Uterus, Uterine Tubes and Cervix Flashcards
What is the inner lining of the uterus called?
→ Endometrium
What is the body of the uterus called?
→ Myometrium
What do the uterine tubes end in?
→ Fimbriae
What increases the size of a newborns uterus?
→ Maternal steroids
What does the myometrium growth depend on?
→ Estradiol
When does the myometrium grow rapidly?
→ During puberty
Where do uterine fibroids originate?
→ Myometrium
In what shape are myometrial fibres?
→ Spiral fibres
When does the endometrium thicken?
→ At puberty
What is a good bioassay of estradiol levels?
→ 7-16mm
What is the stromal matrix?
→ The smallest the endometrium can get
What does the stromal matrix look like after menstruation?
→ Small columnar cells with glandular extensions 2-3mm thick
What is the proliferative phase stimulated by?
→ Estradiol from the dominant follicle
What are the changes that occur in the proliferative phase?
→ Stromal cell division, ciliated surface
→ Glands expand and become tortuous
→ Increased vascularity and neoangiogenesis
When are progesterone receptors expressed?
→ when the endometrium gets to 4mm
When does the secretory phase start and why?
→ 2-3 days after ovulation
→ The gradual rise in progesterone causes a reduction in cell division
What are the changes that occur in the secretory phase?
→ Glands increase tortuosity and distend → Secretion of glycoproteins and lipids → oedema → increased vascular permeability → arterioles contract and grow tightly wound
What happens to the myometrium during the secretory phase?
→ Myometrial cells enlarge
→ movement is suppressed to prevent contractions
→ blood supply increases
What causes menstruation?
→ Falling levels of steroid from the corpus luteum
Describe what happens during menstruation
1) Prostaglandin release causes constriction of the spiral arterioles
2) Hypoxia causes necrosis
3) Vessels then dilate and bleeding ensues
4) Proteolytic enzymes are released from the dying tissue
5) Outer layer of the endometrium is shed and 50% is lost in 24 hours