Testis,epididymis, spermatic cord Flashcards
what is the tunica albuginea, and what does it do?
- fibrous tissue which encapsulate the testicular parenchyma
- it penetrates the testis to form an incomplete septum called Mediastenum testis
what is the mediastinum testis?
an incomplete fibrous septa which forms the SEPTULA TESTIS
what does the septula testis do?
radiates into the tunica albuginea, forming lobules called TESTICULAR LOBULES
what does a testicular lobule contain?
contains the convuluted seminiferous tubules which run towards the mediastinum
what is the tubuli recti
straight ducts which are the continuation of the convuluted seminiferous tubules at the apex of the of the testicular lobule
what happens to the tubuli recti once entering the fibrous mediastinum?
the converge and anastomose and are now called rete testis
what lines the seminiferous tubules lined with
semineferous epithelium, and is supported by spermatogenic and non spermatogenic supporting cells
where are the leydig cell? and what is there function?
located between the semineferous tubules and they are androgen secreting cells (secrete testosterone)
what is the tunica vasculosa?
it is a loose delicate connective tissue which covers the testicular lobule
what is the lamina propria composed of?
of flat myoid cells or peritubular contractile cells
semineferous epithelium has two categories
spermatogonia, and sertolie cells
what are spermatogonia and what types are there?
- diploid cells, that sit on the basal compartment of the seminiferous tubules
- there are type A, and type B
- Type A is sub organised to DARK type A, and PALE type A
what does testosterone induce?
induces derivatives of PALE type A spermatogonia to proliferate producing type B spermatogonia
characteristic of type B spermatogonia
pale, spherical, contains a lot of chromatin, and under go MITOTIC division to produce PRIMARY SPERMATOCYTES
what happens to PRIMARY SPERMATOCYTES? and how many chromatids does it contain?
- once produced they migrate from the basal compartment into the broader adluminal compartment, they exchange genetic material (crossing over)
- under go 1st MEIOTIC DIVISION to produce secondary spermatocytes
- contains 4 chromatids (4n)
what happens to Secondary spermatocytes?
(2n DNA), 23 chromosomes; undergo a second meiotic division to SPERMATIDS / SPERMATOZOA,
what is the size of spermatids? and what do they undergo? how much DNA do they contain?
- 8 micrometers
- they undergo spermiogeneisis (maturation process) where they turn to flagellated sperm
what are sertoli cells? and what do they contain? and what do they line?
- non germinal, tall coloumnar, 1-2 nuclei
- contain cytoplasmic process and invagination on their sides and apical parts
- they line the tubuli recti
what do is the function of the cytoplasmic process of the sertoli cells?
- function to bind nerighbouring sertoli cells which seperates the basal compartment from the luminal compartment creating a BLOOD TESTIS BARRIER
where is the intertubular space? and what is it occupied by?
- between the semineferous tubules,
- occupied by fibroblast, mast cells, macrophages and leydig cells
charecteristics of the leydig cells? and where are they absent in?
- produce testosterone
- polyhedral shaped contain 1-2 nuclei, acidophilic cytoplasm
- absent in the mediastinum
charecteristic of the upper pole of the mediastinum
-the rete testis extend 10 - 20 efferent tubules (ductuli efferent), which perforate the tunica albuginea to each the epididymis
what do the efferent ductule perforate
tunica albuginea and enter the head of the epididymis in which are continued firstly as straight tubules
where does the duct of the epididymis lie? and what is it surrounded by? and what does it include?
- lies in the scrotum along the superior and posterior sides of the testis
- surrounded by connective tissue
- includes a head region where the efferent ductules enter, a body and a tail which opens into the ductus deferens
the efferent ductules enter the head of the epididymis which continue as straight tubules then what happens after?
they become highly convuluted and form conical lobules of the epididymis and open into a single convoluted tubule the DUCTUS EPIDIDYMIS
what is the efferent ductules lined by?
ciliated tall columnar epithelium
what absorbs the fluid secreted by the semineferous tubules?
shorter non ciliated cells among the columnar cells of the efferent ductules
what are PRINCIPLE CELLS and where are they found?
tall coloumnar cells which are a part of the columnar cells that line the ductus epididymis
where are basal cells (stem cells) located
located as a part of the epithelium lining the ductus epididymis, they are the short coloumnar cells which rest on the basal membrane
what extends from the apical surface of the principal cells?
extremely long microvilli called streocilia, and they extend into the lumen.
how is smooth muscle arranged around the epididymis
- head = circularly arranged smooth muscle cells form a thin coat
- tail = muscle coat thickens, displaying inner and outer longitudinal and intermediate circular layers of smooth muscle cells
what is the processus vaginalis? and what does it do ?
- visceral layer of the peritoneal
- covers the right upper surface of the section of the head
how is the coils of efferent ductules and epidiymal duct held together?
by vascular connective tissue
where does the spermatic cord extend to?
from the deep inguinal ring through the superficial inguinal ring to the upper posterior part of the testis
what are the three coverings of the spermatic cord? and where do they originate from?
- external spermatic fascia
- cremasteric fascia
- internal spermatic fascia
- ** originate from the layers of the abdominal wall
what is the external spermatic fascia?
thin fibrous layer originating from the crura of the superficial inguinal ring formed by the aponeurosis of the obliqus externus abdominis
what is the cremasteric fascia?
consists of loops of skeletal muscle, constituting the cremaster muscle.
what is the internal spermatic fascia?
originates from the transversalis fascia
what does the spermatic cord consist of?
- defernt duct
- arteries(testicular,deferential,cremasteric)
- veins(pampiniform plexus)
- lymphatic vessels and nerves,
- testicular sympathetic plexus
what forms a sac like extension around the spermatic cord?
muscle invested by look areolar connective tissue from the cremasteric fascia
information about the ductus deferns
has an extremely thick wall composed of inner mucosal layer and an outer muscular layer surrounded by loose connective tissue
the mucosa of the ductus deferns
forms longitudinal folds whose epithelial lining is simple coloumnar or pseudostratified columnar
cells that are devoid of microvilli show typical signs of?
apocrine secretion
the muscularis externa
extremely thick composed of inner and outer longitudinal layer and an intermediate circular layer of smooth muscle cells
what is the lagest caliber arterty in the spermatic cord?
testicular artery
how do the testicular veins work
they leave the testis, collect the venous blood from the epidiymis and then form a venous plexus around the testicular artery.
what is the largest components of the spermatic cord, and lie anterior to the deferent duct?
- the pampiniform plexus
- the testicular artery
what structures do the veins of the spermatic cord display?
inner longitudinal and outer circular smooth muscle layers in their tunica media
what is PROCESSUS VAGINALIS TESTIS
a cavity can be located between the cremaster muscle and the ductus deferns
