Reproductive System Flashcards
What structures are in the female reproductive system?
Vagina, uterus, cervix, corpus, ovaries, Fallopian tubes
What is the function of the ovaries?
Small, oval-shaped glands that are located on either side of the uterus, produce and store eggs and produces hormones.
What is the function of the Fallopian tubes?
Narrow tubes attached to the upper part of the uterus and serve as tunnels for the ova to travel from the ovaries to the uterus. Conception usually occurs here.
What is the function of the uterus?
Hollow, pear-shaped organ that is the home to a developing foetus it is divided into two parts, the cervix, which is the lower part that opens into the vagina, and the main body of the uterus; called the corpus
What structures are in the male reproductive system?
Penis, scrotum, testes, epididymis, vas deferens, ejaculatory ducts, urethra, seminal vesicles, prostate gland, bulbourethral glands
What is the role of the penis?
The penis contains the urethra, a tube that carries urine and semen to outside the body. When the penis is erect during sex, the flow of urine is blocked from the urethra, allowing semen to be ejaculated.
What is the role of the epididymis in the male reproductive system?
Transports and stores sperm cells that are produced in the testes. The epididymis also matures immature sperm cells that cannot fertilise.
What is the role of the vas deferens?
Long, muscular tube that transports mature sperm to urethra ready for ejaculation.
What is the role of the seminal vesicles?
Sacs that produce fructose (sugar-rich fluid) that provides sperm with energy to help them move
What is the role of the prostate gland?
Walnut-sized structure located below the bladder. Secretes additional prostate fluids to nourish the sperm.
What is the role of bulbourethral glands?
Pea-sized glands below prostate glands. These glands produce a clear liquid to lubricate the urethral and to neutralise any acidity the urine causes in the urethra.
Define sexual reproduction
Refers to the contribution of genetic material from two parents to produce unique offspring
Define asexual reproduction
Generates offspring that are genetically identical to a single parent
What are advantages of sexual reproduction?
- Produced genetically unique individuals
- Promotors survival-sexually produced individuals that are not generally identical to one parent, they have less of a risk of inheriting disease, etc.
- Removes bad genes from the population
What are the phases of the cell cycle (mitosis)?
G1 phase - cell produces new proteins, grows and carries out its normal tasks for the body; ends when cell’s DNA beings to duplicate
S phase - DNA molecules form exact duplicates
G2 phase - preparation for cell division
M phase - cell divides into daughter cells
Describe IPMAT
Interphase - duplication of DNA
Prophase - the centrioles move to either side of cell
Metaphase - chromatid pairs line up on the equator of spindle
Anaphase - each pair of chromatids seperate at the centromere
Telophase - the two sets of chromosomes form tight groups at each pole of the cell, nuclear membrane forms around each group
Define chromosome and chromatid
Chromosome - rod-like structures that appear in the nucleus of a human cell during cell division, threads of DNA
Chromatid - a pair of identical strands formed when a chromosome duplicates
Define haploid and diploid
Haploid - a cell having half the usual number of chromosomes
Diploid - a cell in which the chromosomes exist in pairs
Describe meiosis
- occurs in the sex organs (ovary/teste)
- one duplication and two divisions to produce four new cells
- only get one chromosomes from each homologous pair
- gametes are made by this process
Describe the differences between mitosis and meiosis
Mitosis only has one nuclear division whereas meiosis has two
Mitosis produces two diploid cells, meiosis produces four
In mitosis, homologous chromosomes do not pair, in meiosis they do
In mitosis, each new cells gets a complete set of daughter chromosomes, in meiosis there are four haploid cells.
What is spermatogenesis?
Occurs in seminiferous tubules
Seminiferous tubules lined with immature cells called spermatogenia, they did by mitosis during puberty, then they undergo growth into
-> primary spermatocytes (diploid, undergo meiosis)
-> secondary spermatocytes (haploid, 2nd division occurs)
What is oogenesis?
Production of ova in ovaries
Female is born with approx. 400,000 ovum which develop into oogonia: diploid, divide by mitosis, mature to become primary follicle
At puberty - primary follicle goes through meiosis to become two haploid cels,
Secondary oocytes go through second division meiosis
What does FSH do?
Follicle stimulating hormone
Female: stimulates the development and maturation of the ovarian follicle
Male: production of sperm
What does LH do?
Luteinising hormone
Females: stimulates secretion of oestrogen and progesterone
Males: stimulates secretion of testosterone
What does oestrogen and progesterone do for females?
Oestrogen: development of female reproductive system, development of secondary sexual characteristics
Progesterone: maintenance of endometrium (uterus), development and maintenance of placenta, development of milk-secreting glands (breasts)
What is the relationship between the hormones?
