Reproductive system Flashcards
What is mitosis
It is a type of cell division which results in two daughter cells having the same number and kind of chromosomes as the parent nucleus
It is necessary fro growth and tissue repair
What is meiosis
It is a type of cell division for producing gametes which are haploid sex cells
Here, each cell divides twice into 4 daughter cells. This is different to mitosis as the daughter cells aren’t the same as the parent cells due to the idea of crossing over of the chromosomes
What is interphase
Duplicating chromatids to get a chromosome at 1 centromere (2 chromatids at 1 centromere), compared to just 1 chromatid at 1 centromere previously
What is the approach which is common in both mitosis and meiosis
PMAT (Prophase, metaphase, anaphase, telophase)
However, in meiosis, pmat happens twice whereas in mitosis it only happens once
Explain the process of prophase in mitosis
Chromosomes in the cell nucleus start to condense together in preparation for cell division
Nucleus is still available
Mitotic spindles begin to appear
Explain the process of metaphase in mitosis
Nucleus has been disassembled
Chromosomes are lined up singularly(i think) singleline
Explain the process of anaphase in mitosis
Chromosomes separate and move towards poles of the cell, with assistance from the mitotic spindles
Explain the process of telophase in mitosis
New nuclei starts to form around the separated chromosomes
Each new daughter cell is a diploid cell containing 46 chromosomes each
What is cytokineses
Final separation where cytoplasm is severed to leave two identical cells
Explain the process of Prophase 1 in meiosis
Same process as mitosis prophase, however CROSSING OVER can occur, where random sharing of genes can occur between chromosomes –> increased genetic variation
Explain the process of metaphase 1 in meiosis
Same process as mitosis however some chromosomes may have crossed over.
Nucleus has been disassembled and the chromosomes are lined up in the middle of the cell with mitotic spindles connected
ADditionally, the chromosomes here are lined up in their homologus pairs –> when separation occurs it splits into 23
Explain the process of anaphase 1 in meiosis
Same process as anaphase in mitosis
Chromosomes separate and move towards the poles of the cell
Explain the process of telophase 1 in meiosis
Same as mitosis telophase
New nuclei starts to form around separated chromosomes
Explain the function of cytokinesis in meiosis
It separates where cytoplasm is severed to leave remaining two cells
Explain the process of prophase 2 in meiosis
Same function as prophase 1 but no crossing over
Explain the process of metaphase 2 in meiosis
Chromosomes don’t line up in pairs but are single file
As a result, whe they divide they become haploid (23 chromosomes) rather than diploid (46 chromosomes)
Explain the process of anaphase 2 in meiosis
chromatids (half) are pulled away fro centre of cells not the chromosomes (full)
Explain the process of telophase 2 in meiosis
Four haploid daughter cells are formed
Explain the process of the second cytokinesis in meiosis
Leaves remaining 4 haploid daughter cells
What are the key organs in the female reproductive system
Vagina, cervix, cervical canal, uterus, fallopian tube, fimbriae and ovary
What is the function of the vagina
It provides a passageway for blood and mucosal tissue from the uterus to leave the body during a menstrual period. It’s where the penis is inserted during vaginal sex and it holds sperm until they pass into the uterus. It provides a passageway for childbirth.
What is the function of the cervix
The lower, narrow end of the uterus (womb) that connects the uterus to the vagina (birth canal). The cervix allows fluids, such as menstrual blood, to pass from the uterus into the vagina. It also widens during the birth of a baby.
What is the function of the cervical canal
It allows blood from a menstrual period and a baby (fetus) to pass from the womb into the vagina. The sperm travel from the vagina up the cervical canal into the uterine cavity, then into the fallopian tubes to fertilize the egg.
What is the function of the uterus
The uterus functions by nurturing the fertilized ovum, which passes through the fallopian tube. The ovum then implants into the endometrium, where it receives nourishment from blood vessels, which are exclusively developed for this purpose.
What is the function of the fallopian tube
Your fallopian tubes are an important passageway for an egg and a sperm to meet and for a fertilized egg (embryo) to make its way to your uterus.
Successful fertilisation normally occurs in first third of the fallopian tube
What is the function of the fimbriae
Fimbriae are finger-like projections on the ends of your fallopian tubes closest to your ovaries. Each month, your fimbriae catch the egg that one of your ovaries releases during ovulation. Your fimbriae then sweep the egg (ovum) into the fallopian tube where the egg can be fertilized.
What is the function of the ovary
The ovaries are small, oval-shaped glands located on either side of your uterus. They produce and store your eggs (also called ovum) and make hormones that control your menstrual cycle and pregnancy. During ovulation, one of your ovaries releases an egg
What are the important organs in the male reproductive system
Scrotum, teesticle, vas deferens, epididymis, cowpers gland, ejaculatory gland, seminal vesicle, prostate, urethra
What is the function of the scrotum
he scrotum is responsible for protecting the testes. It helps with the thermoregulation of the testicles. It keeps the temperature of the testis several degrees below the average body temperature, which is an essential factor for sperm production.
