Reproductive System Flashcards
label Male and Female reproductive system - WORD
what are Ovaries?
Females have 2 ovaries
Responsible for oogenesis (the production and maturation of the female gametes eggs/ova).
How often does the maturation of eggs take place?
once a month, and the ovaries take turns.
Fallopian tubes? (2)
Connects the ovaries to the uterus.
Important location for egg fertilisation.
Uterus (3)
where the fertilised egg will implant.
Contains the developing embryo and foetus for the entire pregnancy
has an endometrial lining that is shedded monthly, giving rise to a monthly
bleeding period (periods).
Cervix
where?
produces what?
birth?
common site of what?
Located at the bottom most narrow part of the
uterus
Continuously produces mucous- Mucous viscosity (thickness and stickiness of mucus) is regulated by female sex hormones and affect the sperm’s ability to reach the egg
cervix dilates when giving birth
One of the most common site for cancer- at 25yrs, every three to five years the NHS invites women for cervical cancer screening.
How is cervix cancer tested for?
smearing a small brush against the cervix- sample checked for abnormal shaped cells.
what is cervix cancer associated with
human papillomavirus (HPV)- vaccines available.
*sexually transmitted infections (STIs)
*can affect the skin and mucous membranes of genital area, mouth, and throat
vagina
where?
what?
able to do what?
what does it have?
- Extends from the vestibule (bottom of vagina) to the cervix
- Is an elastic muscular canal
- able to lengthen and dilate during arousal due to muscle relaxation
- Has Bartholin’s glands at the entrance that Secrets small amounts of mucous during arousal.
Hymen
function?
virginity?
testing?
has no biological function
scientifically impossible to tell if someone is a virgin from examining the hymen
testing the hymen called a gynaecological examination.
Clitoris
Its only function is to provide sexual pleasure.
Anatomically similar to penis- both have erectile tissue (corpus cavernosum)
Female Menstrual Cycle (period):
what age does it start?
How long does it last?
Counted from when?
how long does it last?
when does it stop?
when is the female most fertile?
generally age 12- but can range from 8-15.
usually last 4-8 days
from the 1st day
generally 28 days- but can range from 23- 35 days.
stops at menopause- approx. age 52
right after ovulation.
what are females born with? How many chromosomes?
millions of primary oocytes in their ovaries.
these cells have have 46 chromosomes but are not ready for fertilisation
what is an oocyte?
what type of cell are they?
where is it produced?
what happens to them before they can be fertilised by a sperm cell?
An oocyte is an immature egg cell that is involved in reproduction.
Type of germ cell
Produced in the ovaries
They undergo a maturation process.
what is the menstrual cycle regulated by?
sex hormones like oestrogen and progesterone.
what happens every month after menstruation?
- what happens to those which reach full maturation.
- release of more than one causes what?
- what happens to the follicles that have not fully mature?
Every month after menstruation hundreds of primary follicles (containing
primary oocytes) will start maturing:
* One oocyte will reach full maturation and
be released (ovulation)
* Releasing more than one oocyte can lead to non-identical twins (nearly 2% of all pregnancies)
* The other follicles that did not fully mature will be reabsorbed.
cause of twin pregnancies (2).
twin pregnancy from the release of two eggs/oocytes in the same month = due to GENETIC= non- identical twins.
twin pregnancy from the release of one oocyte= due to CHANCE= identical twins.
what happens when primary oocyte matures?
When the primary oocyte matures it will undergo MIEOTIC division
to have 23 (haploid) chromosomes instead of 46 (diploid).
what is ovulation?
- when does it occur?
the process during the menstrual cycle when a MATURE egg is released from one of the ovaries.
typically occurs around the middle of the cycle, about 14 days before the start of the next menstrual period
when the oocyte reaches full maturation and is released (ovulation), what happens?
travels through the fallopian tube to the uterus and of on this path it does not meet a sperm it will proceed into the period. More specifically:
the remains of the follicle forms the corpus luteum (surrounding the oocyte).
The corpus luteum releases hormones (progesterone) to prepare the uterus for a fertilized egg.
If no fertilised oocyte is implanted in the endometrium the endometrial lining will shed.
This shedding causes a period.
testis function?
every male has two testicles.
responsible for spermatogenesis (the production of the male gametes sperm).
Epididymis function (2).
where the Sperm moves to from testis to be stored and to mature further (gain motility).
Secretes immobilin (glycoprotein) that mechanically keeps the sperm immobile until ejaculation
Vas Deferens
HOW!
Transports sperm towards the ureTHRA through peristaltic movement (muscle contractions).
Seminal Vesicle
- what does it do?
- what does it contain?
- Dilutes the sperm to form semen, 75-80% of semen comes from the seminal vesicle
- Contains fructose, citric acid,
prostaglandins, and fibrinogen= Provides nutrition for the sperm and supports fertilisation
Prostate
what does it secrete?
what does it contains?
what else does it do?
common site of what?
- Secrets fluid that becomes a part of the semen
- Contains zinc that helps with sperm motility and fertilisation
-Exerts muscular control of urination and ejaculation (expulsion of sperm, and prevention of urine entry in sperm duct).
- One of the most common organ affected by cancer in men- Benigin Prostrate hyperplasia (enlargement).
urethra function
Transports both sperm and urine through penis.
Penis
what is it?
what happens to it?- what is this caused by?
Organ that swells during arousal and is used for copulation (sexual intercourse)
Erectile tissue (corpus cavernosum) becomes filled with blood due to Nitric Oxide release.
Nitric Oxide release is caused by:
- Vasodilation from muscle relaxation due to cGMP increase.
