Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

biology > 4.1 human reproduction > Flashcards

4.1 human reproduction Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

where are gametes produced?

A

special paired glands called gonads

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

what are the male gametes and where are they produced?

A

spermatozoa in the testis

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

what are the female gametes and where are they produced?

A

ova in the ovaries

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

what is the process of the formation of spermatozoa called?

A

spermatogenesis

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

where does spermatogenesis take place?

A

in the seminiferous tubules of the testes

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

what are Sertoli cells and where are they found?

A

found in the seminiferous tubules
secrete a fluid to nourish the spermatids and protect them from the male immune system

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

what are interstitial cells and where are they found?

A

found in the wallet of seminiferous tubules
secrete testosterone which stimulates spermatogenesis

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

what are the 2 parts to the head of the sperm called and what is their function?

A

acrosome - a specialised lysosome containing hydrolytic enzymes for fertilisation
nucleus - haploid (n), contains the paternal chromosomes

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

what are the 2 parts to the mid-piece of the sperm called and what is their function?

A

mitochondria - provide ATP for movement of the flagellum
centrioles - form the sperm flagellum and involved in cell division of the embryo after fertilisation

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

tail:
what is it called?
what does it do?
what is it made from?

A

flagellum
propels the sperm forwards
made from microtubules (9+2 arrangement)

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

what happens during sexual intercourse? (5)

A
  • movements of the penis result in contraction of smooth muscle in the walls of the epididymis, vas deferens and the penis.
  • this causes the ejaculation of semen
  • the force of ejaculation propels some sperm through the cervix into the uterus
  • the sperm swim through the uterus into the oviducts by their tails
  • out of the millions deposited only a small number of sperm reach the ovum in the fallopian tube.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is ovulation?

A

the release of the secondary oocyte from an ovary

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

what happens after ovulation if no fertilisation has occurred?

A

once the secondary oocyte has been released into the fallopian tube the empty Graafian follicle becomes the corpus luteum. this will regress (break down)

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

what happens after ovulation if fertilisation has occurred?

A

the corpus luteum secretes hormones which:
- aid embryo development
- prevent further ovulations during pregnancy

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

where does fertilisation take place?

A

anywhere in the fallopian tube

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

what are the 3 stages of fertilisation?

A

capacitation
acrosome reaction
cortical reaction

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

what is capacitation?
what does this do?

A

the removal of cholesterol & glycoproteins from the cell membrane covering the acrosome in the sperm head
increases the permeability of the membrane in front of the acrosome

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

what is the acrosome reaction?

A

the exocytosis of protease enzymes and the fusion of the sperm membrane and the oocyte membrane

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

what is the cortical reaction?

A

Ca2+ causes the membranes of the cortical granules to fuse with the oocyte membrane and this secretes its contents to harden the zona pellucida and change it into a fertilisation membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what happens after the cortical reaction?

A

meiosis II within the secondary oocyte will re-commence to form an ovum and a second polar body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what happens when the nucleus of the ovum fuses with the nucleus of the sperm?

A

forms a zygotic nucleus (2n)

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

what does the fertilisation membrane prevent?

A

further penetration of sperm - prevents polyspermy

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

structure of the secondary oocyte from the outside in

A

corona radiata
zona pellucida
perivitelline space
plasma membrane
cortical granules
cytoplasm
nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the corona radiata and what do they do?

A

cells that surround the secondary oocyte and provide it with nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what are the cortical granules and what do they do?

A

they are secretory organelles with the oocyte, prevent the entry of more than 1 sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is oogenesis?

A

the formation of the secondary oocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

where does oogenesis take place?

A

in the ovaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

when does oogenesis take place?

A

starts before the birth of a female, in their developing ovaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what processes are involved in oogenesis?

