life sciences chapter 4

asexual reproduction

production of a new organism by one parent with no gametes present

sexual reproduction

production of a new organism by two parents with gametes present

testosterone

a hormone produced in the testes of males

oestrogen

a hormone produced in the ovaries of females

testes

produce male gametes (sperm cells). produces millions a day

epididymis

temporarily stores and matures sperm cells

vas deferens

connects the testes to the urethra, to allow the ejaculation of sperm cells from the testes

urethra

transfers and transports semen and urine out the body

prostate gland

produces a sucrose fluid to aid in transportation of sperm cells. this fluid makes up about 1/3 of seminal fluid

seminal vesicle

produces an alkaline fluid that forms part of semen, to allow for lubrication and neutralisation of the urethra during ejaculation

penis

contains special tissue that can be filled with blood to make the genitalia erect so it can transfer semen into the vagina

scrotum

sack like structure that holds and protects the testes, its outside the body to help regulate temperature

bladder

temporary storage of urine

circumcision

the process of removing the foreskin of a penis

acrosome

found at the tip of sperm cells, it contains hydrolytic enzymes which digest and penetrate the ovum wall

nucleus (sperm cells)

contains the genetic material of a male

mitochondria (sperm cells)

provides the energy for the sperm cell to move

tail (sperm cells)

responsible for the spiral like propelling movement of the sperm cell

vagina

muscular passage between uterus and outside of body. where semen is deposited during sex. also forms the birth canal during child birth

cervix

separates the uterus and vagina, prevents any harmful bacterias or substances from entering the uterus

uterus

hollow organ that contains endometrium lining so it can house the foetus during pregnancy

endometrium

inner lining of uterus which builds up with blood to thicken, and if no zygote is implanted, the lining is shed which results in a period (menstruation)

fallopian tubes

two tubes lined with cilia which transport the ovum from the ovaries to the uterus. usually the site of fertilisation

ovaries

develops and releases mature ovum cells. also produce and release oestrogen and progesterone

menstruation and developmental stage

days 1-7, endometrium is shed as no fertilisation has occured. this is also known as a period (menstruation)

building and preparation stage

days 8-13, a new endometrium begins to thicken

ovulation

days 13-15, the ovum are released into the fallopian tubes, a female is most fertile during this period

maintenance

days 15-28, the endometrium is maintained in anticipation of a zygote being implanted

menopause

the number of egg cells in a woman decreasing over time

copulation

commonly referred to as sexual intercourse. the erect penis is place into the vagina to ejaculate sperm into the vagina

fertilisation

the fusion of a male sperm with a female ovum to form a fertilised ovum (zygote)

zygote

when a fertilised ovum has not yet become embedded in the endometrium which is called implantation

embryo

what a fertilised ovum is called when it is embedded into the endometrium

foetus

10 weeks after fertilisation, the embryo develops into this

gestation

another term for pregnancy

placenta

forms the attachment between foetus and mother, a blood rich organ that helps for oxygen to pass to the foetus and filter out co2 and other harmful substances

umbilical cord

joins foetus to placenta, carries o2 to foetus and co2 to the placenta

amniotic sac

sac that secretes amniotic fluid

amniotic fluid

surrounds the foetus, absorbs shock, regulates temperature and keeps foetus hydrated

parturition

another term for childbirth

labour and dilation of cervix

1st stage of parturition, uterus walls contract and forces foetus in direction of cervix. amniotic fluid is also released (water breaking)

delivery

2nd stage of parturition, once cervix dilates to 10cm, foetus is pushed out and umbilical cord is cut.

expulsion of placenta

3rd stage of parturition, after 10-30 minutes the placenta and other membranes are forced out the uterus (afterbirth)

caeserean birth (c-section)

when foetus is not facing cervix an incision in lower abdominal region is made to remove the foetus

pre-natal care

ensuring the foetus is healthy, by having a healthy diet and low stress levels (well-being of the mother)

post-natal care

breastfeeding, caring for baby and keeping it nurtured and safe

contraception

methods or devices used to prevent unwanted pregnancy

abstinence

not having sex

withdrawal (pull out)

when a man pulls his penis out right before ejaculation

the pill (morning after pill)

a tablet taken the day after sex to block specific pregnancy hormones from being produced

birth control pills

tablets taken every day to suppress certain pregnancy hormones

vasectomy

when the vas deferens is cut, so no sperm cells can enter the semen

tubal litigation

fallopian tubes are cut to prevent any ova from coming into contact with sperm cells

condom

latex sheath placed over penis to trap semen inside during ejaculation

intra-uterine device (IUD)

a plastic or metal device inserted into the uterus to prevent any egg getting fertilised

sexually transmitted infections (STIs)

infections passed on from one human to another through sexual contact

human immunodeficiency virus (HIV)

a virus spread through sex that affects the immune system of the individual. it has no cure but sometimes can only have minor effects

anti-retroviral pills (ARVs)

pills used to help fight off HIV

acquired immuno-deficiency syndrome (AIDS)

a person has this when their immune system is affected by HIV. aids doesn't kill you but it allows you to get very ill very easily