The Reproductive System Flashcards
1
Q
Where is the female reproductive system located?
A
In the lower abdominal cavity.
Surrounded and protected by the pelvis.
2
Q
What is a gonad?
A
An organ that produces gametes (sex cells).
e.g
Ovaries in females.
Testes in males.
3
Q
What is an oviduct?
A
The collective term for the fallopian tubes and the uterus.
4
Q
Where does insemination occur?
A
At the top of the vagina.
Just outside the cervix.
5
Q
Where does ovulation occur?
A
In the Graafian follicle of the ovary.
6
Q
Where does fertilisation occur?
A
In the fallopian tube.
7
Q
Where does implantation occur?
A
In the endometrium of the uterus.
8
Q
Where does meiosis occur?
A
In the ovary.
9
Q
How many eggs are there at birth?
A
1 million potential eggs as they are still diploid and have not undergone meiosis.
10
Q
What is puberty?
A
The onset of sexual maturity.
11
Q
In terms of egg production, what happens at puberty?
A
Approximately 20 eggs are produced every month by meiosis in the ovary but only one survives and develops while the rest die.
12
Q
What happens after meiosis?
A
The egg is protected and nourished inside the Graafian follicle within the ovary.
13
Q
Give the precise location of production of female gametes in humans.
A
The Graafian follicle in the ovary.
14
Q
Describe the structure of the ovaries.
A
Female sexual organs/ gonads as they produce gametes.
15
Q
Describe the structure of the Fallopian tubes.
A
Muscular tubes with ciliated funnels.
16
Q
What are cilia?
A
Thin, fine hairs.
17
Q
Describe the structure of the uterus.
A
A hollow organ that is the size of a clenched fist.
Consists of involuntary muscle, the lining is called the endometrium.
18
Q
Describe the structure of the cervix.
A
A narrow canal between the uterus and vagina.
19
Q
Describe the structure of the vagina.
A
An elastic muscular tube that is 10cm long.
Labia are folds of skin which protect the vagina.
20
Q
Describe the structure of the hymen.
A
A ring of tissue over the entrance to the vagina- broken by tampons and sexual intercourse.
21
Q
What are the functions of the ovaries?
A
Produce egg cells (ova) by meiosis.
The Graafian follicle of the ovary produces the female hormone oestrogen.
The corpus luteum of the ovary produces the female hormone progesterone.
22
Q
What are the functions of the Fallopian tubes?
A
Site of fertilisation, forming a zygote.
The ciliated funnel collects the egg where peristalsis and cilia move the egg along the Fallopian tubes.
23
Q
What are the functions of the uterus?
A
The endometrium of the uterus is the site of implantation.
The endometrium protects and nourishes the developing embryo.
24
Q
What are the functions of the cervix?
A
Allows the sperm cells to enter there uterus during copulation.
25
What are the functions of the vagina?
It is the female organ of copulation, allows the entry of male gametes into the vagina.
Passageway for the delivery of a baby or menstrual flow.
Beneficial bacteria in the vagina produce lactic acid which inhibits the growth of pathogens.
26
What is the menstrual cycle?
A cycle of events which occurs every 28 days from puberty to menopause, provided that the female is not pregnant.
27
What is negative feedback?
When the level of a hormone in the blood, controls the production of another hormone, or itself.
28
What happens on days 1-5 of the menstrual cycle?
The endometrium breaks down and is shed from the body- this is known as menstruation- triggered by low levels of progesterone.
FSH:
Stimulates the Graafian follicle to develop.
Stimulates the Graafian follicle to secrete oestrogen.
29
What does FSH stand for?
Follicle Stimulating Hormone.
30
What happens on days 6-13 of the menstrual cycle?
Oestrogen repairs and builds up the endometrium.
Oestrogen stimulates the production of LH.
Negative feedback: high levels of oestrogen inhibits the secretion of FSH.
31
What does LH stand for?
Luteinising Hormone.
32
What happens on day 14 of the menstrual cycle?
High levels of LH stimulates ovulation.
LH:
Causes the Graafian follicle to develop into the corpus luteum.
Stimulates the corpus luteum to secrete progesterone.
33
What happens on days 15-28 of the menstrual cycle?
The corpus luteum secretes progesterone which thickens and maintains the endometrium.
Negative feedback: high levels of progesterone inhibits the secretion of FSH and LH.
Egg on day 14 may or may not be fertilised:
If fertilisation occurs-
The corpus luteum persists and secretes progesterone.
High levels of progesterone maintains pregnancy by maintaining the endometrium.
If fertilisation does not occur-
The corpus luteum breaks down at the end of the 28 day cycle.
Levels of progesterone decrease resulting in menstruation and a new menstrual cycle.
34
What is ovulation?
The release of an egg from the Graafian follicle of the ovary into the ciliated funnel of the Fallopian tube.
