6 Flashcards
1
Q
Describe the epididymal maturation of sperm
A
- on entry, spermatozoa is not capable of movement
- once at the tail of the epididymis, they are capable of movement and have the potential to fertilize
- addition of secretory products to surface of sperm
- Maturation is dependent on support of the epididymis by androgens
- look at chart on REPRO getting pregnant bb slide 6
2
Q
What are the functions of semen?
A
- nutrition source for spermatozoa
- acts as a transport medium
- neutralizes the acidic environment of the vagina
- potentially a role for prostaglandins in stimulating muscular activity in the female tract
3
Q
What does semen consist of?
A
- spermatozoa (small portion)
- seminal plasma which is derived from accessory glands of the male reproductive tract
4
Q
Describe what seminal plasma consists of and what glands contribute to it
A
Seminal vesicles
- 60% of volume
- alkaline fluid (neutralizes acid of male urethra and female reproductive tract)
- fructose, prostaglandins, clotting factors (particularly semenogelin)
- acts as a metabolic unit of the spermatozoa
Prostate gland
- 25% volume
- milky, slightly acidic fluid
- proteolytic enzymes (breakdown clotting proteins, re-liquefying semen in 10-20 min)
- citric acid, acid phosphorylate)
Bulbourethral glands (Cowper’s glands)
- very small volume
- alkaline fluid
- a mucus that lubricates the end of penis and urethral lining
5
Q
How do seminal vesicles and the prostate work together in regards to coagulation?
A
- semen clots due to clotting factors from seminal vesicles
- prostate produces a substance with enzymes that can break down the coagulation that occurs
6
Q
What are the normal values of semen analysis?
A
Volume of ejaculate: 2-6mL Viscosity: Liquefaction in 1hr PH: 7-8 Count: >20 million/mL Motility: >50% Morphology: 60% normal
7
Q
List and describe the four phases of the human sexual response
A
- excitement phase: psychogenic and/or somatogenic stimuli
- plateau phase: stimuli is maintained
- orgasm phase: threshold is reached
- resolution phase: return to haemodynamic norm followed by a refractory period only in males
8
Q
What are the stimulants and efferents of the excitement phase (ejaculation)?
A
Stimulants
- psychogenic
- tactile (sensory afferents of penis and perineum) which travel up to a spinal reflex
Efferents
- Somatic and autonomic efferents
- pelvic nerve (Parasympathetic nervous system)
- pudendal nerve (somatic nervous system)
- leads to haemodynamic changes
9
Q
Describe the physiological components of an erection
A
- neuronal input causes sinusoids in corpus cavernosa to relax in order for arterial dilation to occur
- venous compression also occurs even though there is increased blood flow, since there is tunica albuginea surrounding the corpus cavernosa
- tunica albuginea is thick and not distended, very taught and rigid allowing for veins to stay compressed and erection to occur
- corpus spongiosum is not completely compressed so that semen can leave urethra
10
Q
Describe the parasympathetic innervation that causes an erection
A
- sympathetic inhibited while parasympathetic stimulated via pelvic and cavernous nerve
- lumbar and sacral spinal levels involved
- pelvic nerve and pelvic plexus
- cavernous nerve to corpora and vasculature
11
Q
What is the important neurotransmitter in an erection and what is the neurophysiology behind it?
A
- NITRIC OXIDE (NO)
- inhibition of sympathetic arterial vasoconstrictor nerves
- activation of PNS
- activation of non-adrenergic, non-cholinergic, autonomic nerves to arteries
12
Q
What is the role of NO in an erection?
A
- post-ganglioic fibres release ACh
- ACh bonds to M3 receptor on endothelial cells
- rise in [Ca] via M3 receptors which causes activation of NOS and formation of NO
- NO diffuses into vascular smooth muscle and causes relaxation (vasodilation)
- NO also released directly from nerves
- key mediator in this process is cGMP
13
Q
What are some causes of erectile dysfunction?
A
- psychological (descending inhibition of spinal reflexes)
- tears in fibrous tissue of corpora cavernosa
- vascular (arterial and venous)
- drugs
14
Q
How can erectile dysfunction be treated?
A
- must improve erection by increasing amounts of NO and cGMP
- viagra helps to slow rate at which cGMP is degraded which will results in vasodilation, leading to penile erection
15
Q
Explain the emission and ejaculation phase
A
-both under sympathetic control
Emission
- semen moved into prostatic urethra
- smooth muscle contraction in prostate, vas deferens and seminal vesicles
Ejaculation
- expulsion of semen
- requires contraction of glands and ducts but also contraction of the internal sphincter (in bladder) to prevent retrograde ejaculation
- rhythmic striata muscle contractions (pelvic floor, perineal muscles ischiocavernosus, bulbospongiosus)
Point Shoot
- Point (erection requires Parasympathetic stimulation)
- Shoot (ejaculation requires Sympathetic stimulation)
16
Q
Describe the menstrual cycle changes
A
- character of cervical mucus changes over the course of the menstrual cycle
- Oestrogen provides thin and stretchy mucus which allows sperm to travel through female tract
- Oestrogen and progesterone provides thick and sticky mucus which almost acts like a plug
- this occurs right after fertilization to prevent entry of any further sperm
17
Q
Where is sperm deposited and where is the site of fertilization?
