Reproductive System 1 - Reproductive systems and gametogenesis

Question 1

Reproductive system

Answer 1

Produces male and female gametes
Oocyte
sperm
Enhances fertilisation of an oocyte by a sperm
Female: nurtures new individual until birth
Produces reproductive hormones – controls above processes
Birth: Biological Sex
Female (vagina)
Male (penis)
Intersex (variation)
Anatomy doesn’t always dictate gender identity
Covering biological sex

Question 2

Male Reproductive System - overview

Answer 2

Organs
Testes
Penis
Ducts
Epididymis
Ductus deferens
Urethra
Glands
Seminal vesicles
Prostate

Question 3

Testes –anatomy

Answer 3

Testes covered in
Fibrous connective tissue
(under skin- scrotum)
Each testis contains
Connective tissue forms lobes
Seminiferous tubules (produce sperm)
Rete testis
Efferent ductules
Epididymis
Ductus deferens
Leydig cells (outside seminiferous tubule)
Produce testosteron

Question 4

Gametogenesis

Answer 4

formation of the male and female gametes
Gametes (ovum and spermatozoa)
Oogonium/primary oocytes and spermatogonium
Females: oogenesis
Males: spermatogenesis
occurs in the gonads (ovary or testis)

Question 5

Gametogenesis:
Meiosis
Termed

Answer 5

Meiosis
one cell undergoes two consecutive cell divisions
four daughter cells, each half as many chromosomes as the parent cell
Termed
meiosis I (reduction division, 23)
meiosis II

Question 6

During fertilization, zygote receives _ set of chromosomes (23) from each parent

Answer 6

1

Question 7

Seminiferous tubule

Answer 7

Where sperm formed
Mature in lumen, immature on outside
Leydig cells (testosterone)
Sertoli cells (nourish the germ cells and produce hormones)
Germ cells partially embedded

Question 8

Spermatogenesis is the

Answer 8

Creation of sperm cells within the male gonads (testes)

Question 9

What is the function of testes?

Answer 9

Exocrine – produce sperm
Endocrine – produce hormone
Spermatogenesis
Process of sperm maturation
Involves both mitosis & meiosis
Takes ~ 74 days to complete (incl maturation)

Question 10

Spermatogenesis –seminiferous tubules

Answer 10

Germ cells
Immature at periphery
Mature near lumen
Mature (sperm cell or spermatozoa)
(semi mature)
The head, midpiece, and tail
transported through seminiferous tubules and ducts to the exterior of the body
Via rete testis to epididymis
Complete maturation
(although final stage just before fertilisation in oviduct)

Question 11

Male Reproductive System - overview

Answer 11

Spermatozoa journey
Seminal vesicles in testis
Epididymis
Ductus deferens (vas deferens)
loops behind the urinary bladder
peristaltic waves to propel the sperm to approach the prostate gland
Seminal vesicles (semen)
Prostate (semen – surrounds urethra)
Urethra
Semen secretion
Nutrients (inc fructose)
pH regulators
Coagulation proteins (prolong time in vagina)
Proteolytic enzymes – release sperm – swim to oocyte

Question 12

Female systems - medial section

Answer 12

Ovary
Uterine tube / fallopian tube/oviduct
Uterus
Vagina
Distendable smooth muscle tube, 10cm long
Small glands secrete lubricant
Related to rectum posteriorly and bladder/urethra anteriorly
female reproductive and urinary tracts open separately to the exterior

Question 13

Female reproductive system overview

Answer 13

Ovary
Lies close to oviduct
Uterine tube / fallopian tube/oviduct
Uterus
Vagina
Cervix
Oocyte
Sperm cells deposited in vagina
Ampulla-site of fertilization

Question 14

Uterine tissue layers

Answer 14

Endometrium – vascular and glandular
Stratum compactum - cuboidal ciliated epithelium*
Stratum spongiosum - loose connective tissue*
Stratum basale
*Slough during menstruation

Myometrium – 3 layers of smooth muscle

Perimetrium - peritoneum

Question 15

Fallopian tubes

Answer 15

Also known as: Uterine tubes or Oviducts

Each 10cm long (approx.)

Three major components
Isthmus – narrowing
Ampulla – swelling – fertilization usually occurs here
Infundibulum – collecting area with fimbrae
Fimbrae that collect egg when released from ovary

Question 16

Ovary composition:

Answer 16

Outer: connective tissue – ovarian follicles
Oocyte (female sex cell)
Centre: blood vessels nervous tissue
Developing follicles (cellular structures)
Surrounding developing oocytes

Question 17

Ovary: follicular development

Answer 17

Primordial follicles (present at birth)
Puberty:
Primary follicles
Oocyte enlarges
Develops granulosa cells
Build up
Secondary follicle
Fluid filled vesicles
Thecal cells
Grafian follicle (mature)
Ruptures and secondary oocyte surrounded by cells released during ovulation

Question 18

What are Follicles?

Answer 18

Primary follicle surrounded by granulosa cells
No. Layers of granulosa cells increases as maturation proceeds
Cells secrete oestrogen rich fluid into space surrounding oocyte called Antrum
Outer layer of granulosa cells condenses into layer of theca cells

Question 19

Oogenesis

Answer 19

Occurs in the ovaries
Process of creation of an ovum (egg cell) from precursor cells
Begins prior to birth
primordial germ cells (oogonia) in foetal ovary
spans all of pre-reproductive & reproductive life
Similar process to spermatogenesis
Mitosis of primordial cells (oogonia)
(early) meiosis of primary oocytes
(late) meiosis of secondary oocyte

Question 20

Oogenesis > development of oocytes

Answer 20

primitive germ cells (differentiation) > oogonia (mitosis_ > primary oocyte (early meiosis) > secondary oocyte (late meiosis) > Ovum

Stimulated and controlled by hormones secreted from granulosa and theca cells

Question 21

Ovary: follicular and oocyte development

Answer 21

Follicle development 28 days
Hormonal control
Generally only one follicles forms a mature follicle
Remaining degenerate
Post ovulation
Forms corpus luteum
If pregnancy
Corpus luteum enlarges and persists
If no pregnancy
Corpus luteum lasts 10-12 days
degenerates

Question 22

What is unique about final stage of oogenesis?

Answer 22

only occurs if fertilisation happens