Assignment

1. ONLINE ASSIGNMENT
SUBMITTED BY:
LUBENA BASHEER
REG NO:13367008

2. HUMAN REPRODUCTION
• Sexual reproduction is the process involving the joining of the male and female sex cells
• Gametes- sex cells, produced in the sex organs
• Gonads- sex organs
• Fertilization- the fusion of male gametes and female gametes
• Zygote- single cell
• Primary sex organs- gonads- produce gametes
• Secondary sex organs- store the gametes, bring them together for fertilization and support the developing baby
MALE REPRODUCTIVE SYSTEM
• Males gametes (sperm) are produced in the gonads or testes which are held in the scrotum.
• This holds the testes outside the body cavity because the production and development of sperm requires a temperature that is about 2 degrees lower then the normal body temp. therefore to enable sperm production, the testes lie outside the body
Part
description
function
Testes
•
Oval in shape
Produce sperm and hormones
•
4.5cm long, 2.5cm wide
and 3cm thick
Lobules
•
compartments 200-300
Compartments that hold tubes
• filled with fine tubes
called seminiferous
tubules
Seminiferous tubules
•
lined with cells
Produce male gametes (sperm)
•
between the
seminiferous tubules are
clusters of interstitial
cells
Interstitial cells
•
between the
Secrete male hormone testosterone
semininferous tubules
•
they are clusters

3. Epididymis
•
highly, folded tubule that
Stores sperm while they finish maturing (for a
is against the rear surface
month)
of each testes
Vas deferens
•
tubule of epididymis
Carries sperm to urethra
forms this and joins to
form urethra
• Semen or seminal fluid is used to transport the sperm to the females body. It also nourishes and aids the sperm
Semen is made from a mixture of secretions from three glands
• Seminal vesicles- pair of pouch like organs and 5 cm. The fluid is rich in sugars and about 60% of volume of semen
• Prostate gland- 2 vaso deferens join the urethra. It is a single gland and it surrounds the urethra just below the bladder. Secretes a thin, milky alkaline fluid that becomes part of the semen

4. • Cowper’s glands (bulbourethral glands) – 2 small yellow glands located beneath prostate. Secretes clear mucous which acts as lubricant and most precedes the emission of seminal fluid
• The urethra- transports urine and semen
• The penis contains connective tissue with a very rich blood supply (erectile tissue) and it contains many sponge like spaces which fill with blood during sexual arousal
• This causes in an erect and stiff penis, and it can be successfully introduced into the vagina
FEMALE REPRODUCTIVE SYSTEM
Part
Description
Function
Ovaries
Female gonads
Ova is produced
Almond shaped gland
3cm in length located in
body
Stroma
Connective tissue found in
Contains germ cells
ovary
Surrounded by germ cells
Germ cells
Surrounds the stroma
Enclosed in a follicle
Follicle
Contains germ
Surrounds and matures ova
cells(surrounds germ cells)
Numerous follicles
As a follicle matures it
moves to the surface of the
ovary and ruptures

5. Spermatogenesis

6. SPERMATOGENESIS
• Occurs in seminiferous tubules of the testes
• Immature sperm cells line the seminiferous tubules called spermatogenesis
• They contain 46 chromosomes(diploid)
• They divide by mitosis – provide a continuous source of new cells for the production of sperm
• Primary spermatocyte- some spermatogenia are pushed away from the edge and they grow
• These cells undergo the 1st stage of meiosis (reduction stage), to form 2 daughter cells with half the chromosome number (haploid) and are called 2nd spermatocyte
• A further meiotic division produces two spermatids each –total of four daughter cells
• Spermatids have no tail and move towards the centre of the tubule as they mature into spermatozoa
• Maturing sperm are nourished by cells in the tubules called nurse cells
• Takes about 72 days and continues through puberty
OOGENESIS
• Production of ova in the ovaries
• Begins before and after baby is born
• Oogonia develop in the ovaries. These are diploid cells
• At birth the ovary contains several hundred thousand oogonia which have grown to become primary oocytes
• Primary oocytes begin the first phase of meiosis but stop at prophase until puberty
• Each primary oocyte is surrounded by a single layer of cells forming a primary follicle
• At puberty follicles begin to mature

