Male Histology

Question 1

Pathway of excretory ducts of testis

Answer 1

1. Tubuli Recti
2. Rete testis
3. Efferent ducts
4. Epididymis
5. Vas deferens
6. Ejaculatory duct

Question 2

Accessory Glands

Answer 2

Seminal vesicles, prostate, bulbourethral gland

Question 3

Testis functions

Answer 3

Exocrine –> production of spermatozoa by seminiferous tubules
Endocrine - production of testosterone

Question 4

Tunica albuginea of testis

Answer 4

dense fibrous capsule, greatly thickened posterior aspect (mediastinum testis)

Question 5

Tunica vaginalis of testis

Answer 5

serous sac surrounding anterior and lateral portions of testis –> derived from peritoneum
Visceral -> adheres to tunica albuginea
Parietal -> adheres to surface of scrotum

Question 6

Lobules of testis

Answer 6

contain contorted seminiferous tubules

CT contains interstitial cells of Leydig

Question 7

Seminiferous tubules

Answer 7

highly convoluted loops and connect to tubule recti
- supported by CT containing Leydig cells
has outer fibroelastic layer of CT
basement membrane
“stratified” epithleium containing:
- Sertoli cells –> supportive cells
- Germ cells –> spermatogonia, spermatocytes, spermatids, spermatozoa

Question 8

Spermatogenesis

Answer 8

spermatogonia —> spermatozoa (Temperature sensitive)

- ALL meiotic progeny become mature gametes

Question 9

Spermatogonia

Answer 9

located directly next to basement membrane (maturity begins at puberty)

• 3 Types
  1. Dark (reserve stem cells)
  2. Pale (renewing stem cells)
  3. Type B (differentiating progenitors)

Question 10

Spermatocytes

Answer 10

Primary -> largest germ cell
- enter as diploid, come out haploid
Secondary -> cannot see, enter meiosis so quickly

Question 11

Spermatids

Answer 11

haploid progeny of meiotic divisions

- nucleus condenses, migrate close to lumen, synchrony of clones (synctium)

Question 12

Spermiogenesis

Answer 12

morphological maturation of spermatids to spermatozoa

1. golgi phase -> acrosome formation, axoneme assembly
2. cap phase -> elaboration of acrosome cap, enzyme content
3. Acrosomal phase -> orientation of head towards basement membrane, nuclear elongation, mito aggregation in middle piece
4. Maturation phase -> residual body shaped, release into seminiferous tubules

Question 13

Sertoli Cells

Answer 13

pillar-like, extend from basement membrane to lumen

• elongated nucleus, contribute to blood-testis barrier
• zona occludens near basal region of adjacent cells –> provides immune barrier so autoimmune reaction doesn’t occur to haploid (non-self) cells
• assist in transport of maturing germ cells to lumen

Question 14

FSH receptors on sertoli cells

Answer 14

testicular fluid production, increase androgen binding receptors, produce inhibin –> negative feedback to pars distalis on FSH

Question 15

Interstitial tissue of testis

Answer 15

lies between seminiferous tubules

- collagenous fibers, blood and lymph, nerves, contain intersitial cells of Leydig

Question 16

Interstitial cells of Leydig

Answer 16

lie in compact groups, large cells with spherical nucleus

- steroid producing cells (testosterone) with extensive smooth ER

Question 17

Endocrinology of testis

Answer 17

Fertility and sex characteristics depend on androgens
LH -> receptors on Leydig cells –> stimulates androgen output (- feedback to hypothalamus)
FSH -> receptors on sertoli cells -> promotes ABP, promotes high levels in seminiferous tubules, inhibin (- feedbacks on pars distalis)
- Leydig cells are not temperature sensitive

Question 18

Tubuli recti

Answer 18

straight tubules, very short, connect seminiferous tubules to rete testis
simple columnar and sertoli like

Question 19

Rete testis

Answer 19

labyrinthine plexus of epithelial channels in mediastinum

- simple cuboidal

Question 20

Efferent ductule

Answer 20

emerges from mediastinum on posterior-superior aspect of testis -> each tubule spirals toward epididymis
- primarly simple columnar with some ciliated and some microvilli
SAW TOOTH PATTERN

Question 21

Epididymis

Answer 21

receives contents of efferent ductules, highly convoluted duct surrounded by CT
- site of further sperm maturation
PSEUDOSTRATIFIED columnar epithelium
Basal cells --> principle cells
both absorptive and secretory functions

Question 22

Vas deferens

Answer 22

very thick muscular wall -> easily palpable through skin
Mucosa -> pseudostratified with stereocilia
- luminal folds
Muscularis -> 3 distinct layers

Question 23

Ampulla of vas deferens

Answer 23

terminal dilation, high folded mucosa, musculature is less arranged, no stereocilia

Question 24

Seminal Vesicle

Answer 24

elongated saccular organs
unbranched tubular diverticulum of distal end of vas
- doesn’t fully develop until puberty
Mucosa -> lots of folds -> forms sinuses
Function = contributes to volume of ejaculate, rich in fructose (energy source for sperm)

Question 25

Prostate Gland

Answer 25

compound tubuloalveolar gland that surrounds prostatic portion of urethra - not fully developed until puberty - has capsule, stroma, and parenchyma - highly folded epithelium

Question 26

Capsule of prostate

Answer 26

firboelastic tissue, inner zone in rich in smooth muscle

Question 27

Stroma of prostate

Answer 27

makes up 1/4 of gland, dense fibromuscular tissue with collagen and elastin

Question 28

Parenchyma of prostate

Answer 28

3 groups of glands 1. Mucosal -> smallest and located next to urethra (BPH) 2. Submucosal -> found in ring of tissue around periurethral tissue 3. Main prostate glands -> outer and largest portion of gland, provide bulk of gland secretion

Question 29

Function of prostate

Answer 29

secretion -> produces thin, milky, faintly acidic fluid - secretions are continuous but especially during sex - acid phosphatase indicator of potential carcinoma - makes up 25% of seminal fluid - testosterone dependent

Question 30

Prostatic concretions

Answer 30

calcified protein and carbohydrate - may appear lamellated - first appears in adults, increases with age

Question 31

Bulbourethral glands

Answer 31

paired bodies, size of pea | - secrete clear, viscous lubricating material into urethra under sexual excitement

Question 32

Semen

Answer 32

epididymal, seminal vesicle, and prostatic secretions

Question 33

Penis

Answer 33

3 Cylindrical bodies 1&2 -> corpora cavernosa, distally situated 3 -> corpora spongiosum -> ventrally situated and ends in cup shpaed enlargement (glans) - surrounded by tunica albuginea (thick fibrous CT sheath)

Question 34

Erection

Answer 34

parasympathetic stimulation -> smooth muscle of vessels relaxes -> engorgement of thin walled venules compresses them and reduces venous drainage

Question 35

Emission/Ejaculation

Answer 35

Sympathetic response -> smooth muscle undergoes peristaltic contraction Nerve impulses from S1-S2 enter pudendal nerve and cause increased pressure in tissue to express semen from urethra

Question 36

Detumescence

Answer 36

sympathetic stimulation continues and causes arteries to regain tone and improve venous drainage

Question 37

Urethra components

Answer 37

Prostatic --> through prostate (goes from transitional to stratified columnar) Membranous -> stratified columnar Penile urethra -> stratified columnar to stratified squamous non-keratinizing

Question 38

Scrotum

Answer 38

thin skin, more melanin present in epidermis - no fat in subcutaneous tissue, thick layer of dartos smooth muscle - thermoregulator - cold = dartos contracts and pulls testis close (cremaster too) - hot = dartos relaxes and testis descends