As FSH acts on maturing a follicle, it increases. As the follicle matures it increases secretion of oestrogen. So FSH increasing = oestrogen increases. When FSH peaks, it causes a peak of LH, which causes ovulation. The corpus luteum becomes a temporary gland secreting oestrogen and progesterone to maintain and build endometrial lining. No fertilisatition = corpus outermost dies
What do the hormones do for males?
FSH: acts on seminiferous tubules, spermatogenesis
LH: stimulates the secretion of testosterone in the testes
Testosterone: sex drive, maintains and matures male reproductive organs, develops immature sperm cells
What are the secondary sexual characteristics for males and females?
Female: enlarging of breasts, broadening of hips, fat distribution
Male: added hair, change in voice, increase in size of the larynx
What is fertilisation?
The process of sperm being deposited into the vagina. The sperm is ejaculated through rhythmic contraction of epididymis, vas, deferens, seminal vesicles and prostate gland.
The mature eg is surrounded by a layer of follicle cells known as the corona radiata (held together by acid)
Tips of sperm contain an enzyme capable of breaking down the acid
How are stem cells different from other cells?
Stem cells:
- are not specialised
- can differentiate into specialised cells
- are capable of repeated division
Define proliferation and differentiation
Proliferation: when cells replicate themselves many times over
Differentiation: the process by which unspecialised cells develop the characteristics and functions of particular types of cells.
What are totipotent stem cell?
A cell that has the potential to create any type of cell necessary for embryonic development, including the embryo itself, and all the membranes associated with embryonic development.
- in the first few hours of fertilisation, the fertilised egg undergoes several cell divisions that produce identical totipotent cells.
- the totipotent cells undergo several rounds of cell division.
What are pluripotent stem cells?
Cells of the inner cell mass that are able to give rise to many, but not all, cell types necessary for foetal development.For example; they are able to give rise to foetal tissues, but not placental tissue.
What are multipotent stem cell?
Cells developed through specialisation of pluripotent stem cells. They give rise to cells that have a particular function. For example; blood stem cells give rise to red blood cells, platelets and white blood cells.
Describe umbilical and blood and placental stem cells
- Stem cells are present in the blood in the umbilical cord and the placenta (multipotent)
- Once a baby is born, these cells can be extracted from the discarded tissue and used for the benefit of children and adults who suffer from devastating bone marrow and blood diseases
- Can be stored in case baby require replacement tissues or organs
Describe embryonic stem cells
- pluripotent
- cultured from frozen embryos that are obtained from IVF clinics
- they can become any of the cell types in the body and are therefore more versatile than adult stem cells
Describe adult stem cells
- multipotent
- an advantage of using these to treat disease is that a patient’s own cells can be used
- are commonly pre-specialised
Describe the menstrual cycle
- The ‘period’ is occurring as the endometrium lining leaves through the vaginal canal after fertilisation doesn’t occur
- As the follicles continue to develop, the lining of the endometrium begins to thicken and soften, in preparation for the ovum to implant. This occurs as levels of oestrogen and progesterone increase.
- During days 16-26, as progesterone reaches its peak, the endometrium lining is at its thickest.
- As the corpus luteum degenerates due to no fertilisaiton, oestrogen and progesterone levels drop causing menstruation.
Describe the ovarian cycle
- Primary (dormant) follicle
- Developing follicles / ovarian follicle approaching maturity
- Mature ovarian follicle (Graafian follicle)
- Rupturing of follicle, expels ovum
- Corpus luteum forming
- If fertilisation does not occur, stops developing at 6-8 days and degenerates. If fertilisation does occur, it continues to develop and finally degenerates at the 3rd month of pregnancy.
What happens at the third month of foetal development?
- eyelids are closed
- outer ear completed
- forelimbs well developed
- sex distinguishable
- bone marrow formed - blood cells formed in bone marrow
What happens at four months of foetal development?
- arms and hands fully shaped
- skeleton completed
- exercising of muscles evident
- ears stand out from head
What happens at five months of foetal development?
- fine hairs cover body
- gripping reflexes developed
- increase growth
What happens at six months of foetal development?
- respiratory movements
- digestive glands begin to function
- tooth buds evidence
- eyebrows and eyelashes grow
What happens at seven months of foetal development?
- period of greatest growth
- all systems functional except for respiratory
What happens at eight months of foetal development?
- accumulation of fat beneath skin
- growth is slowed
What happens at nine months of foetal development?
- eyes open
- nose well formed
- sucking and grasping reflexes apparent
- fine body hair is shed
