Reproduction and Pregnancy Flashcards by Omole Aigbokhaode

What is the general structure of a Fallopian tube ?

Infundibulum with fimbriae
Ampulla and isthmus
Longitudinal and circular smooth muscle in walls - peristalsis
Highly folded mucosa – ciliated and secretory cells

Transports egg from ovary to uterus

How well did you know this?

Not at all

Perfectly

What are the ovaries

Female gonads

Development and maturation of ova

How well did you know this?

Not at all

Perfectly

What is the structure of the Ovaries ?

Cortex – outer zone with germinal epithelial layer containing oocytes
Inner medulla, – blood vessels and lymph
Oocytes enclosed within follicle
Follicular cells secrete steroid hormones:
Granulosa - 17β-oestradiol
Theca - progesterone

How well did you know this?

Not at all

Perfectly

What is the uterine wall made of ?

Perimetrium
Myometrium 
Endometrium
Endometrium:
thick inner layer
Highly branched
Simple columnar epithelial cells
Compound tubular glands
Spiral arteries

How well did you know this?

Not at all

Perfectly

What is the Cervix and what does it do ?

Connect uterus to vagina

How well did you know this?

Not at all

Perfectly

How does the cervix prevent a moist and warm environment so good breeding ground for microbes ?

Cervical glands secrete mucus.

How well did you know this?

Not at all

Perfectly

What is the thin, distensible wall of the vagina made from ?

Adventia
Muscularis
Mucosa

How well did you know this?

Not at all

Perfectly

What type of epithelia is found in the vagina ?

Stratified squamous epithelium rich in glycogen
fermented by bacteria to lactic acid producing pH 3.5-4 inhibits pathogens
antigen-presenting dendritic cells

How well did you know this?

Not at all

Perfectly

What are the 2 female cycles ?

Ovarian

Endometrial

How well did you know this?

Not at all

Perfectly

How does the Hypothalamic-pituitary-gonadal axis drive the menstrual cycle ?

Hypothalamic neurones release gonadotropin-releasing hormone (GnRH) 1/hr
Hypophyseal portal system connects hypothalamus to anterior pituitary
G-protein coupled GnRH receptor: IP3, DAG, Ca2+ and triggers exocytosis of gonadotropins Follicle Stimulating Hormone and Lutenising Hormone, increase in intracellular calcium
Triggers release by GnRH binding to receptors in anterior pituitary

How well did you know this?

Not at all

Perfectly

What does FSH and LH stimulate ovary to secrete ?

Theca: Progesterone
Granulosa: 17β-oestradiol
Inhibin
Activin

How well did you know this?

Not at all

Perfectly

How is progesterone and 17β-oestradiol synthesized ?

By ovarian follicle granulose and theca cells

Theca cells synthesise and secrete progesterone (from cholesterol) (short pathway)
Androstenedione diffuses from theca to granulosa cells
Granulosa cells produce 17β-oestradiol

FSH and LH stimulate this pathway

How well did you know this?

Not at all

Perfectly

What do 17β-oestradiol and progesterone do ?

Develop ovum
Maintain corpus luteum
Maintain pregnancy

How well did you know this?

Not at all

Perfectly

What does 17β-oestradiol and progesterone control change ?

Endometrium
Feedback regulation of FSH and LH from pituitary
Cervix and vagina:
Cervical mucus

How well did you know this?

Not at all

Perfectly

What does the secretion of 17β-oestra stimulate the growth of ?

Endometrium
Glands
Stroma
Spiral arteries elongate

How well did you know this?

Not at all

Perfectly

Describe the secretory phase of the Endometrial cycle

Following ovulation dominated by progesterone
Endometrial proliferation slows, thickness decreases
Glands – tortuous with accumulated glycogen vacuoles, increased mucus
Stroma – oedamatous
Spiral arteries elongate and coil
Ending in menses

What circumstances can inhibit ovulation ?

Negative feedback on anterior pituitary gonadotrophs to inhibit FSH/LH and prevent ovulation

Low LH (no LH surge) inhibit ovulation

What are some examples of hormonal contraceptives ?

The oral contraceptive pill (OCP) most common UK contraceptive

Numerous combinations:
Oestrogen and progesterone
Progesterone only (mini-pill)
Monophasic or fixed-combination
Multiphasis or varying-dose

What are some examples of hormonal contraceptives ?

The oral contraceptive pill (OCP) most common UK contraceptive

Numerous combinations:
Oestrogen and progesterone
Progesterone only (mini-pill)
Monophasic or fixed-combination
Multiphasis or varying-dose

How does the morning after pill work ?

