repro 1 Flashcards
what do we think about reproduction?
one area of physiology in which we like to think of ourselves as significantly advanced over other animals
-mate for pleasure and procreation
-does not only occur during “fertile” period
humans are ___________________
SEXUALLY DIMORPHIC
-males and females have distinct physical characteristics
what are the three sets of structures of sex organs in female and males?
-gonads: gamete producing organs
-internal genitalia: accessory glands and ducts
-external genitalia: external reproductive structures
what is sex determination?
programmed in the genome
-each nucleated cell of the body except gametes contains 23 pairs of chromosomes (46 total: diploid)
-22 pairs autosomes: direct development of human body
-1 pair sex chromosomes: direct development of internal and external sex organs
-gametes contain 23 single chromosomes (haploid)
what is the graph of sex determination?
what is X-chromosome inactivation?
in females, during early embryonic development, one X chromosome is turned off in each cell
-whether the paternal or maternal X chromosome is shut off differs in each cell
-X-linked recessive genetic disorders more commonly affects males: muscular dystrophy, color blindness, hemophilia
what is the graph showing abnormal sex chromosome distribution?
what are examples of abnormal sex chromosome distribution?
when does an embryo become a fetus?
when does sex differentiation begin during development?
-reproductive structures do not begin to differentiate until the seventh week of development and prior to this time are considered bipotential
what is the bipotential stage of internal sex organ development?
-male or female development depends on the presence or absence of sex determining region of the Y chromosome (SRY gene)
what is the SRY gene?
Sex determining Region of the Y chromosome
testes then (after SRY gene) produce three hormones influencing development:
-anti-mullerian hormone (sertoli cells): causes mullerian ducts to regress
-testosterone (leydig cells): converts Wolfian ducts into male accessory structures (epididymis, vas deferens, and seminal vesicles)
-dihydrotestosterone (leydig cells): differentiation of external genitalia
what is the spiderweb of how the SRY gene directs male development?
what is the difference in males and females at ten weeks of internal genitalia?
what is the development of external genitalia?
external genitalia development driven by presence or absence of androgens (DHT)
what is the difference between males and females at 10 weeks on external development?
what is the differentiation summary?
