Unit 2: book 1 Flashcards
(85 cards)
1
Q
Where is the site of sperm production
A
Testes in seminiferous tubules
2
Q
Where is the site of testosterone production
A
Testes in the interstitial cells
3
Q
Where exactly is the sperm formed
A
Seminiferous tubules
4
Q
What are the cells between the seminiferous tubules
A
Interstitial cells
5
Q
What do interstitial cells produce
A
Testosterone
6
Q
Where are oestrogen and progesterone produced
A
The ovaries
7
Q
What is ovulation
A
When a mature ovum is released from the ovary into the oviduct
8
Q
What is each ovum surrounded by
A
A follicle
9
Q
What does the follicle secrete
A
Oestrogen
10
Q
What does the follicle produce after ovulation
A
Progesterone , as well as oesterogen
11
Q
What is fertilisation
A
Mature ova is released into the oviduct. If sperm is present, fertilisation may take place
12
Q
What is a fertilised egg known as
A
Zygote
13
Q
Name three reproductive processes that hormones control
A
Ovulation, sperm production, puberty
14
Q
Name two female hormones produced by the pituitary
A
LH (luteinising hormone) and FSH (follicle stimulating hormone)
15
Q
What does testosterone do
A
Stimulates sperm production
16
Q
What does high levels of oestrogen do to the cells lining the cervix
A
Increases cell division which repairs the endometrium
17
Q
Name the two hormones that progesterone inhibits
A
FSH & LH
18
Q
What is puberty triggered by
A
The hypothalamus secretes a releaser hormone whose target is the pituitary
19
Q
What is ICSH
A
Interstitial cell stimulating hormone
20
Q
What is negative feedback control
A
As testosterone concentration builds up in the bloodstream it reaches a level that inhibits FSH and ICSH secretion. This leads to a decrease in testosterone production
21
Q
What are the 2 phases of the menstrual cycle
A
Follicular phase and luteal phase
22
Q
How long does the menstrual cycle take
A
28 days
23
Q
What is the first phase of the menstrual cycle
A
The follicular phase
24
Q
What is the second phase of the menstrual cycle
A
The luteal phase
25
What happens during the follicular phase
FSH is produced by the pituitary gland. Oestrogen stimulates the proliferation of the endometrium. When levels of oestrogen peak, this stops the pituitary gland producing FSH and stimulates a surge in secretion of LH
26
What does FSH do
It stimulates the development and maturation of a follicle in the ovary
It also stimulates the wall of the follicle and the ovarian tissue to secrete the hormone oestrogen.
27
What is proliferation of the endometrium
An increase in cell division
28
What is ovulation
Ovulation is the release of an egg (ovum) from a mature follicle in the ovary. This usually occurs around the mid-point of the menstrual cycle
29
What are signs of ovulation
Increase in body temperature
| Cervical mucus becomes watery
30
What happens during the luteal phase
LH caused the follicle to change into the corpus luteum which secretes a hormone called progesterone, progesterone (and oestrogen) cause the continued proliferation and vascularisation of the endometrium in preparation for receiving and embryo
31
What is the negative feedback effect on FSH and LH
The combined high levels of oestrogen and progesterone prevents further follicles from developing and inhibits the production of FSH and LH by the pituitary. If fertilisation does not occur the lack of LH causes the corpus luteum to degenerate and cease producing progesterone. The sudden drop in progesterone and oestrogen caused menstruation to occur
32
What kind of fertility do men show
Continuous fertility
33
What kind of fertility do women show
Cyclical fertility
34
How can you stimulate ovulation
Ovulation can be stimulated by drugs that prevent the negative feedback control of oestrogen on FSH secretion.
Ovulation can be stimulated by drugs that mimic the normal action of FSH and LH
35
What is super ovulation
Super ovulation is when several ova are released at once and can lead to several births
36
What is artificial insemination
This involves the insertion of semen into the female tract by some means other than sexual intercourse
If a male has low sperm count, several samples of semen are collected and frozen until required, they are then defrosted and released together into the partners cervical region during her fertile period.
37
What is intracytoplasmic sperm injection (ICSI)
The procedure involves drawing healthy sperm into a needle and injecting it directly into the egg to achieve fertilisation
38
What is IVF
In-vitro fertilisation (IVF) enables fertilisation, outside the body, in a culture dish.
39
What stages does IVF take place in
- woman is given hormone treatment to stimulate multiple ovulation
- the eggs are surgically removed from the ovary, using equipment like a syringe
- eggs are mixed with sperm in a culture dish, containing nutrients, to allow fertilisation to take place. Alternatively, sperm may be injected directly into the egg using ICSI
- fertilised eggs are incubated for 2-3 days to form embryos of at least 8 cells or more
- two or three embryos are inserted into the uterus form implantation
- remaining embryos are frozen in case a second attempt is needed
40
What is pre implantation diagnosis (PGD)
PGD can be employed to identify genetic disorders and chromosomal abnormalities
41
What is contraception
Contraception is the intentional prevention of conception of pregnancy by natural or artificial means. Avoidance of “fertile period” would be an example of a natural method of contraception
42
What are physical methods of contraception
```
The barrier method physically blocks the ability of the sperm to reach the ovum.
Devices include:
-condom
-diaphragm
-cervical cap
```
43
What is an IUD
An intra uterine device is a plastic T shaped structure with copper wound around its outside.
