histology of male

Question 1

Organs of the male repro system

Answer 1

Organs of the male reproductive system, a testis (male sex gland), a duct system, accessory glands, penis and scrotal sac

Functions- produce and store male gametes, produce the male sex hormones (androgens), deliver the male gametes to the female reproductive tract

Question 2

coverings of testes

Answer 2

From out to in- tunica vaginalis (serous couvering), tunica albuginea (collagenous CT capsule), Tunica vasculosa (vascular capsule)

Question 3

Testiculr structure

Answer 3

mediastinum testis (derived from tunica albuginea, subdivides each testis into 250 lobuli testis)
Each lobule contains 1-4 blindly ending seminiferous tubules surrounded by a CT stroma

600-800 seminfeours tubules in a testes

Question 4

Seminferous tubules

Answer 4

each seminferous tubule is surrounded by Leydeg cells in the interstitial area, they produce testosterone in response to LH (aka interstital stimulating hormone)

Theres a basement membrane with meyloid cells- smooth muscle cells that help move spermatazoa thru the duct

Sertoli cells make up the bulk of the seminferous tubule, theyre circular cells

Typa A and B spermatagonia, 1 the

Question 5

seminiferous epithelium- spermatogenesis, sertoli cells

Answer 5

takes 64 days
initiated or turned on during puberty, continuously renewing process that can be subdivided into 3 phases, Spermatocytogenesis (spermatogonial phase, is the time that spermatogonia divide by mitosis and maintain a stem cell population), the process of meiosis occupies the second or spermatocyte phase. by 2 divisions primary spermatocytes become spermatids. the 3rd phase is speriogenesis/spermatid round spermatids become mature sperm

Question 6

Spermatogenesis phases

Answer 6

Spermatogonia give rise to spermatozoa via 3 phases (name get shorter as you go down, Atocyto, atido, io)
1. Spermatocytogenesis (mitosis)- spermatogonia divide to maintain a stem cell population and to provide a pool of undifferentiated cells committed to meiosis
2. Spermatidogenesis (meiosis) - primary spermatocytes become spermatids
Spermiogenesis (differentiation)- spermatids become mature sperm

Question 7

spermatocytogenesis

Answer 7

spermatogonia- small diploid germ cells located in the seminiferous tubules. Subsequent to puberty spermatogonia become influenced by testosterone to enter the cell cycle,

Types of spermatogonia- Dark type A spermatogonia (stem cells), Pale tyep A spermatogonia (progenitor cells), type B spermatogonia (progenitor cells)

Pale type a and type B spermatogonia are connected by intracellular bridges (cell junctions)

Question 8

Spermatidogenesis

Answer 8

The 1st meiotic division of the primary spermatocyte is followed by the 2nd meiotic division of the secondary spermatocytes that reduces the chromosome number and DNA content to haploid (rarely seen)

Question 9

Spermiogenesis

Answer 9

spermatids discard much of their cytoplasm, remodel organelles and form flagella to become transformed into spermatozoa

Acrosomal vescile derives from golgi apparatus (from trans golci- lysosomal fusion)
Acrosomal vesicle forms acrosomal head cap on one of the poles, centrioles from flagellum opposite head cap, coarse fibrils arrange around flagellum core, cutoplasm surrouds proximal portion of flagellum, excess cytoplasm phagocytized as residual bodies

Question 10

Mature spermatozoa (sperm cellS)

Answer 10

Head- contains the nucleus and the acrosome, tail (connecting piece connects the head with the tail, middle piece contains mito sheat, principle piece, end piece)

the release of the mature spermatozoa from the sertoli cell into the seminferous tubule lumen is called spermiation

Question 11

seminferous epithelium Sertoli cells

Answer 11

Somatic terminally differentiated cells, also called nurse cells, support protect and nourish germinal cells

Phagocytose cytoplasmic remnants of spermatids (residual bodies) express androgen binding proteins (ABPs), secrete hormones (inhibin and a nutritive medium

Form tight junctions (>50 sealing strands)–> B testes B, divides the germinal epithelium into the basal compartment (spermatogonia and adlumninal compartment (Spermatocytes, spermatids and spermatozoa)

Question 12

Tunica propria

Answer 12

Each seminferous tubule is surrounded by a thin layer of contractile myoid (peritubular) cells (3-5 layers) which produces waves of contraction to move immature spermatozoa out of the testes

Basement membrane separates seminferous epithelium from myoid cells

Question 13

Interstitial tissue aka Leydig cells

Answer 13

Comprises 25-30% of the testicular volume, leydig cells secrete testosterone (5-7 mls)
Crystals of reinke are also present although their function is unknown

Question 14

hormonal control of the testis

Answer 14

The hypothalamus releases gonadotropin releasing hormone which controls the release of Anterior pituitary hormones FSH and LH,

FSH indirectly stimulates spermatogenesis, and LH stimulates the interstial cells to produce testosterone

Testosterone triggers spermatogenesis

Testosterone inhibits hypothalamic release of GnRH and acts directly on the anterior pituitary gland and acts directy on the anterior pituitary gland to inhibit gonadotropin release

Inhibin is produced by sertoli cell released when sperm count is high

Question 15

intratesticular ducts

Answer 15

tubuli recti- the distal end of seminferous tubules that contain only sertoli cells, they empty into the rete testis

Rete testis- lined with cuboidal epithelium that is ciliated

Question 16

Extra testicular ducts

Answer 16

ductus efferentes, it is lined with cuboidal and columnar epithelial cells, non ciliated cells reabsorb testicular fluid whereas ciliated cells propel the immobile sperm to the ductus epididymis

a layer of smooth muscle surrouds the walls

Ductus epididymis- can be divided into head (caput), body (corpus), and tail (cauda)

It is lined with pseudostratified columnar epithelium that have sterocilia to facilitate the motility of the sperm by absorbing the fluid

Basal cells are believed to be undifferentiated precursors of the principal cells

Spermatozoa enter the caput epididymis, travel to the corpus epididymis and are stored in the cauda of the epidiymis

Question 17

ductus (vas) deferens

Answer 17

contains pseudostratified columnar epithelium, a prominent muscular layer surrounds the epithelium, the musclular layer contains inner and outer longitudinal muscle and middle circular muscle

A layer of connective tissue surrounds the muscular layer, during ejaculation the muscle propels the sperm forward

Question 18

accessory organs

Answer 18

ductus deeferens extends into the ampula which is lined with columnar epithelium that contains secretory granules and there is less smooth muscle within the wall, after recieving the duct of the seminal vesicle it is within the protstate gland and referred to as the ejaculatory duct which is lined with simple columnar epithelium and a thin smooth muscle coat

Question 19

Urethra

Answer 19

it contains a mucosa lined with epithelium, the prostatic urethra is lined with transitional epithelium, membranous urthra is lined with pseudostratified epithelium, penile urethra is lined with stratified/pseudostrafied epithelium

Question 20

Accessory glands

Answer 20

seminal vesicle, prostate and bulbourethral glands, produce seminal and lubricating fluids, all are exocrine glands, all empty into the male duct system, secretions enhance sperm transport and viability

Question 21

Seminal vesicle

Answer 21

Mucosa is highly folded lined with pseudostratified//simple epithelium surrounded by fibroelastic tissue and smooth muscle cells

Produces seminal fluid (70% of ejaculate)- fructose, semenogelin, prostaglandins, ascorbic acid

Question 22

Prostate

Answer 22

30-50 tubuloalveolar glands, double layer of cells: secretory and basal, subdivider into an anterior fibromuscular stroma, the transitional zone (surrounds the urethra, BPH due to hypertrophy of stroma and glands in this zone), the central zone (surrounds the ejaculatory duct) and the peripheral zone (main glands)

Produces- proteolytic enzymes, prostatic acid phosphatase, B-microseminoprotein, prostate specific antigen

Prostatic concentrations- precipitates of prostatic secretions abundant in ederly men

Question 23

prostate cancer

Answer 23

the most common cancer in men of all races and hispanic origin populations, Accounts for more than .5 mill cancer diagnoses in men,Af am men are at a highest risk for this tyme of cancer

Most prostate cancer arises from peripheral zne, second leading causes of cancer death among white black native, and hispanic men and fourth among asiaans

Question 24

Bulbourethral glands (cowpers glands)

Answer 24

simple columnar epithelium- capsule fibrous Ct, produces mucus containing sugar and glycosamino glycans to lube urethra

Question 25

Penis

Answer 25

3 cylindrical cavernous bodies corpora, a pair of corpora cavernosa, and the corpus spongiosum that surrounds the urethra, ending in the glans penis

Penile skin move freely over the underlying tissues due to the loose hypodermis
Tunica albuginea surrouds each of the corpora, the corpora contain irregular vascular spaces line by endothelium

Question 26

Erection

Answer 26

Erection of the penis follows parasympathetic stimulation, smooth muscle in the thick wall relaxes and the vascular spaces fill with blood

As the corpora distend they press against the inextensible tunica albuginea, compressing the veins so blood is less able to drain away
The corpus spongiosum has a more extensible tunica albuginea, and so becomes less distended avoiding compression of the penile urethra