Female And Male Repro Systems Flashcards
What is a corpus luteum and why do we need it?
Corpus luteum occurs from the remaining follicular tissue following ovulation. It secretes progesterone that prepares the uterus for pregnancy and supports the embryo/fetus until the placenta takes over.
Oestrogen in the ovarian cycle?
Peaks around day 14 plus and stimulates a surge of Luteinising hormone (LH). It then drops off after ovulation but still remains high
Luteinising hormone (LH) - role in ovarian cycle?
Stimulates follicle to produce oestrogen which creates neg feedback cycle to hypothalamus and pituitary reducing GnRH, FSH, and LH. The surge of LH on day 14 stimulates ovulation.
Follicle stimulating hormone (FSH) - role in ovarian cycle?
Stimulates follicular cells of the primary follicle to proliferate and become a secondary follicle.
Progesterone and its role in the ovarian cycle?
Stimulates maintenance of growth of uterus lining in preparation for fertilisation.
Released by the corpus luteum after ovulation - can support embryo for a few weeks
Characteristic of female pelvis?
Pelvis tilted forward
Wide pelvic brim and oval shaped
Ischial tuberosities less prominant
Wider pubic arch
Characteristics of male pelvis?
Not tilted as far forward
Pelvic brim is heart shaped
Ischial tuberosities are more prominent
Narrow pubic arch
The HEAD of the sperm - what are the functions?
Contains nucleus
Capped by acrosyme containing hydrolytic enzymes (which enables penetration of the egg).
Function of the MID PIECE of the sperm?
Contains mitochondria to provide energy
Function of the FLAGELLUM of the sperm?
Provides locomotion
During ejaaculation, sperm goes though which 3 parts?
Mature and stored in epididymis
Ejaculated into vas deferens
Ejaculatory duct - where sperm and seminal fluid combine
Travels out of urethra
Explain oogenesis in utero
Oogonia (2n) undergo mitosis to produce primary oocytes (2n)
Primary oocytes begin meiosis I, but halt (at prophase) around 7 months gestation.
Explain oogenesis from birth to puberty:
Primary Oocytes remain halted in meiosis I, but many are lost.
During childhood, they are surrounded by follicle cells and become primary follicles.
Explain Oogenesis at puberty and every month thereafter (until menopause)
A primary oocyte (2n) will continue and complete meiosis I creating a secondary oocyte (n) and the first polar body.
The secondary oocyte (n) then begins meiosis II, but halts again (at metaphase 2) prior to ovulation.
Explain oogenesis/meiosis with fertilisation
The secondary oocyte will only complete meiosis II if fertilised - this creates an ovum (n) and the 2nd polar body (n)
If fertilisation does not occur, the oocyte will never complete meiosis II
Hormones of menstruation - when do they occur?
Menstruation phase: (day 1-5) decreasing levels of progesterone
Proliferative phase: Day 5 follicle starts to produce oestrogens
Secretory phase: Day 15 - progesterone levels increase
Spermatogenesis occurs ___________ from puberty in the _____________ ____________.
Continuously
Seminiferous tubules
In spermatogenesis, the process of both ________ and ________ producing _____ (number) viable sperm (n)
Mitosis, meiosis, four.
Each spermatogonium (2n) undergoes ________ to generate ______ ___________ _______.
Mitosis, two daughter cells
What happens to type A cells and type B cells after undergoing mitosis (for spermatogenesis)
Type A - remain in seminiferous tubule to continue mitosis.
Types B - become primary spermatocytes
Primary spermatocytes (2n) undergo ______________ to produce two __________ ____________ (n)
Meiosis I , secondary spermatocytes
Secondary spermatocytes undergo _______________ to produce two ___________
Meiosis II, spermatids
Spermatids are:
Immature, non-motile, rounded cells
Spermiogenesis is? What happens?
Transformation of spermatids into sperm.
Cells elongate and shed excess cytoplasm, then form a head, mid piece and a tail.
