PBL 1: Conception Flashcards
(114 cards)
1
Q
What makes up the ovaries histologically?
A
Medulla (in the centre)
Cortex (on the outside)
Capsule of simple cuboidal epithelium
2
Q
Describe the medulla of the ovary?
A
- This is the inner part of the ovary
- Comprised of stroma, containing the neurovascular stuctures (e.g. arteries, veins, nerves)
3
Q
Describe the cortex of the ovary?
A
- Outer part of the ovary
- Composed of developing follicles (at various stages of development)
4
Q
What kind of epithelium surrounds the ovaries?
A
Simple cuboidal epithelium
5
Q
What are the four tunics of the uterine tube (from inner to outer layers)?
A
- Tunica mucosa (inner layer)
- Tunica submucosa
- Tunica muscularis
- Tunica serosa
6
Q
What part of the female reproductive tract is this histological image
A
The uterine tubes
7
Q
Describe the structure of the tunica mucosa of the uterine tube?
A
- Highly folded around the length of the tube.
- Varies from different regions- ampulla is more elaborate folded.
- The isthmus is less elaborately folded
8
Q
What are the sublayers of the tunica mucosa of the uterine tube?
A
Epithelium
Basement membrane
Lamina propria
9
Q
What is the epithelium of the uterine tubes?
A
Simple columnar epithelium that has two different cell types.
Peg cells (also known as secretory cells).
Ciliated cells
10
Q
What is the functions of the ciliated cells in the tunica mucosa layer of the uterine tube?
A
Beats in one direction (the direction towards the uterus)
Has two functions:
- Aids in the movement of the ovum from the ovary to the uterus
- Protects against infection but beating pathogens away from the uterus.
11
Q
Describe the tunica muscularis layer of the uterine tube?
A
Consists of two layers:
- Circular layer of smooth muscle (inner layer)
- Longitudinal layer of smooth muscle (outer layer).
Thick layer of smooth muscle, which contracts to help move the sperm along the uterine tube.
Thickest in the isthmus- as this is the only part prior to the ampulla- where fertilsiation occurs
12
Q
What kind of movement of the tubal musculature in the uterine tube helps move the sperm along the uterine tube to the ampulla?
A
Peristaltic movement i.e. progressive wavelike contractions
13
Q
What are the 3 layers of the uterus?
A
- Endometrium (inner layer)
- Stratum functionalis
- Stratum basalis
- Myometrium (middle layer)
- Peritoneum (outer layer)
14
Q
Name these layers of the uterus?
A
15
Q
Compare the stratum functionalis and basalis?
A
Stratum functionalis
- Superficial layer
- Proliferates in response to oestrogen
- Becomes secretory in response to progesterone
- Shed during menstruation
- Blood supply is coiled arteries.
Stratum basalis:
- Deep layer
- More cellular
- Little to no change throughout the menstrual cycle
- Maintained during menstruation
- Blood supply is straight arteries.
NOTE: both contain uterine glands
16
Q
The stratum functionalis becomes secretory in response to which hormone?
A
Progesterone
17
Q
The stratum functionalis proliferates in response to which hormone?
A
Oestrogen
18
Q
What is the blood supply to the stratum functionalis?
A
Coiled arteries
19
Q
What is the blood supply to the stratum basalis?
A
Straight arteries
20
Q
Describe the histology of the cervix region?
A
- The transition of epithelium occurs here.
- Two parts of the cervix:
- Endocervix
- Ectocervix
21
Q
Compare the endocervix and ectocervix region?
A
Endocervix:
- Upper part of the cervix
- Lined by simpled columnar epithelium
- Contains mucous-secreting glands.
Ectocervix:
- Lower part of the cervix
- Lined by stratified squamous epithelium
22
Q
The transition point between endocervix and ectocervix is called what?
A
External os
23
Q
The endocervix is lined by which epithelium?
A
Simple columnar epithelium
24
Q
The ectocervix is lined by which epithelium?
A
Stratified squamous epithelium
25
Name these regions in the cervix?
26
The peritoneum layer in the cervix is continous which what structure?
