Il mio scaffale about reproduction in humans by Giulia Colao

flcorl63 — 2019-01-27 05:14:48 UTC

in 1654 von leeuwenhoek looked down his microscope a sample of semen

flcorl63 — 2019-01-27 16:48:35 UTC

in 1695 hartsoecker made a drawing of what he tought one might look like under the microscope

this caused difficulties in explaining why children resembled both their father and their mother

flcorl63 — 2019-01-27 17:04:27 UTC

one idea was the homunculus gradually absorbed characteristics of its mother as it developed inside her uterus

the female reproductive organ

flcorl63 — 2019-01-27 17:07:29 UTC

the female gametes (eggs) are made in the two ovaries. leading away from the ovaries are the oviducts, called the Fallopian tubes, that have a funnel-shaped opening at a short distance from ovaries

uterus or womb has very thick walls, made of muscle, which can stretch when a woman is pregnant

flcorl63 — 2019-02-03 04:18:25 UTC

the narrow opening at the base of the uterus is the cervix, also called the neck of the uterus. it leads to vagina, which opens to the outside

urethra, vagina and rectum opens quite separately to the outside

flcorl63 — 2019-02-03 04:23:33 UTC

the male gametes (spermatozoa) are made in two testes

flcorl63 — 2019-02-03 04:28:50 UTC

each testis is outside the body, in two sacs of skin called the scrotum

flcorl63 — 2019-02-03 04:31:38 UTC

the sperms are carried away in each testis in a tube called the sperm duct. each sperm duct is joined up with the urethra just below the bladder

where the sperm ducts join the urethra, there is a gland called the prostate gland

flcorl63 — 2019-02-03 04:36:35 UTC

it makes a fluid which the sperm swim in

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flcorl63 — 2019-02-03 04:46:25 UTC

eggs begin to mature during puberty, usually one at a time

flcorl63 — 2019-02-03 04:48:39 UTC

ovulation takes place when an egg cell bursts out of the ovary and into the funnel at the end of the oviduct (once a month)

flcorl63 — 2019-02-03 04:55:16 UTC

outside the egg cell there is a layer of yelly, whereas cytoplasm contains yolk (a energy store

flcorl63 — 2019-02-03 05:01:00 UTC

the cells in the tubules will not develop into sperm if they get too hot

finding the differences

flcorl63 — 2019-02-03 05:10:23 UTC

flcorl63 — 2019-02-03 05:13:26 UTC

sperm are made in tubules and stored in tube in epididymis

flcorl63 — 2019-02-03 05:18:11 UTC

sperms are made continually from puberty onwards

look at the picture

flcorl63 — 2019-02-03 05:24:36 UTC

after ovulation.....

flcorl63 — 2019-02-03 05:26:49 UTC

the fallopian tube is lined with cilia which beat rhytmically, so that the egg travels toward the uterus, muscles in the wall of the oviduct also help to move it by peristalsis

flcorl63 — 2019-02-03 05:31:53 UTC

the egg must be fertilized within 8-24 hours after ovulation

the sperm must reach egg while it is quite near the top of the oviduct if fertilisation is to be successful

flcorl63 — 2019-02-03 05:35:14 UTC

flcorl63 — 2019-02-03 05:40:52 UTC

when the man is sexually excited, blood is pumped into spaces inside the penis, so that it becomes erect

to bring the sperm as close as possible to the egg, the penis is placed inside the vagina

flcorl63 — 2019-02-03 05:44:39 UTC

that is SEXUAL INTERCOURSE

flcorl63 — 2019-02-03 05:47:45 UTC

sperm swim using their tails up through cervix, uterus and into the oviduct

flcorl63 — 2019-02-03 05:50:30 UTC

they can swim at a rate of 4mm per minute, many will never reach the oviduct. one ejaculation deposits about a million sperm in the vagina

only one sperm enters the egg

flcorl63 — 2019-02-03 05:57:55 UTC

only the head of the sperm goes in

fertilisation

flcorl63 — 2019-02-03 05:59:16 UTC

the nucleus of the sperm fuses with the nucleus of the egg

implantation

flcorl63 — 2019-02-03 06:03:10 UTC

and stages leading to it. into the oviduct the zygote divides by mitosis

until implantation occurs, the embryo obtains food from the yolk of the egg

flcorl63 — 2019-02-03 06:10:02 UTC

the uterus has a thin, spongy lining and the embryo sinks into it

flcorl63 — 2019-02-06 04:55:45 UTC

flcorl63 — 2019-02-06 04:59:01 UTC

muscles in the wall of the tubes containing sperm contract rhytmically (the wave of contraction begins in the testes, travels along the sperm ducts until the penis) so the sperm are squeezed out of the man's urethra

