37 Flashcards
1
Q
- The definition of menarche is:
a. The cessation of menstrual cycles
b. The onset of menstrual cycles
c. The time of ovulation
d. The onset of meiosis
e. The onset of mitosis
A
B
2
Q
- GnRH from the hypothalamus directly
regulates the secretion of:
a. FSH and estradiol
b. LH and estradiol
c. FSH and progesterone
d. LH and FSH
e. LH and progesterone
A
D
3
Q
4.During oogenesis, at what point of Meiosis II is
The secondary oocyte suspended and what event causes the cell cycle to resume
A
Metaphase 2; sperm penetration/fertilisation
4
Q
- What happens to the oocyte if the event above
does not occur?
A
Atresia
5
Q
What is coitus
A
• Sexual intercourse / copulation
6
Q
Where does the word coitus come from
A
• From the Latin ‘a meeting
together; sexual union’
7
Q
What happens during coitus
A
- Erect penis introduced into vagina (intromission)
• Semen released into upper part of vagina (insemination) so that sperm can travel to appropriate site for fertilization (ampulla of uterine tube).
(Assuming correct cervical mucus and correct time of ovulation)
8
Q
structure of the penis
A
9
Q
• The erectile tissues are surrounded by different layers
of
A
fascia
10
Q
Fascia of the penis
A
11
Q
Trabecula
A
- supported with smooth muscle fibres
- fill with blood during erection
12
Q
What allows the erection to take place - yap
A
Blood fills trabeculae it pushes against fashion and also pushes against the network of the venous plexus minimising blood leaving the penis
13
Q
The desce fibrous capsule - albuginea is _____ thick around the ______
A
Less
Corpus spongeusum
14
Q
structure of the clitoris
A
15
Q
Comparative structure of the clitoris and penis
A
• Structure of the clitoris and penis share developmental
origins
• Tissues of clitoris are erectile as in the penis
16
Q
Branches of abdominal aorta
- what is the sequence of branching
A
17
Q
A
18
Q
A
19
Q
What does the Internal pudendal artery feed
A
Internal pudendal artery feeds
perineum and external genitalia,
including penis.
20
Q
• Branches to the penis from the Internal pudendal artery include:
A
• Artery to bulb
• Urethral artery
• Dorsal artery
• Deep (cavernosal) artery
21
Q
A
22
Q
What allows erection to take place
A
- pressure of the filling lacunae on the surrounding fascia
- Compression of the surrounding veins
23
Q
Penis is richly innervate sad by _____ and. _____ nerves
A
• Penis richly innervated by sensory
and motor nerves
24
Q
The penis includes sensory fibres responsive to ….
A
touch, pressure, temperature.
25
What kind of sensory does the pudenal nerve supply? Where does it supply the sensory to?
Pudendal nerve supplies sensory and
somatic motor innervation to
perineum and external genitalia,
including penis (dorsal nerve)
26
Where is the Autonomic innervation to penis
derived from
pelvic plexus
(parasympathetic & sympathetic)
27
3 nerve supply’s on the penis
Parasympathetic = ERECTION
Stimulates the production of nitric oxide (NO, a vasodilator) by the deep arteries of the penis (within corpora cavernosa). The deep arteries dilate as a result, and fill the lacunae in the corpora cavernosa and the corpus spongiosum, allowing erection.
Sympathetic = EJACULATION
Stimulates the contraction of smooth muscle in the ductus deferens and urethra, and the prostate + seminal vesicles
Somatic motor = EJACULATION
Stimulates the contraction of skeletal muscles around the bulb of the penis - required for the expulsion of semen from the penis
28
Stages of the male sexual act:
• Erection of penis (parasympathetic)
• Mucus secretion into urethra
• Ejaculation
• Two phases (both sympathetic)
• Emission
• Expulsion
• Resolution
29
Erection
• Parasympathetic efferent response to stimuli
• Arteries in erectile tissue dilate
• Erectile tissue becomes engorged with blood
• Erect penis can be inserted into vagina (intromission)
Erection - PENIS
parasympathetic response to external stimuli
Production of NO in the deep arteries causes them to vasodilate as NO is a vasodilator
Erectile tissue becomes engorged with blood
Penis becomes erect and can be inserted into vagina (into mission)
BULBUURETHRAL GLANDS
= secretes bulburethral fluid
30
2. Emission
• Sympathetic response
• Smooth muscle of ductus deferens contracts to move sperm into ampulla (peristaltic contractions)
• Smooth muscle of ampulla, seminal vesicles and prostrate gland contract moving sperm and seminal fluid into urethra.
31
3. Expulsion
• Semen in urethra activates somatic and sympathetic reflexes
• Contractions of urethral smooth muscles as well as the bublosponiosus muscle
• Pelvic floor muscles contract
• Semen ejected
Explusion
- semen in urethra activates somatic and sympathetic reflexes
- Additional secretion from prostate gland and seminal vesicles
- Contraction of urethral smooth muscles and internal urethral spincter (urine remains in bladder)
- The bulbospongiosus muscle contracts rhythmically and compresses bulb/ root of penis which compresses urethra
- Pelvic floor muscles contract
- Semen is ejected
32
4. Resolution
• Blood flow to penis is reduced
• Penis becomes flaccid
- refractory period - can’t get hard again
33
Stages of the female sexual response
- engorgement of clitoris, labia and vagina in response to autonomic stimulation
- lubricating fluid secreted through vagina wall; secretion of mucus into vestibule (greater vestibular glands)
- increased width and length of vagina, uterus elevates upward
- rhythmic contraction of vaginal, uterine and perineal (pelvic floor) muscles
- relaxation
Very similar to male
34
Fertilisation
• Semen released into upper part of vagina neat crevix (insemination). Sperm travel (up through cervical canal, into lumen then) to uterine tube for fertilization (ampulla).
• Sperm fuses with secondary oocyte (assuming timing is correct)
• Oocyte completes meiosis II.
• Fertilized oocyte/ovum known as a zygote.
• Zygote initiates cleavage (takes about 7 days) and travels towards the uterus for implantation.
35
What is Contraception? What does it so?
• Any method used to prevent pregnancy
• regulate when and how many pregnancies
36
Two methods of contraception
• Natural methods
• Artificial methods
37
Types of artificial methods of contraception
• Barrier methods
• Intrauterine devices
• Hormonal contraceptives
• Sterilisation
38
Natural methods - what do they rely on?
• Rely on timing of coitus or behavior during coitus
• High failure rate
39
Two methods of natural methods
• Rhythm method (periodic abstinence) - avoid sex around
ovulation
• Withdrawal method (coitus interruptus)
• Lactational infertility - when breast feeding probably not ovulation - must be lactating long enough for it it impact GnRH - females not usually aware of this
40
Barrier methods - Caps, diaphragms
• Imperfect barrier so should be used in conjunction with spermicidal foams / jellies / creams / sponges.
• Needs to remain at least 6 hours after intercourse.
• Not commonly used anymore; preference for more effective and convenient methods.
41
Barrier methods - condoms
• Cheap
• Readily available
• Easy to use
• Reduce risk of sexually transmitted infections (STIs)
42
Non-hormonal Intrauterine device (IUD)
Copper IUD
• Causes low grade inflammation of endometrium making it more difficult for the sperm to travel
• Reduces sperm transport
• Toxic - oocyte and zygote
• Impairs implantation
43
Steroidal contraceptives for females - mechanisms of action
Mechanisms of action
• Variable depending on type, concentration and mode of
delivery of hormones
• Deliver a progestin(group of hormones that act like progesterone) with/without and estrogen (group of hormones that act like estradiol)
Work in two ways
• Suppress ovulation (uses progestin to affect feedback loops to hypothalamus
and pituitary)
• progestin Affect mucus produced by cervix (prevent sperm penetration)
44
Steroidal contraceptives for females - Combined oral contraceptive pills
• Contain estrogen and progestin
• Suppress ovulation (affect feedback loops to hypothalamus
and pituitary)
• Affect mucus produced by cervix (prevent sperm penetration)
45
Steroidal contraceptives for females - Progestin-only contraception - PILL AND IMPLANT
• Progesterone-only pill
• Low doses of progestin
• Effects on cervical mucus
• Subdermal implant / Injectable progestins
• Long acting (over years)
• Act primarily by disrupting follicular growth and ovulation
(affecting feedback loop)
46
Hormonal Intrauterine device (IUD)
Hormonal IUD (e.g. Mirena)
• Contains progestins
• Affects cervical mucus, reducing sperm transport
• Local affects on endometrium
• May prevent ovulation
- effects structure of the endometrium
47
Sterilisation
Females
• Tubal ligation – cut uterine tubes
Males
• Vasectomy – cut vas (ductus) deferens
48
• Only ______ provide contraception and some
protection against STIs
Condoms
49
Variable fail rates depending on type of contraception and how they are used
Yes
50
An elderly man can no longer achieve an erection.
What is the technical term for this condition?
Erctile dysfucnton
51
Erection is a sympathetic response.
True or false
F
52
Ejaculation is a parasympathetic response.
True or false
F
53
The adjacent image shows what type of contraceptive procedure?
Tubal ligation
