PHGY 2 Flashcards
Successful sexual reproduction depends on …
Successful sexual reproduction depends on … the union of male and female gametes in order to form a new individual with a full set of chromosomes
Where do females receive sperm?
vagina
What is the path to get to the fallopian tubes where the sperm/egg is fertilized
vagina -> cervical canal -> uterus -> fallopian tubes
Define: sexual differentiation
Sexual differentiation refers to the embryonic development of both the external genitalia and the reproductive tract
what stimulates the differentiation of the gonads into teste
H-Y antigen
Structurally, what do most testes consist of?
semiferous tubules
Define: Leydig cells
Leydig cells: produce and secrete testosterone under the control of luteinizing hormone. Aka interstitial cells
Where does spermatogenesis occur?
in the seminiferous tubules
define: spermatogenesis
Spermatogenesis is the process in which diploid (46 chromosomes) primordial germ cells are converted into motile sperm cells with a haploid (23 chromosomes) set of chromosomes
What makes up the walls of the seminiferous tubules
serotoli cells
Where is the site of sperm production?
the testes
What comprises the primordial follicle
primary oocytes is surrounded by a single layer of granulosa cells
What are the two options for a primary follicle
○ The developing primary follicle either results in the release of an ova, or it will undergo atresia and decay
- Atresia: the process if degenerating into scar tissue
what are the 2 cycles in females
○ The ovarian cycle - occurs in the ovaries and prepares the ova for release
○ The uterine cycle - prepares the uterus for implantation
What makes up follicular cells
thecal layer + granulosa = follicular cells
What type of cells become the corpus luteum?
What hormones does the corpus luteum secrete?
Follicular cells undergo luteinization to become the corpus luteum
The corpus luteum secretes progesterone and some estrogen
What signifies the end of the ovarian cycle?
The corpus albicans
Which hormones control the ovarian cycle?
FHS, LH, and estrogen
○ FHS and estrogen are important for stimulating early follicular development and formation of the secondary follicle
○ LH is important for producing estrogen, which is secreted in increasing quantities by the secondary follicle
Describe the mechanism of the LH surge?
LH is the circulating estrogen during the follicular phase, and as estrogen levels rise, estrogen then exerts a positive feedback action on the anterior pituitary to cause a surge in LH secretions
Name the actions of the LH surge
○ It stops estrogen synthesis by follicular cells
○ It reinitiates meiosis in the oocyte
○ It triggers release of local factors that increase the swelling of the follicle and weaken the wall
○ It differentiates the follicular cells into luteal cells
Describe the luteal phase
- During the luteal phase, LH continues to maintain the corpus luteum
- The corpus luteum begins secreting large amounts of progesterone in preparation for pregnancy
- Progesterone causes changes in the uterine lining to prepare for potential implantation of an embryo to establish a pregnancy
- If no implantation occurs, the rapid degradation of the corpus luteum results in a rapid drop in circulating progesterone
Name and describe the hormones involved in the luteal phase
Progesterone: causes changes in the uterine lining to prepare for potential implantation of an embryo to establish pregnancy
LH: important in the production of estrogens which is secreted in increasing quantities by the secondary follicles
Estrogen: exerts a positive feedback action to causse a surge in LH secretion
FSH: important for stimulating early follicular development and formation of the secondary follicle
Inhibin: inhibits the production of LH and FSH by the pituitary gland
How many days does the uterine/menstrual cycle last?
28 days
Which parts of the Ovarian and Uterine Cycles align?
- Menstrual phase coincides with the end of the luteal phase and the beginning of a new follicular phase
- The ovarian and uterine cycles begin at the same time
- The proliferation phase of the uterine cycle corresponds with the later stages of the ovarian follicular phase
- The secretory phase coincides with the beginning of the luteal phase and the formation of the corpus luteum
Define: Endometriosis
Endometriosis = a disorder in which the endometrium grows outside of the uterus
When does menopause occur?
when there are no more viable primary follicles in the ovaries and follicular growth stops and the ovaria and uterine cycles cease
What controls the errection
erection is a spinal reflex
Which nervous system is responsible for the female excitement phase
the sympathetic
Where does fertilization occur?
in the ampulla of the fallopian tubes
Where does the egg usually implant?
uterine lining
What controls the secretion of hormones from the placenta?
Unique is that it is a temporary endocrine organ and it secretes hormones without any external control
What are the 3 placental hormones
- Progesterone
- Estrogen
- Human Chorionic Gonadotropin
The timing of which hormone corresponds with morning sickness
hCG
What are the roles of estrogen in paturation
- causes the myometrium to form gap junctions so it can contract
- increases the synthesis of oxytocin receptors in the myometrium
What releases oxytocin
posterior pituitary
