Reproductive system - done Flashcards
1
Q
Label the following:
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2
Q
Label the following:
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3
Q
Label the following:
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4
Q
Label the following:
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5
Q
What hormones are involved in the hypothalamic-pituitary-gonadal axis?
A
Hypothalamus = GnRH
Anterior pituitaty = LH and FSH (stimulate development of follicles)
6
Q
What part of the follicles secrete oestrogen?
A
Theca granulosa cells
7
Q
What effect does oestrogen have on the hypothalamus and anterior pituitary?
A
Negative feedback effect
8
Q
What kind of hormone is oestrogen?
A
Steroid sex hormone
9
Q
What is the most active version of oestrogen?
A
17-beta oestradiol
10
Q
Where does oestrogen work?
A
On tissues with oestrogen receptors to promote female secondary sexual characteristics
11
Q
What changes does oestrogen stimulate?
A
- Breast tissue development
- Development of female sex organs at puberty
- Blood vessel development in the uterus
- Development of the endometrium
12
Q
What kind of hormone is progesterone?
A
Steroid sex hormone
13
Q
Where and when is progesterone formed?
A
Corpus luteum after ovulation
14
Q
After pregnancy where is progesterone mainly formed?
A
Placenta from 10 weeks gestation onwards
15
Q
What does progesterone do?
A
Acts on tissues which have previously been stimulated by oestrogen
16
Q
What does progesterone do?
A
Thickens and maintains the endometrium
Thickens the cervical mucus
Increases the body temperature
17
Q
What age does puberty begin in girls and boys respectively?
A
Girls = 8-14
Boys = 9-15
18
Q
What enzyme is found in adipose tissue which is important in the creation of oestrogen?
A
Aromatase
19
Q
When may puberty be delayed?
A
- Low birth weight
- Chronic disease
- Eating disorders
- Athletes
20
Q
What is the order of puberty in girls?
A
- Breast buds
- Pubic hair
- Menarche (first episode of mensturation)
21
Q
What scale can be used to stage pubertal development?
A
Tanner scale
22
Q
What hormone initially rises during puberty?
A
Growth hormone
23
Q
In puberty what is released after GH and what is its function?
A
GnRH stimulates the release of FSH and LH
24
Q
What does FSH and LH stimuate in the woman?
A
Production of oestrogen and progesterone
25
How does FSH and LH change just before menarche?
**FSH** levels plateau a year before
**LH** continues to rise and spike just before menarche
26
What suppresses GH in women?
**Oestrogen**
27
What are the two phases to the menstural cycle?
**Follicular phase** (start of mensturation to moment of ovulation)
**Luteal phase** (final 14 days of cycle)
28
Which cells have the potential to develop into eggs?
Oocytes
29
Which cells surround the oocytes?
Granulosa cells (forming follicles)
30
What are the 4 key stages of development of the follicles?
**Primordial follicles**
**Primary follicles**
**Secondary follicles**
**Antral follicles** (aka Graafian follicles)
31
When do primordial follicles mature into primary and secondary follicles?
Always occuring, independent of the menstural cycle
32
At what point do the follicles develop the receptors for FSH?
Secondary follicle stage (further development requires FSH)
33
At the start of the menstural cycle, what stimulates further development of the **secondary follicles**?
FSH
34
What secretes **oestradiol** in the woman?
Granulosa cells
35
What effect does this oestradiol have on the pituitary gland?
**Negative feedback** (reducing LH and FSH)
36
What effect does the rising oestrogen have on the cervical mucus?
Makes it **more permeable** allowing sperm to penetrate the cervix
37
What hormone spikes just before ovulation, causing the **dominant follicle** to release the **ovum** (an unfertilised egg)
Luteinising hormone
38
What happens to the follicle that releases the ovum?
Collapses and becomes the **corpus luteum**
39
What hormone does the corpus luteum secrete?
**Progesterone**
(and a little oestrogen)
40
What effect does the progesterone from the corpus luteum have?
Maintains **endometrial lining**
Causes **cervical mucus** to become thick and no longer penetrable
41
Where does human chorionic gonadotrophin (HCG) come from?
**Syncytiotrophoblast** of the embryo
42
What is the purpose of HCG?
Maintains the corpus luteum
43
What causes mensturation?
No production of hCG = corpus luteum degenerates = production of oestrogen and progesterone stops = **endometrium breaks down** and mensturation occurs
44
During mensturation where does prostalandins come from?
**Stromal cells** of the **endometrium**
45
What is the purpose of prostaglandins?
Encourages the **endometrium to break down** and **uterus contracts**
46
What day of the menstural cycle does mensturation occur on?
