Histology Lecture 4 Flashcards
What is the aim of female odontcetes?
- Females single egg
- To rear successful offspring
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What is the aim of male odontcetes?
-To successfully mate with as many females as possible, to pass on as many genes to the next generation
What do you when obtaining testis samples?
- Measure length, width, weight of each testis
- Obtain a cross section
- Fix in formalin
What are germinal cells?
Cells that make sperm
Where are germinal cells found?
In the seminiferous tubules
What are somatic cells?
Supportive cells
What do sertoli cells do?
Nourish developing germ cells
Secretes and regulates hormones
Provides structure
Act as phagocytes
What do leydig cells do?
Produce testosterone in the presence of luteinizing hormone
What does testosterone do?
Stimulates the development of male secondary sex characteristics and spermatogenesis
What stage is this tissue in?
Immature
What does IM stand for?
Immature
What does P stand for?
Pubescent
What does RM stand for?
Resting Mature
What does AM stand for?
Active mature
Describe an immature common dolphin gonadal tissue
- Sertoli cells only ‘3’
- Interstitial tissue ‘3’
- Spermatogonia ‘1-2’
- Mitosis starting but scarce
- Epididymis is empty
- Diameter of tubule < 65 u
Describe pubescent common dolphin gonadal tissue
- Meiosis starting
- Sertoli cells, interstitial cells, spermatogonia and spermatocytes present
- Diameter of tubule <82 u
- Epididymis empty
What stage is this tissue at?
Pubescent
What stage is this tissue at
Active mature
Is this during the mating period or not?
Yes during the mating period
Is this during the mating period or not
Not during the mating period
Describe active mature common dolphin gonadal tissue
- Diameter of tubule <200 u
- Sertoli cells are rare
- Spermatids and spermatozoa’s are numerous
- Epididymis enormous with many spermatozoa
Describe a resting mature common dolphin
- Tubules appear mature
- Large lumens, however a lot of sertoli and few germinal cells
- Spermatozas present, but on occasion, rare occurrence
What stage is this tissue at?
Resting mature
What stage is this pilot whale tissue at
Mature
What stage is this pilot whale tissue at
Immature
What stage is this pilot whale tissue at?
Maturing
What happens to certain types of fish during sexual development?
Some fish undergo a sex change during normal development
What is it called when male fish transform into females
Protandrous
What is it called when female fish transform into males
Protogynous
How does natural intersex fish benefit from this adaptation?
-They can optimise their reproductive output under various environmental conditions