The peritmetrium (aka the abdominal peritoneum)
27
Describe the myometrium layer of the uterus?
* Middle and the thickest layer of the uterus wall.
* Composed of smooth muscle.
* The smooth muscle cells undergo hypertrophy and hyperplasia during pregnancy in preparation to expel the foetus at birth.
28
What are the four layers of the vagina, from inner to outer layer?
* Epithelium (inner layer)
* Lamina propria
* Fibromuscular layer
* Adventitia (outer layer)
29
Name these layers of the vagina?
30
What type of epithelium lines the vagina?
Stratified sqamous non-keratinised epithelium
31
The vagina is lubricated by mucus. From which location is this mucus coming from?
Cervical mucus lubricates the vagina.
The vagina **does not** contain glands
32
What are the 3 phases of the ovarian cycle?
The ovarian cycle represents the changes that occur in/from the ovaries.
1. Follicular phase
2. Ovulation
3. Luteal phase
33
How long does the follicular stage last?
Around 14 days however varies significantly between women
34
Describe what happens during the follicular phase?
* At the beginning of each menstrual cycle, 15 to 20 primordial follicles are stimulated to grow under the influence of FSH
* The follicles develop until one reaches the tertiary stage.
35
The follicles are located at what part of the ovary?
Cortex (outside bit)
36
The follicles develop in stages. Name these stages?
1. Primordial follicle
2. Primary follicle
3. Secondary follicle
4. Tertiary follicle
37
What is the name of the follicles that are in the arrested state?
Premordial follicle
38
Describe the structure of the primordial follicles?
Contains a primary oocyte, which is surrounded by a single layer of squamous (flattened) follicular cells.
39
Which follicle does the primordial follicle develop into?
Primary follicle
40
The primary oocyte is arrested in which stage of development?
Arrested in meiosis I.
41
This histological image represents which stage of follicular development?
Name these parts
Primordial follicle
42
Describe the characteristics of the primary follicle?
* Surrounded by stratified follicular cells
* Follicular cells are now termed granulosa cells.
* Stratified: the follicular cells start to proliferate forming multiple layers i.e. multiple layers of granulosa cells.
* The oocyte secretes glycoproteins, which condense around it forming the zona pellucida.
* Moreover, at this stage the theca cells are being recruited from the surrounding stroma
43
This is an example of which kind of follicle?
Primary follicle
44
Name these parts of the primary follicle?
45
Describe how the zone pellucida is formed? which stage of follicular development does it form
The oocyte secretes glycoproteins, which condense around it forming the zona pellucida.
Formed during the primary follicle stage
46
What kind of follicles are represented by A,B and C?
**A-** Secondary follicle
**B-** Primordial follicle
**C-** Primary follicle
47
Describe the characteristics of the secondary follicle?
* The spaces between granulosa cells develop creating the antrum (fluid filled cavity).
* The theca cells surrounding the follicle are becoming more organised and have formed into two layers:
* Theca interna
* Theca externa
* The theca interna and the granulosa layer worked together to produce oestrogen
48
Describe the process of oestrogen production in the secondary follicles?
* The theca interna and the granulosa layer worked together to produce **oestrogen**.
* The **theca** **interna** cells produce the **androgens** and secrete them onto the **granulosa** **cells**, which convert the **androgens** into **oestrogen** (via aromatase).
49
What is the structure shown in this image?
Secondary follicle
50
What cells are respresented by A, B and C in this image?
**A-** Theca interna
**B**- Theca externa
**C-** Granulosa cells
51
What substance is produced by the cells labelled C?
Aromatase enzymes- to convert androgens into oestrogen
52
When the dominant follicle is picked. What happens to the other 12-14 follicles that have developed?
Undego atresia
53
Define the term "Follicular atresia"
the breakdown of the ovarian follicles, which consist of an oocyte surrounded by granulosa cells and internal and external theca cells.
Normal mechanism- particularly when one follicle is chosen to become the dominant one- the others undergo atresia
54
What happens to oestrogen levels during the follicular phase?
Oestrogen levels rise throughout the phase.
