Exam 1 Lecture Notes Flashcards
seminiferous tubules function
sperm production
rete testis function
network of collecting tubules
efferent ducts function
fluid absorption
epididymis function
transport, concentration, maturation, storage of sperm
vas deferens function
transport of sperm into the body
sperm in the epididymis head vs the tail
in the head the sperm are immature and less concentrated, in the tail the sperm are mature and stored there so they are more concentrated
explain the tubular system of the testis
sperm is made in the seminiferous tubules, the sperm then moves into the collecting tubules called the rate testis, sperm is them moved into the efferent tubules where fluid absorption occurs, then it moves into the head of the epididymis (sperm is not yet matured), then into the body of the epididymis (sperm begins to mature), and finally into the tail of the epididymis where the sperm is matured and stored, when ready to leave the body sperm is moved from the tail of the epididymis into the vas deference where the sperm can be transported to the body
what does the histology of the epididymis look like?
the epididymis is one tube that is highly convoluted so when a cross section is made there are many little circles
histology of the head of the epididymis vs the tail of the epididymis
- head = more white (more of the lumen) because there is a lower concentration of sperm
- tail = more purple (less lumen) because there is a higher concentration of sperm
sperm characteristics at the head of the epididymis
- not motile
- not fetile
- cytoplasmic droplet (attached to the head)
sperm characteristics at the body of the epididymis
- some motility
- some fertility
- movement of cytoplasmic droplet (on tail)
sperm characteristics at the tail of the epididymis
- normal motility
- fertile potential
- distal droplet (will eventually disappear)
- 7-8 times more concentrated
caput
head of the epididymis
corpus
body of the epididymis
cauda
tail of the epididymis
what affects sperm production?
- size of the testes
- size of the tail of the epididymis
- cryptorchidism
- effect of ejaculation on sperm production
false mounting
allowing the male to mount but moving him off before ejaculation to increase the amount of sperm concentration because it allows for multiple emissions
emission
movement of sperm from tail of the epididymis to the vas deference
structures in the spermatic cord
- paminiform plexus
- testicular artery
- ductus deference
- cremaster muscle
somatic cord functions
- provide nerves, blood vessels and lymphatic vessels of the testes
- contain pampiniform plexus
- contains cremaster muscle
- contains ductus deference
semen
sperm and seminal fluid
accessory glands
- vesicular / seminal glands
- prostate gland
- bulbourethral gland
functions of accessory gland fluid
- volume
- nutrients
- buffer
- decapacitation (ensure sperm doesn’t activate immediately)
structures in the penis
- erection canals
- helicine arteries
- corpus spongiosum penis
- corpus caverosum penis
helicine arteries
vasodilate when stimulated by nitric oxide
nitric oxide is turned on by ___________
cGMP
(when GTP is converted to cGMP by guanylate cyclase)
nitric oxide is turned off by ___________
phosphodiesterase
viagra blocks _____________________
phosphodiesterase
why would you give oxytocin to a boar during mating?
to help with ejaculation, oxytocin is needed to have a sudden and powerful contraction of the urethralis, bulbospongiosus, and ischiocaverosus muscles to have an expulsion of semen
ischiocaverosus muscle function
contracts to smash the vessel stopping venous return and keep the penis erect
bulbospongiosus muscle function
assists in ejaculation (explosion of semen)
glans penis
the tip of the penis, looks different in different species
frenulum
a membrane that hold the glans penis back at birth and should sever as the animal grows (bulls and rams)
persistent frenulum
the frenulum does not sever so it must be done surgically
boar glans penis
corkscrew shape to lock into the cervix
stallion glan penis
it will expand so that it can expand the cervix (mare cervix is soft) and deposit sperm directly into the uterus
erection
- vasodilation of the arteries
- ischovernosus muscle contracts to block venous return, compression forces blood into the erection canals to fill the corpus caverosum
- decrease in venous return, increase in blood flow
- retractor penis muscles relax and sigmoid flexure straightens
emission (more detail)
oxytocin stimulates contractions in the tail of the epididymis and vas deference to move sperm into the pelvic urethra in from of the collicus seminalis (mis fluid and sperm)
ejaculation
- contraction of urethras muscle moves sperm to root of penis
- contraction of bulbospngious muscle sends pulse down corpus sponsiosum to move sperm out
after ejaculation
ischiovermosus muscle strops contracting so venous return resumes, blood pressure in corpus cavernous and retractor penis muscles contract to form the sigmoid flexure
3 main parts of sperm
- head
- midpiece
- tail
functions of the 2 centrioles in sperm
one forms the tail, the other is in the midpiece
where is mitochondria located in the sperm
midpiece
acrosome
- contains enzymes to attach and blow open for fertilization
- stains bright green
head of sperm - structure
- apical ridge
- acrosome
- equatorial segment
- post acrosomal region
- inner and outer acrosomal segment
- implantation socket
- nucleus
acrosome
attaches to the egg and will eventually blow the cap off to release the enzymes from the Golgi
