Male Repro Anatomy Flashcards
(105 cards)
1
Q
where is spermatozoa produced?
A
Convoluted seminiferous tubules
2
Q
How does epididymis attach to the testis?
A
By peritoneal fold from the medial side of the epididymis
3
Q
What is attached to the head of epididymis?
A
The head of epididymis is connected to the cranial extremities of the testis by the efferent ductules passing through.
4
Q
What is the tail of epididymis attached to?
A
It is attached to the caudal extremities of testis by proper ligament of the testis (reinforced peritoneal fold)
5
Q
Where did the sperm store?
A
tail of epididymis
6
Q
Why is the ampulla slightly thickened?
A
It is due to the glandular tissue in wall
7
Q
What is gubernaculum?
A
- Embryonic fibrous mass, retroperitoneal, lies at right angles to the mesorchium and mesoductus.
- covered in peritoneum
8
Q
How did the gubernaculum develops?
A
- it grows and extend laterally and ventrally and runs around the abdominal wall, between parietal peritoneum and abdominal wall muscles
- it grows through inguinal canal, taking with it its own covering visceral peritoneum, together with the layer of parietal peritoneum that formerly covered the deep inguinal ring.
- The gubernaculum then swells to form a subcutaneous swelling (still covered by both visceral peritoneum and parietal peritoneum layer).
- subsequent shrinkage of the L and R gubernaculum leaves a pair of adjoining skin pouches lined with parietal peritoneum.
- externally the 2 skin pouches are confluent and constitute the scrotum while internally the 2 cavities remain distinct, each communicating with the abdominal cavity through the inguinal canal of that side.
(contains 2 peritoneal pouches, the 2 vaginal processes)
9
Q
What is the structural similarities of deep ingunial and superficial inguinal ring?
A
both are skeletal structures
10
Q
What does the testicular descent involve?
A
it involves the bending of male genital ducts , the testis moves tail-first down the path created by gubernaculum.
- still suspended by mesorchium and mesoductus containing vessels and nerves
11
Q
When will the testis pass through the inguinal canal and enter the scrotal cavity to replace the gubanuculum?
A
after birth
12
Q
what is covering the testis in the scrotum right after birth?
A
It is covered by a layer of visceral peritoneum, which is continuous by a fold of peritoneum (mesorchium, inside the parietal layer) with the peritoneal lining of the scrotal cavity.
*Same mesorchium suspending the testis continues through the inguinal canal
13
Q
What is vaginal tunic?
A
Vaginal tunic is the cavity between the visceral and parietal layer of the tunica vaginalis.
14
Q
Where is the fibrous remnant of the gubernaculum located?
A
at the distal extremity of the mesorchium
15
Q
What form the ligament of the tail of epididymis?
A
the remnant gubernaculum and its peritoneal covering
16
Q
What is the 4 layers of the wall of scrotum (from externally towards vaginal tunic)?
A
- Skin
- Tunica dartos (smooth muscle)
- Spermatic fascia
- Peritoneum (parietal layer of tunica vaginalis)
17
Q
Describe scrotal skin.
A
- thin
- pigmented
- well supplied with sebaceous glands
- has reduced hair coat
18
Q
Where is the external cremaster muscle located?
A
A slip from the internal abdominal oblique muscle passes through the inguinal canal superficial to the vaginal tunic, and inserts on the parietal layer of the vaginal tunic near the neck of the scrotum.
19
Q
What is the function of the external cremaster muscle?
A
Serves to raise the testis closer to the body wall in cool weather.
20
Q
Where is the proper ligament of testis located?
A
between the caudal extremities of testis and the tail of epididymis
21
Q
Where is the ligament of tail of epididymis located?
A
between the tail of epididymis and the spermatic fascia
22
Q
Where do the testicular veins drain to?
A
Caudal vena cava, renal vein
23
Q
What innervates the testis?
A
Sympathetic nervous system from the lumbar sympathetic trunk
24
Q
What is the interaction between the pampiniform plexus and artery?
A
The connection between them serves as a counter-current heat exchange mechanism to maintain testicular temperature a few degrees below core body temperature.
25
where does the spermatic cord terminate?
it terminates at the abdominal cavity at the vaginal ring
26
What will external cremaster muscle do in hot and cold weather respectively?
Hot weather: relaxes and testis drop further away from the body wall.
