Reproduction Flashcards
Function of the female reproductive system
- Produce Haploid gametes
- Facilitate fertilisation
- Site for implantation of the embryo
- Provide physical and nutritional needs to nurture neonate after birth
Ovarian asymmetry
Only one ovary is active each month
What are the phases of the menstrual cycle and which primary sex hormones are they mediated by
Pre-Ovulatory Phase - Mediated by Oestrogen
Post-Ovulatory Phase - Mediated by progesterone
What region of the ovary contains the majority of the blood supply?
Medulla
Which region of the ovary contains the developing eggs?
Cortex
What is the connective tissue layer that surrounds the ovary?
Tunica albuginea
What is Germinal epithelium?
Cuboidal epithelial cells that surround the ovary and are derived from the peritoneum
Effects of FSH in Females
- Stimulates follicle cells to produce oestrogen during pre-ovulatory stage
- Causes ovulation
- Stimulates corpus luteum to produce progesterone during post-ovulatory
stage
Effects of FSH in males
- Stimulates sertoli cells to produce androgen binding protein
- Stimulates spermatogenesis
- Stimulates sertoli cells to produce inhibin which provides negative feedback to decrease FSH secretion when testosterone levels get too high
Effects of LH in males
Stimulates leydig cells to produce testosterone
Stimulates spermatogenesis
Effects of LH in females
Stimulates follicle cells to produce oestrogen during pre-ovulatory stage
Causes ovulation
Triggers corpus luteum formation
Define Puberty
Period at beginning of adolescence where sex glands become functional and secondary sex characteristics emerge
What changes can be seen during puberty?
Reproductive organs change size
Pubic hair
Deepening of voice
Difference between puberty and adolescence
Puberty - Characterised by physical changes seen
Adolescence - physiological/behavioural changes
Name the mature female reproductive cell
Ovum
Name the mature male reproductive cell
Spermatozoan
Where does fertilisation occur?
Ampulla of uterine tube
What is the size of a human egg?
100-150um
What is the size of a human sperm?
6um
What is syngamy?
Fusion of gametes
How long after ovulation does gamete fusion occur?
12-24 hours
What is the role of female reproductive system with regards to sperm?
Female reproductive tract filters sperm
What happens to sperm in the female tract?
Capacitation
Acrosomal reaction
Motility changes
How long does it take for sperm to develop?
60-75 days
Why is genetic information in sperm supercondensed?
Protects genetic information from damage
What happens during pronuclear fusion?
Sperm nucleus forms male pronucleus, egg completes meiosis and forms female pronucleus, pronuclei fuse on metaphase plate
Define morula
Developmental stage where embryo consists of solid ball of cells within zona pellucida
Layers of uterine wall
Perimetrium
Myometrium
Endometrium
Structure of endometrium
Simple columnar epithelial cells
Compound tubular glands
Spiral arteries
Structure of endometrium
Simple columnar epithelial cells
Compound tubular glands
Spiral arteries
Cervix
Cervical canal connects uterus to vagina
Interior os and exterior os at its margins
Glands secrete mucus to prevent microbes reaching uterus
Structure of vaginal wall
Adventia
Muscularis
Mucosa
What happens during the follicular phase?
Hypothalamus releases GnRH
GnRH stimulates FSH and LH release from anterior pituitary
Stimulate ovary to release oestrogen
Oestrogen negatively feeds back at pituitary and hypothalamus
What happens during Midcycle?
Hypothalamus releases GnRH
GnRH stimulates FSH and LH release from anterior pituitary
Stimulate ovary to release oestrogen
Oestrogen positively feeds back at pituitary and hypothalamus
What happens during luteal phase?
Hypothalamus releases GnRH
GnRH stimulates FSH and LH release from anterior pituitary
Stimulate ovary to release progesterone
progesterone negatively feeds back at pituitary and hypothalamus
What happens during proliferative stage?
secretion of oestrogen increases
Stimulates growth of endometrium, glands, stroma, and spiral arteries elongate
What happens during secretory phase?
Progesterone secretion increses
Endometrial proliferation slows and thickness decreases
How do sperm reach the ampulla?
Their own motile action
Contraction of uterus, cervix and fallopian tube
What happens when sperm encounters the egg?
Acrosomal reaction - Exocytosis of acrosome structure, releasing hydrolytic enzymes, enabling penetration through granular cells
What happens after penetration of the oocyte
Increased intracellular Ca2+ triggers second meiotic division
Granules containing enzymes fuse with the plasma membrane and enzymes act on glycoproteins of zona pellucida to harden the layer
