Term
| Spermatogenesis is __________ sensitive in most mammals. What does this mean? |
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Definition
| temperature; this means that is cannot occur at normal body temperatures |
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Term
| At what temperature can spermatogenesis occur? |
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Definition
| temperatures 3-5 degrees celsius less than body temperature |
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Term
| What is the major factor that contributes to temperature regulation during spermatogenesis? |
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Definition
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Term
| What are the scrotal properties that facilitate thermoregulation? |
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Definition
- location of the testis
- low insulation
- sweat glands
- tunica dartos
- external cremaster muscle
- thermoreceptors
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Term
| How does the location of the testis facilitate thermoregulation? |
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Definition
| they are outside away from the body, allowing air circulation |
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Term
| How does low insulation of the scrotum facilitate thermoregulation? |
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Definition
| ther is thin skin and low subcutaneous fat or hair |
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Term
| How do seat glands on the scrotum facilitate thermoregulation? |
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Definition
| there are many of them which allows evaporative cooling |
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Term
| What is the tunica dartos? |
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Definition
| it is smooth muscle which lines the scrotal wall |
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Term
| How does the tunica dartos facilitate thermoregulation of the testis? |
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Definition
- it can change the testis location: vary closeness to the body wall
- change in scrotal surface area: vary thickness
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Term
| How does the external cremaster muscle facilitate thermoregulation of the testis? |
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Definition
| it relaxes when hot and contracts when cold |
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Term
| How do thermoreceptors facilitate thermoregulation of the testis? |
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Definition
| nerves in the scrotum control the response to temperature of the testis |
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Term
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Definition
| they secrete masculizing testosterone during the breeding season |
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Term
| What are seminiferous tubules? |
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Definition
| highly coiled tubules where spermatogenesis takes place |
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Term
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Definition
| a nurse cell of the testes which is part of the seminiferous tubules |
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Term
| What are Leydig (interstitial) cells? |
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Definition
| endocrine cells that produce testosterone |
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Term
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Definition
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Term
| Starting in the testis, name the duct work going from inside the testis to outside? |
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Definition
| seminiferous tubules, epididymus, ductus deferens |
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Term
| _________ cells surround ________ cells. |
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Definition
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Term
| How does testosterone affect and organism before birth? |
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Definition
- it masculinizes the reproductive tract and external genitalia
- promotes descent of the testes into the scrotum of most mammals
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Term
| How does testosterone affect sex-specific tissues? |
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Definition
- promotes growth and maturation of the reproductive system at puberty
- essential for spermatogenesis
- maintains the reproductive tract throughout adulthood
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Term
| What are two other reproductive effects of testosterone? |
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Definition
- develops the sex drive at puberty
- controls gonadotropin hormone secretion
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Term
| How does testosterone affect secondary sex characteristics? |
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Definition
- induces the male pattern of hair growth or feather growth
- causes the voice to deepen because of thickening of the vocal cords
- promotes muscle growth responsible for the male body configuration
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Term
| What are the nonreproductive actions of testosterone? |
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Definition
- exerts a protein anabolic effect
- promotes bone growth at puberty and then closure of the epiphyseal plates (stops growing)
- induces aggressive behavior
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Term
| What does spermatogenesis yield? |
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Definition
| an abundance of highly specialized, mobile sperm |
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Term
| What happens during spermatogenesis? |
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Definition
| mitotic proliferation, meiosis, and packaging |
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Term
| What is mitotic proliferation? |
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Definition
| spermatogonia located in the outermost layer of the tubule continuously divide mitotically |
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Term
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Definition
| a germ cell that divides into gametocytes during gametogenesis |
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Term
| What are male and female gametogonia called? |
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Definition
- male: spermatogonia
- female: oogonia
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Term
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Definition
| a process by which haploid or diploid precursor cells undergo cell division and differentiation to form mature haploid gametes (spermatogenesis, oogenesis) |
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Term
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Definition