Day 1
47
Why does LH and FSH begin to rise at the beginning of the menstural cycle?
Due to negative feedback from the corpus luteum stopping (so progesterone and oestrogen decreases)
48
What layers of the endometrium are lost during mensturation?
Superficial and middle
49
What layer of the endometrium is kept during mensturation?
Basal layer
50
What type of cells are oocytes?
**Germ cells** - undergo meiosis to become mature ovum (ready for fertilisation)
51
How many chromosomes do ovum contain?
46
52
What layers surround the primary oocyte?
**Pregranulosa cells**
Surrounded by **outer basal lamina layer**
53
What are the three layers to the primary follicle?
- **Primary oocyte** in centre
- **Zona pellucida**
- Cuboidal shaped **granulosa cells**
54
Where does the zona pellucida come from in the primary follicles?
Secreted by the **granulosa cells** (they also secrete oestrogen)
55
What layer develops on top of the granulosa layer?
Theca folliculi
56
What are the two layers of the theca folliculi?
Theca interna and theca externa
57
What does the theca interna secrete?
Androgen hormones
58
What is the theca externa made up of?
Connective tissue containing **smooth muscle and collagen**
59
What is the difference between primary and secondary follicles?
**Secondary are larger** with small fluid-filled gaps between granulosa cells
**Receptors** for **FSH**
60
What is required for the further development of the secondary follicle?
Stimulation from **FSH**
61
What develops in the secondary follicle and what is this called?
Single large fluid-filled area in the **granulosa** called the **antrum**
62
Once the antrum is formed, what surrounds the oocyte now?
**Corona radiata** - made of granulosa cells (surrounding the zona pellucida and oocyte)
63
What causes the follicle to burst during ovulation?
**LH surge** (causes the smooth muscle of the theca externa to burst)
64
What sweeps along the oocyte?
**Fimbriae** of the **fallopian tubes**
65
Once ovulation occurs what happens to the cells of the follicle?
Become **luteal cells**
66
At what point do the 46 chromosomes split to become 23 in the oocyte?
Just **before ovulation** the **primary oocyte** undergoes **meiosis** creating a **haploid** cell (the other 23 chromosomes float off to the side and become a polar body) it is then a **secondary** oocyte
67
When the sperm enters the egg what happen to the chromosomes of the egg?
They multiply into **two sets** and only one set **combines** with the **23 chromosomes** from the sperm to form a diploid set of 46 chromosomes
68
What happens to the other set of 23 chromosomes?
Float off to the side to create the **second polar body**
69
What is the fertilised egg called?
**Zygote**
70
After rapid divison what is the zygote then called?
**Morula**
71
How does the morula change?
A fluid filled cavity gathers within the group of cells and it becomes a **blastocyst**
72
What are the components of the blastocyst?
**- Embryoblast**: main group of cells in the middle
**- Blastocele**: fluid filled cavity
**- Trophoblast**: outer layer of cells
(gradually losing the **corona radiata** and **zona pellucida**)
73
When does the blastocyst arrive in the uterus?
8-10 days after ovulation
74
Which cells of the blastocyst implant on the endometrium?
Cells of the **trophoblast** undergo adhesion to the stroma (supportive outer tissue) of the endometrium
75
What is the outer layer of the trophoblast called?
**Syncytiotrophoblast** (this layer forms projections into the stroma)
76
What do the cells of the **stroma** (supportive outer tissue of the endometrium) convert into?
**Decidua**
77
What is the role of the **decidua**?
Provides nutrients to the **trophoblast**
78
After implantation of the blastocyst, what starts **producing HCG**?
**Human chorionic gonadotrophin**
79
What is the purpose of HCG?
Maintains the corpus luteum in the ovary, allowing it to continue producing **progesterone** and **oestrogen**
80
After implantation when does the blastocyst start to differentiate?
A week after fertilisation
81
What does the **embryoblast** differentiate into?
**Yolk sac**
**Amniotic cavity**
Divided by the embryonic disc
82
What does the embryonic disc divide into?
**Fetal pole** into the fetus
83
What surrounds the yolk sac and amniotic cavity?
**The chorion** (two layer: cytotrophoblast, syncytiotrophoblast)
84
Label the following:
85
What does the connecting stalk eventually become?
**Connecting stalk**
86
When does the **embryonic disc** become the **fetal pole**?
5 weeks gestation
87
What are the three laters of the fetal pole?
**Ectoderm** (outer layer)
**Mesoderm** (middle layer)
**Endoderm** (inner layer)
88
Name some derivatives of the three germ cell layers?