A
- site of sperm deposition: at external os of cervix, where it will be liquified so that the gametes can move up the tract
- site of fertilization: ampulla of Fallopian tube
18
Q
What is capacitation?
A
- further maturation of sperm in female reproductive tract (6-8 hours)
- sperm cell membrane changes to allow fusion with oocyte cell surface
- tail movement changes from wave-like beat to whip-like action
- now capable of undergoing of acrosome reaction
- see diagram in REPRO getting pregnant bb slide 24
19
Q
How long is the fertile window for?
A
- Sperm can survive from 48-72 hours
- oocyte can survive 6-24 hours (max)
- fertile period: sperm can be deposited 3 days before ovulation for fertilization to be successful
Gamete transport
- oocyte: beating cilia and peristalsis of uterine tube
- sperm: own propulsion
Look at diagram on REPRO getting pregnant bb slide 25
20
Q
What is the acrosome?
A
- derived from the golgi region of developing spermatid
- contains enzymes which help to remove the outer granulosa cels that surround the ovum
- necessary for fertilization
21
Q
What is the acrosome reaction?
A
- sperm pushes through the corona radiata
- binding of sperm surface receptor to ZP3 glycoproteins of zona pellucida
- triggers acrosome reaction
- digestion of zona pellucida
- also consequent loss of outer membrane of sperm
- allows single sperm to penetrate the ovum and fuse with membrane
- see diagram on REPRO get pregnant bb slide 28
22
Q
What is the cortical reaction?
A
- after fusion of the plasma membranes, cortical reaction occurs
- blocks polyspermy
- triggers meiosis 2 to finish
- series of calcium waves are activated following fusion of oocyte and sperm membranes
- resumption of meiosis 2 occurs
- pronuclei move together
- mitotic spindle forms leading to cleavage
- look at diagram on REPRO getting pregnant bb slide 29-30
23
Q
What is a morula?
A
- totipotent cells formed from multiple mitotic divisions
- right after fertilization
24
Q
How does fertilization work in assisted reproductive technology?
A
- oocytes are fertilized in vitro and allowed to divide to the 4- or 8- cell stage
- morula is then transferred into the uterus
- PGD (pre-implantation genetic diagnosis)
- cell can be safely removed from the morula and tested for serious heritable conditions prior to transfer of the embryo into the mother
25
Q
What is blastocyst and hatching?
A
- first differentiation into inner and outer cell masses
- formation of the blastocyst
- blastocyst hatches from zona pellucida
- no longer constrained —> now free to enlarge
- can now interact with uterine surface to implant
26
Q
What occurs during implantation?
A
- outer cell mass (trophoblast) interacts with endometrium
- endometrium controls degree of invasion
- ectopic implantation (at sites other than endometrium lined uterine cavity; invasion not controlled)
- implantation in lower uterine segment can cause placenta praevia
- look at diagram on REPRO getting pregnant bb slide 34
27
Q
What are the two ways of classifying reproductive infections?
A
- sexually transmitted vs. Non-sexually transmitted
- based on presenting symptom
28
Q
What are some factors that affect genital tract infections?
A
- age: 15-24 y/o are more likely
- Ethnicity: black or black British have higher rates of STIs
- low socio-economic status (access to education)
- increased number of sexual partners
- sexual orientation (ex. Homosexual men)
- lack of immunization (Hep B, HPV)
- lack of barrier contraception
- “risky sexual behaviours “ such as multiple sexual partners, early age first intercourse, certain sexual practices (homosexual, anal)
29
Q
What is the most common STI in UK?
A
Chlamydia: chlamydia trachomatis
30
Q
How does Chlamydia trachomatis cause discharge in men? Describe it
A
- chlamydia is an obligate intracellular bacterium
- has a unique cell wall which inhibits phagolysosome fusion (virulence factor)
- bacteria gets phagocytosed but inhibits fusion of phagosome and lysosome
- without phagolysosome we cannot digest the bacteria and get ride of it
- not a “true” gram-negative bacteria
- typically asymptomatic in mean
- but can cause mild urethritis, testicular pain, dysuria, or inflammation of other structures (eg. Epididymitis, prostatic is)
- may have discharge
31
Q
How does gonorrhoea (caused by neisseria gonorrhoeal) cause discharge in men?
