7. Getting Pregnant Flashcards
(37 cards)
What is added to the surface of sperm when they mature in the epididymis?
Secretory products.
What is maturation of sperm dependant on?
Support of the epididymis by androgens (need functioning HPG axis).
What are the main functions of the seminal plasma?
Transport medium.
Nutrition.
Buffering capacity.
What does the part of seminal plasma produced by the seminal vesicles contain?
Is an alkaline fluid, containing fructose, prostaglandins and clotting factors.
What does the part of seminal plasma produced by the prostate gland contain?
Milky, slightly acidic fluid, contains proteolytic enzymes (breakdown clotting factors to reliquary semen in 10-20 mins), citric acid, acid phosphatase.
What does the part of seminal plasma produced by the bulbourethral glands contain?
Is an alkaline fluid which is a mucous (lubricates the end of the penis and urethral lining).
What is the normal site of fertilisation?
Ampulla of the uterine tube.
What are the 4 phases of the human sexual response?
Excitement phase.
Plateau phase.
Orgasm phase.
Resolution phase (followed by refractory phase in males).
What 2 types of stimulant lead to an erection in males?
Psychogenic and tactile (sensory afferents of the penis and perineum).
What reflex signals the stimulants for a male erection to the efferents?
Spinal reflex.
What efferents lead to haemodynamic changes causing an erection in males?
Somatic - pudendal nerve.
Autonomic efferent - pelvic nerve, pelvic plexus and cavernous nerve to corpora and vasculature.
What happens neurophysiological in an erection?
Inhibition of the sympathetic arterial vasoconstrictor nerves (causing arterial dilation).
Activation of the parasympathetic nervous system (causing sinusoidal relaxation).
Activation of non-adrenergic, non-cholinergic, autonomic nerves to arteries releasing NO (released both directly from nerves, and from endothelial cells, causing relaxation of vascular smooth muscle - vasodilation).
How is NO formed and released in endothelial cells of the penis?
Post-ganglionic fibres release ACh, which bonds to M3 receptor on the endothelial cells. A rise in [Ca2+]i causes activation of NOS and formation of NO.
Give 3 causes of erectile dysfunction
Psychological (descending inhibition of spinal reflexes).
Tears in fibrous tissue or corpora cavernosa.
Vascular (arterial and venous).
Drugs.
How does viagra work?
Slows the rate at which cGMP is degraded in vascular smooth muscle, so vasodilation is maintained, and therefore so is an erection.
What type of autonomic control is emission and ejaculation of semen under?
Sympathetic control.
What happens in emission of semen?
Movement of the semen into the prostatic urethra. Contraction of the smooth muscle in prostate, vas deferens and seminal vesicles.
What is a dry orgasm?
An orgasm where smooth muscle does not contract and so no semen is expelled.
What happens in ejaculation of semen?
Contraction of the glands and ducts (smooth muscle). The bladder internal sphincter contracts to prevent retrograde ejaculation. Rhythmic striatal muscle contractions of the pelvic floor, and perineal muscles ischiocarvernosus and bulbospongiosus).
What is cervical mucus like under the influence of oestrogen in the follicular phase of the menstrual cycle?
Thin and stretchy.
What is cervical mucus like under the influence of oestrogen and progesterone in the luteal phase of menstruation?
Thick, sticky and forms a plug.
What test can be used to determine if oestrogen is present in the cervical mucus?
Fern test.
What is the site of semen deposition?
Cervix.
How does the tail movement of sperm change once they have undergone capacitation?
Changes from a beat to a whip-like action.