What is the function of the testicle
he scrotum is responsible for protecting the testes. It helps with the thermoregulation of the testicles. It keeps the temperature of the testis several degrees below the average body temperature, which is an essential factor for sperm production.
What is the function of the vas deferens
The vas deferens is a long, muscular tube that travels from the epididymis into the pelvic cavity, just behind the urinary bladder. The vas deferens transports mature sperm to the urethra in preparation for ejaculation.
What is the function of the epididymis
unction of the epididymis is to transport sperm from the rete testes to the vas deferens
What is the function of the cowpers gland
Cowper’s glands are pea sized glands present inferior to the prostate gland in the male reproductive system. They produce thick clear mucus prior to ejaculation that drains into the spongy urethra.
Mucous (released pre ejaculation), lubricate urethra and end of penis to prevent damage to sperm. Alkaline fluid, neutralises acidity of urethra and decreases acidity of vagina to protect sperm
What is the function of the ejaculatory duct
The ejaculatory ducts are a part of the male anatomy that allows the flow of sperm from the testes through the reproductive system and eventually out through the urethra.
What is the function of the seminal vesicle
The seminal vesicles are two small glands that store and produce the majority of the fluid that makes up semen. During ejaculation, the fluid from the seminal vesicles is expelled into the ejaculatory duct where it can then move on to mix with sperm and other reproductive fluids.
Prostaglandin, stimulates motility of sperm
Fructose iis a nutrient source for the sperm
Clotting agents coagulates semen after ejaculation
What is the function of the prostate
The prostate’s most important function is the production of a fluid that, together with sperm cells from the testicles and fluids from other glands, makes up semen. The muscles of the prostate also ensure that the semen is forcefully pressed into the urethra and then expelled outwards during ejaculation.
Citric acid, used by sperm in ATP production
Proteolytic enzymes eventually breakdown clotting agents –> decoagulates for it to flow in female reproductive system
What is the function of the urethra
This tube allows urine and sperm to pass outside the body.
what is spermatogenesis
Spermatogenesis is the process of sperm cell development. Rounded immature sperm cells undergo successive mitotic and meiotic divisions (spermatocytogenesis) and a metamorphic change (spermiogenesis) to produce spermatozoa.
Explain process of spermatogenesis
The germ cell (spermatogonium) undergoes mitotic division, and produces 2 daughter cells (2n). 1 of the daughter cells then becomes the primary spermatocyte (2n)
The spermatocyte then undergoes first meiotic division to form 2 secondary spermatocytes (n). These then undergo second meiotic division to form 4 spermatids (n)
They then go through spermiogenesis. which allows them to develop into sperm cells (involves forming their golgi body, tails, maturation, acrosomes etc)
After spermiogenesis, it still isnt motile, and is thus released into lumen of seminferous tubules to epididymis to gain motility
Explain the process of oogenesis
There are around 5 million oogonia before birth (2nd trimester). At birth, there are around 400 000 primordial follicles (2n). These contain primary oocytes which are paused at prophase 1 until meiosis 1 is finished
It then develops into the primary follicle (2n), whhich still contains the paused primary oocyte, with layers of granulosa cells and the zona pellucida.
This then, develops into the secondary follicle, where there is now fluid filled spaces inside the follicle called the the antrum. Only around 400 of these secondary follicles fully develop in a lifetime.
This is now a mature/graafian follicle (2n), which still contains the primary oocyte. Just before ovulation the oocyte completes Meiosis 1 and pauses during early meiosis 2. Meiosis will be completed if fertilisation occurs. Ovulation triggered by peak in LH from the pituitary causes the secondary oocyte (n) to leave the mature follicle, and the granulosa cells form the corpus luteum, and it completes meiosis.
The corpus luteum secretes progesterone and a small amount of estrogen to be used during the menstrual cycle
Explain the hormones in males before puberty
Testosterone and inhibin inhibit GnRH (secreted by immature hypothalamus) and LH and FSH secretion by the anterior pituitary gland
Explain the hormones in males after puberty
Begins at age 12-14. Hypothalamus maturation reduces sensitivity to testosterone and inhibin. GnRH secretion increases, thuse increasing LH and FSH. This results in spermatogenesis, enlargement of reproductive organs and development of secondary male characteristics
Explain the hormones in females before puberty
Estrogen and progesterone provide a negative feedback. Thus inhbiting GnRH production, and causing low LH and FSH
Explain the hormones in females after puberty
Begins 11-13 years old (menarche). Maturation of hypohalamus –> high GnRH, high LH and FSH, decreased negative feedback of estrogen and progesterone, estrogen production is increased by developing follicle
Enlargement of reproductive organs and development of secondary female characteristics
