Male Reproduction Flashcards
What is the aim of male reproduction?
Produce spermatozoa
Transfer it to the female
What is the HPA axis? What regulates it?
Hypothalamus produces GnRH
Pituitary produces FSH and LH
Adrenal cortex produces androgen
Regulated by oestrogen and testosterone
What hormones are required for spermatogenesis?
FSH
Testosterone (released in presence of LH)
How many weeks doe sit take for spermatogenesis? How many weeks does it take for the spermatids to mature into mature spermatozoa?
5-9 weeks
1-2 weeks
WHat is spermatogonia? How many are males born with?
Undifferentiated haploid sperm
1000-2000
Where are spermatogonia located? When do they undergo mitosis?
Basal lamina of seminiferous tubules
Until puberty
Where are spermatids found? Are they fertile?
Lumen of seminiferous tubule
No
What is the order of sperm development?
Spermatogonia Primary spermatocyte Secondary spermatocyte Spermatid Mature spermatozoa
What is the sperm testis barrier? What does it do?
Physical barrier between blood vessels and seminiferous tubules
Prevents immunological destruction of ‘foreign’ haploid cells
What are the 2 compartments to seminiferous tubules? Which part is in contact with blood vessels?
Adluminal and basal
Basal in contact with blood vessels
What separates seminiferous tubules? What are these cells? What do they contain?
Gap junctions in sertoli cells
Provide nutrition for sperm and release hormones
Spermatogonia in basal lamina
What are Leydig cells?
Cells outside seminiferous tubules
Produce testosterone in presence of LH
What part of the seminiferous tubules is absent in carnivores? What is this?
Seminal vesicles
Folded mucosa
What is the rete testis?
Duct that connects seminiferous tubules to efferent duct
What does the efferent duct connect?
Rete testis to epididymis
GnRH is driven by which hormones? What does this hormone allow and what happens if the pulses are irregular, too slow or too fast?
FSH/LH
Allows reproductive function
Infertility
What is testosterone? How is it stimulated?
Hormone produced by Leydig cells
Stimulated by presence of LH
What is the function of testosterone?
Promotes accessory glands to secrete seminal fluid
Spermatogenesis
Sex drive
Growth of skeletal muscle and bone
What does castration of young animals lead to?
Lower growth rate of skeletal muscle and bone
What controls the temperature of the testes?
Sweat glands
Pampiniform plexus
Tunica Darots (smooth muscle under androgen control)
Cremasteric muscle (skeletal muscle for protection)
What 4 things are needed for successful testes function?
Correct temperature
Pulses of GnRH (3-6 hours)
High concentrations of testosterone in seminiferous tubules
Adequate LH receptors on Leydig cells
What is the epididymis? What does it contain? What parts are there to it?
Duct which sperm passes through to ductus deferens
Single tortuous tube containing smooth muscle and epi cells
Head, body, tail
Where do spermatozoa mature? Where do they concentrate?
Duct in epididymis
Tail
How do spermatozoa mature? How long does this take?
Testosterone causes changes in the membrane and nucleus
1-2 weeks
What are the functions of accessory glands? What hormone are they dependent on?
Produce seminal fluid
Testosterone
What is the function of seminal fluid?
Aid insemination
Not essential
What does the prostate gland produce? What does it cover?
Seminal fluid called prostate fluid
Ampulla of ductus deferens
Which accessory gland is absent in carnivores?
Vesicular gland (no seminal vesicles)
What gland are dogs missing? What does this do?
Bulbourethral gland
Empties seminal fluid into distal urethra
What is the order of male puberty?
First ejaculation
First ejaculation containing spermatozoa
First ejaculation containing enough spermatozoa to fertilise
How is an erection maintained?
Increased arterial flow Decreased venous flow Muscles Vasodilation of corpus sinusoids Increased intrapenile pressure
What is copulation? What are the 4 stages?
Sexual intercourse
Mounting, intro mission, friction, emission
WHat is emission?
Seminal fluid from glands and spermatozoa mix in urethra
Ejacuatlion
