Scenario 21: Fertility Flashcards
1
Q
What are the sexual characteristics of a male?
A
Males are XY, have testis, have vas deferens, seminal vesicles and epididymis, have penis and scrotum, have larger shoulders and muscles, have male behaviour
2
Q
What are the sexual characteristics of a female?
A
Females are XX, have ovaries, have uterus and fallopian tube, have vagina, clitoris and vulva, have wider hips and more body fat, have female behaviour
3
Q
What duct in males leads to development of vas deferens, seminal vesicle and epididymis?
A
Wolffian duct
4
Q
What duct in females leads to development of uterus, upper vagina and fallopian tube?
A
Mullerian duct
5
Q
What leads to the formation of external genitalia in males and females?
A
Urogenital sinus
6
Q
What would be the manifestation of a foetus with XXY chromosomes?
A
Klinefelter syndrome- a male with slowly degenerating testis
7
Q
What would be the manifestation of a foetus with XYY chromosomes?
A
Unusually tall male, heavy acne, mild retardation
8
Q
What would be the manifestation of a foetus with XO chromosomes?
A
Turner syndrome- short stature, ovaries degenerate late in fetal life
9
Q
What is the switch to form the male gender?
A
The SRY gene on the Y chromosome, which remains on the Y chromosome only
10
Q
Which hormone in males prevents uterus and fallopian tube formation?
A
Anti-mullerian hormone
11
Q
What syndrome is present in the absence of anti-mullerian hormone?
A
Persistant Mullerian Duct Syndrome
12
Q
How are scrotum and penis formed from the common primordium?
A
Testosterone is converted to 5a reductase then to DHT which forms the scrotum and penis
13
Q
What is cryptorchidism?
A
Testes fail to descend, inhibits spermatogenesis, may cause testicular tumours
14
Q
What is androgen insensitivity?
A
A person is genetically male but insensitive to androgens so have the phenotype of a female but no menstruation and a blind ended vagina
15
Q
What are the three layers of uterine lining?
A
Serosa, myometrium and endometrium
16
Q
What is the serosa of the uterus formed of?
A
Paterial peritoneum
17
Q
What is the myometrium of the uterus formed of?
A
Smooth muscle
18
Q
What is the endometrium of the uterus formed of?
A
Largely glandular, shed during menstration
19
Q
What are the parts of the uterus?
A
Fundus, body and cervix. Body meets cervix at the isthmus where there is less SM and more collagen
20
Q
What do the cervix and vagina secrete?
A
The cervix secretes alkaline mucus. The vagina secretes glycogen which bacteria consume and produce lactic acid making the vagina acidic
21
Q
What is the angle of anteversion?
A
The angle of the uterus on the vagina. The vagina is directed backward by 15 degrees and the uterus projects forwards by 90
22
Q
How does the position of the uterus change with pregnancy?
A
By the 4/5th month it has reached the level of the mother’s umbilicus and then grows upwards into the upper abdominal cavity compressing abdominal and pelvic organs
23
Q
What is a bimanual palpation?
A
Palpation of the uterus through the anterior abdominal wall whilst palpating the cervix in manual examination
24
Q
What is the broad ligament of the uterus?
A
A double fold of peritoneum which is draped over the uterus and continues to lateral pelvic walls as the suspensory ligament of the ovary
25
What is the mesovarium?
Suspends ovaries from the posterior wall of the broad ligmaent
26
What are fimbrae?
The expanded ends of the ovaries which beat and waft fluid to themsleves
27
What is an ectopic pregnancy?
When an the ovary breaks down the wall of the broad ligament and releases an oocyte into the peritoneum, the oocyte may be fertilised there which would case an ectopic pregnancy
28
When are the ovaries formed in development?
In the 7th week of life on the posterior abdominal wall, guided to the lateral wall by the gubernaculum
29
What is the round ligament of the uterus?
The remainder of the gubernaculum in adults which passes through the broad ligament and to the inguinal canal
30
What are the cervical ligaments?
Condensations of the levator ani fascia which hold the uterus in place (pubocervical, transverse cervical and sacrocervical ligaments)
31
Why may the uterus prolapse after menopause?
The cervical ligaments are controlled by oestrogen and may slacken after menopause when oestrogen is low
32
How does the cervix change in women who have and haven't had children?
