exam 3 Flashcards
where does capacitation occur?
oviduct
which type of sperm loss is when leukocytes attack sperm cells?
phagocytosis
what type of sperm loss is when sperm flows back out the vagina?
retrograde loss
what species is not a short copulator?
stallion
what species is an intermediate copulator?
stallion
which species is a sustained copulator?
boar
when do females exhibit reproductive behavior?
limited to estrus
when do males exhibit repro behavior?
anytime after puberty
what is the most effective way to manipulate male repro behavior?
new female and new environment
do sperm have catabolic (break down) or anabolic (re-build) metabolism?
catabolic
T/F: males have memory when it comes to copulation
true
what receptors do leydig cells have?
LH
what receptors do sertoli cells have?
FSH and T
which phase of spermatogenesis does not have cell division?
differentiation
what process occurs in the basal department of the seminiferous tubules?
mitosis
what process occurs in the adluminal department of the seminiferous tubules?
meiosis
what process occurs in the luminal department of the seminiferous tubules?
spermiation
which phase of differentiation is when the golgi apparatus takes proteins and creates vesicles?
golgi phase
which phase of differentiation is when granules form across al vesicles flatten and make a “cap” over the nucleus of sperm?
cap phase
which phase of differentiation is when the sperm head takes shape and the nucleus begins to elongate?
acrosomal phase
which phase of differentiation is when the entire spermatazoon is covered in the plasma membrane and excess cytoplasm turns into the cytoplasmic droplet?
maturation phase
where are leydig cells located in the seminiferous tubules?
interstitial space
where are sertoli cells located in the seminiferous tubules?
tubular compartment
Thermoregulation is key for successful spermatogenesis, if the temp of the testes becomes too hot or too cold, the spermatazoa lose the ability to fertilize an oocyte. Explain all of the methods used to maintain proper temp (include temp that the testes need to be).
Spermatogenesis = development of male gamete. Provide a detailed description of each developmental stage and where they would be located in the seminiferous tubule.
- proliferation phase: type a spermatogonia develop into intermediate spermatogonia, and those develop into type b spermatogonia; spermatocytogenesis/mitosis is happening; up to 75% apoptosis
- meiosis phase:
- meiosis I: increasing genetic diversity via DNA replication and crossover
- meiosis II: produces 1N spermatids (haploid)
- differentiation phase: changing shape of spermatid to spermatozoa; no cell divisions; morphological change; 4 subphases
- golgi phase: acrosomic vesicle forms around head of sperm
- cap phase: acrosomic vesicle spreads over nucleus
- acrosomal phase: elongation of head (circle to almond shape)
- maturation phase: final assembly; entire spermatozoon is covered with plasma membrane; mitochondria spiral around the tail; proximal droplet will translocate down the tail to a distal droplet
The primary purpose of mating behavior is copulation, thus bringing male and female gametes together to ensure propagation of the species. Does the male/female initiate courtship-specific behaviors? why?
females because they are confined to estrus and will only show reproductive behavior during that time
Once spermatazoa undergo capacitation and reach maximum fertility, the next step in fertilization is the acrosome reaction. Know all the steps of fertilization after the acrosome reaction.
- cortical reaction: cortical granules exocytose to stimulate Zona and vitalline block (prevents polyspermy)
- sperm nucleus de condenses
- fertilization stimulates ooctye to enter meiosis II to reach final haploid state
- male and female pronucleus = syngamy
why are the testes housed outside the body?
spermatogenesis occurs at temps 4-6 degrees less than internal body temperature (37-31 degrees C)
what factors contribute to thermoregulation? how?
1st: scrotum
- sweat glands in scrotal skin
- location
- tunica dartos muscle (sustained contractions)
2nd: spermatic cord
- pampiniform plexus (counter current heat exchange)
- cremaster muscle (contracts to raise/lower the testes)(can not sustain contractions)
what are the two parts of the parenchyma and what do they contain?
- interstitial compartment: leydig cells
- tubular compartment: sertoli cells and seminiferous tubules
what is the CT core of the testes that house the rate tubules?
mediastinum
what is the functional component of the testes?
seminiferous tubules
what cells produce T and where are they found?
leydig cells— found in the interstitial compartment of the parenchyma
where are sertoli cells found and what is their function?
tubular compartment of the parenchyma, provide support to developing germ cells
what are the functions of the testes?
