Ch.27: Reproductive System Part 2:

Question 1

____________, is the sequence of events in the seminiferous tubules of the testes that produce the male gametes: Sperm or spermatozoa

Answer 1

Spermatogenesis

Question 2

Diploid chromosomal number is ___

Answer 2

46

Question 3

The number of chromosomes in a human gamete is ___, referred to as the haploid chromosomal number

Answer 3

23

Question 4

Gamete formation in both sexes involves _______, a unique kind of nuclear division that for the most part occurs only in the gonads

Answer 4

Meiosis

Question 5

These cells called __________ ____, give rise to sperm, goes through In presence of Testosterone and Follicle stimulating hormone (FSH) released by the ant. Pituitary, each spermatogenic cell (2n= 46) undergo meiosis and forms four unidentical sperms ( n= 23

Answer 5

Spermatogenic cells

Question 6

___________, during which it elongates, sheds its excess cytoplasmic baggage and forms a tail. HAS HEAD, MIDPIECE, and TAIL

Answer 6

spermiogenesis

Question 7

The ______ of a sperm consist almost entirely of its flattened nucleus, which contains the compacted DNA

Answer 7

Head

Question 8

A helmetlike _______ adheres to the top of the nucleus. It contains hydrolytic enzymes, which enable the sperm to penetrate and enter an egg.

Answer 8

Acrosome

Question 9

The sperm __________ contains mitochondria spiraled tightly around the microtubules of the tail

Answer 9

Midpiece

Question 10

The long tail is a typical _________ produced by one centriole near the nucleus.

Answer 10

flagellum

Question 11

The __________ provides the metabolic energy needed for the whiplike movements of the tail that will propel the sperm along its way in the female reproductive tract.

Answer 11

Mitochondria

Question 12

Important role of the Sertoli cells/ Supporting Cells/ Sustentacular cells:

Answer 12

• Blood-Testis Barrier (tight Junctions)
• provide nutrients & essential signals (live or die)
• move cells to the lumen
• secrete TESTICULAR FLUID (transport medium)
• Phagocytize faulty germ cells and excess cytoplasm
• produce chemical mediators (inhibin & Androgen-binding protein) which aid in regulating Spermatogenesis

Question 13

Hormonal interactions between the hypothalamus, anterior pituitary gland, and gonads, a relationship called the ___________ _______ _______ (HPG) axis.

Answer 13

hypothalamic pituitary-gonadal axis

Question 14

The hypothalamus releases _________ _________ hormone (GnRH), which reaches the anterior pituitary cells via the blood of the hypophyseal portal system.

Answer 14

gonadotropin- releasing hormone

Question 15

GnRH controls the release of the two anterior pituitary gonadotropins: ________ _____ _______ and _______ ______

Answer 15

Follicle stimulating hormone (FSH)
Lutenizing hormone (LH)

Question 16

_____ stimulates spermatogenesis by stimulating the sustenocytes to release ANDROGEN-BINDING PROTEIN (ABP) ____ enhances testosterone’s stimulatory effects

Answer 16

FSH

Question 17

_______ keeps the concentration of TESTOSTERONE in the vicinity of the spermatogenic cells high.

Answer 17

ABP

Question 18

______ binds to the interstitial endocrine cells (LEYDIG CELLS) in the soft connective tissue surrounding the seminferous tubules, producing them to secrete testosterone.

Answer 18

LH

Question 19

Rising __________ _______ serve as the final trigger for spermatogenesis

Answer 19

Testosterone level

Question 20

__________, a protein hormone produced by the sustentocytes, serves as a “barometer” of the normalcy of spermatogenesis. When the sperm count is high more _______ is released, inhibiting anterior pituitary release of FSH and hypothalmic release of GnRH

Answer 20

Inhibin

Question 21

Like all steroid hormones, testosterone is synthesized from __________ and exerts its effects by activating specific genes

Answer 21

Cholesterol

Question 22

Male Secondary sex characteristics:

Answer 22

appearance of pubic, axillary, and facial hair
deepening of the voice
skin becomes oilier
bones grow and increase in density
high metabolic rate
male libido