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Flashcards in Male reproductive tract Deck (70):
1

What are the two roles of the reproductive system?

Reproduce
Production of reproductive hormones

2

What is involved in reproducing?

Produce gametes
Fertilisation & development of fetus

3

What is involved in production of reproductive hormones?

Development & function of reproductive system
Development of sex-specific body form
Normal sex specific behaviour

4

What is the role of gonads (testes)?

Produce sperm and hormones

5

What is the role of associated ducts?

Transport, store & mature sperm

6

What is the role of accessory glands?

Produce seminal fluid

7

What are the accessory glands?

Seminal glands
Prostate glands
Bulbo-urethral glands

8

What are the external genitals?

Penis
Scrotum

9

Describe the adult testis

Flattened egg shape- 4cm
In scrotum

10

Why are the testis in the scrotum

For temperature regulation
3 degrees celsius cooler than internal body temp

11

What are the endocrine functions of the testis

Produces hormones directly into blood stream

12

What are the exocrine functions of the testis?

Production and release of sperm, leave organ within ducts

13

How is the sac in the scrotum divided?

Divided internally by connective tissue septum
Externally by raphe/ridge

14

What is on the outer layer of the scrotum?

Skin, CT & smooth muscle

15

What is the base of the scrotum covered with?

Pubic hairs

16

Why is temperature regulation important in the scrotum?

Sperm needs to be 3 degrees celsius lower than internal body
If it's too warm sperm can't be produced efficiently and there is an increased mutation rate

17

How is temperature regulation controlled?

By muscles

18

Which smooth muscle controls temperature regulation?

Dartos- reduces scrotum size by firming up skin, sac less spacious spacious, pulls testes closer in

19

Which skeletal muscle controls temperature regulation?

Cremaster- pull testes nearer body, physically pulls testes closer to the body, less likely to loose heat

20

What makes up the testis?

Tunica albuginea
Tunica vaginalis

21

What is the tunica albuginea comprised of?

Septa subdivided into roughly 300 lobules
Lobules= 1-4 seminiferous tubules (roughly 0.5 km per testis)
Tubules empty into efferent ductules
Loose connective tissue surrounds tubules interstitium

22

What is the tunica vaginalis comprised of?

Closed sac of serous membrane
Serous fluid, visceral layer connecting to testes, parietal layer further out

23

What is the rete testis?

Connect efferent tubules to epididymis

24

What is interstium?

Loose connective tissue between seminiferous tubules (produce important hormones)

25

What is spermatogenesis?

The process in which spermatozoa are produced from spermatogonial stem cells by way of mitosis and meiosis

26

What is the initial process in spermatogenesis?

The initial cells in this pathway are called spermatogonia, which yield primary spermatocytes by mitosis

27

How many sperm are produced everyday?

70-100 million

28

How long is the cycle of spermatogenesis?

64 days

29

How long throughout the males life does spermatogenesis occur?

puberty to death

30

What happens when sperm leave testis?

Not fully mature, sit in epididymis where they gain motility and are stored within epididymis

31

How long can sperm survive in the female environment?

48 hours

32

What is the commonest cancer in young men?

Testicular germ cell cancer

33

What does testicular germ cell cancer cause?

Reduced fertility

34

Where does the testis descent begin?

Near kidneys

35

Where do testis descend to?

Into the scrotum

36

When does testis descent begin?

7 month in utero

37

What does INSL3 hormone do?

Insulin-like 3
Regulates growth and differentiation of gubernaculum, and thus mediating intra-abdominal testicular descent

38

What is descent controlled by?

Androgens- controlling own descent as they are released by testis

39

What can be the cause of abnormal descent?

2-4% cryptochidism (absence of one or both testes from the scrotum)
30% premature
70% spontaneous descent

40

What is the risk factor that comes with abnormal descent?

Testis cancer

41

What is the inguninal canal?

Bilateral passeageway at anterior abdominal wall between deep and superfifical inguinal rings

42

What does the ingunial canal contain?

Illioinguinal nerve
Spermatic cord
Arteries, nerves and veins
Vas deferens

43

What is the Epididymis?

Coiled tube roughly 7m long
Head, body and tail
Lined by silia

44

What does the epididymis do?

Recycles damaged spematozoa
Stores and matures spermatozoa (12-16 days)

45

What is the ductus (vas) deferens?

Strong muscular tube- seminal vesicle join to form seminal fluid

46

Where does the ductus deferens come from?

Ascends from epidiymis, through inguinal canal, to pelvis, roughly 30cm long

47

What does the ductus deferens do?

Enlargens post- ampulla- joins seminal vesicle duct= ejaculatory duct

48

Where does ductus deferens empty?

Into prostatic urethra- important for fluid to form with sperm (join here)

49

What happens to the ductus deferens during a vasectomy?

Cut and Ligated

50

What are seminal vesicles?

Paired glands
Post/inf to urinary bladder
Roughly 5 cm
Smooth muscle wall- contract

51

What do seminal vesicles do?

Produces & stores semen:
Contributes 60% volume
Fructose (sugar) & prostaglandins (hormone)
Alkaline secretion- vagina acidic, neutralises and allows sperm to survive

52

Where and what is the size of the prostate gland?

Walnut size- roughly 3-4 cm diameter
Inferior to bladder
Surrounds prostatic urethra

53

What type of gland is the prostate gland?

Smooth muscle gland
Smooth muscle contraction
Produces semen (30%)
Secretions- slightly alkaline
Prostate- specific antigen

54

What infections can occur in the prostate gland?

Infections:
• Protatitis
• Benign hyperplasia
• Prostate cancer
Urethra comes through middle of prostate gland
Smooth muscle for contraction
Aging- prostate swells can cause cancer in males or can stop men being able to urinate

55

How much semen do men have?

2-5ml

56

How much sperm is in a ml of semen?

50-150 million

57

What issues may men that have less than 20 million sperm have?

Struggle to conceive, sub fertile

58

Where does fluid in semen come from?

Accessory glands (95% volume)
Basic pH
Fructose, nutrients and liquid to swim

59

What is ejaculation?

Expulsion from urethra
Peristaltic contraction of smooth muscles in ducts, glands, pelvic floor & base of penis

60

What is the dual function of the urethra in males?

Urinary
Reproductive

61

What is the length of the urethra?

20cm long, 3 segments

62

What are the 3 segments of the urethra?

Prostatic urethra
Membranous urethra
Spongy (penile) urethra

63

Describe the prostatic urethra

Receives ejaculatory & prostatic ducts

64

Describe the membranous urethra

Shortest

65

Describe the spongy (penile) urethra

Through corpus spongiosum to external orifice
Receives bulbourethral gland ducts

66

What does the root and the bulb of the penis do?

Connects penis to pelvic bone

67

What does the shaft of the penis do?

Columns of erectile tissue
Blood sinuses
Corpus spongiosum-ventral
Cavernose (paired)- dorsolateral

68

What does the glans of the penis do?

Prepuce/foreskin- circumcision

69

What disrupt the endocrine system in male reproduction?

Chemicals in the environment
Can affect reproductive development in utero

70

What are the effects of a disrupted endocrine system?

Structure of testes and also fertility
Structure of the penis
Risk of testicular cancer
Testis descent