ejaculation

flcorl63 — 2019-02-06 05:01:48 UTC

sperm are pushed out of the penis into the vagina, one ejaculation deposits about a million sperm in the vagina

the sperm swim using their tails, up through the cervix, the uterus and into the oviduct

flcorl63 — 2019-02-06 05:17:51 UTC

sperm can only swim at a rate of about 4mm per minute

fertilisation

flcorl63 — 2019-02-06 05:25:06 UTC

as the sperm enters the egg, the egg membrane becomes impenetrable, so that no other sperm can get in, and they will all die

from the zygote to the embryo (after eleven weeks the embryo become a fetus)

flcorl63 — 2019-02-06 05:29:47 UTC

before implantation into the thin, spongy lining of uterus, embryo obtains food from the yolk of the egg

placenta grows as the embryo grows and connects embryo to the wall of the uterus, it is where the substances are exchanged between the mother's blood and the embryo's blood, it is the embryo's life support system

flcorl63 — 2019-02-06 05:39:54 UTC

the placenta is soft and dark-red and has finger-like projections called villi which fit closely into the uterus wall

in the placenta are capillaries filled with the mother's blood and the wall of the uterus is filled with the mother's blood

flcorl63 — 2019-02-06 05:40:13 UTC

the fetus's and the mother's blood are brought very close together, because the wall of the placenta is very thin, but they don't mix at all

birth control is important in keeping family sizes small, and in limiting the increase in the human population

flcorl63 — 2019-02-07 04:31:44 UTC

natural methods of birth control

flcorl63 — 2019-02-07 04:37:46 UTC

....avoiding completely sexual intercourse, or....

flcorl63 — 2019-02-07 04:40:34 UTC

flcorl63 — 2019-02-07 04:43:16 UTC

chemical methods

flcorl63 — 2019-02-07 04:44:17 UTC

flcorl63 — 2019-02-07 04:46:25 UTC

but also IUD, intra-uterine device

flcorl63 — 2019-02-07 04:50:47 UTC

has to be fitted by a doctor

or IUS...

flcorl63 — 2019-02-07 04:52:54 UTC

interfere with the ability of sperm to find and fertilise an egg, and also prevents the implantation and the development of any egg that does get fertilised

mechanical methods

flcorl63 — 2019-02-07 04:56:03 UTC

flcorl63 — 2019-02-07 04:57:53 UTC

flcorl63 — 2019-02-07 05:02:09 UTC

diaphragm or cap

flcorl63 — 2019-02-07 05:05:58 UTC

is a circular slghtly domed piece of rubber which is inserted into the vagina, stopping sperm getting through the cervix into the uterus. it is associated a spermicide

vasectomy, quick and simple operation

flcorl63 — 2019-02-07 05:10:03 UTC

sperm ducts cut and the cut ends tied

surgical cutting of the oviducts

flcorl63 — 2019-02-07 05:13:44 UTC

increasing fertility

flcorl63 — 2019-02-07 05:14:11 UTC

the placenta is joined to the fetus by the umbilical cord

flcorl63 — 2019-02-11 04:14:25 UTC

the arteries take blood from the fetus into the placenta, and the vein returns the blood to the fetus

flcorl63 — 2019-02-11 04:28:15 UTC

the dissolved oxygen in the blood passes into the fetal blood by simple diffusion

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flcorl63 — 2019-02-11 04:32:46 UTC

oxygen and food materials in the mother's blood diffuse across the placenta in the fetus's blood, and then are carried along the umbilical cord to the fetus

flcorl63 — 2019-02-11 04:33:25 UTC

as the fetus grows, the placenta grows too. by the time the baby is born, the placenta will be a flat disc, about 12 cm in diameter and 3cm thick

flcorl63 — 2019-02-11 04:38:20 UTC

flcorl63 — 2019-02-11 04:39:09 UTC

flcorl63 — 2019-02-11 04:40:16 UTC

also active transport and pinocitosis

flcorl63 — 2019-02-11 04:40:52 UTC

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flcorl63 — 2019-02-11 04:44:02 UTC

amniotic fluid

flcorl63 — 2019-02-11 04:47:45 UTC

helps to support the embryo and to protect it

all the organs have begun to grow

flcorl63 — 2019-02-11 05:34:11 UTC

8 weeks

flcorl63 — 2019-02-11 05:37:20 UTC

most organs are present, some movements occur

flcorl63 — 2019-02-11 05:39:37 UTC

'ontogenesis is a brief and rapid recapitulation of phylogenesis, determined by the physiological functions of heredity (generation) and adaptation (maintenance)" )

flcorl63 — 2019-02-11 05:40:17 UTC

(Haeckel, E. 1899)