It is fitted into the uterus for several years. It had threads attached for easy removal
The presence of an IUD stimulates the presence of white blood cells which are hostile to sperm
If impairs the mobility of the sperm
It irritates the lining of the uterus, making it unreceptive to the embryo
44
What are the complications that an IUD can cause
Inflammation or the uterus and ectopic pregnancy
45
What are some sterilisation procedures
Vasectomy- this includes cutting and tying the two sperm ducts. This prevents sperm being released. The sperm produced undergo phagocytosis
46
What is an example of a chemical method of contraception and how does it work
Oral contraceptive pill
| It contains synthetic oestrogen combined with synthetic progesterone
47
What is the mini pill
Mini pills are progesterone only pills
| They thicken the cervical mucus, reducing the viability of the sperm
48
What are advantages and disadvantages of the mini pill
```
Advantages:
Can be used during breast feeding
Can reduce cramps and heavy bleeding
Can be taken by women who cannot take oestrogen
Can be taken by women who have high blood pressure
Disadvantages:
Must be taken at the same time every day
Can cause breast tenderness
Can cause mood swings
Can lead to weight gain
Can lead to irregular menstruation
```
49
What does antenatal care involve
Blood pressure, blood type and general health checks (including routine blood and urine tests)
50
What is an ultrasound
An ultrasound scanner picks up high frequency sounds that have bounced off the foetus. Pregnant women are given two ultrasound scans
51
What is a dating scan
A dating scan is performed at 8-14 weeks to determine the stage of pregnancy and to calculate the due date
52
What is an anomaly scan
An anomaly scan is carried out at 18-20 weeks, an anomaly scan checks for physical abnormalities
53
When is a dating scan carried out
At 8-14 weeks
54
When is an anomaly scan carried out
18-20 weeks
55
What is a Nuchal Translucency scan
A NT scan helps experts to estimate the risk of a Down syndrome baby
56
When is a nuchal translucency scan carried out
11-14 weeks
57
What happens during a nuchal translucency scan
An assessment is made or the thickness of fluid at the nape at the neck of the fetus
58
Is a nuchal translucency scan a diagnostic test
No
59
Why is a mother offered a series of blood and urine tests at 16-18 weeks
To check for markers
Example: HCG increases during 6-10 weeks then decrease to a steady low level
It remains high if the foetus has Down syndrome
60
What is AFP marker
Alpha-fetoprotein is produced by the fetus and the concentration in the mother’s blood increases
The normal range of values during pregnancy is 0.5-2.49 units AFP
Levels lower than 0.4 units are found in Down syndrome (trisomy 21) pregnancy snd Edwards syndrome (trisomy 18)
61
What are risks associated with Down’s syndrome testing
1. Age, older woman’s eggs are more prone to a type of mutation that leads to eggs being formed that have an extra copy of chromosome 21
2. Woman are often advised to have invasive diagnostic tests. Amniocentesis or Chorionic Villus sampling- both carry a risk of miscarriage
62
What is a diagnostic test
A diagnostic test is a definitive test which establishes, without doubt, whether a person is suffering from a specific disorder
63
What is health monitoring
The detection of the marker human chorionic gonadotropin (HCG) in the blood and iron is the basis of early pregnancy tests
64
What is pre-eclampsia
This is the most common cause of dangerous complications during pregnancy
The sufferer displays some or all of the symptoms:
High blood pressure
Excess protein in the plasma
Changes to blood biochemistry caused by altered liver and renal function
65
What is amniocentesis
Amniocentesis is carried out at about 14-16 weeks of pregnancy
A small amount of amniotic fluid is withdrawn from the nape of the foetus’ neck and it contains foetal cells
The cells are cultured to produce a karyotype, this usually takes about 2 weeks
66
What is a karyotype
A karyotype is a visual display of a persons complete chromosome complement, arranged in pairs
67
What is chorionic villus sampling (CVS)
This involves taking a sample of placental cells. The cells are cultured and used for karyotyping.
68
What is a benefit and disadvantage of CVS
Benefit: It can be carried out as early as 8 weeks into pregnancy
Disadvantage : carries higher risk of miscarriage
69
What are sex chromosomes
X and Y
70
What are autosomes
Every chromosome except for X and Y which are sec chromosomes
71
What is an example of autosomal recessive inheritance
Cystic fibrosis
72
What are non-sufferers known as
Homozygous dominant (CC) or heterozygous (Cc)
73
What are sufferers known as
Homozygous recessive (cc)
74
What does cystic fibrosis result from
3 base pair deletion on chromosome 7
75
What happens when you have cystic fibrosis
Mucus is found at various sites on the body,
These sites include the lungs, the pancreas and the alimentary canal
The mucus produced by sufferers of cystic fibrosis become thicker and stickier than normal. The organs become congested and blocked
76
What is an example of Autosomal Dominant Inheritance
Huntington’s chorea
77
What is Huntington’s disease caused by
An affected gene on chromosome 4
78
What is an example of Autosomal incomplete dominance
Sickle-cell disease and sickle cell trait
79
What does sickle cell disease involve
Their haemoglobin fails to perform the normal function properly. The sickle shaped cells tend to stick together, interfering with the blood circulation. This results in a severe shortage of oxygen, damage to vital organs and death
80
What is a sex linked recessive gene
The X chromosome is larger than the Y chromosome and carry many more genes which are not present on the Y chromosome. These genes are said to be sex linked
81
What is an example of sex linked gene
Colour blindness, all sufferers are homozygous recessive XcXc (female) or XcY (male) and non sufferers are homozygous dominant or heterozygous “carrier” females
82
What is haemophilia
A disorder in which blood does not clot or takes a very long time to clot
83
What is haemophilia caused by
A recessive gene which is carried on the X chromosome
84
What is postnatal screening
Diagnostic testing for metabolic disorders in a new-born baby.
85
What is PKU
Phenylketonuria is an inborn error of metabolism.
The body provided a non functional from of an enzyme that converts phenylalanine into tyrasine. As a result phenylalanine builds up in the blood
