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what is the function of the reproductive system
function is to produce, store, nourish male and female gametes
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what are the basic components of the reproductive system
- gonads or reproductive organs
- ducts which receive and transport gametes
- accessory glands and organs
- external ganitalia
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what do gonads reproductive organs do
they produce gametes and hormones
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where do spermatozoa form
spermatozoa form in the testes
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how do the sperm travel
sperm travel through epididymis along vas deferens and exit body via urethra
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which glands produce fluids which act as lubricants
seminal vesicle, prostate gland and bulbourethral gland produce fluid which act as lubricants
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what is each testes made up of
each testes is made up of a series of lobules
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what does each lobule contain
each lobule contains 800 tightly coiled seminiferous tubules
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what takes place at the testes
spermatogenesis take place here
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where does spermatogenesis begins
it begins in the outermost layer of cells and proceed towards the lumen
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what do seminiferous tubules merge into
they merge into straight tubules
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what are the three steps involved in spermatogenesis
- mitosis
- meiosis
- spermiogenesis
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describe mitosis
- spermatogonium divides- one daughter cells remains in situ, the other moves towards the lumen of the ST
- differentiates into primary spermatocyte
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describe meiosis
division of spermatocyte produces spermatids
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describe spermiogenesis
- spermatids differentiate into physically mature spermatozoa
- released into lumen of ST
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how long does spermatogenesis take
takes 64 days
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how many chromosomes do spermatids have
- they have half the chromosomes of normal cells
- haploid rather then diploid
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what are spermatids
they are immature sperm
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what can happen to the prostate gland with age
- it can grow with age
- therefor can tighten the urethra
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describe the spermatozoon
- it has 3 distinct regions
- head
- midpiece
- tail
- No ER, Golgi, lysosomes ect.
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describe the head of the spermatozoon
- contains nucleus with densely packed chromosomes
- acrosome- contains enzymes essential to fertilisation
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what does the acrosome do in fertilisation
it degrades proteins to allow way through egg
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describe the midpeice of the spermatozoon
contains abundant mitochondria
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describe the tail of the spermatozoon
flagellum- it has a whip-like, corkscrew motion
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where does the flagellum get its energy from
it gets its energy from fructose in the fluid
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what are the accessory glands
- seminal vesicle
- prostate gland
- bulbourethral gland
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describe the seminal vesicle
- 60% volume of semen
- fluid contains high conc. of fructose
- slightly alkaline
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describe the prostate gland
- 20-30% volume of semen
- encircles the urethra
- contains seminalplasmin
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why is the fluid in the seminal vesicle slightly alkaline
it neutralises acid secretions of prostate and vagina
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what is seminalplasmin
it is a protein with antibiotic properties, prevents infection in males
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describe the bulbourethral gland
- it produces thick, alkaline mucus
- neutralises any remaining urinary acids
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what does GnRH stand for
gonadotrophin releasing hormone
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what does LH stand for
luteinising hormone
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what does FSH stand for
stands for follicle stimulating hormone
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describe the hormonal regulation
- hypothalamus releases gonadotrophin releasing hormone
- stimulates pituitary to produce FSH and LH
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what do these hormones act on
they act on testes to produce testosterone
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what does testosterone do
- it maintains libido
- stimulates osteogenesis and myogenesis
- maintains make secondary sex characteristics
- maintains male accessory glands
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