35
Where is FSH produced?
The pituitary gland.
36
Where is oestrogen produced?
In the Graafian follicle in the ovary.
37
Where is LH produced?
The pituitary gland.
38
Where is progesterone produced?
The corpus luteum in the ovary.
39
When is FSH produced in the menstrual cycle?
Days 1-5.
40
When is oestrogen produced in the menstrual cycle?
Days 6-13.
41
When is LH produced in the menstrual cycle?
Day 14.
42
When is progesterone produced in the menstrual cycle?
Days 15-28.
43
What are the functions of FSH?
Stimulates a Graafian follicle to be developed.
| Stimulates the Graafian follicle to secrete oestrogen.
44
What are the functions of oestrogen?
Repairs and builds up the endometrium.
Stimulates the production of LH.
Negative feedback: High levels of oestrogen inhibits the secretion of FSH.
45
What are the functions of LH?
Stimulates ovulation.
Causes the Graafian follicle to develop into the corpus luteum.
Stimulates the corpus luteum to secrete progesterone.
46
What are the functions of progesterone?
Thickens and maintains the endometrium.
Therefore maintains pregnancy and the placenta.
Negative feedback: high levels of progesterone inhibits the secretion of FSH and LH.
47
Name the female menstrual disorder.
Fibroids.
48
What are fibroids?
A menstrual disorder.
Benign tumours of the uterus.
Cause:
An abnormal response to the hormone oestrogen.
Prevention:
None- recommended to exercise regularly and maintain a healthy diet.
Treatment:
Surgical removal of the fibroids or uterus.
49
When are the primary sexual characteristics in the female present?
During pregnancy/ during development in the uterus- oestrogen causes the development of the primary sexual characteristics e.g growth of sexual organs.
50
What does secondary sexual characteristics mean?
The physical changes that develop at puberty, under the influence of oestrogen in the female and testosterone in the male.
It allows one to distinguish between the sexes, but are not essential for reproduction.
51
When are the secondary sexual characteristics in the female present?
```
At puberty, oestrogen( along with progesterone) causes the development and then maintains the female secondary sexual characteristics.
Examples:
Increased body fat.
Breast enlargement.
Widening of the pelvis.
Growth of the underarm and pubic hair.
```
52
What is the role of meiosis in reproduction?
In humans, gametes are produced by meiosis.
Meiosis is a division of a diploid nucleus, which halves he number of chromosomes.
Meiosis occurs in the ovaries and testes (gonads).
53
What is the role of mitosis in reproduction?
When gametes fuse at fertilisation, a diploid zygote is formed, which undergoes mitosis to allow growth to occur.
54
What is a gamete?
A haploid sex cell that is capable of fusion during fertilisation.
55
Describe the structure of the testes.
Are the male gonads which develop inside the body cavity until a few weeks before birth, when each testis descends into the scrotum outside the body cavity.
This allows sperm production which occurs at 35C.
56
Describe the structure of the scrotum.
A pouch located outside the body cavity.
57
Describe the structure of the epididymis.
A coiled tube on the outside of each testis.
58
Describe the structure of the sperm duct.
A muscular tube.
59
Describe the structure of the seminal vesicles/ prostates gland/ cowpers gland.
Associated glands of the male reproductive system.
60
Describe the structure of the urethra.
A duct (exocrine feature) which runs through the centre of the penis.
61
Describe the structure of the penis.
Made of erectile tissue with a swollen tip, covered in foreskin.
62
What is semen?
Sperm cells and seminal fluid.
63
What are the functions of the testes?
The testes produce sperm cells by meiosis inside tubules, which are lined with diploid sperm producing cells.
The male hormone testosterone is produced in the testes.
64
What are the functions of the scrotum?
Maintains a suitable temperature of 35C which is needed for meiosis to occur and sperm to be produced.
65
What are the functions of the epididymis?
The place where sperm cells mature.
| Where sperm cells are stored for up to 6 weeks.
66
What are the functions of the sperm duct?
Transports sperm from each testes to the urethra by peristalsis.
67
What are the functions of the seminal vesicles/ prostate gland/ cowpers gland?
Produce seminal fluid which is added to sperm cells forming semen.
68
What is the role of seminal fluid?
Protects and provides a medium for sperm to swim.
69
What is the role of semen?
Contains fructose to nourish sperm cells.
70
What is the role of the urethra?
To transport semen or urine through the penis.
71
What is the role of the penis?
The male copulatory organ which introduces semen into the top of the female vagina during intercourse.
72
Compare an egg and sperm cell.
The sperm cell is the smallest human cell and is the male gamete.
The egg is the largest human cell and is the female gamete.
The sperm cell is motile, the egg cell is non- motile.
73
What is the function of the sperm flagellum?
