Human Sexual Reproductive System Flashcards
what is asexual reproduction
process resulting in the production of genetically identical offspring (clones) from 1 parent, without the fusion of nuclei of gametes
what is sexual reproduction
process of involving the fusion of the nuclei of reproductive cells called gametes (fertilisation) to form a zygote and the production of genetically dissimilar offspring
6 points
what are the parts of the human male reproductive system
testes
scrotum
sperm duct
prostate gland
urethra
penis
what is the function of the testis
produces male sex hormone (testosterone) and sperms upon puberty
what is the function of the scrotum
sac which holds the testis outside the body where temperature is lower and optimum for the development of healthy sperm
what is the function of the sperm duct
muscular tube which carries sperms from the testis to the urethra
2 points
what are the functions of the prostate gland
male sex gland produces fluid which:
- contains nutrients which nourishes sperms and enzymes that activate the sperms to swim
- provides a medium for sperms to swim in
^ mixture of fluid and sperms called semen
what is the function of the urethra
tube which carries urine and semen to outside of the body
what is the function of the penis
erectile organ when the male is sexually aroused, to deposit semen containing sperms into vagina during sexual intercourse
6 points
what are the parts of the human female reproductive system
ovary
oviduct (fallopian tube)
uterus (womb)
uterine lining
cervix
vagina (birth canal)
what is the function of the ovary
produces eggs (ova) and female sex hormones (oestrogen and progesterone)
2 points
what are the functions of the oviduct
site where fertilisation occurs
pathway to carry mature egg from ovary to uterus
what is the function of the uterus
organ with thick muscular walls and has inner surface covered with a layer called uterine lining, for implantation of embryo and subsequent development of the fetus
what is the function of the cervix
ring of muscle at lower end of uterus that widens during childbirth
what is the function of the vagina
muscular tube where sperms are deposited during sexual intercourse
how many chromosomes do each human gamete carry
23 chromosomes (22 chromosomes and 1 sex chromosome)
*sex chromosome: sperm carries either X or Y chromosome, egg will always carry X chromosome
what are the 5 stages of fertilisation
1) during ovulation, an ovum is released into the oviduct
2) when the nuclei of a sperm and ovum fuse, fertilisation occurs, forming a fertilised egg called a zygote
3) repeated cell division of the zygote gives rise to an embryo
4) the embryo moves towards the uterus by peristalsis and movements of hair-like structures called cilia
5) the embryo implants in the uterine lining approximately 7 days after fertilisation
3 points
describe pregnancy and birth
in humans, pregnancy lasts about 9 months
during pregnancy, the embryo develops into a fetus (unborn baby)
at the end of the pregnancy, the muscles of the uterus contract to push out the fully formed baby; cervix enlarges to allow baby to pass through (birth)
what is heredity
process by which characteristics are passed down genetically from 1 generation to the next
where are genes carried
chromosomes
what is puberty
period when an adolescent becomes capable of reproducing
6 points
what are characteristics of puberty in a male
facial hair starts to grow
voice-box enlarges and voice deepens
hair starts to grow in armpits
penis and testes increase in size
production of sperms begins and ejaculation occurs
hair starts to grow in the pubic region
4 points
what are the characteristics of puberty in a female
hair starts to grow in armpits
breasts and uterus enlarge and hips broaden
menstrual cycle begins
hair starts to grow in the pubic region
what is menstrual cycle
cycle of natural changes that occur in the uterus and ovary in preparation for possible pregnancy
*starts from puberty until menopause
days 1-5, 6-13, 14, 11-17, 18-28
describe the key events of the menstrual cycle
day 1-5: uterine lining breaks down and menstruation occurs
day 6-13: uterine lining starts to repair (lining becomes very rich in blood capillaries)
day 14: ovulation occurs when a mature egg is released into the oviduct
day 11-17: fertile period which during sexual intercourse around the ovulation period is likely to result in pregnancy
day 18-28: further thickening of the uterine lining to supply embryo with nutrients and oxygen for growth
what is the function of oestrogen
stimulates the repair and growth of uterine lining
what is the function of progesterone
maintains uterine lining in its thickened state
menstruation, after menstruation, ovulation, after ovulation
describe the use of the oestrogen and progesterone in the menstrual cycle
(menstruation) day 1-5: uterine lining breaks down as monthly discharge of blood or menses from the uterus via the vagina
(after menstruation) day 1-13: ovary produces oestrogen, which repairs uterine lining
high oestrogen concentration leads to ovulation
(ovulation) day 14: mature egg released into oviduct
2 ovaries take turns to release an egg
(after ovulation) day 14-28: ovary produces progesterone, maintaining thickness of uterine lining for rest of the menstrual cycle
oestrogen production decreases
if no fertilisation occurs, production of progesterone decreases, leading to menstruation (no menstruation occurs when pregnant)
what are 2 potential consequences of premarital sex
unwanted pregnancies
STDs
what is abortion
termination of a pregnancy where a doctor surgically removes the embryo or fetus from uterus (usually carried out in first 12 weeks of pregnancy)
what is the risk of abortion
infected/damaged reproductive system
2 points
what are effects of drug abuse on a fetus
slows down development and growth of fetus
higher risk of premature birth or miscarriage
3 points
what are the mechanical methods of birth control
condom: prevents sperms from being deposited into vagina, prevents fertilisation
diaphragm: covers cervix preventing fertilisation
intra-uterine device (IUD): prevents implantation of embryo
2 points
what are the chemical methods of birth control
contraceptive pills: prevents pregnancy by inhibiting ovulation
spermicide: chemical that kills or blocks sperms from entering uterus
2 points
what are the surgical methods of birth control
vasectomy: cutting and tying both sperm ducts to permanently prevent fertilisation in males
tubal ligation: cutting and tying both oviducts to permanently prevent fertilisation in males
what is the natural method of birth control
do not have sexual intercouse during fertile period of the woman’s menstrual cycle
5 points
how can STIs be transmitted
sexual intercourse with an infected person
infected blood during blood transfusion
needle sharing with infected person, accidental needle stick injuries
from infected mother to child during childbirth
(in rare cases) through organ/tissue transplants or unsterilised dental or surgical equipment
5 points
how can STIs be prevented/controlled
sexual abstinence and avoiding having multiple sex partners
not abusing drugs or sharing injection needles
practise safe sex by using condoms during intercourse
use only sterile needles or disposable instruments during injection, piercing or tattooing
accept only HIV-screened blood for blood transfusions
2 points
what is the cure for AIDS/HIV
they are viral STIs and cannot be cured
anti-retroviral drugs will only slow down progression
2 points
what is the cure for gonorrhoea/syphilis
caused by bacteria and infected persons are injected with antibiotics (e.g. penicillin)
syphilis treatment is only effective with early diagnosis and in the early stages
