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Flashcards in SPERM Deck (23)
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1

where are the components of ejaculate produced?

10% bulbourethral
30% prostate
60% seminal vesicles

2

what is semen?

fluid + sperm

3

how much semen is expelled during orgasm?

2-5ml

4

what is the normal sperm count?

50-120 million / ml

5

what does semen contain?

sperm
buffers
prostaglandins
chemicals to increase motility

6

what is the role of buffers in the semen?

it protects sperm against acidic environment

7

what is the role of prostaglandins in the semen?

it stimulates female peristaltic contractions

8

what is the role of fructose in the semen?

it increases sperm motility

9

what is the role of the bulbourethral gland?

it releases lubricating mucoid secretions into semen

10

what is the role of the prostate?

it secretes citric acid, acid phosphatase, PSA

11

what is the role of the seminal vesicle?

it produces semen - fructose, prostaglandins, ascorbic acid

12

what is the route of sperm?

1. seminiferous tubules
2. rete testes
3. efferent ducts
4. epididymis
5. vas deferens
6. ejaculatory duct
7. urethra
8. penile urethra

13

what is the blood-testis barrier?

it is formed by sertoli cells
they extend from the basement membrane and are joined to adjacent cells by tight junctions and forms an unbroken ring
it prevents the movement of chemicals

14

what is the role of the blood-testis barrier?

it prevents the movement of chemicals
ensures proper conditions for development and differentiation

15

what are the 2 components of the blood testis barrier?

basal
central

16

how long does spermatogenesis take?

64 days

17

where are spermatozoa produced?

in the testis

18

what are spermatogonia?

they are undifferentiated germ cells
they divide mitotically at puberty into 2 types
- type A remain outside the blood-testis barrier (produce more daughter cells)
- type B in basal compartment and are primary spermatocytes

19

what does spermatogonia differentiate into?

type A = remain outside blood-testis barrier and produce more daughter cells
type B = in basal compartment and are primary spermatocytes

20

what are the stages of spermatogenesis?

primordial germ cell
spermatogonia
primary spermatocyte
secondary spermatocyte
early spermatid
sperm

21

what happens in spermiogenesis?

spermatids develop by growing tails and discarding the cytoplasm - become spermatozoa

22

what is the structure of spermatozoa?

- pear-shaped head
- haploid
- tip of nucleus covered in acrosome (protein filled vesicle containing enzymes)
- tail = flagellum (contains contractile proteins)
- mitochondria = mid piece (provides energy)

23

how does testosterone inhibit LH secretion?

- acts on hypothalamus to decrease amplitude of GnRH burst, resulting in a decreased secretion of LH
- acts directly on the anterior pituitary to decrease the LH response to GnRH