A

mitosis and meiosis 1 and 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

in short terms, what happens before puberty during oogenesis? (4)

A
  • germinal epithelium divide by mitosis to form oogonia and more germinal epithelium cells
  • oogonia undergo mitosis many times and enlarge to form primary oocytes
  • germinal epithelium cells divide by mitosis to form follicle cells
  • primary oocytes are enclosed by a ball of follicle cells and together they form the primary follicles
31
Q

in short terms, what happens after puberty during oogenesis? (3)

A
  • the primary oocytes in the primary follicles undergo the first meiotic division due to the hormones released
  • a polar body and a secondary oocyte is formed
  • the polar body will degenerate
32
Q

in short terms, what is the rest of the oogenesis process? (5)

A
  • the secondary oocyte begins the second stage of meiosis but stops at metaphase 2
  • the secondary follicle matures into the Graafian follicle
  • at ovulation the secondary follicle bursts and releases the secondary oocyte into the fallopian tube
  • the secondary oocyte completes meiosis once fertilisation has taken place
  • an already fertilised ovum is produced and a polar body which degenerates
33
Q

what is spermatogenesis?

A

the formation of spermatozoa

34
Q

where does spermatogenesis take place?

A

in the seminiferous tubules in the testes

35
Q

in short terms, what is the process of spermatogenesis? (5)

A
  • germinal epithelium cells divide by mitosis to form spermatogonia cells
  • spermatogonia grow and increase in size forming primary spermatocytes
  • these undergo the first meiotic division to form secondary spermatocytes
  • these undergo the second meiotic division to form spermatids
  • spermatids attach to Sertoli cells and mature and differentiate into spermatozoa
36
Q

what does fertilisation result in?

A

the formation of a diploid zygote

37
Q

what is a blastocyst?

A

a hollow ball of cells that is formed from the continuous mitosis of the diploid zygote

38
Q

what is cleavage?

A

when the cell numbers increase exponentially during mitosis in implantation

39
Q

what are the trophoblast?

A

the cells around the outside of the blastocyst

40
Q

what is an embryo blast?

A

the distinctive inner cell mass when the trophoblast divides

41
Q

in simple terms, what is the process of implantation?

A
  • the diploid zygote undergoes continuous mitosis
  • cleavage
  • blastocyst is formed
  • the trophoblast divides to make an embryo blast on one side
  • this process is occurring as the zygote travels down the fallopian tube to the uterus
  • the blastocyst implants itself into the endometrium of the uterus after about 3 days
42
Q

how long does the diploid zygote undergo continuous mitosis for?

A

approx. 8-10 days

43
Q

what are trophoblastic villi and what do they do?

A

finger-like protrusions that develop on the trophoblast which penetrate the endometrium

44
Q

what is the benefit of trophoblastic villi?

A

increase the surface area for the absorption of nutrients from the endometrium

45
Q

in short terms, explain the development of the placenta

A
  • the trophoblast develops into the chorion
  • the chorion secretes hCG
  • cells of the chorion move into the trophoblastic villi to form chorionic villi
  • the villi gain capillaries which connect to the umbilical arteries and the umbilical vein.
  • these vessels connect the embryo to the uterus wall via the umbilical cord
46
Q

what does hCG do?

A

prevent the breakdown of the corpus luteum

47
Q

what is the chorion?

A

the outer membrane of the embryo

48
Q

what is there an exchange between at the placenta?

A

maternal blood and foetal blood

49
Q

what components are exchanged?
give examples of each

A

gases (oxygen and carbon dioxide)
nutrients (glucose, amino acids, fatty acids, glycerol)
waste (urea)

50
Q

how does exchange take place? (5)

A

osmosis, active transport, diffusion, facilitated diffusion, pinocytosis

51
Q

what is the mechanism called in which exchange works?

A

counter current flow

52
Q

what happens in counter current flow?

A

the maternal blood and foetus blood flow in opposite directions to ensure a concentration gradient is maintained

53
Q

what is rhesus disease?

A

if a rhesus negative mother has a rhesus positive foetus, her immune system will make antibodies to the protein which results in the destruction of the red blood cells of the foetus

54
Q

what determines if the mother is rhesus negative or rhesus positive?

A

the rhesus factor - if the protein is present on red blood cells or not (present = positive)

55
Q

what is the role of the placenta?

A

secrete hCG, oestrogen and progesterone to support pregnancy

56
Q

how does the placenta act as a physical barrier?

