Male Anatomy Flashcards
What is the spermatic cord and what is the purpose?
connects testis to body, suspends testis in scrotum
What is the scrotum and the function?
Scrotum is the skin surrounding testis, purpose is to surround/support/ protect and thermoregulate
What are the 4 major components of the scrotum?
epidermis, tunica dartos, scrotal fascia, parietal tunica vaginalis
What are the 2 parts of the scrotum that play a role in testis thermoregulation?
epidermis: allows for evaporate heat cooling
tunica dartos: smooth muscle, that draws testes close to abdomen or relaxes “pushes”
cremaster muscle: pulls closer for short term heat conservation
name the layers consisting the testicular capsule, starting from the inner most compartment outward
tunica albuginea, visceral vaginal tunica, vaginal cavity, parietal tunica vaginalis, scrotal fascia, tunica dartos, scrotal skin
explain the process of thermoregulation by scrotum
- uses evaporative heat transfer/ sweating (regulates scrotal sweating)
- thermo sensor via sympathetic nerves in the skin (regulates respiratory rate)
when the male has an increase in scrotum/body temp, there will be a increase in RR, due to the neural pathway starting in the scrotum and terminating in brain.
Why is thermoregulation important for the testes?
Cooling of testes is vital for spermatogenesis, although constant cooling is not necessary. This reflex pathway that results in panting/sweating is not activated until the scrotum temp reaches about 39 C.
DNA in sperm is damaged by heat and that eggs fertilized by these sperms have a low probability of surviving.
What is another way of testicular cooling involving the spermatic cord?
pampiniform plexus and counter current heat exchange
efficient testicular cooling requires scrotal cooling occurs so venous blood in testicle can be cooled. only after the venous blood is cooled can the vascular countercurrent heat exchange function properly.
Describe the counter current heat exchange process
the pampiniform plexus is a venous network that eventually forms a single vein that drains into the caudal vena cava.
the relationship w/ the testicular artery and plexus (finger- like wrappings wrapping around artery) allows close proximity for heat exchange
39 C-34 C, drop in temperature because the blood temp needs to be lower for sperm. Blood is reheated through process, re- entering the body
What is the primary reproductive organ in males and what are the major functions?
testis, main function: spermatozoa, hormones/protein, fluids
What is the fluid that contains products synthesized by Sertoli cells?
rete fluid
What are the 4 major components of the testes?
testicular capsule, parenchyma, mediastinum, seminiferous tubules
What makes up the testicular capsule and what is the purpose of these structures?
- Visceral tunica vaginalis: connective tissue
- Tunica albuginea: dense white connective tissue. Encloses testis and sends finger like projections into the parenchyma
What is the parenchyma, where is it found and what does it make?
parenchyma is found in the testis, it is the major cellular mass of the testis, spermiogenesis and hormones are take place/made here.
What makes up the parenchyma and how are they separated?
TUBULAR COMPONENT
1. seminiferous tubules: sperm is made
2. interstitial cells of Leydig
INTERSITIAL COMPONENT
1. blood vessels
2. lymphatic vessels
3. connective tissue
What is the blood teste barrier and what is the importance? Name the cell and junction that is important.
prevents immunologic destruction of developing germ cells
- the tight junctions between Sertoli cells serve as the second barrier against immune cells and immunoglobins
-peritubular cells surrounding the seminiferous tubule and Sertoli cell complexes the barrier
What is the mediastinum and what is the importance?
the central connective tissue core of the testis
- dense connective tissue of the mediastinum helps prevent compression of the rete tubules
-spermatozoa and fluid from seminiferous tubules moves freely from the testis
What is the order of layers within the testes?
Parenchyma to tubular compartment to seminiferous tubules
What is the tubular component, importance and compartments?
seminiferous tubules, end joins rete tubules (tiny channels through which spermatozoa are transported from the testis)
- tubular compartments consists of
1. seminiferous epithelium
2. Sertoli cells
3. developing germ and peritubular cells
Describe the loops of the seminiferous tubules and where does spermatogenesis takes place?
each loop of the semini. tubule is comprised of a convoluted portion (tubulus contortus) and a straight portion (rectus)
- spermatogenesis takes place mainly in the tubulus contortus
what type of cells maintain the blood teste barrier?
peritubular cells
Describe the seminiferous epithelium/ germinal epithelium (found in the seminiferous tubules)
tubule is surrounded by contractile peritubular cells
- contraction/ flow of fluid secreted by Sertoli cells allows newly formed spermatozoa to move into rete tubules
What are the major compartments of the seminiferous epithelium?