- Production of phosphodiesterase 5 (PDE5) after ejaculation or interruption breaks down cGMP.
where are spermatozoa (single sperm) produced?
is spermatogenesis lifelong?
what is spermatogenesis regulated by?
in testis, specifically in Seminiferous tubules.
Spermatogenesis is continuous through life, but production is decreased after the age of 35.
by the male sex hormone testosterone.
Females are born with millions of primary oocytes in their ovaries, the primary oocytes still have 46 chromosomes and are not ready for fertilisation.
What is the case for men?
In males, the process is different. Men are not born with a set number of sperm cells. Instead, they continuously produce sperm throughout spermatogenesis.
How does the continuation of spermatogenesis work?
Spermatogonia: These are the stem cells that divide by mitosis to produce primary spermatocytes.
Primary Spermatocytes: These cells undergo meiosis I to form secondary spermatocytes, each with 23 chromosomes.
Secondary Spermatocytes: These cells undergo meiosis II to form spermatids, each with 23 chromosomes.
Spermatids: These immature sperm cells undergo a series of changes to become mature spermatozoa (sperm).
The sexual response cycle is divided into 4 stages. what are they?
+ Arousal Graph
- Excitement
- Plateau
- Orgasm
- Resolution
Excitement
what is it controlled by?
experience
- Controlled by parasympathetic nervous system (PNS)
- Both males and females will experience:
- Increased heart rate
- Increased blood pressure
- Increased blood flow to the skin
- Vasocongestion (Swelling of corpus cavernosum)
-Males: Leads to erection
-Females: Swelling of clitoris
(up to 2-3 times larger) - Females also experience vaginal elongation and uterine elevation
what is it called when a male is unable to have or maintain an erection?
Affects how many men?
Erectile Dysfunction
50% of men between the ages of 40 and 70.
Plateau
- both men and female
- males
-females
in Both males and females , many of the PNS effects continue in the plateau phase and breath rate increases.
Males:
* The internal urethral sphincter will contract (close) to prevent urine mixing in the semen.
* Prevents retrograde (backward movement) ejaculation
* Pre-ejaculate fluid, some studies say it can contain sperm
Females:
* The Bartholin glands PRODUCE mucous
* Clitoris is sensitive
Orgasm
what is it?
what does it cause?
where does it occur?
how is it experienced in men and females?
- a neurological phenomenon- involves multiple regions of the brain.
- causes the release of pelvic vasocongestion and neuromuscular tension= leads to relaxation.
- felt in genital area, experienced as pleasure in the brain.
males= ejaculation
females= vaginal contractions
Ejaculation
what does it accompany?
what does ejaculation contain?
what does ejaculation during vaginal sex cause?
Orgasms are mostly accompanied by ejaculation in males but not always
- Separation in timing between orgasm and
ejaculation can occur.
- It is also possible to have an orgasm without erection.
37 million sperm and has a volume of 1.5 cl*
Ejaculation during vaginal sex can lead to pregnancy
Resolution
The body slowly returns to normal levels of functioning
- Heart rate goes back to normal
- Blood pressure goes back to normal
- Breathing rate decreases
Fertilisation of an oocyte
The oocyte will move along the fallopian tube towards the uterus- Will survive for 24 hours without being fertilised.
Sperm will swim from the vagina, through the cervix and uterus to meet the oocyte in the fallopian tube - Sperm can survive for 3-5 days
The 23 chromosomes from the oocyte will combine with the 23 chromosomes from the sperm- Forming a complete set of 46 chromosomes in the embryo
what chromosome does the oocyte (immature egg cell) carry?
what chromosome does the sperm carry?
Oocyte= X chromosome
Sperm = can either carry an X or Y chromosome after the second Meiotic division.
The 23 chromosomes from the oocyte will combine
with the 23 chromosomes from the sperm Forming a complete set of 46 chromosomes in the embryo.
* XY = Male baby
* XX = Female baby
when does pregnancy start?
what are the 4 stages involved?
when the blastocyst implants into the uterus wall (endometrium).
Hatching- the outer layer of the fertilised oocyte called the Zona pellucida sheds.
Apposition – Trophoblasts of the fertilised oocyte form a weak attachment to the endometrium.
Adhesion – A stronger attachment mediated by microvilli and glycoproteins.
Invasion – Trophoblasts grow invasively further into the endometrium leading to the formation of the placenta.
what do pregnancy test measure?
Human chorionic gonadotropin (hCG) in urine.
what is hCG made by?
by trophoblasts from the placenta
what is the placenta?
what does the mothers blood do? How does the baby receive it?
a TEMPORARY organ that provides nutrition to the foetus.
The mothers blood bring nutrients and oxygen to the placenta.
The baby receives the nutrients and oxygen via the umbilical cord - not directly connected to the blood circulation systems.
what hormones does the placenta produce? (3)
- Human chorionic gonadotropin (hCG)
- Oestrogen and progesterone- Essential for maintaining pregnancy
what is the amniotic sac?
a membrane that surrounds the foetus.
what does the amniotic sac contain? what is it produced by?
From week 16 what does it contain? From where?
what are the functions of this?
amniotic fluid produced by the MOTHERS PLASMA.
- From week 16 it also contains urine from the foetus
This helps :
Cushion and protect the foetus.
Important for exchange of nutrients.
what is child birth also known as.
labour/ parturition/ delivery
when does childbirth happen?
what happens during chidlbirth?
what are the three stages of giving birth?
between week 37 and 42
contractions and the amnionic fluid comes out (water breaks)
three stages of giving birth
* Dilation
* Birth
* Afterbirth delivery – delivery of the placenta
An ovum only has 24 hours to be fertilised after ovulation but sperm cells can live for 5 days after sex. Between which days can a female risk to become pregnant if she ovulated on day 12?
7-13
