Male reproductive lecture content (exam #4)

Question 1

What the components of the male repro system?

Answer 1

Testes, excretory ducts, penis, and accessory sex glands

Question 2

What are the structure of the testis?

Answer 2

-tunica albuginea testis

-Septuli tetis

-Seminiferous tubules

-Mediastinum testis

-Rete testis

Question 3

Tunica albuginea testis

Answer 3

-dense connective tissue capsule covering

-serous membrane (visercal vaginal tunic) adhered to the surface

Question 4

Septuli testis

Answer 4

-loose connective tissue trabeculae subdividing testis into lobules

-leydig cells

Question 5

Leydig cells (testis)

Answer 5

-interstitial polyhedral cells

-eosinophilic cytoplasm. Large spherical nuclei, distinct nucleoli

-secretes testosterone, insulin-like protein 3, and oxytocin

Question 6

Seminiferous tubules

Answer 6

-sertoli cells

-spermatogonia

-primary spermatocytes

-secondary spermatocytes

-spermatids

-mediatstinum testis

-rete testis

Question 7

Sertoli cells (seminiferous tubules)

Answer 7

-columnar cells, pale staining nucleus, distinct nucleolus

-extend through full thickness of epithelial surface

-cytoplasmic process surround adjacent spermatogenic cells

-secretion of estrogens

-formation of blood testis barrier

Question 8

Blood-testis barrier

Answer 8

isolates haploid germ cells (secondary spermatocytes, spermatids, and sperm) from blood stream and immune cells. Prevents immune response against sperm ad infertility.

Question 9

Mediastium testis

Answer 9

-connective tissue cord extending through long axis of testis

-connected with tunica albuginea testis via septuli testis

-atypical and inconspicuous in horses

-contains rete testis

Question 10

Rete testis

Answer 10

-complex series of interconnecting channels with the mediastinum

-receives fluid from the seminiferous tubules

-connects to the head of the epididymis

Question 11

What are the developmental cell stages in spermatogenesis?

Answer 11

-spermatogonia

-primary spermatocytes

-secondary spermatocytes

-Spermatids

Question 12

Spermatogonia (spermatogenesis)

Answer 12

-large, spherical, basally-located cells with variable morphology

-undergo mitosis to form continuous supply of germ cells

Question 13

Primary spermatocytes (spermatogenesis)

Answer 13

-second layer of cells adjacent to spermatogonia

-undergo DNA replication (2n and 4d), then division into 2 secondary spermatocytes (2n and 2d)

Question 14

Secondary spermatocytes (spermatogenesis)

Answer 14

-undergo meiotic division into 4 spermatids (1n and 1d)

-smaller than primary spermatocytes

-difficult to identify (pass through 2nd meiotic phase and form spermatids quickly)

Question 15

Spermatids (spermatogensis)

Answer 15

-small round to tadpole shaped cells

-thick layer of cells nearest lumen of seminiferous tubule

Question 16

What are the functions of the epididymis

Answer 16

-storage and maturation of sperm

-decapacitation factor added to the sperm surface

-removal of degenerating sperm

Question 17

Structure of the epididymis

Answer 17

head body tail

Question 18

Epididymis

Answer 18

-crescent-shaped, elongated structure lying along surface of the testicle

-Regionally divided into head body and tail

-covered with collagenous connective tissue

-connective tissue separate from inner tunica albuginea epididymis segregates organ into lobules

Question 19

efferent ductules of epididymis

Answer 19

-Begins as 6-20 straight vessels that become coiled and form 6-10 coiled masses

-thin walled

-lined with alternating clamps of tail (ciliated) and short (microvilli) pseudostratified epithelial cells

-thin collagenous lamina propria with circular smooth muscle

Question 20

Ductus epidiymis (body, tail)

Answer 20

lined with pseudostratified ciliated columnar epithelium

-decreased coiling of ducts as tail region is approached

Question 21

The route developing sperm take as they move through the male duct system from seminiferous tubule to urethra

Answer 21

The sperm travels from the testes to the epididymis, then to the vas deferens, then to the prostate, and ultimately to the urethra

Seminiferous tubules –> Rete testis –> Vasa efferentia –> Epididymis –> Vas deferens –> Ejaculatory duct –>Urethra –>

Question 22

Regional anatomy of the male penis

Answer 22

Root (radix)

Body

Glans

Question 23

Root (Radix)

Answer 23

crura and penile bulb

Question 24

Body (penis)

Answer 24

corpus cavernosum penis, corpus spongiosum penis

Question 25

Glans (penis)

Answer 25

corpus spongiosum penis

Question 26

Know the basics of ejaculation and how they are controlled by the nervous system

Answer 26

For coitus to occur, the cavernous erectile tissue of the penis must fill with blood. This is accomplished through stimulation from the parasympathetic nervous system. Blood flow is increased to the erectile tissue spaces, while simultaneously decreasing venous return. The erectile spaces gradually fill with blood, and the penis increases in length and girth. The degree of expansion is dependent on species. The body of the penis is the segment spanning the distance between the glans and root. Once the penis is intromitted (placing one organ or organ segment inside another) into the vagina, the sympathetic nervous system stimulates accessory sex glands to secrete into the urethra. Next, rhythmic contractions of skeletal muscle covering the cavernous erectile tissue compartment housing the urethra cause a
transduction of these wave-like contractions into the underlying blood-filled spaces and onto the surface of the urethra. This results in propelling the ejaculate through the urethra, out of the penis and into the vagina.

Question 27

What are the accessor sex glands present in males

Answer 27

-prostate

-vesicular glands

-ampulla gland

-bulbourethral gland

Question 28

Prostate gland

Answer 28

-Body and disseminate part-species dependent

-surroundns urethra (partially or wholly, depending on species)

-compound tubular gland

-watery secretions

Question 29

Vesicular glands

Answer 29

-paired organs

-contributing to ejaculate

-white gelatinous secretion provides energy source

Question 30

Ampulla gland

Answer 30

-present in species dependent

-branched tubular structure with sparse glandular tissue

-simple columnar epithelium

-thick tunica muscularis

-white serous secretion

Question 31

Bulbourethral gland

Answer 31

-presence is species dependent

-paired organs

-connective tissue capsule containing smooth muscle in most species

-trabeculae radiate from capsure to form lobules

-simple columnar eptithelium

-clear mucus-like secretion

Question 32

Know the structure and function of the urethra.

Answer 32

The male urethra can be divided into three sections: the prostatic urethra (the uppermost segment within the prostate), the membranous urethra (the segment within the urethral sphincter), and the spongy urethra (the lowermost and longest section within the penis)

Overall, the function of the male urethra is to allow passage of urine and semen. The urethra connects the distal portions of the urinary system, such as the urinary bladder, to the external environment and allows for urine excretion from the body.

The penile urethra is enclosed by the corpus spongiosum and lined with stratified columnar and pseudostratified epithelium with stratified squamous epithelium distally. The entire posterior urethra is lined with a submucosa and a series of muscular sphincters.

Question 33

Understand the influence of testosterone and estrogen on the male reproductive system.

Answer 33

Leydig cells –> secrets testosterone (testicle development, development of accessory sex glands, secondary sex characteristics, maintains spermatogenesis), Insulin-like protein 3 (stimulates testicular descent, marker for evaluating fertility),

Testosterone –> Testosterone is an androgen that are produced in the testes. It is responsible for the development of male accessory sex organs, muscular growth, and secondary sexual characters. It regulates spermatogenesis and libido in males. They also regulate bone mass, fat distribution, muscle mass, and strength.

Estrogen (estradiol) –> However, estradiol, the predominant form of estrogen, also plays a critical role in male sexual function. Estradiol in men is essential for modulating libido, erectile function, and spermatogenesis.