Cold weather: pull testis closer to the inguinal canal > draw the testis closer to body wall and warm it up
27
where does the mesorchium located?
within in the parietal layer of the vaginal process
28
What is the subdivisions of male urethra?
1. Preprostatic part
2. Prostatic part
- enclosed by prostate
- share the urinary and reproductive status
3. pelvic urethra
4. spongiosus urethra
29
Where does the prostate locate?
- lies at the caudal extremity of the vesicogenital pouch
- the dorsal surface of the prostate is eparated from the ventral surface of the genital fold and the 2 ductus deferentia by the fold of peritoneum that bounds the vesicogenital space.
- dorsal surface is flattened
- the ventral surface of prostate: retroperitoneal
30
How is the prostate gland divided?
The gland is divided into left and right lobes by a median septum, apparent externally by a dorsal sulcus
31
What is the consequences for prostatic enlargement?
- can constrict the urethra passing through it > reduce urination
- push dorsally and compress the rectum > causing obstipation
- restricting normal micturition
32
What kinds of erectile tissue rods does penis consist of?
Corpora cavernosa penis x2
Corpora spongiosum penis x2
33
What is the two separate structures in glans penis?
- pars longa glandis (rostral)
- pars bulbus glandis (caudal)
34
what is the difference between pars longa glandis and pars bulbus glandis?
Pars bulbus glandis is much larger at full erection.
Bulbus glandis is the more distensible part and forms a bulbous swelling that serves to lock the penis into vagina of bitch during copulation.
(The difference in diameter of the pars longa glandis and the pars bulbus glandis is relatively subtle in the non-erect state)
35
How is the pars longa glandis connect to the pars bulbus glandis?
The longa glandis is connected to the bulbus glandis by venous passage, the deep veins of the glans.
Pars longa glandis is partially overlapping the pars bulbus glandis.
36
What is external urethral ostium?
the termination of urethra
37
What direction does the external urethral ostium opens during erection?
Due to deformation of longa glandis during erection, external urethral ostrium in the erect penis opens craniodorsally, with urethra bending dorsally around the apex of the os penis.
38
What direction does the external urethral ostium opens in the non-erect penis?
it opens cranioventrally just caudal to the tip of the longa glandis in the non-erect penis.
39
What is the 4 muscles of penis?
1. bulbospongiosus
2. Ischiocavernosus
3. Ischiourethralis
4. Retractor penis
40
What is the function of bulbospongiosus?
Earlier in erection, compression of the bulb of penis pushes the blood in the bulb cranially into the corpus spongisum of the body of the penis
41
Where is ischiocavernsus muscle located?
it is a paired fusiform skeletal muscles enclosing the crura of penis, originating from each ischiatic tuberosityu, and terminating by inserting onto the corpora cavernosa as the 2 crura join to form the body.
42
What is the function of ischiocavernosa
contraction of ischiocavernosus muscles results in compression of the crura , forcing blood to enter the crura > assists in erection.
43
What type of muscle is ischiourethralis?
It is a small paired fusiform skeletal muscles, arising from ischiatic tuberosity to insert on a small median fibrous ring surrounding penile veins.
44
What is the function of ischiourethralis?
contraction of 2 muscles pulls on the side of the fibrous ring, compressing the penile veins, and assisting with erection by obstructing venous drainage from glans penis.
45
What is the function of retractor penis?
Contraction of retractor penis muscles draws the penis caudally following erection, and withdraws penis into the prepuce.
46
State the arterial blood supply of the penis.
Internal pudendal aa > Ventral perineal a
Internal pudendal aa > artery of penis > 1. artery of bulb of penis (corpus spongiosum) & 2. deep artery of penis (corpus cavernosum) & 3. dorsal artery of penis (bulbus glandis)
47
State the venous drainage system of the penis.
Superficial vv. of glans (pars longa glandis) > external pudendal vv.
Dorsal vv of penis (pars longa bulbus) > fuse in ischial arch and divide > Internal pudendal vv.
Ventral perineal vein > internal pudendal vein
Deep v. of the penis (corpus cavernosum) & vein of the bulb of penis (bulb of penis) > common trunk > dorsal vv. of the penis
48
Where is the deep vein of the glans runs located?
