Scrotum Flashcards
How many sacs in the testes
2 lobed sac
Explain the layers of the scrotum
The scrotum has 2 main layers
Skin + Tunic dartos (dartos m)
The tunica dartos = external spermatic fascia Cremasteric fascia ( cremaster m) Internal spermatic fascia Tunica vaginalis
explain which layer are around both testis and layers around one
The tunic dartos separates the two testis
Explain the scrotal skin
Usually thin
Maybe hairy
XX- contains thermosensitive nerves and sweat glands
Explain the tunica dartos
Tunica darto = dartos muscle smooth muscle layer close to scrotal skin Fx = testis regulation Forms the septum between testes Able to maintain prolonged contraction Can raise testes close to body Contraction = scrotal skin wrinkle Relation = scortal skin increase in surface area
External scrotal fascia
Loose connective tissue directly under the tunica dartos
Cremasteric fascia
Continuous from the spermatic cord
Internal scrotal fascia
Loose connective tissue directly under the cremasteric fascia
Scrotum vascualture
By internal and external iliac arteries and veins
Internal iliac—> internal pudendal —> posterior scrotal
External iliac —> external pudendal —> anterior scrotal
Relation between scrotum and testis blood supplies
They are different and distinct, not continuous of each other
List the nerves of the scrotum
Genitofemoral
Pudenal
Ilioinguinal
Genitofemoral nerve innervates?
(Genital branch) Innervates cranial scrotum and cremaster m
Puedendal (perineal branch)
Innervates caudal scrotum
Ilioinguinal
Innervates dorsal scrotum
Explain how temperature of the testes is controlled through the actions of bloody supply, musculature and general thermoregulatory responses
Moderate high temp affect on sperm
Sperm mobility decrease
Morphology becomes abnormal
Sperm DNA may be damaged
Extremely high temp
All sperm production stops
List the 3 Testis temperature control mechanisms
Vasculature
Musculature
General thermoregulatory responses
Vasculature temp control for scrotum
- Counter current between testicular artery and pampiniform plexus
- Testicular artery is highly coiled an superficial on the ventral part of the testis = radiant heat loss
How does counter-current heat exchange
Passive heat transfer from arteries to veins
Warm arterial blood to cool veins
Cremaster muscle helps by promoting venous return = enhancing cooling
Dartos muscle role in thermoregulation
Scrotal nerves detect temp
—> contration influences SA for radiant and evaporative heat loss
Also able to lower and raise the testes
Explain the general thermoregulation for scrotum
Sweating - localised to scrotum
Panting - (polypnea) - these response decrease temp via evaporative heat loss