A
- most common cause of urethral discharge
- “gonococcus” is gram negative, diplodocus, unencapsulated and Pilated
- pili on bacteria helps to adhere to mucosal membrane (i.e. urethra, cervix, pharynx, rectum)
- 90% of men ARE symptomatic
- causes yellow discharge and possibly dysuria (painful urination)
- can cause epididymo-orchitis
- treatment: ceftriaxone to treats gonorrhoea and azithromycin to “boost” effect of antibiotic
- also helps to treat chlamydia as a common co-infection
32
Q
How does Non-gonococcal urethritis (NGU) cause discharge in men?
A
- is a non-STI
- inflammation of urethra with associated discharge
- can possible be sexually transmitted (common):
- chlamydia trichomatis
- mycoplasma genitalium
- trichomonas vaginalis
- can be “pathogen negative” where you cannot find an organism but it is less common and occurs in older men
33
Q
What investigations can be done to detect STIs in men?
A
Urine sample
- “first catch” urine for gonorrhoea/chlamydia
- “mid-stream” urine for culture and sensitivities
- gonorrhoea: microscopy and culture, NAATs (Nucleic Acid Amplification Test)
- chlamydia: NAATs (most sensitive and specific)
- urethritis: as above
- excludes UTI as a cause of dysuria (more common in older men than younger men)
Urethral swab
- gonorrhoea
- should be done if pt. Is symptomatic
Men who have sex with men
-take rectal and pharyngeal sampling or swabs at an ulcer site
Blood tesT
-for syphilis and blood borne viruses
34
Q
What is the physiological discharge in women?
A
- menstrual cycle
- progesterone in the secretory phase (post-ovulation) which leads to thicker cervical mucus
- features of this are:
- cyclical
- no other associated symptoms
- clear
35
Q
How chlamydia cause discharge in women?
A
- c. Trachomatis
- most women are usually asymptomatic
- can cause complication such PID and reactive arthritis
- may cause discharge
- may cause postcoital (bleeding after sex) or intermenstrual bleeding
- may cause dyspareunia
- can also cause infections (conjunctivitis) in neonates if patient is pregnant
- treat with doxycycline or azithromycin
- if pregnant use ezithromycin
36
Q
How does gonorrhoea cause discharge in women?
A
- N. gonorrhoeae
- typically asymptomatic but can cause vaginal discharge and lower abd pain
- can cause PID
- treat same as men
37
Q
How can trichomoniasis cause discharge in women?
A
- bacteria: trichomonas vaginalis
- Protozoa (flagellates)
- presences of flagella (mobility) which help propel it through the reproductive tract
- optimal growth is at pH 6.0 but vagina has pH 4
- if there is increased alkalinity of vagina, then it will likely flourish
- causes copious, yellow, odourous discharge
- can cause irritation of vulva and vagina
- typically diagnosed with swabs
- treatment: metronidazole
38
Q
How does candidas cause discharge in women?
A
- Candida albicans is a yeast in normal vagina
- is activated in immunocompromised states (pregnancy, HIV), diabetes, antibiotics and oestrogen-containing oral contraceptives (COCP)
- is VERY ITCHY
- white non-offensive vaginal discharge with pruritis, pain and/or dyspareunia
- investigated with high vaginal swabs and treated with oral and/or topical anoles
39
Q
How does bacterial vaginosis cause discharge in women?
A
- non STI
- caused by pH imbalance in vagina which allows growth of certain bacteria such as Gardeneralla vaginalis
- thus normal bacteria (lactobacillus) is diminished
- risk factors: practices that disrupt the vaginal flora such as washing it
- increases risk of contracting STIs
- presents with very offensive vaginal discharge, WITHOUT pruritis or pain
- diagnosed by high vaginal swabs
- treatment: metronidazole
40
Q
What investigations are done to check for STI in women?