It runs between th pars longa glandis and pars bulbus glandis
49
Which part of the penis is filled with blood first during erection
1. Corpora cavernosa fill firse, largely through increased arterial flow via helicine arteries (first stage erection).
2. The bulbus glandis and longa glandis fill later, following intromission (second stage errection), mostly due to restricted drainage.
50
Why is the venous drainage restricted?
1. Partial occlusion of fused dorsal v. - tension of the fibrous ring due to the contraction of ischiolurethralis mm.
2. Partial occlusion of deep vv and vein of bulb of penis - contraction of ischiocavernosus and bulbospongiosus mm respectively > decrease drainage from corpus cavernosum and bulb of penis.
3. Partial occlusion of superficial vv of glans - by mm. constrictor vestibili of bitch, decreasing drainage from the pars longa glandis.
4. Passive occlusion of venous drainage by a lateral bend in the penis during "tying", subsequent to intromission.
51
2 parts of prepuce
external and internal laminae
52
Difference between external and internal laminae.
external laminae is hairy (continuous of abdominal wall) while internal laminae is not haired.
External laminae is continuous cranially with the internal lamina while the internal lamina is caudally continuous with the skin of glans at the fornix.
53
What are the stages of spermatogenesis?
Spermatogonia > Primary spermatocyte > Secondary spermatocyte > Spermatid > Spermatozoa
54
Describe the gross anatomy of testis.
Testicular parenchyma with the seminiferous tubules in ti, but that testicular parenchyma is given shape and structure into an ovoid shape testis by a fiber skeleton of the testis (external albuginea tunica, a central mediastinum with septula testis radiating out.
55
What is tunica albuginea covered by?
Tunica albuginea is covered by visceral peritoneum.
56
What is tunica albuginea composed of?
The tunica albuginea is composed of dense fibrous connective tissue with some elastic fibres.
It contains a number of arteries and veins (terminal branches of arteries and veins)
57
Definitions:
(i) Mediastinum
(ii) Septula testis
(iii) Testicular parenchyma
(iv) Rete testis
(i) Central connective tissue
(ii) Radiating out from mediastinum
(iii) Located between one septula and next septula
(iv) Irregular channels that are running through the mediastinum that will collect the sperm from the seminiferous tubules and will transport sperms towards the cranial end of the testis.
58
What type of epithelium does rete testis have?
simple epithelium (either cuboidal through through to columnar; sometimes down to squamous)
59
What does Interstitial tissue consist of?
1. various fibrocyte with flattened nucleus
2. mononuclear cells derived from the white blood cell line
3. Interstitial cells (cluster of cells) = Leydig cells
60
What is the function of leydig cells?
1. Cells of endocrine system
2. Producing testicular androgen e.g. testosterone
- Testosterone is produced by the interstitial cells within the parenchyma of the testis.
61
What is convoluted seminiferous tubule covered by?
It is externally covered by a basement membrane, a layer of thin peritubular contractile cell (thin dark staining layer)
62
What is the function of peritubular contractile cells?
Peritubular contractile cells contract at a peristaltic fascia (wave like fascia), they compressed the seminiferous tubule and transport the sperm along the convoluted seminiferous tubule into rete testis.
63
What type of epithelium does seminiferous tubule have?
Thick epithelium consists of 2 completely different cell lines which have different arrangement.
64
What cell types can be found in the cell linings of seminiferous tubules?
1. Sustentacular cells:
- tall columnar cells
- extend full thickness of the epithelium from basement membrane to lumen
- pale basal staining nucleus
- connect to the basement membrane via the hemidesmosomes
- with tight junctions between one sustentacular cells and the adjacent sustentacular cells
2. Spermatogenous cells:
- producing sperm
- lie between the sustentacular cells
- lie in the pocket in the luminal end of sustentacular cells
- life begin near basement membrane > proliferate > migrate up through zone of tight junction between one sustentacular cells and the next > spermatogenous cells end up lie in deep pocket within the apical end > develop into spermatozoa
65
What is the tight junction between sustentacular cells?
The tight junction is referred to the blood testis barrier, which:
(i) provide a barrier to the immune system from expose to those developing spermatic cells especially when they moved up to the apex which its function is different
(ii) provide a barrier to the immune system and physical and nutrition support to the spermatogenous cells
(iii) involve in the release of the spermatozoa into the lumen of the seminiferous tubule
(iv) secrete fluid that the sperm will initially be suspended within
(v) producing hormones and mediates other hormones
66
What is the three phase of spermatogenesis?
1. Spermatocytogenesis: from spermatogonia to primary spermatocytes by mitotic divisions
2. Meiosis: from primary spermatocytes to spermatids by meiotic division
3. Spermatogenesis: from spermatid to spermatozoa by cell maturation without division.
67
what is spermiation?
the release of spermatozoa from the epithelium into the lumen.
68
What is spermatogonia?
- round and flat cells located in the basal zone between sustentacular cells, and contact the basement membrane.
- each stem cells divides into 2 daughter cells, which themselves divide mitotically several times
- some of the daughter cells continue divide and mature as spermatogenic series while others remain dominant as new stem spermatogonia for future cycles.
- the terminal mitotic division of spermatogonia results in primary spermatocytes.
69
How does synchronised maturation happen?
all descendants of one proliferating spermatogonium remain connected by cytoplasmic bridges during maturation, resulting in synchronised maturation.
70
Describe primary spermatocytes.
- lose contact with the basment membrane, and migrate lumenally along the margins of the sustentacular cells.
- primary spermatocytes are large cells with large nuclei.
- At the completion of first mitotic division, each primary spermatocyte divided into 2 secondary spermatocytes.
71
List the stages of prophase.
Preleptotene > Leptotene > zygotene > pachytene (mostly observed) > diplotene > diakinese
72
Describe secondary spermatocytes.
- short lived
- smaller than primary spermatocytes but with complete chromosomes
- Secondary mitotic division is rapid
- they undergo second mitotic division and form two spermatids, each of which is haploid and has only a single set of chromatids.
73
Describe spermatids.
- do not further divide, but undergo cellular maturation
- spermatids are smaller than secondary spermatocytes.
- Spherical spermatids: initial spermatids which the cell and nucleus are round.
- then the nucleus becomes elongate > Elongated spermatids
74
Describe the 4 processes occur to change the spermatid into a spermatozoa
1. Condensation and inactivation of nuclear chromatin
2. Formation of a cap (acrosome) at one pole of the nucleus
3. Formation of flagellum at the opposite end of the cell
4. Expulsion of most of cytoplasm
75
What is spermatogenic waves?
Along the length of a seminiferous tubule, adjoining segments of epithelium will be slightly out phase with their neighbours, either one stage ahead or behind. Thus, it is possible to recognise spermatogenic waves along the length of a tubule.
76
What is the 4 sequential phases in the maturation of spermatids?
1. Golgi phase
2. Cap phase
3. Acrosomal phase
4. Maturation phase
77
Describe Golgi phase.
- involves spherical spermatids
- proacrosomal granules appear in vesicles of golgi complex (in cytoplasm). These fuse into a single acrosomal vesicle, which lies adjacent to a dimple in the nucleus.
- Proacrosomal granules > proacrosomal cap
78
Describe cap phase.
- involves spherical spermatids
- the acrosomal vesicle grows out to form a cap (acrosome) that covers more than half of nucleus.
- nucleus becomes eccentrically placed in the spermatid while centrioles polarise at the opposite end.
- the more distal centriole gives rise to the developing flagellum
- flagellum starts to grow in this phase
79
Describe acrosomal phase.
- more elongated spermatids
- cell body and nucleus elongate, and the spermatid rotates so that the flagellum faces the lumen, and the head faces the periphery of the seminiferous tubule.
- Nucleus condensed and DNA is inactivated
- whole cell rotates > elongated spermatids (head) become deeply embedded in apical recesses of the sustentacular cells.
- acrosomal continues to develop
- relatively flattened head
80
Describe maturation phase.
- nuclear condensation completed
- the flagellum matures
- mitochondria cluster around the base of the tail in a spiral arrangement
- intercellular bridges between spermatids of a single clonal generation are broken
- Excess cytoplasm forms a residual body and is detached > residual body is released.
- Finally spermatozoa are released into the lumen of the seminiferous tubule (spermiation)
81
What is the subdivisions of the tail in sperm?
neck, middle piece, principal piece and end piece.
82
Describe the head of the sperm.
- Consists of a dense flattened nucleus covered apically by an acrosomal cap
- The cap is flattened and hollow, it consists of outer and inner acrosomal membranes.
- The cavity of the acrosome contains enzyme
- Base of the head is covered by sulphated fibrous proteins (postacrosomal sheath)
83
Describe the neck of the sperm.
