Unit 4: Reproduction Flashcards
1
Q
What are the components of the male reproductive system? (9)
A
- testes
- scrotum
- epididymis
- penis
- urethra
- prostate
- seminal vesicle
- bladder
- vas deferens
2
Q
Testes (2)
A
- produces sperm
- it is outside the body because the optimal temperature for producing sperm is below body temp
3
Q
Epididymis
A
finishes sperm production
4
Q
Vas deferens (2)
A
- the tube where sperm leaves
- passes through prostate
5
Q
What are the components of the female reproductive system? (8)
A
- fallopian tube
- ovary
- uterus
- bladder
- urethra
- vagina
- cervix
- large intestine
6
Q
Ovaries
A
where eggs are produced
7
Q
Fallopian Tube
A
- where gametes will be released
- this is where pregnancy occurs
8
Q
Uterus
A
where the zygote implants itself, develops, and becomes a fetus
9
Q
Cervix
A
junction between vagina and uterus
10
Q
When does puberty begin in males? (2)
A
- upon an increase in testosterone production
- starts around age 13 or 14
11
Q
Where is testosterone produced?
A
the testes
12
Q
What do high testosterone levels cause?
A
the display of secondary sex characteristics
13
Q
What are the male secondary sex characteristics? (8; choose 4 or 5 to remember)
A
- increase in bodily hair (chest and face)
- the larynx grows and the voice deepens
- seminal fluids are produced and ejaculation is possible
- genitals increase in size
- testes drop away from the body
- bones and skeletal muscle undergo growth
- personality development
- changes in behavior
14
Q
When does puberty begin in females? (2)
A
- increased release of estrogen by the ovaries
- begins around age 13 or 14
15
Q
What do higher estrogen levels cause?
A
the display of secondary sex characteristics
16
Q
What are the female secondary sex characteristics? (4)
A
- breasts increase in size
- pubic and armpit hair increases
- genitals increase in size
- pelvis growth and adipose tissue is deposited around it
17
Q
How many hormones are the menstrual and ovarian cycles controlled by?
A
4
18
Q
What hormones control the menstrual and ovarian cycles? (4)
A
- estrogen
- progesterone
- LH
- FSH
19
Q
Where are estrogen and progesterone secreted from?
A
the ovaries via the corpus luteum
20
Q
Where are LH and FSH secreted from?
A
anterior pituitary gland
21
Q
Where does oogenesis take place?
A
in the ovaries
22
Q
What are the stages of oogenesis? (6)
A
1) diploid oogonium (stem cell) divide by mitosis, then grow into large diploid primary oocytes
2) Primary oocytes being to go through meiosis I and follicle cells grow around them
3) Follicle matures and grows in size
4) After puberty begins, ovulation occurs and meiosis I is complete
5) Corpus luteum grows
6) Corpus luteum degenerates, completing cycle
23
Q
What part of oogenesis takes place before birth? (2)
A
- the division of the oogonium into primary oocytes
- females are born with around 500,000 of them
24
Q
What happens during oogenesis after puberty? (3)
A
- ovulation occurs
- haploid secondary oocyte travels through fallopian tube to the endometrium
- Meiosis also produces polar body
25
What happens if a secondary oocyte is not fertilized?
the secondary oocyte is shed from the menses
26
Polar Body (PB)
small unfunctional cell that is broken down then absorbed into the body
27
What happens if a secondary oocyte is fertilized?
meiosis II occurs to become a haploid ovum with another polar body
28
Where does spermatogenesis occur?
in the seminiferous tubules of the testes
29
What are the stages of spermatogenesis? (5)
1) Diploid spermatogonium (stem cell) divides by mitosis
2) Spermatogonium divide by mitosis and grow into diploid primary spermatocytes
3) Phase I of meiosis (beginning after puberty) produces haploid secondary spermatocytes
4) Phase II of meiosis produces haploid spermatids which are nourished by Sertoli cells and differentiate into spermatozoa
5) Spermatozoa mix fluids to become semen
30
How many steps are there to fertilization?
6
31
What is the process of fertilization? (6)
1. Sperm enter woman and become fully capacitated; they use chemical signals to reach the egg as it swims past the cervix and into a fallopian tube
2. Hundreds of sperm bind to zona pellucida, triggering
acrosome reaction
3. Proteases in the acrosome are released, digest zona pellucida and allow sperm to reach plasma membrane
4. A single sperm membrane fuses with the egg plasma membrane; the egg prevents more sperm from entering
5. Oocyte performs meiosis II
6. Nuclei of sperm and egg undergo mitosis. A 2-celled diploid zygote is formed.
32
How does the egg prevent more sperm from binding to its plasma membrane? (2)
- fast block polyspermy
- slow block polyspermy
33
Fast block polyspermy
when the oocyte's membrane depolarizes
34
Slow block polyspermy
Cortical granules in the egg react with the zona pellucida, forming a tough, impermeable layer
35
How long can an oocyte be fertilized after ovulation?
12-24 hours
36
For how long can sperm remain viable?
4 days
37
What happens after fertilization?
the zygote migrates towards the
endometrium, while undergoing cleavage
38
How many steps are there to early embryo development?
6
39
What is the process of early embryo development? (6)
1. Ovulation
2. Fertilization
3. Cleavage begins after fertilization
4. After 4-5 days, the embryo (now blastocyst) reaches the end of the fallopian tube
5. Blastocyst (made up of 100 cells) implants into the endometrium
6. Enzymes in the blastocyst allow it to penetrate the
endometrium, and the endometrium begins to envelop the blastocyst
40
Blastocyst (3)
- hollow ball of cells
- outer layer called trophoblast; later develops into placenta
- inner mass develops into embryo; contains pluripotent stem cells
41
Placenta
structure connected to the uterus where nutrients are exchanged between the mother and child
42
What does the placenta do? (3)
- Through the umbilical cord, components are exchanged between fetal and maternal blood
- secrete estrogen and progesterone after 2 months
- BLOOD IS NOT EXCHANGED
43
What is a structural component of the placenta?
chorionic villi, which increase the
surface area for exchange
44
What types of things are exchanged between mother and child? (2)
- glucose
- oxygen
45
Amniocentesis (2)
- the removal of amniotic fluid which contains fetal cells
- fetal cells are tested for chromosomal abnormalities
46
How many steps are there to in vitro fertilization (IVF)?
6
47
What is the process of IVF? (6)
1. the female's menstrual cycle is stopped
2. FSH is injected in order to stimulate growth of numerous follicles
3. hCg (in place of LH) is injected to make it easier to harvest the follicles
4. The oocytes are extracted and mixed with semen
5. Any eggs which have fertilized are kept to be re-inserted into the woman
6. The early embryos still must implant into the uterine wall in order to pregnancy to occur
48
Where is sperm produced?
in the seminiferous tubules
49
What do the seminal vesicles and prostate gland produce?
fluids that mix with sperm during ejaculation
50
What does semen contain? (3)
- sperm
- fructose
- alkaline mucus
51
Why does semen need fructose?
fructose is a sugar that allows the sperm to move
52
Why does semen need alkaline mucus?
to navigate the acidic environment of the urethra and vagina
53
How many hormones are involved in spermatogenesis?
3
54
What hormones are involved in spermatogenesis? (3)
- FSH
- LH
- Testosterone
55
What does FSH do in spermatogenesis?
activate Sertoli cells to induce primary spermatocytes to undergo meiosis I to become secondary spermatocytes
56
What does LH do in spermatogenesis?
stimulates secretion of testosterone by the testes
57
What does testosterone do in spermatogenesis?
stimulates development of secondary spermatocytes into spermatids, maintain all stages of spermatogenesis
58
What secretes testosterone?
Leydig cells in the testes
59
Sertoli cells
nourish developing sperm and are activated by FSH
60
How many hormones are involved in the menstrual cycle?
4
61
What hormones are involved in the menstrual cycle? (4)
- LH
- FSH
- Estrogen
- Progesterone
62
What are the stages of the ovarian cycle? (3)
1. Follicular phase
2. Ovulation
3. Luteal Phase
63
What happens in the follicular phase? (5)
1. begins on day 1
2. FSH levels rise stimulating follicle cells to grow
3. follicle releases estrogen and estrogen stimulates follicle to grow (positive feedback)
4. high estrogen levels causes LH to surge and the spike causes meiosis I to complete
5. 1 follicle cell grows large enough that the secondary oocyte bursts out
64
What happens during ovulation?
24 hours after LH surge secondary oocyte is released into the fallopian tube
65
What happens during the luteal phase? (4)
1. follicle becomes corpus luteum
2. corpus luteum mainly produces estrogen, but also produces progesterone
3. corpus luteum degenerates as secondary oocyte migrates to the uterus
4. if there is no fertilization, the corpus luteum degenerates, progesterone and estrogen levels fall, and FSH rises
66
How many stages are in the uterine cycle?
3
67
What are the stages of the uterine cycle?
1. Menses
2. Proliferative Phase
3. Secretory Phase
68
What happens during the menses phase? (3)
1. endometrium of uterus is shed along with unfertilized eff
2. low levels of progesterone activates menstruation
3. menstruation ends during follicular phase as estrogen levels rise
69
What happens during the proliferative phase? (3)
1. estrogen causes endometrium to grow
2. endometrium thickens and repairs itself
3. this phase ends at ovulation as estrogen levels decrease and progesterone levels begin to rise
70
What happens during the secretory phase? (2)
1. progesterone causes vascularization of the endometrium
2. phase ends when corpus luteum degenerates, progesterone levels fall, and endometrium is shed
71
What happens to the uterine cycle if an oocyte is fertilized?
- second division of meiosis occurs and menses is inhibited
- no new follicle will develop
72
What does LH do in the menstrual cycle? (2)
- causes corpus luteum to grow
- causes ovulation
73
What does FSH do in the menstrual cycle?
stimulate follicle growth
74
What does estrogen do in the menstrual cycle? (3)
- stimulate LH secretion prior to ovulation
- inhibits FSH
- repairs uterine lining
75
What does progesterone do in the menstrual cycle? (2)
- prepares uterus for implantation
- inhibits LH and FSH
76
What are the components of a sperm cell? (6)
- haploid nucleus
- plasma membrane
- centriole
- flagellum
- mitochondria
- acrosome
77
mitochondria
produces the ATP needed to move and swim
78
acrosome
pouch of digestive enzymes
79
What are some structures in the testes? (2)
- Leydig cells
- Sertoli cells
80
Leydig cells (2)
- produce testosterone
- not inside the tubes
81
Sertoli cells (2)
- nourish developing sperm
- inside tubes
82
What are some of the structures in the oocyte?
- corona radiata
- zona pellucida
- plasma membrane
- cytoplasm
- haploid nucleus
83
Corona Radiata
go around the outside of cells, layer of follicle cells that stick around the egg
84
Zona Pellucida
extra layer of glycoproteins
85
Cytoplasm
contains centrioles and cortical granules
86
What hormones are needed throughout pregnancy? (2)
- estrogen
- progesterone
87
What does the blastocyst secrete when it implants into the uterus?
hCG
88
hCG
prevents the corpus luteum from degenerating, allowing continued secretion of progesterone and estrogen
89
Amniotic Sac (3)
- surround developing embryo
- acts as a shock absorber
- helps with temperature regulation
90
What is the process of birth? (4)
1. pregnancy ends as progesterone levels fall, it allows oxytocin to be made
2. oxytocin causes the uterine walls to contract and the contractions cause more oxytocin to be released (positive feedback)
3. The cervix opens and the amniotic sac bursts, releasing amniotic fluid
4. Fetus is pushed out the uterus, the umbilical cord is cut, and the placenta is expelled