Smaller os circular in nuliparous women and parous or multiparous women there is a larger, slit like os
33
How does the feel of the cervix change throughout different stages of a woman's life?
Ovulation- may drop and be firm/painful to touch
| Pregnancy- rises and os is blocked by mucus plug, becomes softer and more vascular near the end of pregnancy
34
What are the four parts of the fallopian tube?
Infundibulum, ampulla, isthmus and intramural region
35
Where may an oocyte be fertilised?
In the ampulla of the fallopian tube
36
How is the fertilised oocyte transported from the ampulla of the fallopian tube to the uterus?
Peristaltic contractions and wafting of cilia
37
What is the nerve supply of the female reproductive system generally?
Inferior hypogastric plexus with parasympathetic component of this S2-4
38
What is the blood supply of the ovaries, uterus and vagina?
Ovarian arteries for the ovaries, anastomosing branches of the internal iliac for vagina and uterus
39
How does an ovarian follicle develop?
Primary follicle grows with egg inside, follicle matures and follicular fluid surrounds egg, follicle releases egg surrounded in protective cells in ovulation, empty follicle is corpus luteum which regresses
40
What are the 3 phases of the ovarian cycle?
Follicular phase- days 1-10. Ovulatory phase- days 11-14. Luteal phase- days 14-28
41
What happens in the follicular phase of the ovarian cycle?
Hormones signal 10-20 follicles to grow on ovaries, oestrogen matures one oocyte
42
What happens in the ovulatory phase of the ovarian cycle?
Oocyte undergoes cell division, follicle wall thins and ruptures. Oocyte enters abdominal cavity near fimbrae of fallopian tube
43
What happens in the luteal phase of the ovarian cycle?
Oestrogen levels drop, egg travels through fallopian tube towards uterus.
44
What is the function of oestrogen as a reproductive hormone?
Affects maturation of reproductive hormones, menstruation and pregnancy
45
What is the function of progesterone as a reproductive hormone?
Maintains uterine lining
46
What is the function of gonadotrophin releasing hormone as a reproductive hormone?
Promotes gonad maturation, regulates menstrual cycle
47
What is the function of FSH as a reproductive hormone?
Regulates ovarian function and maturation of ovarian follicles
48
What is the function of lutenising hormone as a reproductive hormone?
Aids protection of oestrogen and progesterone, regulates maturation of ovarian follicles, triggers ovulation
49
What is the function of human chorionic gonadotrophin as a reproductive hormone?
Helps sustain pregnancy, embryo and placenta
50
What is the function of testosterone as a reproductive hormone?
Stimulate sexual interest
51
What is the function of oxytocin as a reproductive hormone?
Stimulate uterine contraction and childbirth
52
What is the function of prolactin as a reproductive hormone?
Milk production
53
What is the function of prostaglandins in reproduction?
Mediate hormonal response, stimulate muscle contractions
54
What happens in days 1-5 of the menstrual cycle?
Functional layer is detached from uterine wall resulting in menses
55
What happens in days 6-14 of the menstrual cycle?
Proliferative phase. GnRH stimulates FSH and LH to stimulate follicular development leading to increased oestrogen levels. This causes the endometrium to proliferate and thicken, tubular glands and spiral arteries form.
56
What happens in days 13-14 of the menstrual cycle?
Ovulatory phase, glands are long and tortuous due to active growth. Stoma gradually becomes oedematus
57
What happens in days 15-22 of the menstrual cycle?
Rising levels of progesterone. Enlargement of glands which begin to secrete mucus and glycogen in preparation for implantation of the fertilised ovum. Increased fluid in stroma
58
What happens in days 23-28 of the menstrual cycle?
Premenstrual state. If fertilisation has not occured then the corpus luteum degrades, progesterone levels drop and endometrium degenerates. Withdrawal of LH results in luteolysis. Uterine glands are wide tortuous and sacular. Spiral arteries begin contracting, the capillary beds they supply in the stroma begin to seep blood into endometrium then into uterine cavity.
59
How do steroids affect GnRH release?
Inhibit it in hypothalamus, sensitise or desensitise pituitary to GnRH depending
60
How do steroids affect oestrogen release?