7. • The primary oocyte completes its 1st division of meiosis to form two haploid cells. These are uneven in size. The larger one receives most of the cytoplasm and is called the secondary oocyte. The smaller one is called 1st polar body
• The secondary oocyte immediately begins the 2nd meiotic division but stops at metaphase
• When ovulation occurs the follicle ruptures and the secondary oocyte is released
• If it is fertilised by a sperm, meiosis is quickly completed
• The 2nd stage of meiosis also produces cells of uneven size, and again the smaller one is the 2nd polar body. The larger of the two develops into mature ovum
• The 1st polar body may also complete its 2nd meiotic division and produce 2 more polar bodies
• All polar bodies disintegrate
• A female only produces 1 ovum from every primary oocyte
• And males produces for sperm from every primary oocyte
Differences between O and S
• Spermatogenesis takes place in the testes of males, oogenesis takes place in the ovary of the females.
• Spermatogenesis produces small, motile spermatozoa whereas in oogenesis the ovum is spherical, not motile and is much larger with more food reserves and cytoplasm.
• Spermatogenesis involves a metamorphosis stage called spermiogenesis, in oogenesis there is no metamorphosis stage.
• In spermatogenesis, 4 gametes are produced from each meiotic division, whereas in oogenesis there is only 1 gamete produced from each division as the unequal cytokinesis leads to the formation of polar bodies.
• Spermatogenesis occurs in males (human males) continuously from puberty to death whereas oogenesis starts in females at puberty and then occurs on a monthly basis until the menopause. It takes 70 days for sperm to be produced in males.

8. Ovarian cycle
• It is a series of events that occurs in the ovaries under the control of hormones from the pituitary gland situated in the brain
• At birth a females ovaries contain about 400000 immature eggs which remain in a resting phase until puberty
• At puberty some primary follicles begin to enlarge and divide creating a layer of cells around the developing ovum
• These layers of cells secrete fluid unto the follicle causing it to continue to enlarge
• It then begins to move to the surface of ovary. Now is called secondary follicle
• Primary follicle secondary follicleovummature folliclefluidruptured follicle corpus luteum corpus albicans
• Ovulation- mature follicle bursts releasing ovum
• After ovulation the ruptured follicle falls and forms an endocrine gland called the corpus luteum (secretes hormones which influence the development of endometrium)
• If no fertilization corpus luteum degenerates into corpus albicans (mass of fibrous scar tissue)
• If fertilization occurs, corpus luteum develops and ovarian cycles cease
The menstrual cycle
• Changes in the lining of the uterus (endometrium)
• Menstruation is the monthly shedding of the lining of a women’s uterus (more commonly known as the womb)
Stages
• Menstruation (1-4 days)
Uterine bleeding and shredding of endometrium (glands, blood vessels)
• Pre ovulationproliferation (5-12 days)
Endometrium repairs, then thickening. Ovarian follicles develops (developing of a new lining )
• Ovulation (13-15 days) Rupturing of a mature follicle

9. • Secretion (16-20 days)
Secretion of water mucous by endometrium glands, cervix and uterine tubes Unfertilized egg breaks down and corpus luteum develops
Uterus is ready for implantation
• Pre menstruation (21-28 days) Detoriation of endometrium Corpus luteum degenerates
2 stages in an ovary
Follicular phase (0-14)
- development of follicles
- forming of glands and blood vessels in endometrium
- and is the menstrual and proliferative stage
- secretion of oestrogen by the ovarian follicle (follicular cells)
- In the menstrual and proliferation stage in the uterus
Luteal phase (14-28)
- development of corpus luteum
- secretion of oestrogen and testosterone
- secretion of mucous from glands
- in the secretory phase of stage in uterus

10. Link between ovarian cycle and reproductive hormones
1. When Follicle stimulating hormone released – the follicle matures, grows and produces (helps ovarian cycle)
2. Release Oestrogen – in endometrium
FSH levels decrease
Lutenizing hormone increases
3. When LH is released – ovum ruptures (ovulation), follicle changes to corpus luteum and changes into a gland
4. Progesterone is produced by CL and oestrogen is produced
LH levels decrease
FSH levels decrease
5. If implantation occurs CL supports pregnancy for 3 months
6. If no implantation CL degenerates, menstruation occurs and lowers oestrogen levels