- produce sperm/spermatogenesis (via sertoli cells)
- transport sperm out of the testes
- 3 ways: tunica albuginea, myopic cells, and fluid absorption - produce T (via leydig cells)
what are the functions of T in males?
- stimulates secondary sex characteristics
- maintains libido
- maintains function of male repro tract, penis, and muscles for ejaculation
what are the components of the spermatic cord? what is its function?
- cremaster muscle: raises and lowers to regulate temp and protect the testes (fight or flight)
- pampiniform plexus: blood supply to the testes, counter current heat exchange
- vas deferens: transports sperm into the body, connects the cauda epididymis to the ampulla
what is counter-current heat exchange?
causes the cooling of arterial blood supply, warms blood as it leaves the testes, exchanging of the entropy of heat into the blood
what factors does each portion of the epididymis add to sperm?
- caput: add fertilization factors
- corpus: add decapacitation factors (army gear)
- cauda: add motility factors
where is sperm matured?
epididymis
where is sperm stored?
caudal epididymis
what epithelium layer makes up the epididymis and what function does it serve?
pseudostratified columnar epithelium that secretes and absorbs fluid vehicle
what is the chemical composition of of seminal plasma?
- energy sources: fructose is necessary for sperm activity and function
- buffers: bicarbonate maintain pH (bc there are rapid changes in the pH of the uterus)
- prostaglandins: stimulate muscle contractions for sperm movement
- glycoproteins: protects genetic material and retards capacitation
what are the three accessory sex glands and their functions?
- seminal vesicles: makes up the majority of seminal plasma
- prostate: prostatic secretions are generally composed of simple sugars
- cowper’s gland: lubricates the urethra, ~5% of ejaculate, helps clean out the urethra
what are the two types of penile tissues and how do they differ from each other?
- fibroelastic penis: have a sigmoid flexure allowing the penis to be retracted inside the body (retractor penis muscle) (boars, bulls, rams)
- musculovascular penis: fills with blood to increase in length and diameter (stallion, humans, dogs)
pathway of sperm:
seminiferous tubules —> rete tubules —> efferent ducts —> capcut, corpus, cauda epididymis —> vas deferens —> ampulla —> colliculus seminalis —> urethra
what is the colliculus seminalis?
where sperm and seminal plasma are mixed
why do males have pulsatile secretions of testosterone?
T has a negative feedback on GnRH, LH, and FSH; LH decreases = less T = reduce sertoli cell function = decrease in spermatogenesis
what are the phases of spermatogenesis? what is occurring during each stage? what cell types are present in each stage?
- proliferation: mitotic division, A/I/B spermatogonia
- meiosis: genetic diversity between haploid cells, primary/secondary spermatocytes
- differentiation: morphological changes, spermatids into spermatogonia
where are the most immature sperm located?
basement membrane
what are the phases of the differentiation phase? what is happening to each spermatid in each phase?
- golgi phase: golgi apparatus forms acrosomc vesicles that sit poon top of the nucleus; centrioles migrate to distal nucleus
- cap phases: acrosomal vesicle flattens to form a ‘cap’ over the nucleus
- acrosomal phase: nucleus begins to elongate and acrosome continues to spread; mitochondria make it to the mid-piece
- maturation phase: chromatins condense; DNA is non-functional; entire spermatozoa are covered with plasma membrane
why is the blood testis barrier so important?
provide environment for sperm undergoing spermatogenesis; protecting them while entering and completing meiosis
how do sperm develop post gonadally?
epididymis matures sperm by adding fertilization, decapacitation, and motility factors
what sperm cells are most susceptible to heat stress and why?
- spermatocytes: actively undergoing meiosis
- spermatids: undergoing morphological changes
when is repro behavior programmed?
pre-natally (feminization and masculinization—embryonic development)
what are the stages of male behavior?
pre-copulatory, copulatory, post-copulatory
what are reproductive behaviors in the female?
attractivity, proceptivity, receptivity
what senses are used in the precopulatory stage?