When E2 low negative feedback occurs, when it's high positive feedback occurs
61
How does increased age affect the child-bearing abilities of women?
Decreases pregnancy, increases miscarriage rate, increase aneuploidy due to non-disjunction
62
Why does fertility decrease with age?
Germ cells in the female are not replenished in life, number of oocytes decreases from birth to menopause, quality decreases with age (as are subject to more mutations throughout life). Inhibitin B production by small follicles decreases, suppression of FSH decreases and secretion of FSH by pituitary increase.
63
What is a test for depleted ovarian pool in women?
Elevated day-3 FSH level in women
64
What is the membraneous fascia of the scrotum?
Colle's fascia
65
What is the superficial fascia of the scrotum?
Dartos fascia with dartos muscle
66
What is the deep fascia of the penis?
Buck's fascia forming the suspensory ligament of the penis
67
What connects the glans to the foreskin?
The frenumlum
68
Which nerves supply the anterior part of scrotal skin?
Lumbar nerves
69
Which nerves supply the posterior part of scrotal skin?
Sacral nerves
70
What is the contents of the spermatic cord?
Testicular, cremasteric and ductus deferens arteries and veins, T10-11 sympathetic nerves and genital branch of genitofemoral and ilioinguinal nerves. As well as the ductus deferens, lymphatics and processus vaginalis remnant (fibrous cord)
71
What are the fascial layers of the spermatic cord?
External spermatic, cremasteric and internal spermatic formed of external and internal oblique abdominis and transversalis fascia respectively
72
Which nerves maintain an erection?
Parasympathetic outflow from S2-4 pelvic splanchnic nerves.
73
What are the stages of ejaculation and which nerves control these?
SM in walls of vasa deferentia and epididymis contracts rhythmically and peristaltically to move spermatozoa into prosthetic urethra via T10-L2 sympathetics.
Internal urethra sphincter closes to prevent reflux of semen. Ejection involves contraction of skeletal muscles to pump semen down the urethra.
74
Which nerves control touch and general sense of penis?
Somatic pudendals S2-4
75
Where does lymph from tests, epididymis and ductus deferens drain?
To pre aortic nodes around the origin of testicular arteries
76
How does spermatozoa reach the corpus spongiosum from the testes?
Travels along epididymis then ductus deferens to the prostate gland. Here it is joined by the duct from the seminal vesicles which brings fructose rich alkaline secretion, the prostate adds citric acid and acid phosphate rich secretion. Then from here it enters the prostatic urethra to the membraneous and finally spongy urethra.
77
What do bulbourethral and urethral glands secrete in males?
Clear vicious mucoid fluid that lubrictaes the urethra and is secreted prior to ejaculation in apocrine secretion
78
Where does spermatogenesis occur?
In interstitial cells of Leydig of testes
79
What divides the testis into functional units?
The thick capsule, tunica alburginea, sends septa to divide the testis into lobules
80
What is hypospadias?
Abnormal urethral opening in males during to failure of development
81
What is the blood supply of the testis?
Testicular arteries from abdominal aorta at L2. Complex venous plexus forming singular testicular vein to join IVC at L2
82
What is the position of the seminal vesicles?
Posterior to bladder, anterior to rectum and posterio-superior to prostate gland
83
Where does the prostate gland lie?
Below bladder and anterior to rectum on pelvic floor, encloses urethra
84
What is the seminal colliculus of the prostate?
Where it receives the ejaculatory ducts
85
Why does prostate cancer spread so aggressively?
Rich venous plexus around prostate which allows it to spread to spinal cord, brain and beyond.
86
What is the histological appearance of the cortex and medulla of the ovaries?
Cortex- follicles embedded in stroma of fibroblast like cells
Medulla- highly vascular, coiled helicine arteries. Covered in germinal epithelium and tunica albuginea
87
What are the zones of ovary primary follicle maturation?
Zona granulosa, zona pelucida, theca folliculi, theca interna and theca externa
88
What is the appearance of the zona granulosa of the ovary?
Flattened follicular cells proliferative and become cuboidal to form stratified epithelium
89
When are primary follicles formed in the ovaries?
When primordial follicles spontaneously activate even before puberty
90
What is the appearance of the zona pelucida of the ovary?
