Topic 2.2 (male anatomy) Flashcards
describe the location of the testes
descend ouside body into the scrotum
describe the tract of sperm in the testes
rete tubule -> effrent ducts -> caput (head) epidiymis -> corpus (body) epididymis ->cauda (tail) epididymis
what is the spermatic cord made from
arteries and veins, the testicular artery branches from the abdominal aorta, which is rather straight until it passes the inguinal canal, from there it becomes convoluted.
ductus defrons and surronded by the cremaster muscle
describe the pempinform plexus
highly convulated network of artiers and veins that cup the testes (spermatic cord). the unit to form a single vein that connects to the caudal vena cava.
describe the scrotum
dual lobbed sac supporting/ protecting testes. made from four layers: Skin tunica dartos, scrotal fascia and parietal vaginal tunic
list the four layers of the scrotum
skin, tunica dartos, scrotal fascia and parietal vaginal tunic.
what do the testes consist of (four things)
They consist of testicular capsules, parenchyma, mediastinum and rete tubules.
descibe the testicular capsule
suborgan that covers the testes (two layers: visceral vaginal tunic and tunica albuginea)
describe the parenchyma in the testes
Made from the seminiferous tubules, interstitial cells of Leydig, capillaries, lymphatic vessels, connective tissue. The parenchyma refers to the specific mass of glands, supported by connective tissue networks. Divided into the tubular (seminiferous tubules and all the material inside) and interstitial compartment (made from material outside the seminiferous tubules)
describe the tubulus contortus
a portion of the seminiferous tubule where spermatogenesis predominantly takes place. It is composed of a basement membrane and a layer of seminiferous epithelium. And surrounded by contractile peritubular cells.
descrbe the excurrent duct
The excurrent duct is made from the efferent duct, epididymal duct, and ductus deferens.
describe the epididymak duct
Epididymal duct is 30 - 60 meters and surrounded by smooth muscle which pumps the sperm along the duct. In the tail of the duct the smooth muscle is inactive during sexual excitation.
In the head of the epididymis head the sperm encounters a cytoplasmic droplet (proximal cytoplasmic droplet). The sperm then moves to the middle of the epididymis which it then encounters the translocating cytoplasmic droplet. Then once it reaches the tail it reaches the distal cytoplasmic droplet.
Describe the ampullae
The ampullae are enlargement of the ductus deferens that link to the pelvic urethra, the expansion is to accommodate for the mucosa added.
Descibe the Vesicular glands
Vesicular glands are paired and sit dorso-cranial to the pelvic urethra.
Describe the prostate gland
Prostate gland is close to the junction between the bladder and pelvic urethra. It has two structural forms which depend on the age of the creature. Firstly the corpus prostate which is when it lies outside the urethralis muscle and is visible in a heart (boar) / H (stallion) shape. The other is the disseminate prostate in which granular tissue spreads along the dorsal and lateral walls of the pelvic urethra.
describe the bulbourethral gland
The bulbourethral gland is a paired organ on either side of the pelvic urethra near the ischial arch, they are very small and dense.
they fill with blood at time of erection
describe the penis
Penis is made from three segments, the base which is attached to the ischial arch, shaft (main portion) and the glans penis, which is the end.
describe the Glans penis
Glans penis holds many nerves on the tip and is the homologue of the clitorus fossa.
describe the tip of the penis
tip of the peins has a spongy rectile tissue called the corpus cavernosum, this makes up most of the penis interior, ventral of this surrounding the penile urethra is the corpus spongiosum(also spongy erectile tissue)
describe the ischiocavernosus muscles
in the root of the penis connecting the penis to the ischial arch, it causes erections.
deescribe other muscles associated with the penis
Urethralis (striated surrounding pelvic urethra, it moves the seminal fluid and sperm)
Bulbospongiosus (overlaps the root of the penis and ventral/caudal surfaces, it empties the extrapelvic part of the urethra)
Ischiocavernosus,
Retractor penis.
function of the spermatic cord
Provide vascular, lymphatic and neural connection to the body. Provide a heat exchanger and house the cremaster muscle. The pampiniform plexus (vascular bundle that cups the testis) keeps it around 4 -6 degrees for spermatogenesis to occur, this is achieved via a countercurrent exchange
function of the scrotum
Scrotal skin is a temperature sensor and cooling system.
