summary

• what is the usual thickness of a paraffin section used in microscopy?

  4um
• What specific cell tissue is stained well with Alcian Blue?

  cartilege
• Fist organs to develop in a human embryo? and when ___ ___ and number of days ____

  heart brain 24
• After how many weeks does an embryo become a foetus?

  8
• At the transition from embryo to foetus at 8 weeks, how big is the embryo?

  30mm
• the change from light to dark colour of the gametes as you look down the flow diagram suggests? they have become ____

  differentiated
• which cells prevent the germ-line cells from developing along the egg pathway and help direct them down the sperm pathway of development

  Sertoli cells
• What are two important things sertoli cells do for the germ cell travelling to the gonads? stops them ______ along the pathway and helps d_____ them

  developing direct
• what do sertoli cells secrete to cause the mullerian duct to regress?

  anti-mullerian hormone
• sertoli cells stimulate which cells? and what do they secrete?

  leydig cells, testosterone
• in the absence of SRY germ line cells become..


  egg
• in the presence of SRY germ line cells become..

  sperm
• what factor differentiates germ line cells into spermatagonia?

  SRY
• when does the testis start secreting testosterone?

  fetus
• when does the ovary start secreting oestrogen?


  puberty
• what two structures does the sperm head consist of?

  haploid nucleus and acrosome
• what important thing is between the sperm head and its tail and what does it contain? the ____ containing ______ and a ______

  neck mitochondria centriole
• what two things does the centriole in the sperm neck do? generates the ______ of the _____ and forms the _____ _____

  microtubules flagellum mitotic spindle
• what are microtubules composed of?

  tubular profilaments
• two tubular profilaments make a ____ and these make up the ______

  doublet axoneme
• in the acrosomal reaction _____ from the sperm acrosome digest the ______

  enzymes zona pellucida
• the enzyme that facilitates ferilization?

  acrozen
• what is the process in which enzymatic secretions from the uterus and oviducts strip the glycoproteins from the sperm membrane required for penetration?

  capacitation
• during capacitation the ____ and ____s strip the glycoproteins from the sperm ______ required for penetration.

  uterus oviducts membrane
• the fast block polyspermy results from a change in the oocyte membrane potential True or False?

  true
• fertilization normally occurs in the

  oviduct
• the oviduct is where _____ normally occurs.

  fertilization
• the secondary oocyte becomes an ovum when the secondary meiotic division occurs, when and where does this occur? during _____ in the _____

  fertilization oviduct
• what type of pregnancy does the zona pellucida prevent?

  ectopic pregnancy
• when does the embryo 'hatch' from the zona pellucida? when it ____ in the ____

  implants uterus
• what describes the cells produced by cleavage of the zygote?

  blastomeres
• blastomeres describe cells produced by ____ of the _____

  cleavage zygote
• corticle granules stop ____ The cortical granule contents modify the zona proteins so sperm cannot bind to the zona, and also harden the zona.

  polyspermy
• the egg nucleus is arrested in which meiotic stage before fertilization?

  metaphase
• what causes the second meiotic division in the oocyte to complete.

  fertilization
• what is in direct contact with maternal blood in lacunae of the placenta? cells of the _____ and this envades the ______

  syncytiotrophoblast endometrium
• Primary villi consist of _______ which are in direct contact with maternal blood.

  syncytiotrophoblasts
• the cytotrophoblast is made of cells which later become the fetus True or False?

  false
• the difference between the cytotrophoblast and the syncytiotrophoblast in that the cytotrophoblast is a deep layer of individual cells. true or false?


  true
• the yolk sac is the initial site of hematopoiesis (formtion on blood) true or false?


  true