Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology: Component 2 > Human Reproduction > Flashcards

Human Reproduction Flashcards

1
Q

What is the function of the testes?

A

Contain the seminiferous tubules and epididymis which are crucial for sperm production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the function of the scrotum?

A

An external sac that protects the testes and maintains them at a temperature lower than the body’s core temperature (37 degrees C)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the function of the penis?

A

Intromittent organ that is responsible for delivering sperm into the female reproductive system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of the seminiferous tubules?

A

Structures within the testes where spermatozoa are produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the function of the epididymus?

A

Where spermatozoa mature and are stored until ejaculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of the vans deferents?

A

Spermatozoa travel along this tube from the epididymis to the urethra during ejaculaton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What s the function of the seminal vesicle?

A

Gland that produces a mucus secretion that enhances sperm motility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the function of the prostate gland?

A

Glands that produce an alkaline fluid that neutralises urine and supports sperm motility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the function of the urethra?

A

Tube that carries urine from the bladder to the outside of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the function of the ureters?

A

Tubes connect the kidneys to the bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the function of the ovary?

A

Pair of organs where both mitosis and meiosis occur to produce primary and secondary oocytes

FSH and LH regulate the development and release of secondary oocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the function of the oviducts?

A

Pathways through which ova travel to reach the uterus

Lined with ciliated epithelial cells and are the site of fertilisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the function of the uterus?

A

Has muscular walls (myometrium) and is lined with endometrium

During childbirth, oxytocin induces contractions through a positive feedback mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the function of the endometrium?

A

Mucus membrane lining of the uterus, with a rich supply of blood

Where the embryo implants during pregnancy, with no pregnancy the endometrium is shed during menstruation

Maintenance is regulated by oestrogen and progesterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the function of the cervix?

A

The ring of muscle and connective tissue at the entrance to the uterus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of the vagina?

A

Canal that provides a passageway for menstrual blood and mucosal tissue from the uterus

Serves as the birth canal during childbirth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is gametogenesis?

A

The process of producing gametes

Occurs in specialised paired glands (gonads)

Spermatogenesis = formation of spermatozoa in the testes
Oogenesis = formation of ova in the ovaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why is it important that gametes are haploid?

A

So that when fertilisation occurs, the diploid chromosome number is restored and the zygote has two sets of homologous chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What leads to genetic variation in gametes?

A
  • crossing over (chiasmata formation) of chromatids between homologous chromosomes during prophase I
  • independent assortment of bivalents during metaphase I
  • independent assortment of sister chromatids during metaphase II
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where does spermatogenesis occur and what does it require?

A
  • spermatozoa are produced within the seminiferous tubules of the testes
  • germinal epithelial cells in these tubules give rise to approximately 120 million viable spermatozoa daily
  • development of spermatozoa requires the hormones FSH and testosterone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the process of spermatogenesis?

A

A germinal epithelial cell in the seminiferous tubules replicates its DNA during s-phase to form spermatogonium (2n), which then undergoes mitosis many times to produce diploid primary spermatocytes. Primary spermatocytes undergo meiosis I to form haploid spermatocytes, which undergo meiosis II to form spermatids. Spermatids differentiate and mature to form spermatozoa (n). These are all genetically unique because of crossing over in prophase I, and independent assortment in metaphase I and II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are Sertoli cells?

A

A type of somatic cell around which spermatids develop located in the seminiferous tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the role of the Sertoli cells?