function of scrotal skin
Lots of sweat glands to maintain temperature, innervated with sympathetic nerves, it connects to the hypothalamus which adjusts secretion. (evaporative cooling aka swamp cooler)
function of the tunica dartos
Ability to elevate testes for long periods of time. This smooth muscle lies below the scrotal skin and adjusts contraction to suit the skin temperature. (testes held close to the body during cold temperatures) androgen controls the development of these muscles.
function of the testes
The tests are paired primary reproductive organs, they produce spermatozoa and androgen testosterone (as well as inhibin, estrogens, and proteins for spermatozoal function. They produce fluid originating from the seminiferous tubules. This fluid suspends the spermatozoa and facilitates their ejection from the testes. The fluid contains sertoli cells.
function of the testicular capsule
This undergoes change in response to hormones and neurons. As well has smooth muscle that pumps rhythmically, thought to help move the sperm.
function of the mediastinum
Central connective tissue in the core of the testis, it houses ducts called the rete tubules. Dense connective tissue helps prevent compression or collapse of the rete tubules.
function of Interstitial cells of Leydig
Produces testosterone in the parenchyma.
function of the rete tubule
channels of which sperm is transported out of the testes
function of tubule contortus
portion of the seminiferous tubules where spermatogenesis takes place
function of Sertoli cells
Anchored to the basement membrane they surround developing germ cells. Nurture developing sperm, each sertoli cell has a maximum amount of sperm it can nurture.the are susceptible to FSH and testosterone. They can produce Androgen binding protein, testosterone transport protein, sulfates glycoproteins, transferrin.
function of peritubular cells
able to contract they surrond the tubule contortus they aid in the secretion of sertoli cells which helps new sperm move to the rete tubules.
Cremaster muscle
Supports the testes and follows the length of the spermatic cord. Aid in controlling testicular temperature, by contracting (promote venous return) /relaxing to produce a pump action, increasing blood flow.
function of Epididymis
Produces seminal plasma
Blood testis barrier function?
Prevent the auto immune system from destroying the developing germ cells. It is made from two layers, a seminiferous tubule and the sertoli cell junctional complex. The junction complex (tight junction) serves as a second barrier against immune cells and immunoglobulins.
what are the two segment of the blood testis barrier
seminiferous tubule and the sertoli cell junctional complex.
function of the excurrent duct
Allows for final maturation, storage and delivery. Ejactulation is from a combined effort from the epididymis and the ductus deferens. Rete fluid is thinned in the epididymis and thus the head there is less sperm then in the tail, where it is most concentrated.
funtionc of seminal plasma
Not crucial for fertility but for delivery in the uterus.
function of accessory sex gland
Produces seminal plasma, secreted into the pelvic urethra.
function of the vesicular gland
stores and secrete similar fluid into the pelvic urethra
function of the bulbourethral glands
Produce viscous secretions that are the gel-like fraction of the ejaculate, it also causes the seminal fluid to coagulate once ejaculated.
function of the penis?
copulatory organ which is made from three parts, bas, shaft and glans penis
function of the glans penis
filled with nerves and the point of ejaculation
what is unique about animal which have retractible penis?
Animals whose testes are located inside the body do not have a scrotum.
why might marien animal not need to worry about tempreture regulation of the testes
Some mariene animals have testes inside the body
describe the uniques mechanisms of animals with a fibroelatic penis
Species which have a fibroelastic penis have a sigmoid flexure, which is an S shaped configuration along the shaft. This allows it to be retracted into the body until erect. It is maintained by the retractor penis muscles which are attached dorsally to the coccygeal vertebrae and attached ventrally to the ventrolateral side of the penis. Contracted = inside. Relaxed = outside
how dose scrotum tempreture effect industry
Scrotum temperature affects the sperm’s motility, affecting reproductive rates. this can be used to manipulat animals fertiliy, especially artifical insemination.
what is the pampiniform plexus
serves as a pulse pressure eliminator, the pressure is eliminated between the inguinal ring and the surface of the testis so the blood entering has little to no pressure.
leydigs have receptors for what hormone
LH, this stimulates testosterone production