A
- urine samples are iNEFFECTIVE
- chlamydia: Vulvo-vaginal swabs (VVS), endocervical (go with camera into cervix
- gonorrhoea: VVS (if asymptomatic), endocervical
- trichomoniasis: high vaginal swab (HVS) (posterior fornix)
- BV: gram staining, KOH test (add KOH to sample and observe if there is a fishy smell)
- Candida: HVS; Microscopy > culture
- also consider ulcer swabs, rectal/pharyngeal swabs and serology
- look at summary in Infections of the reproductive tract_student slide 24
41
Q
Describe Human Papillomavirus (HPV)
A
- most common viral STI
- most common cause of genital warts
- warts typically regress without treatment, although topical treatments are available
- DNA virus (non-enveloped)
- many different types
- types 6 and 11 cause 90% of genital infections
- types 16 and 18 have the highest association with cervical cancer
- can do PCR to identify high risk types (biopsy/swab)
- can be vaccinated: gardasil (6,11, 16, 18) and cervarix (just 16 and 18)
42
Q
What is Herpes Simplex virus (HSV -1 and -2)
A
- two strands: -1 and -2
- HSV-1 can cause oral and genital herpes, also associated with “cold sores”
- HSV-2 typically causes genital herpes and often leads to recurrent infection; can be particularly dangerous in pregnancy as vaginal delivery means the baby can develop complications of herpes; more likely to become infected with HIV
- DNA virus (enveloped)
- viral infection that lays dormant
- lifelong infection: initial then recurrent infection
- can be asymptomatic initially, or present with painful ulcers/blisters
- can be accompanied by systemic symptoms such as fever, malaise and myalgia
- should check all areas such as genitals, mouth, and anus
- swabs: PCR and NAATs
- Management: can use antivirals (eg. Aciclovir)
- cannot eradicate the infection
- reduce the severity and duration of the current episode
- limited effect frequency/severity of repeated episodes
43
Q
What is syphilis (treponema pallidum)?
A
- spirochete bacterium
- transmission: direct contact, vertical transmission
- not as common generally: 40% co-infected with HIV
- prevalent among homosexuals (male) and 24-35 y/o men
- can affect pregnant women and their babies
Primary Syphilis
- typically painless ulcer(s) in the genitals, or other sites involved in sexual contact
- initial infection
- it is very infectious at this stage, but the lesion will usually disappear
Secondary Syphilis (25% of untreated cases)
- 4 to 10 weeks after initial infection (more severe)
- multi-system (occurs a few months later)
- can enter a latent phase (can cause skin rashes)
Tertiary syphilis
-infection can remain latent and become reactivated late in life (ex. In pregnancy, which can lead to congenital syphilis)
- Microscopy/PCR
- serology (will usually do serology to see antibody effect)
- management: penicillin-based antibiotics
44
Q
How can we manage STIs
A
- co-infections are very common
- similar route of transmission
- may be asymptomatic
- consider screening for others
- consider presenting complaint
- appropriate investigation and therapy
- bacterial: can give multiple antibiotics (ex. Azithromycin and ceftriaxone)
- targets different organisms
- one antibiotic can augment the effect of the other
- educate patients on safe sex and to avoid sex until course of treatment is completed
45
Q
What is PID?
A
- infection of the uterus, Fallopian tubes, and ovaries
- typically because of ascending infection:
- chlamydia trachomatis
- neisseria gonorrhoeae
- gardnerella sp.
- others eg. Mycoplasma genitalium
- often polymicrobial
- other sources of infection: intrauterine contraceptives (more to come), other uterine interventions
- largest risk factor: infection
46
Q
What is endometritis?
A
- inflammation of the endometrial lining of the uterus, and can be acute or chronic
- affects uterus
47
Q
What is Salpingitis?
A
- inflammation of Fallopian tubes
- significant clinical complication when thinking about long-term damage to the ciliated epithelium of the Fallopian tubes
- inflammatory exudate can cause the tubes to fill with pus, leading to adhesions and obstruction of the tube and can lead to turbo-ovarian abscess formation
- typically stays within the Fallopian tube
48
Q
What are the risk factors of PID?
A
- young age
- multiple sexual partners
- lack of barrier contraception
- low socio-economic status
- IUCD
49
Q
What are the signs and symptoms of PID?
A
Signs
- Pyrexia (+/-)
- pain on palpitation: abd, biannual vaginal exam
- evidence of discharge/cervix it is (speculum)
Symptoms
- lower abd pain
- dyspareunia
- pure lent discharge
- abnormal uterine bleeding (ex. Intermenstrual or postcoital)
50
Q
What are some other causes of the symptoms of PID?
A
- Constipation
- ectopic pregnancy
- appendicitis
- UTI
- endometriosis
- ovarian cyst
- postcoital/intermenstrual bleeding
51
Q
What are some complications of PID?
A
- chronic pelvic pain
- pelvic abscess (tube-ovarian)
- can lead to subfertility:
- adhesions from chronic inflammation will result in an increased risk of ectopic pregnancy since the tubes would be blocked by adhesions; reduces likelihood of successful fertilization
- peritonitis
- fitz-Hugh Curtis syndrome (peri-hepatitis)
52
Q
How can we manage PID?
A
Prevention > Cure
- antibiotics
- give if clinically suspected, dont delay because of investigations
- negative swabs DO NOT exclude PID
- broad spectrum
- IV in more severe cases
- analgesia
- offer screening to sexual partner (Genital urinary medicine aka GUM)
- in those who fail to respond to treatment, laparoscopy is essential to confirm the diagnosis or to make an alternative diagnosis