Prominent glycoprotein coat surrounding primary oocyte
91
What is the appearance of the theca folliculi of the ovary?
Stroma fibroblast like cells form a sheath around primary oocyte
92
What does the theca folliculi divide into?
A highly vascularised theca interna in which the cells acquire to ability to synthesise steroid hormones. Theca externa is a sheath of fibroblast-like cells
93
When does a primary follicle become secondary?
When it has an antrum (fluid filled space) in the zona glomerulosa (still has primary oocyte)
94
What happens to the secondary or antral follicle at the start of the monthly cycle?
FSH triggers many follicles to develop, LH stimulates theca interna to secrete androgens (converted to oestrogen), oestrogen suppresses FSH, only dominant follicle survives, increases in size to Graafian follicle
95
What does the mid cycle LH do to the oocyte?
Primary oocyte undergoes meiosis II to become secondary oocyte
96
What happens to the follicle after ovulation?
Follicle collapses, granulosa cells reorganise to form corpus lutem and secrete progesterone under influence of LH. Theca interna resumes androgen secretion.
97
When does the corpus albicans form?
When the corpus lutem is starved of LH due to progesterone secretion 10-14 days after ovulation.
98
What is the histological appearance of the uterine tubes?
Highly convoluted mucosa with inner circular and outer longitudinal smooth muscle layers, simple columnar epithelium containing ciliated and secretory peg cells
99
Which part of the endometrium persists from month to month and which is shed?
The stratum basalis persists, the stratum functionalis is shed
100
What causes the death of stratum functionalis in menstruation?
Spasmodic contraction of spiral arteries caused by loss of progesterone results in ischemia and degeneration
101
How does the epithelium change from uterus to vagina?
Simple columnar to stratified squamous epithelium
102
Where is the zone of HPV induced carcinoma?
The transformable zone between uterus and vagina (cervix), screened for neoplastic changes early on
103
How does spermatozoa reach the epididymis?
Produced in seminiferous tubercles which drain into rete testis then into epididymis
104
What lines the seminiferous tubercles?
Compex stratified germinal epithelium
105
How are primary spermatocytes formed?
Spermatogonia type A (dark) cells give rise to s permatogonia type A (pale) cells which give rise to spermatogonia type B cells which complete mitosis and enter meiosis as primary spermatocytes
106
How do primary spermatocytes become secondary spermatocytes?
Do normal S phase and enter prophase of first meiotic division where crossing over occurs (leave basal layer of epithelium)
107
How are spermatids yielded?
Secondary spermatocytes undergo the second meiotic division to become haploid
108
What is spermatogenesis?
The morphological maturation of spermatids to spermatozoa. Involves: condensation of nucleus, formation of acrosome and flagellum, shedding of unwanted cytoplasm
109
What is the function of Sertoli cells?
Provide mechanical and nutritive support for developing spermatozoa, generate blood-testis barrier via tight junctions to protect developing spermatozoa from immune system, ingest unwanted cytoplasm during spermatogenesis, produce testicular fluid, secrete androgen binding protein to concentrate testosterone
110
What is the histological appearance of Sertoli cells?
Tall cells spanning entire thickness of germinal epithelium. Oval nucleus and prominent nucleolus. Extensive lateral processes connected by junctional complexes.
111
Where are Leydig cells found and what do they do?
In between seminiferous tubercles and produce testosterone in response to LH
112
What is the function of the sterocilia of the epididymis?
Giant microvilli which reabsorb 90% testicular fluid
113
What is the vas deferens lined by?
Pseudostratified epithelium with sterocilia. Thick SM coat with inner and outer longitudinal layers and circular layer in between.
114
What are the four zones of the prostate?
Transition zone (around urethra) central zone (around ejaculatory ducts) peripheral zone (70% gland) anterior fibromuscular stroma (no glandular tissue)
115
What is the histological appearance of the prostate?
The tubuloaveolar glands are lined by columnar secretory cells, which rest on an incomplete layer of flattened basal cells. The epithelial lining is thrown into complex, papillary folds. The stroma is unusual in containing abundant smooth muscle cells. With age, spherical bodies called corpora amylacea (CA) accumulate, consisting of multiple lamellae of condensed glycoprotein, and become progressively calcified (“prostatic concretions”)
116
How does mid-cycle cervical mucus promote penetration of sperm?
