Histology Flashcards
What is the superficial fibrous cortex of the ovary covered by?
Epithelium
Where do the group of helicine arteries of the ovary enter the hilum from?
The broad ligament
What is the outer epithelium of the ovary?
Simple cuboidal
What is the dense connective tissue of the ovary below the epithelium?
Tunica albuginea
What do germ cells from the yolk sac form when the invade the ovaries and proliferate by mitosis?
Oogonia
When are oogonia formed?
Around week 6
What do oogonia go onto form via meiosis?
Oocytes, aka ova
What is oogenesis?
Development of oocytes, the female germ cells, from oogonia
What is folliculogenesis?
Growth of the follicle, which consists of the oocyte and any associated support cells
What is the apoptosis-based process which cause loss of oogonia and oocytes?
Atresia
When does meiosis initially halt in follicular development?
Prophase I
What happens if an oocyte fails to associate with pregranulosa cells?
It will die
What type of cell are pregranulosa cells?
Squamous prior to growth phase, upon entry to this cuboidal
What is the zona pellucida?
A layer of special extracellular matrix formed between the oocyte and granulosa cells
What is the theca interna?
A layer formed by the transformation of inner layers of the adjacent stromal cells
What does the theca interna do?
Secrete oestrogen precursors which will be converted to oestrogen by the granulosa cells
What forms the theca externa?
Outer layers of stromal cells, they remain fibroblast like
What space filled with follicular fluid begins to form and enlarge in the granulosa layer, forming a secondary follicle?
The antrum
What are the largest antral follicles called?
Graafian follicles
After ovulation what does the follicle transform into?
Corpus luteum
Assuming no implantation occurs, what does the corpus luteum become?
Corpus albicans
What happens to the corpus luteum if implantation occurs?
Placenta secretes HCG which prevents degeneration of CL for a time and maintains progesterone levels, which maintains pregnancy
What are the parts of the uterine tube from outwards to inner?
Fimbria Infundibulum Ampulla Isthmus Interstitial part
Where does fertilisation usually occur?
Ampulla
Describe the ampulla
Folded mucosa and lined by simple columnar epithelium with ciliated and secretory cells
Surrounded further by smooth muscle
What is the lining of the isthmus?
Secretory epithelium with few ciliated cells
How many layers of smooth muscle are there in the ampulla and isthmus?
2 and 3 respectively
What is the uterine wall made up of?
Endometrium
Myometrium
Perimetrium
What is the endometrium?
Inner secretory mucosa which is shed during menstruation.
Made up of tubular secretory glands embedded in a connective tissue stroma
What is the myometrium?
A coat of 3 layers of smooth muscle, combined with collagen and elastic tissue
What is the perimetrium?
An outer visceral covering of loose connective tissue covered by mesothelium
What is the endometrium divided into?
Stratum Functionalis: sheds
Stratum Basalis: regenerates SF
What lines the glands within the epithelium?
Pseudostratified columnar epithelium
What happens to the uterine glands during the secretory phase?
They become coiled with a corkscrew appearance and secrete glycogen
What happens in the uterus during the menstrual phase?
Arterioles in the functionalis undergo constriction, depriving the tissue of blood and causing ischemia, with resultant tissue breakdown, leakage of blood and tissue sloughing
What is the cervix covered by?
Stratified squamous epithelium on its vaginal surface, but transitioning to mucous secreting simple columnar epithelium
What is the cervix made of?
Fibrous connective tissue
How does the secretion of the endocervical glands vary?
Thin and watery in the proliferative phase (allowing the passage of sperm) to thick and viscous following ovulation (preventing the passage of sperm, or microorganisms).
What are the 4 layers of the vagina?
Non-keratinized stratified squamous epithelium. During reproductive years, this layer is thicker and cells are enlarged due to glycogen accumulation.
Lamina propria: connective tissue rich in elastic fibres and thin-walled blood vessels.
Fibromuscular layer: inner circular and outer longitudinal smooth muscle.
Adventitia.
What is mons pubis?
Skin which contains highly oblique hair follicles (produce coarse, very curly hair characteristic of pubic hair), overlying a substantial subcutaneous fat pad, which itself overlies the pubic symphysis.
What is labia majora?
Extensions of mons pubis, similar structure and rich in apocrine sweat glands and sebaceous glands and with small bundles of smooth muscle. Hair follicles on the outer surface, but not the inner
What is labia minora?
Thin skin folds that lack subcutaneous fat and hair follicles, but are rich in vasculature and sebaceous glands that secrete directly onto the surface of the skin.
What is the labia minora covered in?
Keratinized epithelium extends into the opening of the vagina to the level of the hymen, where there is a transition to non-keratinized stratified squamous epithelium.
What makes up the clitoris?
Two tubes of erectile vascular tissue (corpora cavernosa), covered by a fibrocollagenous sheath covered by skin with rich innervation and a thin epidermis.
What is the secretory tissue of the breast made up of?
15-25 lobes
What does each lobe of the breast consist of?
A compound tubule-acinar gland which drains via a series of ducts leading to the nipple
What is found adjacent to the secretory lobules?
Dense fibrous tissue surrounded by adipose tissue
Describe the flow of the duct system of the breast
Terminal ductules> intralobular collecting duct> lactiferous duct> nipple (passing through an expanded duct region near nipple called lactiferous sinus
What epithelium is present in the larger breast ducts?
Columnar
What epithelium is present in the secretory acini of the breast?
Cuboidal or low columnar
What is the nipple covered by?
Highly pigmented keratinised stratified squamous epithelium
What is the core of the nipple made of?
Dense irregular connective tissue mixed with bundles of smooth muscle
Near the surface, what is the lining of the lactiferous duct?
Stratified squamous epithelium
Deep to the surface, what is the lining of the lactiferous duct?
Stratified columnar epithelium
At it’s deepest point, what is the lining of the lactiferous duct?
1 cell thick epithelium
Where do the sebaceous glands of the nipple end?
Directly on the surface of the skin
What are the larger ducts and secretory acini of the breast surrounded by?
Myoepithelial cells
What happens to the breast during the luteal phase?
Epithelial cells increase in height
Lumina of the ducts become enlarged
Small amounts of secretions appear in the ducts
During the first trimester what changes occur in the breast?
Elongation and branching of the smaller ducts, combined with proliferation of the epithelial cells of the glands and myoepithelial cells
During the second trimester what changes occur in the breast?
Glandular tissue continues to develop with differentiation of secretory alveoli
Plasma cells and lymphocytes infiltrate the nearby connective tissue
During the third trimester what changes occur in the breast?
Secretory alveoli continue to mature, with development of extensive RER
What changes to the breast occur during all 3 trimesters?
Reduction in the amount of connective tissue and adipose tissue present
What do oestrogen and progesterone stimulate in the breast during pregnancy?
Proliferation of secretory tissue and fibro-fatty tissue becomes sparse
What is the approximate composition of human milk?
88% water
1.5% protein (mainly lactalbumin and casein)
7% carbohydrate (mainly lactose)
3.5% lipid
Small quantities of ions, vitamins and IgA antibodies
Describe apocrine secretion
Lipid droplets are within mammary acini
Droplets bud off, surrounded by membrane, carrying a small amount of cytoplasm with it
Describe merocrine secretion
Proteins in milk are made in RER, packaged in Golgi apparatus, and secreted via vesicles
Vesicles merge with apical membrane to release only their contents into duct system
What changes to the mammary gland occur post menopause?
Secretory cells of the TDLU’s degenerate leaving only ducts
In connective tissue, there are fewer fibroblasts and reduced collagen and elastic fibres