This is because the follicles are becoming more developed and therefore produce more oestrogen
55
Describe the characteristics of the tertiary follicle?
* Also known as the Graffian follicle
* One follicle is picked as the dominant one
* The rest undergoes atresia (Degenerates)
* The domiannt follicle has grown in size and is now mature. Ready for ovulation.
56
Describe the The Hypothalamic-Pituitary-Gonadal (HPG) Axis relationship during the follicular stage?
* The low level of oestrogen and progesterone inhibits the release of gonadotropin and the androgen hormones (LH and FSH) via negative feedback loops.
* Therefore, levels of FSH and LH remain low
57
Describe the hormonal changes that trigger ovulation?
* As the follicle matures, it releases higher levels of oestrogen. Eventually, the level of oestrogen is high enough it switches off the negative feedback and switched on the positive feedback. The positive feedback stimulates the release of GnRH, FSH and LH.
* During the negative feedback, the anterior pituitary still produced LH and FSH but did not release them. Therefore, when the feedback loop is switched to positive, there is a surge in LH
* A surge in LH triggers the rupture of the dominant follicle, releasing the secondary oocyte. It does this by stimulating enzymes that initiate the breakdown of the follicle wall.
58
What does the surge in LH (ovulation stage) trigger?
* The rupture of the dominant follicle, releasing the secondary oocyte.
* The completion of the first meiotic division of the oocyte (now known as the secondary oocyte)
59
What causes the change from primary oocyte to secondary oocyte?
The LH surge at the end of the follicular stage.
meiosis I is now complete- changing the primary oocyte into secondary.
60
Describe the secondary oocyte?
Oocyte has completed meiosis 1.
Arrested in the metaphase stage of meiosis 2
61
When will the secondary oocyte complete meiosis 2?
At fertilisation
62
When in the cycle is there the surge in LH?
Around day 12 of the cycle
63
When does the LH surge occur in relation to ovulation?
LH surge occurs 24-36 hours prior to ovulation.
64
How long does the luteal stage last?
* Length approx. 14 days
65
The length of time of the luteal stage is similar in all women. Why?
Similar
Why? because the corpus luteum survives 14 days (no matter the lady)
66
Describe what happens during the luteal phase?
* In the ovulation stage: The oocyte is released with few granulosa cells.
* The remaining granulosa cells and theca cells undergo massive amounts of reorganisation- becoming lutein cells
67
Describe the histological characteristics of the lutein cells in relation to its previous state (granulosa and theca cells)?
Lutein cells are more foam appearance due to their new endocrine function (releasing progesterone mainly and oestrogen)
68
the corpus luteum has a life span of about ___ weeks?
Two weeks
69
Describe the formation of the corpus luteum?
* The granulosa cells undergo hypertrophy becoming lutein cells. Lutein cells derived from granulosa cells form the bulk of the corpus luteum.
* Capillaries invade the lutein cells forming blood vessels.
The lutein cells produce mainly progesterone and a small amount of oestrogen.
70
What is the secretions of the corpus luteum?
Mainly progesterone and a small amount of oestrogen
71
Describe the The Hypothalamic-Pituitary-Gonadal (HPG) Axis relationship during the luteal stage?
* The lutein cells of the corpus luteum produce mainly progesterone and a small amount of oestrogen.
* The levels of oestrogen and progesterone inhibit the secretion of LH and FSH via the negative feedback loop
* Low level of oestrogen switches the feedback loop to negative
* High levels of progesterone highly inhibit the release of FSH and LH.
* Therefore, low levels of FSH and LH in this phase
72
What happens to the corpus luteum if pregnancy occurs?
* The embryo release human chorionic gonadotropin (hCG), which rescues the corpus luteum.
* Therefore, the corpus luteum does not degenerate.
73
Compare the ovarian and uterine cycle?
_Ovarian cycle_: refers to the changes that occurs in the ovaries during menstruation.
_Uterine cycle_: refers to the changes that occurs in the uterus during menstruation.
74
What hormone related to menstruation is released from the hypothalamus?