Inhibit ovulation
Interfere with implantation
Therefore can be used as a postcoital contraceptive

How does a sperm fertilise an egg ?

Around 50-100 sperm reach the ampulla of the fallopian tube, this is through their own motile action, but also though the contraction of the uterus, cervix and fallopian tubes after the initial propelling action of cervical mucus

When the sperm encounters the egg it undergoes an acrosomal reaction, exocytosis of the acrosome structure releasing hydrolytic enzymes and enabling penetration through the granulosa cells.

When the sperm reaches the glycoprotein layer beneath called the zona pellucida, it attaches to the specific ZP3 sperm binding proteins and, through the action of hydrolysing enzymes and flagellum movement, moves through enabling fusion of the membranes between sperm and oocyte and entry of contents of the sperm cell into the oocyte

What happens when oocyte is penetrated ?

Penetration of the oocyte raises intracellular calcium which triggers the second meiotic division of the oocyte

This cortical reaction also triggers small granules containing enzymes to fuse with the plasma membrane.

The exocytosis enables the enzymes to act on the glycoproteins of the zona pellucida to harden the layer, destroy the ZP receptors and prevent further entry of sperm

No polyploid

How does a blastocyst invade the endometrium ?

Hatching
Apposition
Adhesion
Invasion

How does a blastocyst invade the endometrium ?

Hatching
Apposition
Adhesion
Invasion

How does the placenta develop ?

The placentas a life support system - ~120 maternal spiral arteries bring pulsatile blood ``` In mature placenta, foetal + maternal blood separated by: Foetal capillary endothelium Mesenchyme Cytotrophoblasts Syncytiotrophoblast ```

What molecules does the mother transfer to the foetus ?

Glucose - Facilitated diffusion Amino acids - secondary Active transport Vitamins - Active transport Large molecules by receptor-mediated endocytosis: LDL, hormones, antibodies Oxygen exchange facilitated by higher affinity for oxygen of foetal haemoglobin

What does the foetus transfer to the mother ?

Waste urea, creatinine diffusion

What does the foetus transfer to the mother ?

Waste urea, creatinine diffusion

How do hormones change during Trimester 1 of pregnancy ?

Corpus Luteum: | continues secretion oestrogen and progesterone to support endometrium

How does the placenta contribute to Trimester 2-3 ?

Placenta 1° hormone source Human placental lactogens (human chorionic somatomammotropins [hCS] Coordinate fuel economy, glucose to FA – energy source Ketone storage for neonate Development mammary glands Progesterone synthesised from circulatory cholesterol Oestrogen (oestriol): placenta-foetal synthesis

What is Quiescence ?

Stage 0 of Parturition Braxton-Hicks contractions Relaxed uterus and insensitive to uterotonic hormones 95% of gestation

What is Stage 1 of Parturition ?

Activation/transformation Prior to labour Oestrogen stimulates prostaglandin (PG) release Prostaglandin : Promotes formation of gap junctions Softening, thinning and dilation of cervix Cortisol increases to increase oestrogen and progesterone to increase contractility

What happens during Stage 2 Parturition

Stimulation/Labour/Birth ``` Increased PG levels: Myometrial contraction (+ OT) Cervical dilation Increased myometrial connectivity Increased myometrial responsiveness (PG & OT) Positive feedback: Ferguson reflex – neuroendocrine regulation OT Uterine contraction stimulates Prostaglandins Stages of labour and delivery: Dilation (placental relaxin) Expulsion Placental (separation from decidua) ```

What is Stage 3 of Parturition ?

Involution Recovery from birth ``` Haemostasis Vasoconstriction spiral arteries (OT – myometrium) decreases haemorrhage decrease in placental oestrogen Myometrial atrophy – involution Regression uterine vasculature Cervix remodelling ``` Reestablishment endometrial cycle - 3-5 months

What is the difference between Colostrum and Milk ?

``` Colostrum – first milk High fat + protein Antibodies Milk – fat emulsion in aqueous solution: Sugar (lactose) Protein (lactalbumin + casein) Cations and anions ```

How does the breast secrete milk ?

via Alveoli

What are the hormones used to promote milk production postpartum ?

Mammogenic (promote cell proliferation) e.g. oestrogen Lactogenic (promote initiation milk production) e.g. PRL Galactokinetic (promote myoepithelial contraction) e.g. OT Galactopoietic (maintain milk production) e.g. PRL + cortisol

What does oestrogen and progesterone inhibit during pregnancy ?

Inhibits anterior pituitary prolactin (PRL)

What does oestrogen and progesterone inhibit during pregnancy ?

Inhibits anterior pituitary prolactin (PRL)