flcorl63 — 2019-02-11 05:41:38 UTC

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flcorl63 — 2019-02-11 05:43:03 UTC

birth

flcorl63 — 2019-02-17 04:19:10 UTC

a few weeks before birth, the fetus usually turns over in the uterus, so that its head lies just over the opening of the cervix

flcorl63 — 2019-02-17 04:24:42 UTC

flcorl63 — 2019-02-17 04:26:53 UTC

the contractions of the muscles of the uterus are painful; the mother can help herself by preparing her body with exercises before labor begins, by breathing in a special way during labor, or taking on pain-killing drugs

flcorl63 — 2019-02-17 04:31:44 UTC

cutting the umbilical cord is painless, because there are no nerves in the cord

flcorl63 — 2019-02-17 04:33:21 UTC

the stump of the cord forms the baby's navel

flcorl63 — 2019-02-17 04:36:53 UTC

ante-natal care

flcorl63 — 2019-02-17 04:47:26 UTC

importance of diet when a woman is pregnant

flcorl63 — 2019-02-17 04:55:37 UTC

calcium for the fetus's bones, extra iron because she need more blood and her growing baby is also forming blood (to form haemoglobin)

flcorl63 — 2019-02-17 05:08:08 UTC

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flcorl63 — 2019-02-17 05:42:51 UTC

"what even is this?" (feline thoughts)

flcorl63 — 2019-02-17 05:49:29 UTC

a human baby is helpless when it is born, and both parents should help to care for it

during pregnancy....

flcorl63 — 2019-02-17 05:57:55 UTC

flcorl63 — 2019-02-17 06:06:20 UTC

the baby needs to be kept warm

flcorl63 — 2019-02-17 06:11:36 UTC

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flcorl63 — 2019-02-17 06:22:29 UTC

usually one egg is released into the oviduct every month in an adult woman

flcorl63 — 2019-02-17 06:23:37 UTC

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flcorl63 — 2019-02-17 06:37:12 UTC

hormones and the menstrual cycle

flcorl63 — 2019-02-17 06:41:35 UTC

oestrogen is not the only female sex hormone

first, a follicle develops inside an ovary. this is stimulated by FSH. the developing follicle secretes oestrogen which makes the lining of the uterus grow thick and spongy. throughout this time, the pituitary gland secretes FSH and LH which stimulate the follicle to keep on secreting oestrogen. when the follicle is fully developed, raises the production of LH, this causes OVULATION. the empty follicle stops secreting oestrogen and becomes a corpus luteum, which starts the secretion of progesterone, while levels of FSH and LH fall. progesterone causes prepares the uterus (it becomes thick spongy and well supplied with blood) in case the egg is fertilized. if this doesn't happens, the corpus luteum gradually disappears, progesterone is not secreted and the lining of the uterus breaks down. if the egg is fertilized the corpus luteum carries on secreting progesterone until the embryo sinks into the uterus wall, and a placenta develops. the progesterone mantain the uterus lining, so menstruation doesn't happen during the pregnancy

flcorl63 — 2019-02-17 06:55:37 UTC

flcorl63 — 2019-02-18 04:30:18 UTC

flcorl63 — 2019-02-18 04:34:22 UTC

sexually transmitted infections are caused by bacteria or viruses

flcorl63 — 2019-02-18 04:34:49 UTC

passed during sexual intercourse

aids is caused by HIV

flcorl63 — 2019-02-18 04:39:33 UTC

human immunodeficiency virus

HIV infects LYMPHOCYTE T

flcorl63 — 2019-02-18 04:42:19 UTC

over a long period of time, HIV slowly destroiys T cells, many years after the infection the number of T cells which would normally kill viruses is very low, so it's very difficult for someone's own immune system to protect them against HIV

about ten years after initial infection with HIV, a person is likely to develop symptoms of AIDS unless they are given effective treatment

flcorl63 — 2019-02-25 03:44:42 UTC

flcorl63 — 2019-02-25 03:48:59 UTC

a person with AIDS usually dies from a collection of several illnesses

flcorl63 — 2019-02-25 03:49:38 UTC

flcorl63 — 2019-02-25 03:53:58 UTC

as yet, no vaccine has been produced to prevent HIV infection, despite large amounts of money being spent on research

flcorl63 — 2019-02-25 03:57:04 UTC

....questo però ce lo leggiamo in italiano...

flcorl63 — 2019-02-25 03:59:20 UTC

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2019-03-07 10:36:36 UTC

ahahahah

flcorl63 — 2020-01-23 03:08:11 UTC

chorionic villi

...but....I think this is a bad mistake

flcorl63 — 2020-01-25 03:47:30 UTC

flcorl63 — 2020-02-01 04:06:25 UTC

flcorl63 — 2020-02-08 03:24:33 UTC