Gonadotropin Releasing Hormone (GnRH)
75
What is the effect of follicular inhibin in the follicular phase?
Inhibits FSH release
76
How long does a mature oocyte roughly remain viable once released?
24 hours
77
In the follicular phase, what do the follicular cells proliferate to form?
Granulosa cells- in the primary follicle stage
78
What are the 3 phases of the uterine cycle?
1. Proliferation phase
2. Secretory phase
3. Menses
79
The proliferative phase runs alongside which phase in the ovarian cycle?
Follicular phase
80
The secretory phase runs alongside which phase in the ovarian cycle?
Luteal phase
81
Describe the proliferatory phase of the uterine cycle?
* The endometrium is “proliferating” –hence the name
* Oestrogen secreted by the granulosa cells in the follicles stimulate the repair of the endometrium
82
What are the 3 mechanisms that occur in the proliferatory phase of the uterine cycle?
* Thickening of the endometrium
* The cells of the stratum basalis undergo mitosis to produce the stratum functionalis i.e. thickening the endometrium.
* Elongation of the uterine glands
* The short, straight endometrial glands develop and elongate
* Growth of the spiral arteries
83
\_\_\_\_ secreted by the granulosa cells in the follicles stimulate the repair of the endometrium
Oestrogen
84
The uterus becomes ___ in function in response to oestrogen?
A) Secretory
B) Proliferatory
B) Proliferatory
85
The uterus becomes ___ in function in response to progesterone?
A) Secretory
B) Proliferatory
Secretory
86
Describe the secretory phase of the uterine cycle?
* Initiated after ovulation
* The corpus luteum secretes mainly progesterone and a bit of oestrogen.
* Progesterone produced by the corpus luteum cause the uterus to become secretory in function
87
How does the glands differ structurally in the secretory stage in relation to the proliferatory stage?
The uterine glands undergone hypertrophy (increased in size)
88
What does the uterine glands produce when they become secretory (in the secretory phase) and what is its function?
Secretes glycogen
It provide the initial nutritional support (glycogen) to support the embryo prior to the connection via the placenta to the maternal blood
89
Progesterone produced by the corpus luteum causes many changes in the uterus in the secretory phase.
Outline the 3 changes it causes?
* Promotes the growth and coiling of the uterine glands
* Glands are hypertrophy and become secretory. They secrete glycogen.
* Promotes the vascularisation of the superficial endometrium (coiled arteries)
* Thickening of the endometrium
* As the uterine glands become more developed and hypertrophic.
90
Name the uterine cycle phases the pictures correspond to?
91
Menses phase only occurs if ___ does not occur
Pregnancy
92
Describe the menses phase of the uterine cycle?
* The corpus luteum has degenerated into a corpus albicans.
* Low levels of progesterone and oestrogen
* This means there are no hormones to support the endometrium functionalis.
* As a result, the stratum functionalis shrinks that compresses the spiral arteries (the blood supply to the stratum functionalis).
* The spiral arteries are compressed causing the stratum functionalis tissue to become necrotic- as it no longer has a blood supply.
* As more tissue is becoming necrotic, less tissue is compressing on the spiral arteries. This results in a final relaxation of the arteries.
* As a result of the relaxation, the coiled arteries release the backed up blood. Resulting in a flow of blood.
* The flow of blood is released from the body, carrying with it the necrotic stratum functionalis tissue.
* This process happens in patches in the uterus (instead all at once). Hence, the bleed usually last approx. 7 days.
93
The corpus luteum has degenerated into a corpus \_\_\_?
Corpus albicans
94
During a normal menstrual cycle, through which three phases does the endometrium pass and on which days of the cycle do they occur?
95
Describe the hormonal changes that are occuring in the proliferatory/follicular stage of the mentruation cycle?
* In this stage the follicles are developing
* As they develop, the follicle produces mainly oestrogen and progesterone
* The oestrogen and progesterone, through the negative feedback loop, inhibiting the release of GnRH, LH and FSH.
96
Describe the hormonal changes that are occuring in the pre-ovulation stage (around day 12) of the mentruation cycle?