11. Puberty
• When a person reaches sexual maturity
Females (11-14)
• Oestrogen – responsible for : Breasts
Broadening of hips Female contours Voice deepens a little
Pubic hair- armpits and groin Sex organs enlarged
Males (15-16)
• Testosterone Facial and chest hair
Increase in size of larynx Lengthning of vocal cords Pubic hair- armpits and groin Sex organs enlarge
Sexual intercourse
Male
When sexual arousal has occurred, the sperm in the epididymis move to the prostate gland and the seminal vesicle via the vas deferens. They are nourished at the prostate and seminal vesicle and then by the contracting of the epididymis, prostate, and vas deferens the sperm move out of the penis via urethra into the cervix of vagina. (ejaculation)
Female
When arousal in female occurs the erectile tissue fills with blood near vaginal opening. This reduces the size of the opening which increases stimulation for penis. Increase in mucous secretions for use as lubricant for penis
The sperm is ejaculated through the cervix and into the uterus where they make their way to the uterine tubes. Muscular contractions and the beating of the cilia on the lining of the cells of the tubes help move the ovum down the tubes

12. Fertilization
• Cells of corona radiata are held together by an acid
• The head of the sperm contains an enzyme that breaks down the acid of the corona radiata
• Many sperm needed for the break down of the corona radiata
• When one sperm penetrates egg, egg forms a ‘fertilization membrane’ so no sperm can enter
• The male pro nucleus (head of sperm) moves towards females pro nucleus
• The ovum completes its 2nd meiotic division and nucleus of egg develops into female pro nucleus
• Male pro nucleus fuses with female pro nucleus to form single nucleus with diploid number of chromosomes (46)
• Fertilized egg called a zygote
Implantation
• Process in which the egg implants into the uterus wall and its journey to the uterus and in the uterus
• Within a few hours of conception, tiny hair-like structures called cilia push the zygote towards the uterus. During this journey to the uterus, the zygote starts the process of cell division

13. • At around 4 days, the zygote is a 16-cell mass and it enters the uterus where it floats freely for about 2 days
• Cleavage is the term used for the rapid division of cells that happens in the first 24-48 hours after fertilization.
• At around 6 days, the zygote has become mass of more than 100 cells called a Blastocyst and it has the shape of a hollow ball with inner and outer layers. The out layer will become the placenta and the inner layer will become the feotus.
• The zygote implants (attaches) to the wall of the endometrium at around 10 days. After implantation, the zygote is officially known as an embryo.

14. Embryonic membranes – two month –foetus
• protect and nourish embryo Four membranes
• Amnion
secretes amniotic fluid protection (shock absorber) maintain constant temp baby can move freely
• Chorion
Surrounds embryo and other 3 membranes
Made from the outer cells of blastocyst and mesodermal cells
Becomes the main part of the featul position of the placenta
Placenta
• Substances are exchanged between the foetal and maternal blood supplies by diffusion and active transport
The umbilical cord contains 2 umbilical arteries- They carry the deoxygenated blood from foetus to mother
• A single umbilical vein- carries oxygenated blood from the mother to foetus
• Blood from mother enters the placenta though the uterine arteries, and flows through the blood spaces where he exchange of substances occurs and leaves again through the uterine veins
• Oxygen and nutrients from mother diffuse into foetal blood and wastes leave foetus by diffusing into maternal blood
• Many villi for large SA of exchange
• Umbilical cord attaches placenta to baby

15. 1st trimester (1-12 weeks)
• No period
• Swelled breasts
• Enlarged nipples
• Nausea
• Pressure on bladder
2nd trimester (13-28 weeks)
• Enlarged uterus
• Blood volume and heart rate increase
• Movement of baby week 18
3rd trimester (29-40 weeks)
• Sharp pains due to kicking
• Uncomfortable
• Lower back pain
• More rest needed for big weight
Maternal diet
Requirement
Reason
Food source
Folic acid
Cell division
Whole grain breads,
Protein production
cereals, leafy green veges
Calcium
Bone growth and baby
Dairy
teeth
Vitamin A
Normal cell growth
Yellow and green veges
Iron
Blood cell production
Red meat, green veges
Protein
Structural materials
Meat, dairy, nuts
Avoid- raw fish, unfresh foods, soft cheese, pre packed food
Teratogenic agents
• Substance that causes physical defects in embryo
• E.g. some hormones, antibiotics, drugs

16. Watching baby
Ultra sound
• High frequency sound waves to produce image of baby
• Probe placed on abdomen and sound waves reflected from feotel tissue to obtain echoes of what is inside uterus
• Determines sex of baby, and any defect e.g. spina bifida
Fetoscopy
• Looking at foetus from telescope like instrument
• Inserted into uterus through abdominal wall
• Foetus examined for – missing ears, absent limbs Hormonal intervention
• If progesterone levels drop due to inadequate progesterone production then a premature delivery or miscarriage could result
• Women affected are given progestin – helps mother retain foetus
3 stages of labour
Stage 1 of labour
• contractions of the uterus wall opens up the uterus 10 cm
• 10-12 hours approx
• amniotic sac breaks
• cervix opens wide enough for babys head to pass through
• a show- discharge of mucus mixed with blood which has come away from the cervix where it has formed a plug
• regular and strong contractions
Stage 2 of labour
• baby passes through birth canal
• the uterus, cervix and vagina are now a continious birth canal
• pushing of babies head
• babies head emerging from vagina (crowning)
• when baby is out mucus must be cleared from nose and mouth of baby
• baby must start to breathe and cry
• episiotomy- small cut made to widen opening of vagina to prevent tearing
Stage 3 of labour

17. • baby is a separate person
• once baby Is breathing the umbilical cord is cut of
• contractions continue until the placenta is expelled
• the mother may be given an injection of syntometrine to speed up process and to prevent excess loss of blood
• left side pump O blood to body
• right side pump DO to lungs
• foetal blood returns to heart through liver and inferior vena cava
• most of the blood bypasses liver and flows through vessel called ductus venosus and  inferior vena cava
• blood flows into the right atrium of heart and it may-
Flow into right V and then to lungs
From from RV though ductus arteriosus(lung bypass to aorta) (carries O2 blood to body)
Flow through opening called foremen ovale and  in LA
Motor development
• Cephalocaudal
Head to foot development e.g. raise head, grasp
• Proximodistal

18. Outwards development. Movements of part of limb closest to body comes first e.g. control forearm then fingers
• Gross to specific
Larger muscle movements then the finer movements
e.g. whole arm movement, then grasp a ball with hand, then picking up object between thumb and finger
Socilisation- learning to behave in a manner accepted by others
Infertility
• Infertility is the inability to conceive a child after 12 months of regular sexual intercourse without the use of birth control. There are two types of infertility; primary infertility and secondary infertility
• Causes in females - Pelvic inflammatory disease, endometriosis
• Causes in males- Autoimmunity, Chronic prostate infections
Artificial insemination
• Success rate- 70-80%
• Major risk- transmission of disease from the donor to the receiver
• All donors are screened for STI’s, genetic diseases, mental problems or general health
• The physical characteristics of the donor are the closest to the partners
• When ovulation is expected a women visits the doctor. The next 3-4 days the donors semen is injected into the upper vagina of the women
• 3 seminations per month for 3 months are necessary for successful conception
• insemination is done on day of ovulation and this is detected by testing the LH surge in the blood or urine
In vitro fertilization
• mature eggs are removed from the mother by laparoscopy
• sperm are added to an egg which is stored in a glass dish in a lab (fertilization)
• it is incubated until it grows (3 days)
• after fertilization the dividing cells are implanted into the uterus
• excess embryos are frozen for future use
Gamete intrafallopian transfer
• it is a variation of IVF
• the sperm and the egg are mixed together and are then immediately transferred into the uterine tubes
• it is done in one procedure- not in 2 like IVF
• it is a natural way of fertilization