A

protects the foetus capillaries from damage by the mothers high blood pressure

57
Q

what 4 hormones control the menstrual cycle?

A

FSH
LH
progesterone
oestrogen

58
Q

what does FSH do? (2)

A
  • stimulates follicular growth in ovaries
  • stimulates oestrogen secretion
59
Q

what does LH do? (2)

A
  • surge causes ovulation
  • results in the formation of a corpus luteum
60
Q

what does oestrogen do? (3)

A
  • thickens endometrium
  • inhibits FSH and LH for most of the cycle
  • stimulates FSH and LH release pre-ovulation
61
Q

what does progesterone do? (2)

A
  • thickens endometrium
  • inhibits FSH and LH
62
Q

where is each hormone secreted from?

A

FSH and LH - anterior pituitary gland
oestrogen and progesterone- ovaries

63
Q

what are the 4 phases of the menstrual cycle?

A
  • follicular phase
  • ovulation
  • luteal phase
  • menstruation
64
Q

in short terms, describe the follicular phase

A
  • FSH is secreted from the anterior pituitary and stimulates growth of ovarian follicles
  • the Graafian follicle produces oestrogen
  • oestrogen inhibits FSH secretion to prevent other follicles developing (negative feedback)
  • oestrogen acts on the endometrium to stimulate its repair following menstruation (thickens)
65
Q

in short terms, describe ovulation

A
  • midway through the cycle, oestrogen stimulates the anterior pituitary to secrete (LH)
  • there is a large surge of LH and a lesser surge of FSH (positive feedback)
  • LH causes the Graafian follicle to rupture from the ovary and release its secondary oocyte
66
Q

in short terms, describe the luteal phase

A
  • the Graafian follicle develops into a slowly degenerating corpus luteum
  • the corpus luteum secretes high levels of progesterone, as well as lower levels of oestrogen
  • oestrogen act on the uterus to thicken the endometrium
  • progesterone maintains the endometrium
  • oestrogen and progesterone also inhibit secretion of FSH and LH from the pituitary gland which prevents any follicles from developing (negative feedback)
67
Q

in short terms, describe the menstruation

A
  • no implantation = falling FSH and LH levels cause the corpus luteum to degenerate
  • progesterone levels fall, the endometrium breaks down and is lost during menstruation
  • FSH secretion is no longer inhibited, and another menstrual cycle is initiated
68
Q

what is the amnion?

A

when the embryo blast of the implanted blastocyst develops into a membrane

69
Q

what components are in the amniotic fluid? (6)

A
  • water
  • urea
  • salts
  • some protein
  • trace sugars
  • sloughed cells from foetus
70
Q

what is the function of amniotic fluid? (5)

A
  • maintains foetus temperature
  • provides lubrication
  • contributes to lung development
  • allows movement (bones and muscle can function before birth)
  • acts as a shock absorber (protects foetus from physical injury)
71
Q

explain the role of hormones in early pregnancy

A
  • the developing embryo (blastocyst) secretes hCG from the chorionic villi
  • hCG maintains the corpus lute for the first 16 weeks
  • the corpus lute secrets progesterone
  • progesterone maintains the endometrium
  • the endometrium contributes to the structure of the placenta
72
Q

explain the role of hormones in later pregnancy

A
  • the placenta starts to secret both oestrogen and progesterone
  • the levels of both hormones will remain high in the blood plasma until the end of pregnancy
73
Q

explain the role of hormones during birth

A
  • just before birth oestrogen levels will increase while progesterone levels decrease
  • this results in the contraction of the uterus wall (myometrium layer)
  • oxytocin is no longer inhibited
  • oxytocin is secreted from the posterior pituitary gland and causes the myometrium to contract
  • a positive feedback mechanism is in place as contractions cause further oxytocin secretion
  • therefore, contractions become stronger and more frequent
74
Q

explain the role of hormones during lactation

A
  • as progesterone levels decrease, prolactin is no longer inhibited
  • prolactin is secreted from the anterior pituitary gland during and after birth
  • it stimulates the mammary glands to produce milk
  • milk is released when oxytocin causes the muscles around the milk ducts to contract

biology (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions