Getting Pregnant Flashcards
What are leydig cells?
Prod testosterone in response to LH
What are Sertoli cells?
Cells are the testis
Create right environment for the sperm
Secretes aromatase
Outline the purpose of the ‘waiting stage’ after ovulation
Built in to the normal lifespan of the corpus luteum
Stops the degeneration of the corpus luteum
What is the cumulus oophorus
Oocyte surrounded by clump of granulosa cells = corona radiata
Sperm needs to penetrate this
What makes up the semen and where does it come from?
Testes = sperm
Seminal vesicle = alkaline fluid, fructose, prostaglandins
Prostate gland = milky, slightly acidic, proteolytic enzymes, citric acid
Bulbourethral gland = alkaline fluid, lubricates
What are the functions of the semen?
Transport medium
Nutrition
Buffering capacity of acidic vaginal environment
Prostaglandins stim muscular activity in the female tract
What factors are examined during a semen analysis?
Volume Viscosity PH Count Motility Morphology
The human sexual response can be divided into what phases?
Excitement Plateau Orgasm Refractory period (MALES ONLY) Resolution
What are the stimulants and efferents involved in achieving an erection?
Stim = psychogenic, tactile (sensory afferents of penis/perineum)
Effer = somatic and autonomic, pelvic N, pudendal N
Outline the neurophysiology of an erection
Inhib of sympathetic arterial vasoconstriction Ns
Active parasympathetic
Activate autonomic Ns to arteries = release of nitric oxide (NO)
Outline how anatomically how an erection is achieved
Tough tunica albuginea surrounding corpora cavernosa (erectile tissue that swells with blood)
Sinusoidal expansion = trapping incoming blood
Arterial dilation = increased blood delivery
Venous compression = reduces venous outflow
During an erection why does the corpus spongiosum not fill with blood to the extent that the corpus cavernosa does?
Allows the urethra to remain patent for ejaculation
What is the parasympathetic innervation involved an in erection?
Pelvic N
Pelvic plexus
Cavernous N to corpora cavernosa and vasculature
What is the role of nitric oxide in an erection?
Post-ganglionic fibres release ACh = binds endothelial receptor = release Ca inside the cell = NO formed = vascular smooth muscle relaxation
What are the causes of erectile dysfunction?
Psychological – inhib spinal reflexes
Tears in fibrous tissue of corpora cavernosa
Vascular
Drugs
Outline the mechanism of Viagra
Inhibits the enzyme that causes cGMP degradation = cGMP rises = increase NO levels = vascular smooth muscle relaxation
What is emission?
Movement of semen into prostatic urethra
Contraction of SM in prostate, vas deferens, seminal vesicles
Under sympathetic control
What happens during ejaculation?
Expulsion of semen
Under sympathetic control
Bladder internal sphincter controls
How does the characteristics of the cervical mucus change over the menstrual cycle?
Oestrogen environment = thin mucus
Oestrogen/progesterone (after ovulation) = thick, forming a plug
What is capacitation?
Maturation of sperm in the female repro tract = membrane changed to allow fusion with oocyte, tail movement also changes to whip-like action
What is the fertile window?
Survival time
Spermatozoa = 4-72hrs
Oocyte = 6-24hrs
Fertile period = sperm deposition up to 3 days prior to ovulation
What is the acrosome reaction?
Sperm push through corona radiata by hyaluronidase
Need a large number of sacrificial sperm to aid hyaluronidase release
Reaction between sperm and ZP3 glycoprotein of zona pellucida = acrosome reaction
What are the stages of fertilisation?
Acrosome reaction
Sperm penetrates
Fusion of plasma membranes
Cortical reaction = blocking polyspermy
Complete meiosis II
Pronuclei move together
Mitotic spindle forms leading to cleavage
What is the morula?
Solid ball of cell resulting from division of fertilised ovum
Every cell present is identical to original cell
Capacity to become any cell