A
  • to secrete a fluid which nourishes the spermatids and protects them from the immune system of the male
  • to provide oxygen and remove waste products
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
A
  • to secrete a fluid which nourishes the spermatids and protects them from the immune system of the male
  • to provide oxygen and remove waste products
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are Interstitial cells?
A type of somatic cell that is stimulated by the hormone LH that is located outside the seminiferous tubules
26
What is the role of the Interstitial cells?
Secretes testosterone
27
What is the role of testosterone in spermatogenesis?
It stimulates spermatogenesis and causes male secondary sex characteristics to develop
28
What is the contents and function of the spermatozoon’s head?
Contains a haploid nucleus and is covered at the end by a structure called the acrosome The acrosome is a large lysosome which contains enzymes used in fertilisation
29
What is the contents and function of the midpiece of the spermatozoon?
Packed with mitochondria for aerobic respiration to provide ATP for movement
30
What is the function of the tail of the spermatozoon?
Also known as the flagellum, it makes lashing movements that propel the spermatozoon, enabling its motility
31
Why is mitosis important in spermatozoon production?
It produces large numbers of primary spermatocytes. This leads to large numbers of spermatocytes, to increase the chances of fertilisation
32
Why is meiosis important in spermatozoon production?
It produces haploid spermatozoa and leads to genetic variation
33
What is the process of oogenesis?
Before birth, as the female foetus develops, cells of the germinal epithelium divide by mitosis to make diploid oogonia and more germinal epithelial cells. The oogonia undergo mitosis many times, and enlarge to form diploid primary oocytes. These primary oogonia begin meiosis I, but are arrested during prophase I. A baby girl is born with millions of primary oocytes arrested at prophase I of meiosis I in her ovaries. Before each ovulation, a primary oocyte matures, completing the first meiotic division to form a haploid secondary oocyte and a polar body (smaller cell with less cytoplasm that often degenerates). The secondary oocyte is released from the ovary during ovulation and begin meiosis II. It pauses at metaphase II until fertilisation takes place. On fertilisation, meiosis II completes, resulting in the formation of a large ovum and a second polar body.
34
Why do the polar bodies contain less cytoplasm?
This is a benefit as at fertilisation, the resulting zygote will have sufficient cytoplasm to provide nutrients for rapid cell division
35
What is the purpose of the second polar body?
It serves to halve the DNA content so the ovum is haploid with a full set of sister chromosomes = the sperm nucleus and the ovum nucleus then fuse inside the ovum = diploid zygote
36
How do Graafian follicles form?
- during oogenesis, the germinal epithelial cells also divide to form follicle cells which surround the primary oocytes to form primary follicles. During puberty, hormones stimulate the primary follicles develop further, and every month, it will mature not a Graafian follicle containing a secondary oocyte
37
What happens to a mature Graafian follicles develop further?
- it migrates to the surface of the ovary, where it bursts to release the secondary oocyte in ovulation - after ovulation, the Graafian follicle becomes the corpus luteum which secretes hormones for pregnancy if fertilised (progesterone to maintain the endothelium thickness) - if fertilisation does not occur, the corpus luteum degenerates into the corpus albicans
38
What is the zona pelludica?
A clear glycoprotein layer that surrounds the cell membrane of the secondary oocyte, the chromosomes of the secondary oocyte are in metaphase II
39
What is the corona radiate?
Cells that surround the secondary oocyte and provide nutrients for respiration and cell divison
40
What does the theca of the Graafian follicle do?
Secretes oestrogen
41
What does the antrum of the Graafian follicle do?
It is the liquid in the follicle
42
What stages of oogenesis occurs before birth?
Diploid germinal epithelial cells divide by mitosis to form diploid oogonia Oogonia undergo mitosis to form diploid primary oocytes which the commence meiosis I but arrest in prophase I and are contained in a primary follicle
43
What stages of oogenesis happen during puberty to menopause?
- the primary oocyte completes meiosis I to form a haploid secondary oocyte - this commences meiosis II but stops at metaphase II - the primary follicle develops into a Graafian follicle containing the secondary oocyte
44
What stages of oogenesis happen during fertilisation?
The secondary oocyte completes meiosis II to form an ovum
45
What does FSH do in the menstrual cycle?
It is secreted by the anterior pituitary gland, and stimulates the maturation of the follicle and stimulating the production of oestrogen
46
What does oestrogen do in the menstrual cycle?
Oestrogen secreted by the developing follicle increases in the blood to trigger the repair of the endometrium, inhibiting the FSH production and stimulates LH production
47
What does LH do in the menstrual cycle?
High levels are secreted by the anterior pituitary gland and initiate ovulation and causes the Graafian follicle to develop into the corpus luteum which secretes progesterone
48
What does progesterone do in the menstrual cycle?
Secreted by the corpus luteum, causing further development of the endometrium prior to menstruation
49
Why does the corpus luteum degenerate?
If implantation does not occur, FSH and LH levels fall, causing the corpus luteum to degenerate, so progesterone levels fall and the endometrium breaks down and is lost during menstruation
50
What are the phases in the menstrual cycle?
Follicular phase: days 0-14 Luteal phase: days 14-28
51
What happens if fertilisation occurs?
The body secretes hCG, and the corpus luteum remains intact for 12 weeks
52
How can oestrogen be used as a contraceptive pill?
- oestrogen inhibits FSH production and secretion - so without FSH, the primary follicles can’t develop - so without a mature Graafian follicle, ovulation and fertilisation can’t take place
53