Allows the sperm to swim to the egg cell using energy from aerobic respiration in the mitochondria.
74
What is the function of the sperm acrosome?
It contains the enzymes that digest the egg membrane allowing the sperm nucleus to gain access to the egg nucleus.
75
How long can sperm survive in the female reproductive tract.
Sperm can survive for up to 7 days inside the female reproductive tract.
76
Why does the sperm cell not contribute mitochondrial DNA to the zygote, while the egg does?
As the mid- piece, containing mitochondrial DNA in not used during fertilisation- only the head enters the egg cytoplasm.
77
Write a note on the survival times of sperm and ova.
Sperm survive for up to 7 days.
Ov a survive for up to 2 days.
Longer survival times means a greater chance of fertilisation.
Sperm cells are nourished in the female reproductive tract.
78
What are male hormones called?
Androgens.
79
What is the role of FSH in males?
Stimulates the production of sperm by meiosis, inside the tubules of the testes.
80
What is the role of LH in males?
Stimulate the testes to produce testosterone.
81
What are the functions of testosterone in males?
It causes the development of primary sexual characteristics in early life.
At puberty, it causes the development of secondary sexual characteristics.
Causes sperm production.
82
What does secondary sexual characteristics in males mean?
The physical changes that develop at puberty, under the influence of testosterone that allows one to distinguish between the sexes.
Example:
Muscle growth and greater bone density.
Voice breaks and deepens.
Increased secretion of sebum by sebaceous glands.
83
What does infertility mean?
The inability of a sexually mature person to become a parent.
84
What is the name of male infertility?
Low sperm count.
85
What is the cause of male infertility?
Alcohol abuse.
| Persistent smoking.
86
How is male infertility treated?
Taking remedial action once the cause is identified, e.g stop smoking.
87
What is the name of female infertility?
Endocrine gland failure, resulting in a failure to ovulate.
88
How is female infertility treated?
By in-vitro fertilisation.
89
What does in-vitro fertilisation mean?
The fusion of the egg and sperm cell outside of the body.
90
Outline the process of in-vitro fertilisation.
Females are given hormones to stimulate of the Graafian follicle with their eggs inside the ovary.
The eggs are removed using surgery on day 14.
The egg cells are fertilised externally with sperm in a glass Petri dish.
The embryos are removed and screened for genetic abnormalities like cystic fibrosis.
Normal embryos are then implanted into the endometrium.
Remaining embryos are frozen and stored.
91
Why are babies conceived using in-vitro fertilisation wrongly called test tube babies?
Only fertilisation is external to the body, the baby develops normally inside the uterus as naturally fertilised babies do.
92
What does copulation mean?
To have sexual intercourse.
93
Outline the three stages of copulation.
Sexual Arousal:
In the female- arousal causes the vagina to become lubricated with mucus, longer and wider.
In the male- increased blood flow to the penis which becomes rigid and erect so it may be inserted into the lubricated vagina.
Copulation:
During copulation, the penis moves inside the vagina.
Breathing and heart rates increase in both partners.
Orgasm:
Orgasm is the physical and emotional sensation experienced during the peak of sexual excitement.
In the male: ejaculation occurs- the propelling of semen through the urethra of the penis.
Results from contraction of muscle in the epididymis, sperm duct and urethra, allowing semen to enter the vagina.
During ejaculation, sphincter muscles at the base of the bladder contract to prevent the release of urine.
In the female: results in contractions of the vagina and uterus which draws sperm cells towards the uterus.
In both partners: blood pressure, heart rates and respiration increase dramatically.
94
What are the events leading up to and including fertilisation?
Insemination occurs- the release of semen into the top of the vagina, just outside the cervix.
The sperm swim through the cervix, uterus and into the Fallopian tube.
They are attracted to a chemical released by the egg cell in a process called chemotaxis.
Contractions of the uterus also aid sperms movement.
When the sperm reaches the Fallopian tube, they swarm around the egg cell.
Many sperm cells die due to lactic acid in the vagina or attacked by white blood vessels.
One sperm penetrates the jelly coat of the egg, the other sperm die.
When the sperm reaches the egg membrane, the acrosome releases an enzyme to make an opening in the membrane.
The head of the sperm is released into the egg cytoplasm, where the nucleus of the egg fuses with the nucleus of the sperm to form a diploid zygote.
The egg membrane thickens to become the fertilisation membrane, which prevents the entry of further sperm cells.
Fertilisation takes place from days 11-16 of the menstrual cycle in what is known as the fertile period.
95
What is the sequence of development from the fertilised egg to the baby?
Zygote- morula- blastocyst- embryo- foetus- baby.
96
Outline the sequence of development from the fertilised egg to the implanted blastocyst.
wow
97
What is the placenta?
wded
98
What is the placenta formed from?
dowdy
99
What are the functions of the placenta?
deede
