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Flashcards in Male Histology Deck (38):
1

Pathway of excretory ducts of testis

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

2

Accessory Glands

Seminal vesicles, prostate, bulbourethral gland

3

Testis functions

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

4

Tunica albuginea of testis

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

5

Tunica vaginalis of testis

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

6

Lobules of testis

contain contorted seminiferous tubules
CT contains interstitial cells of Leydig

7

Seminiferous tubules

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

8

Spermatogenesis

spermatogonia ---> spermatozoa (Temperature sensitive)
- ALL meiotic progeny become mature gametes

9

Spermatogonia

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)

10

Spermatocytes

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

11

Spermatids

haploid progeny of meiotic divisions
- nucleus condenses, migrate close to lumen, synchrony of clones (synctium)

12

Spermiogenesis

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

13

Sertoli Cells

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

14

FSH receptors on sertoli cells

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

15

Interstitial tissue of testis

lies between seminiferous tubules
- collagenous fibers, blood and lymph, nerves, contain intersitial cells of Leydig

16

Interstitial cells of Leydig

lie in compact groups, large cells with spherical nucleus
- steroid producing cells (testosterone) with extensive smooth ER

17

Endocrinology of testis

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

18

Tubuli recti

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

19

Rete testis

labyrinthine plexus of epithelial channels in mediastinum
- simple cuboidal

20

Efferent ductule

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

21

Epididymis

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

22

Vas deferens

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

23

Ampulla of vas deferens

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

24

Seminal Vesicle

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)

25

Prostate Gland

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

26

Capsule of prostate

firboelastic tissue, inner zone in rich in smooth muscle

27

Stroma of prostate

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

28

Parenchyma of prostate

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

29

Function of prostate

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

30

Prostatic concretions

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

31

Bulbourethral glands

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

32

Semen

epididymal, seminal vesicle, and prostatic secretions

33

Penis

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)

34

Erection

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

35

Emission/Ejaculation

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

36

Detumescence

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

37

Urethra components

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

38

Scrotum

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