Welcome to Dr. Kate Brilakis' Learning Portal

review question:
explain the connection between hormones, the ovarian cycle and the menstrual cycle. 

hormonal control

review question:
what role to Sertoli cells play in sperm development?

review question:
trace the path of semen during ejaculation. include the accessory glands

corona radiata: 
cells that surround and protect the oocyte when it is released during ovulation.

             Oogenesis

             Accessory glands:
1.  seminal vesicles (2) secrete                  fructose for energy and                        prostaglandins which play a role        in sperm transport
​2. prostate secretes buffering fluid
3. bulbourethral (2) lubricant

zona pellucida:
surrounds the oocyte and binds with proteins on the sperm. this induces the acrosome of the sperm to release its enzymes so it can fuse with the egg's membrane.
this fusion triggers the cortical reaction = exocytosis of cortical granules forming a hard barrier which prevents polyspermy.
  

a sphincter muscle at the bladder neck contracts, preventing urine from entering the urethra and semen from flowing into the bladder.   

review question:
list the hormones produced by the hypothalamus, pituitary and ovaries that control female the reproductive system and provide their functions.

                parturition

review question:
during ovulation, an ovum is released from a ruptured ___. What then happens to this structure after it releases the ovum?

                the placenta

the corpus luteum secretes progesterone
which helps develop and maintain the endometrium. It also produces relaxin which is a hormone that makes the pubic symphysis more pliable...think child birth

 overview of meiosis

​If fertilization does occur and the embryo implants, cells of the blastocyst secrete
human chorionic gonadotropin (hCG)
which maintains the corpus luteum and its progesterone secretion. The placenta eventually starts to produce progesterone causing the corpus luteum to degrade into a corpus albicans. 

             fertilization (or not...)

the ovarian and menstrual cycles are closely linked hormone controlled processes that prepare the female body for potential pregnancy.
the ovarian cycle controls the maturation and release of the egg.
the menstrual cycle prepares the â€‹uterine lining for implantation. 

Estrogen stimulates parturition by upregulating the expression of genes in uterine cells that code for oxytocin receptors.

 ovulation occurs.
fimbriae guide the egg into the fallopian tube where it travels down towards the uterus with the help of by cilia and muscular contractions.
​
 millions of sperm are ejaculated into the vagina but only a fraction of these sperm successfully navigate through the cervix and uterus to reach the fallopian tube.

sperm undergo a process called capacitation within the female reproductive tract which increases their motility and ability to penetrate the egg's outer layers.

the egg is surrounded by the corona radiata and the zona pellucida.

upon reaching the egg, sperm release enzymes that help them penetrate the zone pellucida but only one sperm can successfully penetrate and fertilize the egg.

once a single sperm enters the egg, the egg undergoes a cortical reaction which makes
the zona pellucida impenetrable to other sperm preventing polyspermy.

the sperm's nucleus contains 23 chromosomes as does the egg's nucleus.
when they fuse, the fertilized egg with 46 chromosomes is called a zygote.
​
the zygote begins cell division as it travels down the fallopian tube towards the uterus. after several days, the zygote becomes a cluster of cells called a blastocyst

which implants into the uterine lining = pregnancy.  

review question:
describe how sperm develop in the lumen of the seminipherous tubules.

                                     pathology

If fertilization does not occur, or the embryo does not implant, the corpus luteum degenerates into scar tissue called the corpus albicans.

review question:
describe how hormones regulate testes function.

       Reproductive System 

timing from ovulation to implantation

 the acrosome contains enzymes that permit the sperm to penetrate the zona pellucida but only one sperm can be successful.

    Spermatogenesis

at 10 to 12 weeks after fertilization, the placenta takes over from the corpus luteum. for most of the first trimester, however, the corpus luteum continues to produce progesterone and some estrogen. 

oxytocin is released by the posterior pituitary

   hormonal control