Lecture 1 Flashcards
What does sexual reproduction allow
Genetic mixing which increases genetic diversity and increases offspring fitness
Why is meiosis of gametes essential
To avoid polyploidy which would be detrimental
What are gametes made of
Testes and ovaries
Define heterozygous
2 different chromosomes (male)
Define homozygous
2 same chromosomes (female)
Define haploid gametes
contains only 1/2 number of chromosomes of a diploid adult
What determines the sex
Sperm
What controls maleness
A single gene on the Y chromosome
What do the gonads produce
Produces testis determining factor
What are the future of mesonephric and paramesonephric ducts
Epididymis/vas deferens or oviduct/uterus respt
When do Steroli cells form
Mesonephric tubules, rete testis and sex cords interconnect
What do the sex cords and mesonephric duct become
seminiferous tubules and epididymis/vas deferent respt
What happens to the mesonephric duct
degenerates
Paramesonephric duct becomes
oviduct and uterus
Define a hormone
Hormones are chemical messengers that bind to specific receptors of target cells/tissues
Name the types of reproductive hormones (3)
Lipids
Proteins
Monoamines
Where are all steroids derived from
Cholesterol
What are the 2 major classes of eicosanoids
- Prostaglandins
2. Leukotrienes - minor role in reproduction
What is a common precursor in eicosanoids
Arachidonic acid
What is PGF2a important to reproduction
- Stimulates uterine smooth muscle
List 3 somatomammotrophic polypeptides
Prolactin (lactation) Placental lactogen (lactation) Growth hormone (puberty)
List 4 reproductive cytokines
- Inhibins
- Activins
- Follistatins
- Relaxin
List 5 small peptides
- gonadotrophin releasing hormone
- thyrotropin releasing hormone
- corticotrophin releasing hormone
- growth hormone releasing hormone
- oxytocin
What does strength of hormone actions depend on
- Pattern and duration of secretion
- Half-life
- Receptor density
- Receptor