- small connecting segment between head and the tail
- consists of a central centriole and nine longitudinally oriented dense fibers
84
Describe the middle piece.
- not in the middle
- has a core (axoneme) with typical flagellar structure: 2 central microtubules + nine doublets of microtubules
- the axoneme is surrounded by the nine dense fibres continuing distally from the neck, and these are surrounded by the mitochondria, arranged spirally.
- the middle piece terminates distally with a thickened ring of plasmalemma.
85
Describe Principal piece
- consists of same axoneme and surrounding dense fibres but NO mitochondria
- surrounding this is the fibrous sheath of semicircular protein molecules spirally arranged, but attached at each end to a dense fibre
- longest portion of the tail
86
Describe end piece.
- Consists solely of the axoneme (no more dense fibres or fibrous sheath), gradually tapering firstly by reduction of peripheral doublets to singlets and then terminating.
87
What type of epithelium does efferent ductule have?
simple columnar epithelium (with ciliated and non-ciliated cell, with lymphocytes basally in the epithelium)
88
How does sperms be transported in the efferent ducts?
Sperm transport is via cilia. they are smaller in diameter than the epididymal duct (with thinner epithelium)
89
What is epididymal duct surrounded by?
Smooth muscle (transport sperm in the absence of cilia)
90
What does the mucosa layer of epididymal duct consists of?
1. pseudostratified columnar epithelium
2. principal cells (columnar)
3. basal cells
91
Is there any changes on the length of apical microvilli in principal cells?
long at the proximal end of the duct;
short at the distal part of the duct.
Because:
In the more proximal parts of epididymal duct (head and body), these cells reabsorb water and proteins from the rete testis fluid, and the spermatozoa mature by losing their small residual cytoplasmic droplet and becoming motile.
As a result of fluid absorption and hence sperm concentration along the length of the epididymal duct, the duct becomes gradually shorter (less fluid absorb).
Epididymal duct in the tail serves as a storage reservior for mature motile spermatozoa, and has much greater diameter than at the proximal end, but with a much lower epithelium with even shorter microvilli
92
Where is the sperm being activated?
In the tail of Epididymal duct (as they loose residual cytoplasm droplet)
93
What type of epithelium does ductus deferens have?
it consists of pseudostratified columnar epithelium
- gradual loss of microvilli from principal cells
94
What shape is the lumen of the ductus deferens in?
The lumen of the duct is usually compressed and stellate due to the longitudinal muscosal fold when not passing semen.
95
Describe the lamina propria of ductus deferens.
the lamina propria is very vascular, and is surrounded by a thick tunica muscularis, with inner circular (well-developed) and outer longitudinal fibres.
96
What is the function of ductus deferens?
rapid transport and expulsion of sperm from epididymis to urethra.
97
Describe ductus deferens in ampullary region.
The duct becomes more convoluted and the submucosa contains branched tubuloalveolar glands with mucosa of columnar to cuboidal epithelium. (these constitute the ampullary glands)
98
What does urethral walls consist of?
1. mucosa
2. submucosa
3. tunica muscularis
4. tunica adventitia
99
Why is the lumen of urethra compressed?
it is due to the longitudinal mucosal foldes
100
What types of epithelium can be found in the mucosa of urethra?
The mucosa is predominantly transitional epithelium (capable of great stretching), patches of simple to stratified cuboidal to columnar epithelium.
101
Describe the submucosa layer of urethra.
The submucosa is thick, with many smooth muscle cells and elastic fibres, and a variably expressed network of vascular channels capable to columnar epithelium.
102
Describe the tunica muscularis of the urethra.
The tunica muscularis consists of smooth muscle proximally and skeletal muscle distally in the pelvic urethra (muscle urethralis)
*No sphincters anywhere in the duct system of male genital system.
103
describe prostate histologically.
- contains many highly branched tubuloalveolar glands, opening independently into the prostatic part of the urethra.
- Secretory parts of the glands have simple cuboidal to columnar epithelium, wit secretory cells containing proteinaceous or mucus granules, and columnar cells with microvilli.
-Ducts have stratified columnar to transitional epithelium, and they may have irregular dilations for storage of secretions.
104
What is the arterial blood reaches the vascular space of corpus cavernosum called?
Coild helicine arteries
105
