Chapter 19: Male and Female Reproductive System

Question 1

Genetic Male

Answer 1

Without Testosterone = female anatomy

Question 2

Genetic Female

Answer 2

With Testosterone = male anatomy

Question 3

Androgen-Insensitivity Syndrome

Answer 3

Genetic males without testosterone receptors = female body

Lack ovaries and do not menstruate.

Question 4

Testosterone during and after Puberty

Answer 4

Puberty range (8-14 years old): testosterone stimulates development of secondary sexual  characteristics:
General growth of body and genitalia, ↑libido (sexual drive), ↑erythropoiesis, ↑frequency of erections and ejaculations 

Stimulates spermatogenesis
Process of making sperm
Androgen binding protein (ABP) must be present

Question 5

GnRH - Gonadotropic Releasing Hormone

Answer 5

Gonadotropic Releasing Hormone (hypothalamus) normally regulated by a negative feedback loop,

During puberty - hypothalamus less sensitive to high testosterone levels,

Question 6

Sertoli Cells

Answer 6

(Sustentacular or nurse cells)
Secrete ABP (permissive to testosterone)

Question 7

Leydig Cells (Interstitial cells)

Answer 7

Secrete testosterone

Question 8

Inhibin decreases Sperm Count

Answer 8

Normal sperm count ranges between 20-140 million sperm per ml of ejaculate.

Inhibin - selectively inhibits FSH but not LH or testosterone, this mechanisms decreases [ABP] to regulate sperm count while maintaining other characteristics.

Question 9

ACROSOME

Answer 9

Contains digestive enzymes that breakdown the ovum’s zona pellucida (glycoproteins)

Once it crosses, it must then deliver its nucleus into a ‘receptive’ secondary oocyte

Question 10

Fertilization

Answer 10

requires two gametes (sperm and ovum) each has to be haploid (n)

Question 11

Spermatogenesis

Answer 11

The formation of spermatozoa (takes ~64-74 days).

Testosterone stimulates Spermatogenesis (ABP must be present)

Question 12

Mature Spermatozoon Characteristics

Answer 12

Head contains:
Very little cytoplasm and organelles
Genetic material (n=23 chromosomes),
Acrosome has lysosomes with digestive enzymes (Helps penetrate the ovum)

Midpiece (body): numerous mitochondria
Produce ATP for locomotion.

Tail:
Microtubules for locomotion,
Principal Piece: Largest part of tail.
End piece: Smallest part of tail

Question 13

Female Puberty

Answer 13

Puberty onset 10 – 16 years of age
Estrogen (from ovary),

Gonadotropin releasing hormone (GnRH) from hypothalamus stimulates:
FSH and LH secretion from adenohypophysis,
FSH - stimulate oogenesis of a dominant oocyte,
LH - followed by ovulation and menstruation in each cycle

Question 14

Oogenesis

Answer 14

Secondary oocyte development during puberty

Question 15

Ovarian Cycle (in ovary)

Answer 15

Follicular phase (day 1 -13): Graafian Follicle Develops (with Secondary oocyte inside)
Ovulation (day 14): 2nd oocyte leaves ovary
Luteal phase (day 15 – 28): Follicle becomes corpus luteum and produces Progesterone and Estrogen

Question 16

Menstrual Cycle (in uterus)

Answer 16

Menstruation (day 1 - 5): Shedding of endometrium
Proliferative phase (day 6- 13): 1st estrogen peak develops ‘new’ endometrium
Secretory phase (day 15 – 26): 2nd estrogen peak and PROGESTERONE increase thickness of endometrium (implantation)
Premenstrual phase day (27 – 28): ADH Oxytocin