| a cell that fuses with another gamete during fertilization (conception) in organisms tha reproduce sexually |
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Term
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Definition
| an organelle that develops over the anterior half of the sperm's head. It is a cap-like structure. |
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Term
| Where are acrosome derived from? |
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Definition
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Term
| When is acrosome formation completed? |
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Definition
| during testicular maturation |
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Term
| In Eutharian mammals, what does the acrosome contain and what do these products do? |
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Definition
- they contain digestive enzymes (including hyaluronidase and acrosin)
- these enzymes break down the outer membrane of the ovum called the zona pellucida, allowing the haploid nuclei in the sperm to join with the haploid nucleus found in the ova
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Term
| Starting with spermatogonium, name the stages of tranformation form spermatogonium to spermatozoa. |
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Definition
- spermatogonium
- spermatogonia
- primary spermatocytes
- secondary spermatocytes
- spermatids
- spermatozoa
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Term
| Are spermatogonium haploid or diploid? |
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Definition
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Term
| What forms of sperm are part of the stage of mitotic proliferation? |
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Definition
| spermatogonium and spermatogonia |
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Term
| Once there is a spermatogonium, what happens to it? |
|
Definition
- two daughter cells are produced (spermatogonia):
- one daughter cell remains at the outer edge of the seminiferous tubule to maintain the germ cell line
- the other daughter cell moves towrds the lumen to produce spermatozoa
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Term
| Are spermatogonia haploid or diploid? |
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Definition
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Term
| Once a spermatogonia is formed, what happens? |
|
Definition
| mitotic proliferation continues until primary spermatocytes are formed |
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Term
| Are primary spermatocytes haploid or diploid? |
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Definition
|
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Term
|
Definition
| once primary spermatocytes have been formed |
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Term
| What happens after primary spermatocytes are formed? |
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Definition
| secondary spermatocytes are formed through meiosis |
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Term
| Are secondary spermatocytes haploid or diploid? |
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Definition
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Term
| What is produced from secondary spermatocytes? |
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Definition
| spermatids through meiosis |
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Term
| When does the packaging phase begin? |
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Definition
| once spermatids have been formed |
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Term
| Are spermatids haploid or diploid? |
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Definition
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|
Term
| What is produced from spermatids? |
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Definition
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|
Term
| Are spermatozoa haploid or diploid? |
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Definition
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|
Term
| What is located in the head of a sperm? |
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Definition
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|
Term
| What is located in the midpiece of a sperm? |
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Definition
|
|
Term
| What is located in the tail of a sperm? |
|
Definition
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Term
| Where is the centriole of a sperm located? |
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Definition
| between the head and the midpiece |
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Term
| Throughout their development, vertebrate sperm remain intimately associated with ________________. |
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Definition
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Term
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Definition
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Term
| What is located between adjacent sertoli cells? |
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Definition
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Term
| What do the tight junctions between sertoli cells form? |
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Definition
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Term
| The blood testis barrier allows _____. |
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Definition
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Term
| What is the function of the blood testis barrier formed by the tight junctions between sertoli cells? |
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Definition
| it preevents the formation of an anitbody for highly differentiated sperm |
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Term
| What do sertoli cells provide for spermatozoa? |
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Definition
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Term
| How are sertoli cells related to an immune response? |
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Definition
| they carry out a phagocytic function to destroy defective germ cells |
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Term
| Sertoli cells secrete _____________ and ____________. |
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Definition
| seminiferous tubule fluid, androgen binding protein |
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Term
| What is the function of seminiferous tubule fluid? |
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Definition
| it flushes the released sperm from the tubule into the epididymus for storage |
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Term
| What is the function of androgen binding protien? |
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Definition
| it causes a high androgen concentration which is required for maintaining high testosterone concentration |
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Term
| _____ and _______ from the ____________ control testsosterone secretion and spermatogenesis. |