89
At what point gestation have all the major organs developed?
**8 weeks gestation**, from this point the fetus matures and grows until birth
90
What are the **spiral arteries**?
**Artery branches** in the endometrium from the myometrium
91
What is the chorionic villi?
Finger-like projections from the **syncytiotrophoblast** into the endometrium containing **foetal blood vessels**
92
Where is the chorionic villi most vascular?
**Chorion Frondosum**: nearest the connecting stalk - these contain **mesoderm**
93
What cells become the placenta?
Cells of the **chorion frondosum**
94
When is placental development complete by?
10 weeks gestation
95
What signal reduces **vascular resistance** of the **spiral arteries**?
Signals from the trophoblast invasion of the endometrium make the spiral arteries more fragile
96
When the spiral arteries break down, what is left?
**Lacunae** = pools of blood
97
What does the maternal blood flow through?
From **uterine arteries** into **lacunae** and back out through **uterine veins**
98
What point in gestation does **lacunae** form?
20 weeks gestation
99
What separates the **lacunae** from the **chorionic villi**?
**Placental membrane**
100
What can result if the process forming lacunae is inadequate?
**Pre-eclampsia**
101
What is **pre-eclampsia** caused by?
High **vascular resistance** in the **spiral arteries**
102
What are the functions of the placenta?
**Respiration**
**Nutrition**
**Excretion**
**Endocrine**
**Immunity**
103
Where does the foetus' oxygen come from?
**Placenta**
104
How does foetal Hb differ from adult Hb?
Foetal Hb has a **higher affinity for oxygen**
105
What is exchanged in the placenta which helps with **acid-base** balance?
**Carbon dioxide**
**Hydrogen ions**
**Bicarbonate**
**Lactic acid**
106
What is the main form of nutrition for the foetus?
**Glucose** used for energy and growth
107
What substances can a mother consume which will harm a foetus?
Medications
Alcohol
Caffeine
Cigarette smoke
108
What are the waste products from a foetus?
**Urea**
**Creatinine**
109
Where does hCG come from and what is its purpose?
**Syncytiotrophoblast** (increasing in early pregnancy and then plateauing)
110
What is the purpose of hCG?
Maintains the **corpus luteum** until the placenta can take over the production of **oestrogen** and **progesterone**
111
What is a side effect of hCG production?
Nausea and vomiting in early pregnancy
112
When are there higher levels of hCG?
**Twins**
## Footnote
**Molar pregnancies**
113
The placenta produces oestrogen, what is it's purpose?
**-** Allows **expansion** of the muscles and ligaments of the uterus and pelvis
- **Softens** the cervix, ready for birth
- **Enlarges** the breast and nipples for breastfeeding
114
The placenta produces **progesterone**, what is it's purpose?
**Maintain the pregnancy**
**Relaxes** the uterine muscles
**Maintains** the endometrium
115
Progesterone can relax other muscles, what are the side effects of this?
- **GORD** due to relaxation of the LOS
- **Constipation** due to relaxation of the bowel
- **Hypotension** due to relaxation of the blood vessels (causing hypotension, headaches and skin flushing)
116
How much does body tempterature increase during pregnancy?
0.5 to 1 degree celsius
117
What carries oxygenated blood to the fetus?
Umbilical vein
118
What is produced in excess in pregnancy?
**ACTH**
**Prolactin**
**Melanocyte stimulating hormone**
119
What does the rise in **ACTH** cause?
**Rise in steroid hormones**: cortisol and aldosterone
120
What does the higher steroid levels cause in pregnancy?
- **Improvement** in autoimmune conditions
- Susceptibility to **diabetes** and **infections**
121
What does the increase in prolactin during pregnancy cause?
Suppression of FSH and LH
122
What does the increase in **melanocyte stimulating hormone** cause in pregnancy?
Increased **pigmentation** of the skin during pregnancy
123
What does the increase in skin pigmentation during pregnancy cause?
**Linea nigra**
**Melasma**
124
How do thyroid hormones change during pregnancy?
**TSH** remains normal
**T3** and **T4** levels rise
125
When do hCG levels fall during pregnancy?
Around 8-12 weeks
126
What is the role of progesterone in pregnancy?
**Maintains** the **pregnancy**
## Footnote
**Prevents contractions**
**Supress the mother's immune system**
127
How does the uterus change in size during pregnancy?
Increases from **100g to 1.1kg**
128
How does the myometrium change during pregnancy?
**Hypertrophy** of the **myometrium** and the blood vessels
129
How may the cervix change during pregnancy?
**Cervical ectropion**
**Increased cervical discharge**
130
What causes increased vaginal discharge in pregnancy?
