Human Reproduction Flashcards
Draw a labeled diagram of the male reproductive system
.
What are the parts of the male reproductive system?
Bladder, Seminal vesicle, prostate gland, Cowper’s Gland, Sperm duct, Urethra, Epididymis, Testis, Penis, Scrotum
What are the two main parts of the male reproductive system?
the penis and the scrotum
What is a gonad?
A gonad is an organ that produces a sex cell in animals
What are male gonads called?
testes
How and where do testes develop?
Testes develop inside the body at first, but a few weeks before birth descend into the scrotum.
What temperature are the testes kept at? Why?
This means they are kept at slightly lower than body temperature (35 degrees) which is the ideal temperature for sperm production.
What are seminiferous tubules? Where are they and what is their function?
Seminiferous tubules inside the testes are lined with sperm producing cells.
What do cells between the seminiferous tubules produce?
Cells between the tubules produce the hormone testosterone.
What do seminiferous tubules join to form?
the epididymis
What happens in the epididymis?
Sperm mature and are stored here
What does the epididymis lead to?
The sperm duct (vas deferens)
What does the sperm duct do?
Brings sperm to the urethra
What is the urethra responsible for?
The urethra is responsible for carrying sperm and urine out of the body
What are the glands in the male reproductive system?
Seminal vesicle, prostate gland, cowper’s gland
What do the glands in the male reproductive system produce?
These glands produce seminal fluid which nourishes the sperm and provides a medium in which to swim.
What is semen made up of?
seminal fluid and sperm
What are the functions of the seminal vesicle, prostate gland and Cowper’s Gland?
Produces Seminal Fluid
- For sperm to swim in
- Nourishment for sperm
What is the function of the penis?
Places sperm in the female body
What does an acrosome contain?
contains digestive enzymes
What does a nucleus contain?
23 chromosomes
What are the three parts of the sperm?
Head, middle, tail
What does the collar contain?
contains mitochondria
What is the function of the flagellum?
It allows sperm to swim
What are sperm and egg producing cell and what do they contain?
Sperm and egg producing cells are diploid i.e. they contain 46 chromosomes.
How do sperm and egg producing cells form sperm and egg cells?
They divide by meiosis to form sperm and egg cells.
What number of chromosomes do each sperm and egg cell contain due to them dividing by meiosis?
Each sperm and egg cell, therefore, has a haploid number of chromosomes i.e. they have 23 each
What is testosterone?
Testosterone is the male hormone responsible for the development of the primary and secondary male sexual characteristics
What are the primary sexual characteristics?
The primary sexual characteristics are the presence of the male and female reproductive parts
What are the secondary sexual characteristics?
Secondary sexual characteristics refer to features that distinguish males from females, apart from the sex organs themselves.
What are the male secondary sexual characteristics?
The growth of pubic, facial and body hair
The enlargement of larynx and “breaking” of the voice
Increased muscular development and bone development
A growth spurt at puberty
An increased secretion of sebum in the skin
Draw a labeled diagram of the female reproductive system
.
What is the fallopian tube also known as?
Oviduct
What is another word for the womb?
Uterus
Where does the bladder lie in the female reproductive system?
In front of the uterus
What is the function of ovaries?
To produce the eggs and female hormones.
How many eggs are present at birth?
all of them
What happens to eggs after puberty?
After puberty 20 eggs mature each month. Only one will be released from the ovary - the rest will die.
What happens to 20 eggs every month?
Only one will be released from the ovary - the rest will die.
How many eggs mature each month?
20
What is the structure of the Fallopian tubes?
The Fallopian tubes are muscular and approx 12 cm long.
Where do the eggs go after they have been released from the ovary?
Funnels at the tip of each tube catch the egg after it is released from the ovary.
What happens to the egg after it is caught by funnels at the tip of the fallopian tube?
The egg is moved along the tube by cilia and muscular peristalsis.
What happens to the egg after being moved along the tube by cilia and muscular peristalsis?
The egg is either fertilised or dies in the fallopian tube
What is the uterus? (not function)
A muscular structure approximately the size of your fist.
What is the outer wall of the uterus made of?
Outer wall made of involuntary muscle
What is the inner lining of the uterus called?
Inner lining is called the endometrium
What happens to the inner lining of the uterus each month? Why?
This lining thickens each month with cells and blood vessels to nourish the embryo
What does the cervix do?
The cervix separates the uterus from the vagina
What is the vagina? (not function)
Elastic muscular tube 10cm long.
What does the vagina allow?
Allows entry of sperm
What is the vagina for the exit of a baby?
The birth canal
What is the function of the vagina to do with birth?
The birth canal for the exit of a baby
What is the vagina lined with? Why?
Lined with cells that produce mucous. This serves to protect against the entry of pathogens.
What are the female hormones?
Oestrogen and progesterone are the female hormones
What causes the development of the secondary female characteristics?
A combination of oestrogen and progesterone at puberty causes the development of the secondary female characteristics
What are the secondary female characteristics?
The maturing and enlargement of the breasts.
The widening of the pelvis to allow for birth.
The growth of pubic and underarm hair.
A growth spurt.
What happens once meiosis is complete?
The egg is surrounded within a structure called the Graafian follicle.
What structure produces the female hormone oestrogen?
The Graafian follicle
What happens to the Graafian follicle when mature? What happens at ovulation?
When mature the follicle forms a swelling on the outside of the ovary. It bursts at ovulation to release the egg.
What happens to the Graafian follicle after ovulation?
After ovulation the follicle fills with yellow cells and becomes the Corpus luteum (yellow body).
What is the function of the Corpus luteum?
The secretes the hormone progesterone
What is the mentrual cycle?
The menstrual cycle is a 28 day sequence of events that produces an egg and prepares the body for pregnancy.
When does the menstrual cycle begin and end?
This cycle begins at puberty and continues until the menopause (the end of the woman’s reproductive life).
What is the menopause?
The end of the woman’s reproductive life
What happens on day 1-5 of the menstrual cycle?
The old lining of the uterus (endometrium) breaks down and is shed from the body. The loss of this blood and tissue is called menstruation (period). A new egg is produced in the ovary by meiosis. This new egg is surrounded by the Graafian follicle.
What is the old lining of the uterus called?
The endometrium
What is another word for period?
menstruation
What happens on days 6-14 of the menstrual cycle?
The hormone oestrogen is produced by the developing Graafian follicle. This has two functions: It causes the lining of the uterus (endometrium) to build up again in preparation for implantation. Oestrogen also prevents the development of any more eggs.
What happens on day 14 of the ovulation cycle?
Ovulation. This occurs when the Graafian follicle bursts to release the egg into the fallopian tube
What happens of days 14 - 28 of the menstrual cycle?
The Graafian follicle now develops into the Corpus Luteum (yellow body). This has two functions:
It causes the endometrium to thicken even further.
It also prevents new eggs from forming.
What will happen to the egg that was released in the menstrual cycle?
The egg that was released will die by day 16 if it is not fertilised. Thus days 12-16 of the menstrual cycle are referred to as the Fertile Period.
What are days 12-16 of the menstrual cycle referred to?
the Fertile period
What happens if fertilisation does not take place?
The Corpus Luteum starts to degenerate around day 22. This results in a reduction in progesterone levels. As a result the lining of the uterus breaks down again on day 28. The menstrual cycle begins again with day 1.
What does the degeneration of the Corpus Luteum result in?
A reduction in progesterone levels
What does the degeneration of the Corpus Luteum resulting in a reduction in progesterone levels result in?
The lining of the uterus breaks down again on day 28.
What is another word for sexual intercourse?
copulation
What are the stages of sexual intercourse?
Sexual arousal, Copulation, Orgasm
What is involved in sexual arousal?
The penis becomes erect
The vagina becomes lubricated
What is involved in copulation?
The penis is inserted into and moved inside the vagina
What is involved in orgasm?
Sperm is released from the penis (Ejaculation)
Contraction of vagina and uterus
What is it called when sperm is released from the penis?
Ejaculation
What is insemination?
Insemination is the release of sperm into the female
What happens during insemination?
Contractions of uterus and fallopian tubes move the sperm to the fallopian tubes within 5 minutes
What happens if an egg is present during insemination?
If an egg is present it releases chemicals to attract the sperm this is called chemotaxis
What is fertilisation?
Fertilisation is the fusion of the egg and sperm nuclei to form a diploid zygote
Where does fertilisation occur?
in the fallopian tube
What is implantation?
Implantation is the embedding of the fertilised egg into the lining of the uterus
When does implantation occur?
This occurs 6-9 days after fertilisation