- olfactory: recognizing pheromones
- visual: sexual posture
- auditory: females changes in vocalization
why are courtship-specific behaviors under the influence of the female?
females are confined to estrus and will only show repro behavior during that time
as a producer, how can you increase and enhance repro behaviors?
introduce novel animals, change stimulus setting, sexual preparation
(increase in semen collecting for AI or diagnostic testing)
sialomucin and sulfomucin
sialomucin: helps with forward movement; under the influence of estrogen
sulfomucin: “washes” sperm out; thick; under influence of P4
female vs male: contractions and a fluid vehicle
- female: myometrium contractions and sialomucin
- male: PGF2a in seminal plasma stimulating contractions in female
decapacitation factors are added in the _________ and capacitation factors in the ________.
corpus epididymis; uterus
what is capacitation?
biochemical change to sperm that allows the true acrosome reaction to occur (penetrate the ZP)
how does the fusion of the sperm plasma membrane and outer acrosomal membrane happen?
ZP3 (receptor) that binds to the zona binding region (sperm)
what is the function of hylurinidase?
breaks down cumulus oophorous
what is the function of acrosin?
digest zona pellucida
why are chromatins are condensed before fertilization (maturation phase)?
preserving DNA: protamines replace histone tails
(sperm nucleus is decondensed when engulfed by oocyte)
what is syngamy?
fusion of the male and female pro nucleus (haploid)
what is the function of cortical granules?
to fuse to oocyte plasma membrane and release contents that degrade receptors for sperm making it less penetrable by sperm
where are leydig cells located in the seminiferous tubules?
interstitial space
where are sertoli cells located in the seminiferous tubules?
tubular compartment
what is spermiation?
when sperm are released into the lumen of the seminiferous tubules
what are the accessory sex glands?
cowper’s gland, prostate gland, seminal vesicles
what are the identifying qualities of a fibroelastic penis?
limited erectile tissue, erection results in increased length, contains sigmoid flexure
what are the identifying qualities of a musculovascular penis?
limited CT, erection results in increased circumference, lots of erectile tissue
what is the function of the retractor penis muscle?
maintains the sigmoid flexure in a fibroelastic penis
what does the ischiocavernosus muscle do?
compresses the curve and stops return of blood through veins
what does the bulbocavernosus muscle do?
empties the extra-pelvic part of urethra
what is unique about the ram reproductive anatomy?
does not have body of prostate
what is unique about the boar reproductive anatomy?
no ampullae and larger cowper’s gland
what is unique about the stallion reproductive anatomy?
no disseminate prostate
where does sperm go immediately after leaving the seminiferous tubules?
rete tubules
what takes sperm from the epididymis to the urethra?
vas deferens
T/F: sperm must go through epididymal maturation in order to be fertile.
true
T/F: the acrosomal reaction comes before capacitation
false
what temp do the testes have to be at in order for spermatogenesis to accur?
4-6 degrees less than body temp
when does reproductive behaviors develop?
prenatally
T/F: sperm swim through the female repro tract
false
T/F: sperm travel through the female repro tract via contractions
true
T/F: decapacitation sperm are not fertile
true
what happens when males have a small LH episode?
T is secreted soon after
how often to small LH episodes happen in males?
once every 2-6 hours
T/F: T has a positive feedback on LH and FSH
false
what factors are added in the caput epididymis?
fertilization factors
what factors are added in the corpus epididymis?
decapacitation factors
what factors are added in the cauda epididymis?
motility/swimming factors
which type of sperm are most sensitive to heat stress?
spermatids
two weeks of heat stress in bulls will equal how many days of damage?
65 days
T/F: the freshmen response is a way for males to detect pheromones
true
T/F: initiation of courtship behaviors is generally under the influence of the male
false
what is sialomucin?
when mucus in the cervix is watery, allows passage
what is sulfomucin?
when mucus in cervix is thick and viscous
if the acrosome is not intact, can it still fertilize the oocyte?
no
which enzyme in the acrosome reaction digests the ZP?
acrosin
which enzyme in the acrosome reaction breaks down the cumulus oorphous mass?
hyaluronidase
where does sperm attach to the ZP?
ZP3
T/F: there are two blocks to polyspermy: the zona block and the vitelline block
true