- basal compartment
2.adluminal compartment
What are Sertoli cells?
“nurse cells”, attached to the basement membrane by tight junctions
What is the cremaster muscle and the function? Difference from the tunica dartos?
short-term muscle contraction, pumping action for blood flow (involuntary muscle)
-cremaster “pulls” in spermatic cord
-tunica dartos “pushes” in scrotum
What are the Sertoli cell functions (part 1)?
- provide Sertoli-cell barrier to chemicals in the plasma
- nourish developing sperm “nurse cells”
3.secrete luminal fluid, including androgen-binding protein - receive stimulation by testosterone (made by Leydig cells) and FSH to secrete paracrine agents that stimulate sperm proliferation/ differentiation
What are the function of Sertoli cell (part 2) ?
- secrete protein hormone inhibin, which inhibits FSH secretion
2.secretes paracrine agents that influence function of Leydig cells - phagocytize defective sperm
- during embryonic life, secrete MIS
What is the spermatic cord?
suspends the testis in the scrotum
provides vascular, lymphatic and neural connection to the body
provides a heat exchanger
T/F: The tuncia dartos muscle pushes the testis away from the body for a short period of time, while the cremaster muscle pulls the testes closer for an extended period of time.
false, the tunica dartos does push but it does this for a prolonged period of time. while the cremaster muscle pulls the testes closer for only a short period of time.
Thermoregulation is essential for spermatozoa to develop in the testes. What is the network of blood vessels and artery called that are responsible for decreasing body temperature in the testes?
pampiniform plexus
what are the two main components that help maintain the blood testis barrier?
tight junctions between Sertoli cells and peritubular cells
What components make up the seminiferous tubule/tubular component of the testes?
peritubular cells, seminiferous epithelium, basement membrane
T/F: Immature “sperm” can be found in basal compartment of the seminiferous tubules.
True: The seminiferous tubules of the testes are the starting point for the process, where spermatogonial stem cells adjacent to the inner tubule wall divide in a centripetal direction—beginning at the walls and proceeding into the innermost part, or lumen—to produce immature sperm. Maturation occurs in the epididymis.
What accessory sex gland provides the gel fraction with the boar’s ejaculate?
Bulbourethral gland
T/F: The retractor muscle is important for extending the penis and is found in the stallion.
true
match the pharm. drug with the correct hormonal analog.
follitropin-
cystorelin-
factrel-
ECP-
- FSH
- GnRH
- GnRH
- Estradiol
What does the spermatic cord house?
cremaster muscle, vas deferns, pampiniform plexus
What is the pampiniform plexus?
venous network, countercurrent heat exchanger (drops about 6 degrees before entering the testicle.
How does countercurrent heat exchange work?
relationship w/testicular artery and pampiniform plexus (finger-like wrappings. plexus surrounds the artery) which provides the heat exchange
What is the excurrent duct system/consists of?
Consists of efferent ducts, epididymal duct, ductus deferens
- allows for final maturation, storage and delivery of spermatozoa to pelvic urethra
Describe the network of tubules
spermatozoa passes from seminiferous tubules through rete tubules-to efferent ducts-single duct/ epididymis
What is the epididymis and its function/ how it helps move sperm?
a single convoluted duct, provides environment for a final maturation of spermatozoa, storage reservoir for spermatozoa.
surrounded by smooth muscle that aid in moving sperm along duct from peristaltic contractions
What are the three parts of the epididymis and their purpose? Describe the sperm in this region?
Head(caput)
-reabsorbs rete fluid, secretes fluid into the lumen of epididymal duct
-sperm is not motile, not fertile, contains a cytoplasmic droplet (low disulfide crosslinking)
Body(corpus)
-parallel to vas deferens, concentrations of sperm throughout the body are relatively constant
-some motility/character (can bind to oocytes)
Tail (cauda)
-sperm are ejacualted from here, moves through the ductus deferens,
-sperm has full motility, fertile potential, bind to oocytes
high degree of disulfide crossing
What is the main passage for spermatozoa?
vas deferens
What is seminal plasma produced by?
epididymis, ampulla, vesicular glands, prostate gland, bulbourethral glands
what species does not have a conscious ampullae?
boar
What species has only one accessory gland?
Dog
what species have a paired bulb. gland?
ram, bull, stallion
What species has a large/dense bulb gland?
boar
what species has a fibroelastic and cork screw shape penis
boar
what species has a fibro elastic penis?
bull, ram,boar
what is the name of the “s” shape that allows the penis to be retracted inside the body and what maintains it?
retractor penis muscle