Increase in **oestrogen** (also causes hypertrophy of the vaginal muscles as it increases throughout pregnancy)
131
How does the cervix change before delivery?
132
What are the cardiovascular changes in pregnancy?
**Increased**: blood volume, plasma volume, cardiac output
**Decreased:** preipheral vascular resistance, blood pressure
Varicos veins (peripheral vasodilation and obstruction of the IVC), peripheral vasodilation causing flushing and hot sweats
133
What are the **renal changes** in pregnancy?
Increased **GFR**
Increased **aldosterone** = increased salt and water reabsorption
Increased **protein excretion** from the kidneys
Dilation of the **ureters** leading to **physiological hydronephrosis**
134
What are the haematological changes in pregnancy?
Increased RBCs
Increased plasma volume
135
What nutritional demands do the increase in RBCs cause?
Higher **iron**, **folate** and **B12**
136
Why is there a lower concentration of RBCs in pregnancy?
As plasma volume increases more than RBC volume
137
Why does anaemia occur in pregnancy?
High plasma volume means the **haemoglobin concentration** and **red cell concentration** fall in pregnancy
138
What clotting factors increase in pregnancy?
**Fibrinogen**
**Factor VII, VIII and X**
139
What is a result of the increase in clotting factors in pregnancy?
Increased risk of VTE
140
What are the other blood changes during pregnancy?
**Increased** white blood cells, ALP (from the placenta), ESR, D-dimer,
**Decreased** platelet count and reduced albumin
141
What are the skin changes in pregnancy?
- **Pigmentation** (due to increase in MSH = linea nigra and melasma)
- **Striae gravidarum** (stretch marks on the abdomen)
- **Pruritus** (normal / obstetric cholestatsis)
- **Spider naevi**
- **Palmar erythma**
142
What are the hair changes in preganancy?
**Postpartum hair loss** (normal and usually improves in 6 months)
143
When does labour usually occur?
Between 37 and 42 weeks gestation
144
What are the 3 stages of labour?
**First stage** = onset of labour to 10cm cervical dilation
**Second stage** = from 10cm dilatation to delivery of baby
**Third stage** = from delivery of the baby to delivery of the placenta
145
What role do prostaglandins have in pregnancy?
- Stimulate **contraction** of the uterine muscles
- Ripening the cervix before delivery
146
What is in the pessaries which induce labour?
**Prostaglandin E2** (dinoprostone)
147
What are **Braxton-Hicks** contractions?
**Occasional** and **irregular** contractions of uterus - don't progress and become regular - **not true contractions** (staying hydrated and relaxing can help reduce)
148
What are the components of the **first stage** of labour?
**Cervical dilation** (opening up)
**Effacement** (getting thinner)
149
What is the purpose of "the show" - the mucus plug in the cervix?
- Prevents bacteria from entering / falling out
150
What are the 3 phases of the first stage of pregnancy?
**Latent phase** = 0 to 3cm dilation of cervix, irregular contractions (0.5cm per hour)
**Active phase** = 3 to 7cm dilation, regular contractions (1cm per hour)
**Transition phase** = 7 to 10cm dilation, strong and regular contractions (1cm per hour)
151
What are the 3 Ps of the second stage of labour?
**Power**
**Passenger**
**Passage**
152
What does power depend on?
**Strength** of uterine contractions
153
How can the **passenger** be described?
**Size** (of head)
**Attitude** (posture of the fetus - how back is rounded /head and limbs are flexed)
**Lie** (longitudinal/transverse/oblique)
**Presentation** (part of fetus closest to cervix = cephalic / shoulder / breech)
154
What are the 3 different types of breech
**Complete** (hips and knees flexed)
**Frank** (bottom first - hips flexed and knees extended)
**Footling** (foot hanging through cervix)
155
What does **Passage** stand for?
Size and shape of the passageway, mainly **pelvis**
156
What are the seven cardinal movements of labour?
Engagement
Descent
Flexion
Internal rotation
Extension
Restitution and external rotation
Expulsion
157
How is the babies head position described during delivery?
In relation to the mother's **ischial spines** during the descent phase:
-5cm
0
5cm
158
What are the different **management options** for the **3rd stage of labour**?
**Physiological management** (placenta is delivered by maternal effort only)
**Active management** (midwife/dr helps with delivery of the placenta, shortens phase and reduces risk of bleeding) - haemorrhage or 60 min delay should prompt active management - associated with N&V
**Intramuscular oxytocin** can be given to help the uterus contract and expel the placenta (careful traction is applied to the umbilical cord to guide the placenta out of the uterus)