More hydrated and glycoproteins more aligned.
117
Describe fertilisation
Sperm attracted to oocyte by chemotaxis. Capacitation and acrosomal reaction of sperm occur. Sperm penetrates oocyte. Cortical reaction of oocyte occurs to prevent any other sperm fertilising it. Pronuclei complete mitosis and begin cleavage
118
Describe cleavage up to day 4.
Zygote divides into 2 blastomeres, then 4, then 8. At day 4 the 16 cell Morula occurs. Up to this stage the blastomeres are totipotent but after they begin to specify and become pluripotent.
119
Which parts of the blastomere form placenta and embryo?
Inner cell mass- embryo. Outer part (trophoblast) forms placenta
120
What are some possible causes of sub fertility?
Anovulation, tubal damage, male factors (infection like mumps or STI, trauma, drugs, radiotherapy, congenital) azoospermia
121
What are some possible causes of anovulation?
Hypothalamic, pituitary, thyroid dysfunction, ovarian failure, PCOS, anorexia, hyperprolactinaemia
122
What are some possible causes of tubal damage in women?
Infection (PID, STI) surgery, ectopic pregnancy, endometritis
123
What are some possible causes of azoospermia?
Obstructive, post infection, post vasectomy, congenital vas deferens absence, impaired spermatogenesis
124
What is the current guidance for couples hoping to conceive?
Sex every 2-3 days, no smoking, no drinking, healthy BMI, take folic acid, have rubella immunity
125
Why are big babies dangerous?
More vaginal tearing, more stillbirths, more C-sections, shoulder and arm damage on delivery
126
Why is iron deficiency especially dangerous in pregnancy?
Increased red blood cell mass
127
Why does TAG concentration rise in pregnancy?
Form babies plasma membranes. LpL release FA from TAG to trophoblast cells
128
Why are folate and B12 essential in pregnancy?
DNA methylation and imprinting of pyridine and purine formation. Reduce neural tube defects.
129
What do oestrogens cause in pregnancy?
Stimulate liver fatty acid synthesis and cholesterol. CV pregnancy changes are increase HR, BV, dilation but no increase in BP, growth of uterus, uterine priming, anti-insulin activity, cervical ripening, RAAS axis for H2O reabsorption
130
Why are the obese more at risk for gestational diabetes?
Already insulin resistant and oestrogens cause anti-insulin activity
131
What does progesterone cause in pregnancy?
Prepares and maintains endometrium to allow implantation, produced initially by corpus luteum then placenta. Suppress maternal immunological response, mammary gland growth, pregnancy maintenance (inhibition of uterine contraction, prevent cervical ripening)
132
What is the biological function of hCG in pregnancy?
Rescue and maintain corpus luteum for progesterone production until the 7th week. Also stimulates maternal thyroid activity by binding to TSH receptors
133
What is the biological function of hPL in pregnancy?
Maternal lipolysis to increase FA for maternal and foetal nutrition. Anti-insulin action, increase maternal insulin, favouring protein synthesis and provision of mobilisable amino acids and glucose for foetus. Potent angiogenic hormone for foetal vascularisation
134
Which cells secrete leptin in pregnancy?
Cytotrophoblast cells and syncytiotrophoblast cells
135
What does leptin do in pregnancy?
Stimulates placental amino acid/FA transport
136
Why does peripheral resistance fall in pregnancy?
Increased nitric oxide, relaxin, compliance of vessels and prostaglandins
137
Why does cardiac output increase in pregnancy?
Oestrogen increases RAAS activity, progesterone and prostaglandins increase aldosterone activity. Shunting of blood to uterus causes sympathetic stimulation, hCG increase and Na loss due to increased GFR increase renin.
138
How does the urinary system change in pregnancy?
Increased urine frequency, decreased plasma conc of urea and creatinine, calciuria, glycosuria
139
How does the respiratory system change in pregnancy?
Increased tidal volume, progesterone stimulates deep breathing, respiratory rate unchanged, expiratory reserve reduced, decrease pCO2, increase pO2, pH unchanged
140
How does the GI system change in pregnancy?
Less motile, biliary statis, increase gastric reflux, increase nutrient and water absorption
141
What is the difference in the age of the foetus as seen by clinicians and embryologists?
