1) Origin of the Sexes

Question 1

What are the male internal genitalia?

Answer 1

Testis
Epididymis
Ductus deferens
Seminal glands
Ejaculatory ducts
Prostate
Bulbourethral glands

Question 2

What are the male external genitalia?

Answer 2

Glans penis
Shaft of penis
Scrotum

Question 3

What are the female internal genitalia?

Answer 3

Ovaries
Uterine tubes
Uterus
Vagina

Question 4

What are the female external genitalia?

Answer 4

Labia majora
Labia minora
Clitoris

Question 5

How are the testes suspended in the scrotum?

Answer 5

By the spermatic cords

Question 6

What do the testes produce?

Answer 6

Spermatozoa

Male hormones, primarily testosterone

Question 7

What covers the surface of each testis?

Answer 7

Internal to External:
Tunica albuginea 
Visceral layer of tunica vaginalis
Cavity of tunica vaginalis (contains fluid)
Parietal layer of tunica vaginalis

Question 8

What are the components of the testes?

Answer 8

Seminiferous tubule
Straight tubule
Rete testis
Head, body, tail of epididymis
Ductus deferens

Question 9

Where are sertoli cells found and what is their function?

Answer 9

Seminiferous tubules of testes

Spermatozoa development

Question 10

Where are Leydig (Interstitial) cells found & what is their function?

Answer 10

Cells in the interstitial tissue, adjacent to seminiferous tubules of testes
Secrete testosterone

Question 11

What is spermatogenesis?

Answer 11

The process in which spermatozoa are produced from male primordial germ cells by way of mitosis and meiosis

Question 12

A1 spermatogonia arise from stem cells. What do they further differentiate into?

Answer 12

More type A (stem) cells

Type B cells, committed to differentiation to spermatozoa

Question 13

How many primary spermatocytes are usually produced?

Answer 13

64

All linked together by cytoplasm bridges

Question 14

How many spermatids are produced in total?

Answer 14

up to 256

Question 15

What process do spermatids undergo to form sperm?

Answer 15

Spermiogenesis

Question 16

How long does spermatogenesis usually take?

Answer 16

70 days

New A1 spermatogonia arise every 16 days so 4 spermatogenic processes occur simultaneously

Question 17

Where do spermatozoa finally mature?

Answer 17

During progress through the epididymis

Question 18

Briefly describe what happens during emission

Answer 18

Contractions of vas deferens
Sweep & mix sperm with other components of semen from seminal vesicles & prostate

Dependent on SNS

Question 19

What is the spermatogenic cycle?

Answer 19

Development of A1 spermatogonia through to 256 sperms

The amount of time it takes for reappearance of the same stage of the cycle within a given segment of the tube

Question 20

What is the spermatogenic wave?

Answer 20

Different parts of tube begin spermatogenic cycle at different times in a ‘wave’
Production of sperm constant
The distance in the tube between parts that are in the same stage of the spermatogenic wave

Question 21

What is the rete testis?

Answer 21

Network of canals in mediastinum of testis that seminiferous tubules drain into

Question 22

What is the epididymis?

Answer 22

Convoluted duct

Sperms stored & continue to mature

Question 23

What is the vas deferens?

Answer 23

Continuation of epididymis
Thick muscular walls, minute lumen
Walls contract during copulation, force sperm along tube to mix with semen

Question 24

What is the function of the seminal vesicles?

Answer 24

Secrete thick, alkaline fluid rich in:
- fructose (energy source for sperm)
- coagulating agent
Makes up 60% volume of semen

Question 25

What is the function of the prostate?

Answer 25

Prostatic fluid 20% of semen | Role in activating sperms

Question 26

What is the significance of the bulbourethral glands?

Answer 26

Lie posterolateral in intermediate part of urethra Ducts of the glands open into proximal part of spongy urethra in bulb of penis Mucus-like secretion enters urethra during sexual arousal

Question 27

How big are the ovaries?

Answer 27

Almond shaped & sized

Question 28

What is the function of the ovaries?

Answer 28

Oocyte development | Endocrine glands, produce reproductive hormones

Question 29

What is the location of the ovaries?

Answer 29

Each ovary suspended by a short peritoneal fold - the mesovarium Within the mesovarium, a short ovarian ligament tethers the ovary to the uterus

Question 30

What is the ovarian ligament a remnant of?

Answer 30

Superior part of the ovarian gubernaculum

Question 31

What surrounds the ovaries?

Answer 31

Tunica albuginea | covered with a smooth layer of ovarian mesothelium

Question 32

Why does the ovarian mesothelium become progressively scarred & distorted?

Answer 32

Repeated rupture of follicles

Question 33

How do oogonia arise?

Answer 33

Primordial germ cells colonise the cortex of the primordial gonad

Question 34

How many oogonia begin meiosis before birth to become primary oocytes?

Answer 34

2 million

Question 35

What stimulates the entry of oogonia into meiosis 1?

Answer 35

Mesonephric cells/Follicular cells | surround primary oocytes to become primordial follicles

Question 36

When and why is meiosis arrested during the ovarian cycle?

Answer 36

Diplotene stage of prophase | due to Oocyte Maturation Inhibitor secreted from follicular cells

Question 37

Between what ages do follicles further develop?

Answer 37

Puberty to menopause | 13 to 53?!

Question 38

Which 3 stages must a follicle go through to form a mature gamete?

Answer 38

1. Pre-antral or primordial follicle 2. Antral, or secondary follicle 3. Pre-ovulatory follicle

Question 39

How is the corpus luteum formed?

Answer 39

Remains of follicle reorganised CL secretes progesterone & oestrogen under influence of LH CL lives for 14 days before regressing spontaneously if ovum not fertilised

Question 40

Give a brief description of the pre-antral or primordial follicle phase of development

Answer 40

Primary oocyte grows dramatically Granulosa cells secrete glycoprotein, form zona pellucida around oocyte Surrounding stroma (c.t) form theca folliculi Theca & granulosa cells secrete oestrogens

Question 41

Give a brief description of the antral or secondary follicle phase of development

Answer 41

Granulosa cells proliferate, antrum forms between Secondary follicle expands to 2mm Continued development req. FSH & LH

Question 42

Give a brief description of the pre-ovulatory follicle phase of development

Answer 42

37 hours before ovulation Oestrogen causes LH receptors to appear on granulosa cells LH surge Follicle restarts meiosis After meiosis 2, secondary follicle arrests 3 hours prior to ovulation (completes if fertilised) Follicle increases Follicle rupture

Question 43

What are the 2 layers of the Theca Folliculi?

Answer 43

Theca Interna - vascular & endocrine | Theca Externa - fibrous capsule

Question 44

During the antral phase what do FSH & LH bind to?

Answer 44

FSH - Granulosa cells only | LH - Thecal cells only