How can progesterone be used as the contraceptive pill?
- progesterone inhibit LH secretion, so no ovulation - progesterone increases the level of mucus in the cervix and blocks the entry of sperm into the uterus - no ovulation or no sperm means no fertilisation can take place in the fallopian tubes
54
What hormone would be provided to IVF patients?
- FSH is injected - many primary follicles develop into Graafian follicles - many secondary oocytes are extracted from each ovary - increases chances of more fertilisation
55
What is capacitation? (Exam answer)
Can talk several hours, and sperm can only fertilise after this - spermatozoa swim through the oviduct and become hypermobile - cholesterol and glycoprotein is shed/removed from the cell membrane of the sperm head so the cell membrane becomes more fluid and permeable - the acrosome fully forms, containing hydrolytic enzymes, called the acrosome cap
56
What is the acrosome reaction? (exam answer)
- spermatozoa swim through the cells of the corona radiata - when spermatozoa contact the zona pelludica, the acrosome fuses with the sperm cell membrane, releasing hydrolytic enzymes by exocytosis - endopeptidases hydrolyse non-terminal peptide bonds in the glycoproteins of the zona pelludica - digesting a pathway through the zona pelludica - sperm injects the haploid nucleus into the secondary oocytes cytoplasm
57
What is the cortical reaction? (exam answer)
- injection of the sperm into the nucleus causes the release of Ca 2+ ions into the cytoplasm of the secondary oocyte from the smooth endoplasmic reticulum - higher Ca 2+ concentration stimulates the mitigation of cortical granules to fuse with the cell membrane - chemicals are released by exocytosis - causing the zona pelludica to thicken and harden, forming the fertilisation membrane - preventing polyspermy
58
Why is it important that the cortical reaction occurs?
If polyspermy occurs, the oocyte would receive too many chromosomes, resulting in an unviable zygote
59
What does the entry of the spermatozoon’s genetic material trigger?
The continuation of meiosis II, to form the ovum and the polar body The nuclei of the spermatozoon and ovum fuse to form a zygotic nucleus, the fertilised ovum (zygote) is now diploid
60
What is implantation?
- the zygote undergoes repeated mitotic divisions to form a ball of cells in a process known as cleavage - by day 7, the cleavage has resulted in the production of a hollow ball of cells - blastocyst - the blastocyst moves into the uterus, where it attaches and embeds into the endometrium - the endometrium lining continues to thicken due to high progesterone levels from the corpus luteum (in ovary)
61
Why does the corpus luteum not degrade for the first 12 weeks of pregnancy?
Human chorionic gonadotropin (hCG) secreted from the chorion (trophoblast of blastocyst) maintains the corpus luteum
62
What is the role of the amniotic fluid?
- maintains the foetal temperature - acts as a shock absorber, protecting the foetus from injury from outside the uterus
63
What is the amniotic fluid?
The embryo develops and grows into foetus in the uterus, enclosed by the amnion (membrane derived from the blastocyst)
64
What do the umbilical vein and artery do?
Umbilical VEIN: carries oxygenated blood and nutrients (such as glucose) to the foetus Umbilical ARTERY: carries deoxygenated blood and waste products (such as carbon dioxide) away from the foetus
65
How does blood transfer between the placenta and the foetus?
- foetal capillaries are located within chorionic villi, which for the boundary between foetal and maternal blood - blood from maternal arteioles empties into an intervillus space - the absence of maternal capillaries between maternal arteriole and venule reduces the number of cell layers to be crossed, providing a short diffusion pathway for materials - foetal capillaries immersed in the intervillus space to allow the exchange of materials to occur. Blood containing waste materials returns to the maternal venules from the intervillus space - maternal and foetal blood flow in opposite directions to maintain a concentration gradient (countercurrent flow)
66
What is the role of the placenta?
- facilitates the exchange of materials across a thin barrier which separates maternal and foetal blood > into the foetal blood = glucose, amino acids, oxygen, salts > out of the foetal blood = carbon dioxide, nitrogenous waste - provides protection from the immune system of the mother - protects the foetus from the differences in maternal and foetal blood pressure (mothers blood pressure is higher and can cause damage) - allows the passage of maternal antibodies into the foetus to provide short term immunity (passive immunity)
67
Describe and explain the position of the foetal oxygen dissociation curve and how this benefits the foetus?
- foetal haemoglobin has a higher oxygen affinity at any given ppO2 value, so the oxygen dissociation curve shifts to the left - foetal Hb can load O2 from the mothers blood at all partial pressure of oxygen - foetal Hb becomes highly saturated with O2 to form foetal oxyhaemoglobin
68
Why are FSH, LH, oxytocin, and prolactin suppressed during pregnancy?
FSH = no more follicles mature LH = so ovulation isn’t possible Oxytocin = no uterine contractions Prolactin = so no milk is made
69
Why are progesterone and oestrogen in high levels during pregnancy?
Progesterone = suppresses uterine walls ability to contract, and maintains the endometrium Oestrogen = stimulates the growth of the uterus to accommodate the growing foetus and stimulates the growth and development of the mammary glands
70
What causes birth?
- oestrogen levels increase and progesterone levels decrease so the uterine wall can now contract - oxytocin secreted by the posterior pituitary gland stimulates the contraction of the myometrium - the contractions stimulate the secretion of more oxytocin (positive feedback) - as oxytocin levels increase the contractions become stronger and more frequent - prolactin is released from the anterior pituitary gland during and after birth to stimulate milk production by the mammary glands - after birth, the oxytocin releases milk for the current feed and helps the baby to easily get milk

Biology: Component 2 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions