12.2 Female Reproductive System - Introduction Flashcards
1
Q
Describe the size and shape of ovaries
A
Almonds
2
Q
Where are ovaries located? Is this internal or external?
A
- Internal
- On either side of the uterus in the upper pelvis
3
Q
Are ovaries exocrine, endocrine, or both? How does this differ from the testes?
A
- Both
- It doesn’t differ; the testes are also both
4
Q
What is the name of the dense connective tissue capsule that surrounds the ovaries?
A
Tunica albuginea
5
Q
What is a follicle made of?
A
- Oocyte
- Follicular cells
6
Q
What type of connective tissue can be found in the cortex of the ovaries?
A
Dense connective tissue (supports follicles)
7
Q
Where are follicles located in the ovaries?
A
Cortex
8
Q
What occurs in the cortex of the ovaries?
A
- Folliculogenesis
- Oogenesis
9
Q
What is located in the ovarian medulla?
A
- (More) blood vessels + nerves
- Loose connective tissue
10
Q
Why does it make sense for there to be many blood vessels in the ovaries?
A
So hormones that are produced can enter systemic circulation
11
Q
What occurs during folliculogenesis, broadly speaking?
A
- Oocyte maturation
- Increased number of follicular cells
12
Q
Describe a primordial follicle
A
- Oocyte surrounded by single layer of (squamous) follicular cells
13
Q
Describe a primary follicle
A
- Primary oocyte
- 1-2 layers of CUBOIDAL follicle cells
14
Q
Describe a secondary follicle
A
- Enlarged oocyte
- Additional follicle cells
- Multiple, small fluid-filled spaces develop between follicular cells
15
Q
Describe a tertiary follicle
A
- Single, large, fluid filled space called antrum (cave)
- Oocyte surrounded by specialised follicular cells called granulosa cells
16
Q
Recall the name of the specialised follicular cells around the oocyte in a tertiary follicle
A
Granulosa cells
17
Q
What hormones does the corpus luteum secrete?
A
- Estrogen
- Progesterone
18
Q
Up until ovulation, what hormone do folliucular cells secrete?
A
Estrogen
19
Q
In the absence of fertilization, what is the rough lifespan of the corpus luteum?
A
10 days
20
Q
What does the corpus luteum degenerate into? What is it made of?
A
Corpus albicans. Made of dense connective tissue.
21
Q
What hormones does the corpus albicans make?
A
Nothing. Zip.
22
Q
When does the formation of oocytes/follicles start? How does this differ from men?
A
- Starts before birth (in an embyro)
- In males, spermatogenesis begins from puberty onwards
23
Q
How many follicles are produced from one oogonia stem cell? How does this differ from males?
A
- One produced per stem cell
- Different to males, who produce four sperm for every spermatogonia
24
Q
How many oogonia per ovary?
A
2-3 mil
25
When do oogonia stop dividing by mitosis?
Around month three or four of embryonic development
26
What are oocytes called after mitotic replication of oogonia stops?
Primary Oocytes
27
In which types of follicles do we find primary oocytes?
Primordial and primary
28
What triggers meiosis I to become "unfrozen" from their paused state part-way through meiosis 1?
Puberty
29
Name one hormone that triggers primary oocytes to finish meiosis 1?
FSH
30
What is the function of polar bodies produced during meiosis 1 of primary oocytes?
To collect half the genetic information that isn't required. These cells are not fertilized.
31
Meiosis II is blocked in secondary oocytes until a certain event occurs. What is this event?
Fertilization by a sperm
32
What happens to an oocyte in terms of cell division when it is fertilized by an egg?
- Meiosis II
- One of the resultant cells becomes a polar body, and is discarded
33
What is the name of a fertilized egg?
(Villain since an itsy bitsy) zygote
34
Is oogenesis continuous? How does this differ from spermatogenesis?
- Oogenesis is not continuous, as the cell replication pathways are blocked at certain points until puberty/fertilization
- Spermatogenesis is continuous once it begins during puberty
35
How long are uterine tubes approximately?
13cm
36
Are uterine tubes connected to the ovaries? What about the uterus?
- Not connected to ovary
- Connected to uterus
37
What are the three segments of the uterine tube?
1. Infundibulum
2. Ampulla
3. Isthmus
38
What is the function of uterine tubes?
- Transport oocytes from ovaries to uterus
- Sperm maturation (capacitation)
- Site of fertilization
39
Where in the uterine tubes does fertilization occur?
Ampulla
40
Where in the uterine tubes does sperm maturation occur?
Isthmus
41
Describe the wall of uterine tubes
- Simple, ciliated columnar epithelia with mucous-secreting cells
42
Describe the size and shape of the uterus
Pear
43
Describe the position of the uterus relative to the rectum and the urinary bladder
- Anterior to rectum
- Posterosuperior to bladder
44
What are the three regions of the uterus?
- Fundus (superior to attachment of uterine tubes)
- Body (large, central region)
- Cervix (Narrow, inferior region that projects into vagina)
45
What are the three layers of the uterus?
Endo/Myo/Perimetrium
46
Endometrium
Innermost layer containing epithelium and connective tissue containing glands.
47
Myometrium
Thick layer of smooth muscle.
48
Perimetrium
External layer composed of epithelium.
49
What are the two layers of the endometrium?
- Stratum Basalis
- Stratum functionalis
50
What are the finger-like projections on the infundibulum of oviducts called?
Fimbriae
51
What is the widest, longest region of the uterine tubes?
Ampulla
52
What is the function of the glycogen-rich mucous in the uterine tubes?
- Provides energy for sperm
- Provides energy for zygote if fertilization occurs in ampulla
53
What is the function of cilia in fallopian tubes?
Help to move oocyte or zygote towards uterus
54
What is the function of smooth muscle in uterine tubes?
Peristaltic movement moves oocyte/zygote down towards uterus
55
What is the narrowing of the body of the uterus called?
Isthmus
56
What type of membrane is the perimetrium?
Serous membrane; secretes protein rich fluid that lubricates outer surface of uterus
57
How many layers of muscle are in the myometrium? Describe their orientation
- Three layers
- Outermost: longitudinal
- Middle: Circular
58
What hormones does the myometrium contract in response to?
Oxytocin
59
Describe the density of connective tissue in the functional endometrium
Loose
60
Which of the layers of the endometrium does not change during the menstrual cycle?
Stratum basalis
61
Describe the connective tissue in the stratum basalis of the endometrium
Denser
62
How is a new stratum functionalis formed after menstruation?
- Stem cells in stratum basalis give rise to new stratum functionalis
63
Describe the mucous produced by the mucous glands in the cervix near/during ovulation. How does this differ from usual?
- Less viscous (more watery)
- Usually thicker to impede sperm penetration
64
Describe the epithelium on the inner lining of the vagina. What is under it?
- Stratified squamous (non-keratinized)
- Under this is a thin layer of connective tissue containing mucous glands
65
What is the mucous produced by glands in the vagina rich in?
Glycogen
66
Why is there glycogen-rich mucous in the vagina?
- Good bacteria break down glycogen, creating organic acids
- Acidic environment retards microbial growth, but..
- Is harmful to sperm
67
Describe any smooth muscle that may be present in the wall of the vagina
- Present
- Thick layer
68
Describe the external structures within the vulva
- Vestibule
- Labia minora/majora
- Clitoris
- Prepuce
- Bartholin's (greater vestibular) glands
69
Does the reproductive cycle occur during pregnancy?
No, you idiot.
70
What are the two cycles within the female reproductive cycle?
- Ovarian cycle
- Uterine cycle
71
What three structures control the reproductive cycle hormonally speaking? How do they work together?
- Hypothalamus triggers ant. pituitary
- Pituitary triggers ovaries
- Ovaries secrete more hormones
72
What are the three phases of the ovarian cycle?
- Pre-ovulatory (follicular)
- Ovulation
- Post-ovulatory (luteal) phase
73
What are the three phases of the uterine cycle?
- Menstrual phase
- Proliferative phase
- Secretory phase
74
How long is the follicular/proliferative phase?
First 10-14 days of cycle
75
What decides which follicle develops into a tertiary follicle during folliculogenesis?
The "strongest" follice with the most FSH receptors
76
What structures secrete oestrogen during the proliferative/pre-ovulatory phase, and what effect does this have on the uterus?
- Released by follicular cells
- Causes stratum basalis to divide and regerate the stratum functionalis layer
77
What structures secrete oestrogen during the proliferative/pre-ovulatory phase, and what effect does this have on the uterus?
- Released by follicular cells
- Causes stratum basalis to divide and regenerate the stratum functionalis layer
78
What is the typical effect of oestrogen on the production of GnRH? How does this differ in the female reproductive cycle?
- Usually, results in negative feedback
- In this rare instance, POSITIVE feedback occurs, causing more FSH and surge of LH
79
Which hormone keeps the corpus luteum alive and tells it to make an additional hormone?
LH
80
What hormones does the corpus luteum make?
- Progesterone
- Oestrogen
81
What is the effect of progesterone released by the corpus luteum on the uterus?
- Activates endometrial glands to produce glycogen-rich mucous
82
Why is the mucous release by endometrial glands rich in glycogen?
Provides energy for zygote if fertilization occurs
83
How long is negative feedback on GnRH suppressed? Why
~10 days. This is to give the oocyte time to be fertilized
84
What causes menstruation
- GnRH stops
- LH stops, killing luteum
- PG and OE stop
- Spiral arteries in basalis constrict
- Less blood to functionalis
- These cells die, and are sloughed off
85
What does the contraceptive pill contain (usually)
Oestrogen and/or progesterone (or synthetic versions)
86
Effect of contraceptive pill on cancer risk?
- Inc. breast cancer
- Dec. Ovarian cancer
87
Contraceptive pill mech
- By increasing oestrogen and progesterone, GnRH drops
- No FSH, LH, no folliculogenesis
- During placebo pills, functionalis cannot be maintained, and so menstruation occurs
88
What hormone do newly-fertilized embryos release? Why?
- hCG (human chorionic gonadotropin)
- Mimics LH, sustaining corpus luteum until placenta develops
