branch
→ radial arteries → transverse myometrium
→ spiral arteries + basal arteries in endometrium
What are 2 differences between spiral and basal arteries of the endometrium?
1) Spiral respond to hormones, basal don’t
2) Spiral constrict @ end of cycle → ischemic phase → mensus
Basal support basal endometrial layer → proliferative cells for endometrial growth
What are the histological changes in the early vs late proliferative phase?
Early:
- tubular glands w columnar cells and surrounding dense stroma proliferate
Late:
- endometrium thickens further
- glands coil and become closely packed
What is the histological appearance of the endometrium in secretory/luteal phase?
Glands are complexly coiled as endometrium reaches max thickness (only stratum functionale thickens)
- saw-tooth glands w glycogen and glycoprotein rich secretions in lumina
True or false: During pregnancy, under the influence of hormones, the myometrium increases in size through both hypertrophy and hyperplasia.
True
What is endometriosis?
Painful condition where tissue lining uterus grows outside uterine cavity
→ chronic inflammation + complications (eg. adhesions, pelvic pain, subfertility)
What are 3 signs and symptoms of endometriosis?
1) Dysmenorrhea
2) Dyspareunia (pain during sex)
3) Pain during urination or bowel movements
4) Bleeding between periods
5) Infertility
What is a “chocolate cyst”?
Endometrioma
The endocervix is lined by ___________ epithelium whereas the ectocervix is lined by _______________ epithelium.
Endocervix: simple columnar epithelium (w thick LP)
Ectocervix: Non-keratinised stratified squamous epithelium
What is the main histological difference between the cervix and uterus?
Cervix contains ««< smooth muscle compared to uterus
Which part of the cervix can nabothian cysts be found?
Ectocervix (can only form from glands on stratified squamous epithelium)
What is the other name for the transformation zone between the endocervix and ectocervix and what is its clinical significance?
Squamo-columnar junction
- high risk of malignant change
True or false: Vaginal mucus/secretions are produced by glands within the walls of the vagina.
False.
No glands within vaginal wall, all mucus produced by cervical glands
What are the layers of the vagina?
Lumen to basal:
1) Mucous layer
- non-keratinised stratified squamous epithelium
2) Lamina propria
- contains elastic and collagen
3) Muscular layer
- ill-defined smooth muscle layer
4) Adventitia
- connective tissue layer mostly elastic fibres
The cells of the vaginal wall typically contain a large of cytoplasm as it _________________. This is why the epithelial cells appear slightly vacuolated due to __________ which is removed during histological fixation.
Contains glycogen
Why is the vagina physiologically acidic?
Estrogen → ↑ epithelial glycogen in vagina
→ commensal Lactobacilli convert glycogen into lactic acid
What are 2 histological differences between the labia minora and labia majora?
1) Epithelium
Majora: keratinised
Minora: non-keratinised
2) Hair follicles and adipose tissues
Majora: present
Minora: absent
What type of glands are mammary glands?
Modified apocrine sweat glands
The glandular elements of the breast are __________________ and thus modified apocrine sweat glands consisting of __________________________.
Branched tubulo-acinar glands
- multiple acini lined by epithelial cells surrounded by myoepithelial cells
What is the stroma of the breast made of?
Connective and adipose tissue
What kind of epithelium lines the nipple and areola?
Stratified squamous
What is the term for ligaments within the stroma of the breast?
Ligaments of Cooper
Which cells in the breast produce milk?
Luminal cells in terminal duct lobular units
What cells form the innermost layer lining the ducts and acini of the breast?
Luminal cells
What are 3 histological features of luminal cells of the breast?
1) Cuboidal to columnar
2) Small, round to oval nuclei w inconspicuous nucleoli
3) Moderate amount of eosinophilic cytoplasm
4) Small have hormonal (estrogen/progestrone) receptors
What are the main precursor cells for malignant breast cancers?
Luminal cells
What cells form the outermost layer between the luminal cells and basement membrane of the breast?
Myoepithelial cells
What is the function of myoepithelial cells in the breast?
1) Help in contraction for milk ejection during lactation
2) Produces basement membrane (under oxytocin influence)
What are 2 histological features of myoepithelial cells in the breast?
1) Flattened
2) Small round nuclei
3) May become spindled with aging
How do prolactin and oxytocin work together for breastfeeding?
Prolactin (from AP) stimulate milk secretion by luminal cells in acini/alveoli
Oxytocin stimulate myoepithelial contraction surrounding alveoli deep in breast → squeeze secreted milk into larger ducts
What are the 2 types of connective tissue in the breast and how are they different?
1) Intralobular:
- loose
- more vascular
- more cellular (fibroblasts, plasma cells)
2) Interlobular:
- dense
- more collagen
- less cellular
What type of tissue replaces fibrous tissue in the breast with age?
Adipose tissue
What is the clinical significance of the ratio of ductal/fibrous tissue to adipose tissue in a woman’s breast?
Determines mammographic density → ↓dense → ↑radiolucency → ↑sensitivity to calcification/small masses with age
What are 4 histological differences between a breast in inactive and active breast?
Inactive:
1) Only 2 layers of epithelium
2) Dense irregular interlobular connective tissue between quiescent lobules that have few ducts surrounded by less dense intralobular connective tissue
Active:
1) ↑glandular tissue
2) ↓connective tissue
3) ↑epithelial and myoepithelial cells (form secretory alveoli)
4) Epithelial cells have large clear areas of apical cytoplasm full of glycogen and lipid
5) ↑plasma cells in intralobular connective tissue (secreting IgA into milk)
Describe the superficial and deep lymphatic drainage of the breast
1) Superficial lymphatics drain skin (except nipple an areola)
2) Deep lymphatics drain parenchyma + skin of nipple and areola
What are the components of a mammary gland?
1) Parenchyma
- non-lactating/lactating
2) Ducts
- lactiferous, interlobar, intralobar, alveolar
3) Stroma
- intralobular/interlobular
Describe the drainage of the breast in quadrants.
1) Upper medial → Internal mammary
2) Lower medial → (i) Internal mammary (ii) Subperitoneal → ovary
3) Upper lateral → Axillary → Deltopectoral → Apical
4) Lower lateral → (i) Axillary → Deltopectoral → Apical (ii) Posterior intercostal
What is the lymphatic route of a metastatic breast cancer spreading to the ovaries?
Lower medial quadrant → subperitoneal lymph plexus → ovary
What is the lymphatic route of a metastatic breast cancer spreading to the contralateral breast?
Medial breast quadrants → internal mammary lymph nodes → internal mammary lymph nodes on other side → other breast
What causes the “Peau d’orange” breast appearance?
Lymphatic blockage → (i) edema (ii) retraction of ligaments of cooper → pitting
What is the lining of the scrotal skin?
Keratinised stratified squamous epithelium
The skin of the scrotum is often (darker/lighter) than the skin in neighbouring regions.
darker
The skin of the scrotum contains long and thin hairs and contains ______________ and thus a common site for sebaceous cysts. It also (has/does not have) subcutaneous layer of adipose tissue.
Contains sebaceous and apocrine glands
No subcutaneous layer of adipose tissue
The dartos muscle is a sheet of _______ muscle innervated by___________________.
Smooth muscle
- by sympathetic fibres from genital branch of genitofemoral nerve (L1/2)
The cremaster muscle is a ____________ muscle innervated by _______________________.
Skeletal
- genital branch of genitofemoral nerve
How do the dartos and cremaster muscles maintain scrotal temperature homeostasis?
Cold → muscles contract → draw testes closer to body
→ ↓SA of scrotal skin exposed to cold environment
Warm → muscles relax → tests hang further away → ↑SA of scrotal skin exposed to external environment → ↑heat dissipation
What is the major lymphatic drainage pathway of the perineal structures?
Inguinal lymph nodes:
1) Horizontal/superficial
- directly below inguinal ligament & extends horizontally
2) Vertical/deep
- along great saphenous vein & extends vertically
True or false: It is normal for 1 testis to be bigger than the other and thus for the right testicle to usually hang lower than the left.
False.
Normal but left lower than right
Where is testosterone mainly produced in females?
Peripheral tissues
Describe the arterial supply of the testes.
Testicular arteries from abdominal aorta
Describe the venous drainage of the testes.
Right → IVC
Left → L renal vein → IVC
Describe the lymphatic drainage of the testes.
Follows testicular arteries → para-aortic nodes
What is the primary function of the pampiniform plexus?
Regulate temperature of the testes
- countercurrent heat exchanger
- cools arterial blood before reaching the testes
Where does the spermatic cord terminate?
Posteromedial border of the testis
What is cryptorchidism?
Undescended testis
What are the contents of the spermatic cord?
1) Vas deferens
2) Testicular artery
3) Pampiniform plexus
4) Genital branch of genitofemoral nerve
5) lymphatics
6) ANS fibres
What is the surgical correction of cryptorchidism?
Orchidopexy/Cryptorchidopexy
What is a variocele?
Enlarged pampiniform plexus veins in scrotum due to valvular defects
“Bag of worms”
What are 3 symptoms of a varicocele?
1) Dull to sharp discomfort
2) Worsening pain w standing or physical exertion esp for long hours
3) Worsen over course of the day
Describe the superficial reflex arc of the cremasteric reflex.
Afferent:
Sensory by ilioinguinal & femoral branch of genitofemoral nerve
Spinal cord:
L1-2
Efferent
- Genital branch of genitofemoral nerve
What are the risks of an cryptorchidism?
1) Infertility
2) testicular cancer
3) hernias
4) testicular torsion
What is used to diagnose testicular torsion?
Cremasteric reflex
Describe the gross structure of the testis.
Superficial to deep:
1) Tunica albuginea
2) Testicular lobules → seminiferous tubules
3) Septae (inbetween testicular lobules)
4) Rete testis
5) Efferent ductules
In which part of the testis does spermatogenesis occur?
Seminiferous tubules
The tunica albuginea which subject the seminiferous tubules to rhythmic contractions and is composed of which cells?
1) Fibroblasts
2) Myofibroblasts
3) Very few smooth muscle cells
What are the 2 layers of the tunica albuginea?
1) Tunica vasculosa (inner)
- connective tissues, lymphatics, blood vessels
2) Tunica vaginalis (outer)
What is the histological appearance of the spermatogonium?
Large round nucleus with condensed chromatin, peripheral nucleoli and nuclear vacuole
What is the histological appearance of a primary spermatocyte?
Copious cytoplasm, large nuclei, thin-thread chromatin
What is the histological appearance of secondary spermatocytes?
Smaller than primary spermatocytes, with dispersed chromatin
Sertoli cells are ________ cells with extensive _______________ that surround and support adjacent spermatogenic cells.
Columnar, extensive apical and lateral processes
Which cells form the blood testis barrier?
Sertoli cells
What are 4 functions of sertoli cells?
1) Structural support
2) Nutritional support
3) Secrete important substances: inhibin B, Androgen-binding protein, anti-mullerian hormone
4) Phagocytic
- clean up cellular debris
Where are leydig cells found in the testes?
In interstitial supporting tissues be the seminiferous tubules
What is the characteristic feature of leydig cells?
Abundant SER for steroid hormone synthesis
What is the function of leydig cells?
1) Testosterone synthesis
2) Hormonal regulation
- produce testosterone in presence of LH
What are the parts of the epididymis and their respective functions?
1) Head
- receives spermatozoa from testis via efferent ductules
2) Body
- facilitates functional maturation of spermatozoa (where they develop motility)
3) Tail
- where sperm are stored until ejaculation
The epididymis is a long coiled tube that transports sperm from ___________ to ______________.
From testes to vas deferens
Where in the scrotum is the epididymis located?
In scrotum along superior and posterolateral side of each testis
What is the lining epithelium of the epididymis?
Pseudostratified columnar epithelium
What are the 3 cell types of the epididymis?
1) Principal cells
- tall columnar cells
- stereocilia
- faciliates absorption and secretion functions
2) Basal cells
- small, round cells near basement membrane
- produces new cells
3) Smooth muscle layer
- increases from single later @ proximal end to triple layer @ distal end
Principal cells form most of the epithelium and have long stereocilia. What is their function?
Help absorb excess fluid and dead/defective sperm
How long does a sperm usually take to pass through the epididymis?
2-4wks
The vas deferens is a long, thick-walled muscular tube with a relatively small lumen that transports sperm from __________ to ______________.
Epididymis to prostatic urethra
What is a vasectomy?
Permanent sterilisation method via cutting and tying the vas deferens on either side.
The lumen of the vas deferens is lined by what kind of epithelium?
Pseudostratified columnar epithelium
What are the layers of the vas deferens?
Lumen to basal:
1) Pseudostratified columnar epithelium (w few stereocilia vs epididymis)
2) Lamina propria
- both fold to allow expansion
3) Thick muscular layer:
a) inner and outer longitudinal
b) middle circular
What is the major energy source for spermatozoa?
Fructose
What is the main function of the secretions of the bulbourethral glands?
1) Contribute to final volume of semen
2) Lubricates urethra and tip of penis
Seminal vesicles contribute up to 70-80% of seminal fluid containing ___________________.
1) Protein
2) Mucus
3) Fructose
4) Prostaglandins
Where are the seminal vesicles located?
Below posterior wall of urinary bladder
What is the function of prostaglandins in semen?
1) Aid in sperm movement
2) Soften mucus of cervix
Why do the lumen of seminal vesicles have a “honeycomb appearance” at low magnification?
Lumen are highly irregular
What is the lining epithelium of the seminal vesicles?
Pseudostratified columnar epithelium
What are the histological features of seminal vesicles?
1) Pseudostratified columnar epithelium
2) Lamina propria
- w blood vessels, lymphatics, elastic fibres
3) Primary, secondary and tertiary folding of mucous membrane
4) Inner circular and outer longitudinal layers
What are the components of prostatic fluid?
1) Zinc
2) Citric acid
3) Calcium
4) Phosphates
5) Other enzymes essential for sperm health and motility
What is PSA and why is it used in cancer screening?
Androgen-regulated serine protease produced by both prostate epithelial cells and prostate cancer
- usually liquifies semen to facilitate sperm swimming
- normally, small amounts leak into vasculature → elevated levels → abnormal glandular mucosa (usually due to prostatic cancer or inflammation)
The prostate gland is composed of ____________ glands with a surrounding ______________.
Tubuloacini/alveolar glands
Surrounded by prostatic stroma
- fibromuscular w abundant smooth muscle cells admixed with fibroblasts, blood vessels and nerves
- NO adipose tissue
What is the lining epithelium of the prostate gland?
Pseudostratified columnar epithelium
What cells rest on the basement membrane of the prostate gland?
Basal cells
- small, round stem cells
What is the unique histological feature of the prostate gland?
Corpora amylacea
- concentrations of prostatic fluid in lumen of some glands in older men
- contain glycoprotein and keratin sulfate
- concentric lamellar appearance
- increase in number and size w age
What are 2 histological differences between corpora cavernosa and corpus spongiosum?
Corpora cavernosa:
- numerous sinusoids lined by endothelial cells
- cavernous spaces separated by trabeculae containing smooth muscle fibres and connective tissue
Corpus spongiosum:
- Fewer and smaller sinusoids
- more elastic tissue
- surrounds urethra
What are the changes to the lining epithelium along the male urethra?
1) Pre-prostatic: transitional
2) Prostatic: transitional
3) Membranous: transitional → pseudostratified columnar epithelium
4) Spongy: Pseudostratified columnar except terminal portion → stratified squamous epithelium
What type of cells make up the urothelium?
Large, polyhedral umbrella cells
- uniquely can stretch and flatten when bladder is full
What are the general layers of the male urethra?
Luminal to basal:
1) Inner epithelial lining
2) Lamina propria
3) Inner longitudinal
4) Outer smooth muscle
5) Outer fibroelastic connective tissue layer
What are Littre’s glands?
Tubulo-acinar glands located within mucosa of male urethra
- pale eosinophilic w clear cytoplasm and flat nucleus
- lubricate urethra