Clinicians measure the embryos age from the day of last period whereas embryologists measure the actual embryos age
142
What are the stages of implantation?
Apposition, attachment and penetration
143
What structures on blastocyst and endometrium facilitate attachment?
Cytokine signalling between blastocyst and endometrium. Pinopodes from surface epithelial cells on endometrium and microvilli on trophoblast facilitate attachment
144
What mediates the penetration stage of implantation?
Increased vascular permeability at the site of blastocyst attachment. Prostaglandin synthesis is mediated by COX 1 and 2,
145
What does the outer cell mass differentiate into to after implantation?
Inner cell layer of mononuclear cells (cytotrophoblast) and outer cell layer of multinuclear cells with no clear boundaries (syncytiotrophoblast). Lacunae (fluid filled communicating surfaces) after from the 8th day
146
What is the function of cells of the syncytiotrophoblast?
Penetrate deeply and erode the lining of maternal sinusoids, produces hCG
147
What do the different subunits of hCG do?
A subunit produces LH, FSH and TSH
B subunit prevents apoptosis of granulosa lutem cells of corpus lutem so it will continue to make progesterone to prevent menustration
148
How to chorionic villi form at the end of the second week?
Primary villous stems (derived from proliferation of cytotrophoblast) gradually develop cores of extraembryonic mesoderm forming secondary villi. Tertiary villi are formed when mesenchymal cells differentiate into blood vessels. These vessels become connected with the heart.
149
What forms the placenta in development?
The villi on the decidua capsularis pole degenerate to form chorion lacuae. The adjacent villi grow rapidly to form chorion frondosum. Together these form the placenta.
150
What are the different types of multiple pregnancy and the risks associated with these?
Dichorionic and diamniotic is lowest risk
Monochronic and diamniotic is middle risk
Monochronic and mono amniotic is high risk
Conjoined is rare but highest risk
151
What is gastrulation?
The formation of 3 germinal layers from epiblast (ectoderm, endoderm, mesoderm)
152
What is holoprosencephaly?
Forebrain doesn't divide and develop, midline and facial effects. Death or retardation.
153
What is cardiogenesis?
Mesoderm and neural crest used for heart formation, canalisation of cardiogenic clusters in the mesoderm results in the formation of 2 heart tubes. Cardiomyocytes migrate and transform to form the heart.
154
How is HCO3- transported across the placenta?
Via conversion to CO2 carbonic anhydrase
155
How are glucose, fatty acids transported across the placenta?
Sodium dependant glucose transport (then GLUT-1 in second half), lipases allow the transport of fatty acids.
156
How are amino acids transported across the placenta?
Sodium dependant for small non-essential amino acids. There are 3 isoforms SNAT1, SNAT2, SNAT3. Non essential amino acids are then exchanged for essential ones.
157
What happens to the fatty acid transport of obese mothers?
Obese mothers have FA which the DHA compete for which means babies don't get the FA they need for brain development
158
What regulates growth and development of the GI tract?
Gastrin, motilin and somatostatin
159
What is macrosomia?
Overweight at birth, hyperinsulinemia at birth so without placental glucose become hypoglycaemic quickly
160
How is foetal urine related to amniotic fluid?
Important component, 3% of cardiac output goes to kidney. Foetal bladder empties every 30 min with hypotonic urine due to ADH
161
What is the contents of amniotic fluid?
Urine, amniotic membrane secretion, fetal lung secretions, salivary secretions, fetal epithelial cells, amniotic cells, dermal fibroblasts
162
What happens to the foetus in hypoxia?
HR falls, resistance in umbilical artery increases, resistance in middle cerebral artery decreases protecting the foetal brain, increase blow flow to heart and adrenals, blood flow reduced to kidneys
163
How does foetal circulation changes at delivery?
Cord occlusion decreases right atrial pressure so foramen ovale closes. Inspiration causes vasodilation of pulmonary circulation reducing flow through ductus arterioles. Increased aerial PO2 closes ductus arterioles.
164
How does foetal circulation work?
Umbilical vein carries oxygenated blood to foetus from placenta. 1/3 enters IVC via ductus venosus. Rest passes to RA. Most flows to LA by foramen ovale (rest goes through pulmonary system) Blood goes through to LV and to body via aorta. Some is returned to the umbilical arteries via internal iliacs.