* Follicles developing increasing the levels of oestrogen they are producing.
* A high level of **oestrogen** switches the negative feedback to positive.
* Positive feedback loop= increasing the release of LH and FSH.
97
Describe the hormonal changes that are occuring in the luteal/secretory stage of the mentruation cycle?
* Corpus luteum produces mainly progesterone and a little of oestrogen.
* A low level of oestrogen switches the positive feedback loop to negative.
* Inhibition of the release of GnRH, LH and FSH
98
Define the term "secondary follicle"?
A follicle in which the antrum has formed
99
What is a "combined oral contraceptive pill"?
The combined oral contraceptive pill consists of oestrogen and progesterone in varying proportions.
100
What is a "uncombined oral contraceptive pill"?
The uncombined oral contraceptive pill consists of low dose of progesterone, varying proportions.
101
Describe the three major actions of the combined oral contraceptive pill
* Prevents ovulation
* Oestrogen and progesterone inhibit gonadotrophin release from the anterior pituitary.
* Inhibits sperm penetration of the cervical mucus
* Progesterone alters the consistency of the cervical mucus, making it impenetrable to spermatozoa.
* Prevents implantation
* Oestrogen and progesterone results in inadequate endometrial proliferation
102
What is the common course for the combined oral contraceptive pill
* Commonly the oral tablet is taken for 21 days with a 7 pill-free days afterwards.
* During these 7 pill-free days the patient will have bleeding (does not reflect a true ovarian cycle)
103
Why can some women not be allowed the combined oral contraceptive pill
Not suitable for women over 35 who smoke or women with certain medical conditions
104
What is the common course for the uncombined oral contraceptive pill
1 tablet taken daily, at the same time, for the full cycle
105
Describe the two major actions of the uncombined oral contraceptive pill
* Prevents ovulation (in some cases- approx 40%)
* Thickening of the cervical mucus
* Progesterone alters the consistency of the cervical mucus.
106
Outline factors which may impair fertility in the female
* **Uterine** **tube** **damage** is often a consequence of pelvic infection e.g. gonorrhoea.
* **Endometriosis** can result in scarring and adhesion formation. Scarring and adhesion can restrict the oviduct movement or can physical block the fimbria, entry point of the oocyte.
* Anything that can effect the hypothalamus can cause disorders of ovulation
* Stress
* Obesity
* Strenuous exercise
* Anorexia nervosa
107
Outline factors which may impair fertility in the male
* Oligo-astheno-teratozoospermia syndrome
* Usually all linked together
* Oligospermia- **too few spermatozoa**
* Asthenozoospermia- **low sperm motility**
* Teratozoospermia: **too many abnormal sperm**
* Cryptorchidism (**undescended testes**)
* Usually problems are in the left testis, due to the arterial supply (more 90 degree angle)
108
Outline the investigations that would be conducted in females with impaired fertility?
* Examine female pelvic area for infection
* Blood tests
* Looking for high level of progesterone around 14 days into the cycle
* Can determine if ovulation is occurring.
* STI test
* STI can affect fertility.
* Transvaginal ultrasound
* Check the ovaries, uterine tube and uterus for any abnormalities e.g. endometriosis or blockage in the uterine tube.
* Hysterosalpingogram (X-ray)
* X-ray of the uterus and uterine tubes
* Useful to detect blockages
109
Outline the investigations that would be conducted in males with impair fertility?
* Examine male testicles to identify any abnormalities e.g. lumps
* Semen analysis
* Sperm sample to detect if there is any abnormalities in the spermatozoa
* STI test
110
The stratum functionalis proliferates in respones to ____ and becomes secretory in response to \_\_\_\_\_\_\_
The stratum functionalis proliferates in respones to **oestrogen** and becomes secretory in response to **progesterone**
111
The blood supply to the startum functionalis is by the ____ arteries
Coiled arteries
112
The blood supply to the startum basalis is by the ____ arteries
Straight
113
The stratum functionalis **proliferates** in response to which hormone?
Oestrogen
114
The stratum functionalis becomes **secretory** in response to which hormone?
Progesterone