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Definition
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|
Term
| _____________ hormones activity increases at puberty. |
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Definition
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Term
|
Definition
|
|
Term
| What is the function of the ducts in the reproductive tract? |
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Definition
| they store and concentrate sperm and increase their fertility |
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Term
| What are three main functions of the testis? |
|
Definition
- spermatogenesis
- transport sperm out of the testis
- produce testosterone
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|
Term
| How do the testis produce sperm? |
|
Definition
| sertoli cells are stimulated by FSH |
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|
Term
| How do the testis transport sperm out of the testis? |
|
Definition
- myoid cells contract
- smooth muscles in the testis capsule (tunica albuginea)
- water absorption draws sperm towards the epididymus
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|
|
Term
| How do the testis produce testosterone? |
|
Definition
| leydig cells are stimulated by LH |
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Term
| What are the three main functions of the epididymus? |
|
Definition
| transport of sperm, concentration of sperm, and maturation of sperm |
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Term
| What are the three factors that play into the role of the epididymus transporting sperm? |
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Definition
- pressure of new sperm
- regular contraction of smooth muscles
- stimulated contractions of the cauda
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Term
| How does the pressure of new sperm aid in the transport of sperm through the epididymus? |
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Definition
| sperm moving into the caput from the efferent ductules creates a pressure gradient |
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Term
| How does regular contraction of smooth muscle aid movement of sperm through the epididymus? |
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Definition
| the muscle surrounds the duct and causes peristaltic contractions every 6 seconds in the caput and corpus (independent of sexual activity) |
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Term
| How does stimulated contractions of the cauda aid in transport of sperm through the epididymus? |
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Definition
| increased contractions stimulated by sexual activity may reduce trasnport time in the cauda itself |
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Term
| How does the epididymus concentrate sperm? |
|
Definition
| fluid is absorbed by the efferent ductules (concentration doesn't change much after the proximal caput) |
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Term
| How does the epididymus function in the maturation of sperm? |
|
Definition
- sperm gain motility and fertility (this process is helped by androgen binding protein bound testosterone)
- biochemical and physical changes to the sperm
- controlled by rate of transport throught the epididymus and epididymal secretions: allows time for maturation
- epidyidymal fluid changes: secretions are different in various segments of the epididymus: used to stimulate maturation and motility
- capacitiation: removal of seminal plasma protein in the surface of sperm cells by secretion from the female reproductive tract anhances the sperm's capacity
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Term
| The _____________ contribute to the bulk of semen. |
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Definition
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|
Term
| What happens to the cells within the epididymus during breeding season? |
|
Definition
| they undergo hypertrophy and secrete seminal fluid |
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|
Term
| What are the five main fucntions of seminal plasma? |
|
Definition
- transport media
- culture media
- stimulates sperm motility
- retards sperm capacitation
- stimulates sperm transport in the female
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|
|
Term
| In what way is seminal plasma a transport media? |
|
Definition
| it gives fluid volume to sperm and helps move the sperm through the urethra |
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|
Term
| How does seminal plasma act as a culture media? |
|
Definition
| it provides the proper environment for sperm viability and motility in the female reproductive tract |
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|
Term
| How does seminal plasma stimulate sperm motility? |
|
Definition
| biochemical stimulation and it activates metabolic activity |
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|
Term
| How does seminal plasma retard sperm capacitation? |
|
Definition
| it prevents the sperm from fertilizing immediately because we don't won't the sperm to activate until it is at the site of fertilization. Secretions in the cervix, uterus, and oviduct remove the coating on the sperm so they can fertilize |
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|
Term
| How does the seminal plasma stimulate sperm transport in the female? |
|
Definition
| uterine muscle contractions |
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|
Term
| What are the four main functions of the male accessory sex glands? |
|
Definition
- supply fructose
- secrete prostaglandins
- provide more than half of semen volume
- secretes fibrinogen
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|
|
Term
| What is the functions of the fructose that is supplied by male accessory sex glands? |
|
Definition
| it serves as the primary energy source for ejaculated sperm |
|
|
Term
| What is the function of the prostaglandins that are secreted by the male accessory sex glands? |
|
Definition
| they stimulate contraction of smooth muscle in both male and female reproductive organs to help trasnportation to the fertilization site |
|
|
Term
| What is the purpose of accessory sex glands providing more than half of the semen volume? |
|
Definition
| it helps wash semen into the urethra and dilute sperm to help motility |
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|
Term
| What is the function of the fibrinogen that is secreted by the male accessory sex glands? |
|
Definition
| it keeps the semen where it was deposited where it's at; it forms a network to trap the semen |
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|
Term
| With regards to the ejaculation characteristics of animals, ______________ and ___________ are inversely related. |
|
Definition
| volume, sperm concentration |
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|
Term
| With regards to the ejaculation characteristics of animals, total _______ is related to total ________. |
|
Definition
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Term
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Definition
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