165
What is the function of pulmonary surfactant?
Forms lattice like structure to decrease surface tension and stabilise the lung. Prevents alveoli from collapsing inwards and increases compliance.
166
What does the late pregnancy rise in cortisol cause?
Stimulate surfactant synthesis and secretion, epithelial cell differentiation, lung liquid reabsorption and increases activity of anti-oxidants
167
What are the differences between foetal haemoglobin and adult haemoglobin?
HbF has higher affinity for O2 than HbA due to lower sensitivity for DPG
168
What stimulates the baby's first breath?
Asphyxia of normal birth, physical manipulation and compression, cold shock, visual stimulation, gravity
169
What is the difference between spermatogenesis and spermiogenesis?
Spermatogenesis is production of spermatids. Spermiogenesis is production of mature sperm from spermatids.
170
What are the four shapes of the pelvis?
Gynaecoid, android, anthrapoid, platypelloid
171
What are the features of the gynaecoid pelvis?
Oval shaped inlet, obtuse infra-pubic angle, greater sciatic notch of 90 degrees or more
172
What are the features of the android pelvis?
Heart shaped inlet, acute infra-pubic angle, greater sciatic notch of less than 90 degrees
173
What is the obstetric conjugate diameter?
The minimum distance between the sacral promontory and superior border of pubic symphysis
174
What is the value of the obstetric conjugate, oblique and transverse diameters?
11, 12 and 13 cm
175
How does the foetal head twist to get out of the pelvis in birth?
Positioned transversely as the greater diameter of the obstetric pelvis is the transverse one. As the outlet is reached the head rotates so the face points backwards as the baby is delivered.
176
What is the corpora cavernosa?
In males they are longer and form the root of the penis and in females they form the body of the clitoris by folding over on themselves.
177
Where do the bulbospongiosus and ischiocaverosus muscles lie? What is their function?
Bulbospongiosus surrounds bulb of penis and contracts to empty urethra, inchiocaverosus surrounds crura and contracts to form an erection. Contract to compress bulbourethral glands expelling mucus into bulbar urethra.
178
What is the nervous supply of the bulbospongiosus and ischiocaverosus muscles?
Pudendal nerve S2-4
179
What is the fourchette?
The fold of mucus membrane posterior to the vagina
180
What is the cutaneous supply of the vagina?
Iliohypogastric, ilioinguinal and genitofemoral nerve
181
What can we assess in a vaginal examination?
Blood or amniotic fluid, vaginal dryness/tearing, tone, laterally can check if ischial spines will impede childbirth, anteriorly the pubic symphysis, urethra and posterior bladder can be felt, posteriorly the pouch of Douglas and rectum, laterally ovaries and uterine pouch if enlarged or diseased
182
What is a cystocele?
Bladder pushing into the anterior wall of the vagina on examination
183
What is a rectocele?
Rectum or pouch of Douglas pushing into posterior wall of vagina on examination
184
What is the course of the pudendal nerve?
Winds around ischial spine, passes out of greater sciatic foramen and into lesser sciatic foramen, and along pudendal canal along inferior border of obturator internus
185
What are mammary glands?
Modified apocrine glands, epithelial in origin
186
What is the border of the breasts?
Medial border doesn't usual expand beyond lateral border of the sternum, lateral border is mid-axillary line, superior border is rib 2, inferior border is rib 6, lies on pectorals major, serratus anterior separated by retro mammary fascia
187
Where may additional nipples or breasts be found?
Along the embryological ridge along milk lines
188
Where is most of the glandular tissue of the breast found?
Axillary tail (of Spence)
189
Describe the nipple
Mamillary papilla surrounded by areola, many sebaceous glands and Montgomery's tubercles. Supplied by T4
190
What are Colle's suspensory ligaments?
Dense bands of collagen which hold up the nipple
191
What are the signs of breast cancer?
Lump, redness/rash, texture changes (peau d'orange) nipple discharge, nipple inversion
192
What are the stages of labour?
Contractions develop, cervix softens. Regular contractions, steady dilation. Cervix fully dilated, strong propulsive contractions. Baby delivered. Placenta delivered.
