Female Reproductive System Flashcards
During the ovarian cycle, the secondary follicles that do not develop into mature follicles degenerate and become known as?
atretic follicles
The highest number of primary oocytes are present in the human body at which of the following times?
The fifth month of gestation
Which of the following interactions is NOT a feature of the luteal phase of the ovarian cycle?
All of the above ARE features of the luteal phase of the ovarian cycle.
Oestrogen exerts a positive feedback effect on the hypothalamus.
Progesterone exerts a negative feedback effect on the hypothalamus.
Oestrogen exerts a positive feedback effect on the anterior pituitary.
Progesterone exerts a negative feedback effect on the anterior pituitary.
All of the above ARE features of the luteal phase of the ovarian cycle.
Which of the following changes occur during the female orgasm?
contraction of perineal muscles.
rhythmic contraction the distal portion of the vagina.
waves of contraction in the uterus.
ALL
The typical age range during which ovarian cycles start to become anovulatory and menstrual periods become shorter and less frequent is?
46-54
Towards the end of the luteal phase of the ovarian cycle, circulating levels of oestrogen and progesterone gradually decline because?
The corpus luteum begins to degenerate.
The phase of the uterine cycle which coincides with ovulation is the ?
proliferative phase
The highest levels of oestrogen are found during which of the following phases of the ovarian cycle?
Ovulatory phase.
Which of the following is NOT a feature of the hormonal control of the follicular phase of the ovarian cycle?
- Oestrogen stimulates the hypothalamus and anterior pituitary gland to release GnRH and LH/FSH respectively.
- Circulating levels of LH and FSH cause a few primordial follicles begin to develop.
- GnRH secretion by the hypothalamus increases.
- Oestrogen stimulates the hypothalamus and anterior pituitary gland to release GnRH and LH/FSH respectively.
The highest levels of progesterone are found during which of the following phases of the ovarian cycle?
Mid luteal phase.
High levels of progesterone and oestrogen and declining levels of LH and FSH are all features of which part of the ovarian cycle?
Middle of luteal phase
The cells of the corpus luteum secrete which of the following hormones?
- follicle stimulating hormone
- oestrogen
- progesterone
2 & 3
Which of the following statements regarding the luteal phase of the ovarian cycle is FALSE?
The luteal phase typically occupies days 15-28 of the cycle.
During the luteal phase the corpus luteum acts as an important exocrine gland.
During the luteal phase the corpus luteum secretes a little oestrogen.
During the luteal phase the corpus luteum secretes progesterone.
The lifetime of the corpus luteum is determined by whether or not fertilisation of the oocyte occurs.
During the luteal phase the corpus luteum acts as an important exocrine gland.
During which of the following phases of the ovarian cycle do the flattened follicular cells of the primordial follicles become cuboidal in shape?
menstrual phase
follicular phase
luteal phase
ovulatory phase
primordial phase
follicular phase
Days 6-9 of a typical 28 day uterine cycle would be referred to as?
early proliferative phase
Approximately what percentage of ovulations have the potential to give rise to non-identical twins?
1 - 2%
Which of the following is/are features of the middle portion of the follicular phase of the ovarian cycle?
- Relatively low and stable levels of LH.
- Relatively low and stable levels of FSH.
- Relatively low and stable levels of progesterone.
all
Towards the end of the follicular phase of the ovarian cycle, circulating levels of oestrogen gradually increase because of which of the following?
- secretion of oestrogen from the corpus luteum.
- secretion of oestrogen from the proliferating follicular cells of the dominant mature follicle.
- positive feedback of oestrogen onto the hypothalamus and anterior pituitary.
- secretion of oestrogen from the proliferating follicular cells of the dominant mature follicle.
The initial development of a few primordial follicles into primary follicles typically occurs in the age range?
8-13
Which of the following is NOT a function of oestrogen?
Development of female libido. Stimulation of growth.
Stimulation of follicular development. Stimulation of progesterone secretion. Development of female secondary sex characteristics.
Stimulation of progesterone secretion.
The hormonal trigger that cause the arteries of the endometrium to go into spasm during the menstrual phase of the uterine cycle is?
increasing oestrogen levels
decreasing oestrogen levels
increasing progesterone levels
decreasing progesterone levels
decreasing oestrogen levels
decreasing progesterone levels
The MAJOR source of lubrication for sexual intercourse is mediated by which of the following?
increased parasympathetic tone to arterioles supplying the female external genitalia.
increased parasympathetic tone to the vaginal epithelium.
increased parasympathetic tone to the bulbourethral glands.
increased parasympathetic tone to the vaginal epithelium.
Ovarian Cycle
Follicular phase - 1-10
Ovulatory phase - 11-14
Luteal phase - 15-28
Uterine Cycle
Menstrual phase - 1-5
Proliferative phase - 6-14
Secretory phase - 15-28
Know what the female gonads are, where they are located and what they do.
Ovaries - located in the pelvic cavity and closely associated with the distal portions of the fallopian tubes - production of female gametes (oogenesis) and the secretion of female sex hormones
Fallopian tubes
- who named them & when
- what are they
- how long
- whats it lined by
- it’s 3 parts
- Gabrielle Fallopius in 1561
- pair of ducts which connect the uterus with each of the ovaries
- 13cm
- finger-like extensions (frimbriae)
- isthmus, ampullae (fertilisation takes place) and infundibulum
Uterus:
- its 3 layers and the 2 layers of one of them
- Perimetrium - outer most layer of connective tissue
- Myometrium - most thick layer of smooth muscle
- endometrium - inner most layer and site of implantation which which consists of 2 layers:
- basal layer - deepest which isn’t
shed
- functional layer - layer of simple
epithelium on its lumenal surface
and inner of the 2 layers that is
shed during menstruation
Oogenesis occurs in _____ life and remain unchanged until ______ when a small no. of gametes continue the process of ________ each month until _________ - takes places in ovary and divided in 3 stages:
foetal
puberty
maturation
menopause
mitosis
maturation
ovarian cycle
Mitosis:
Beginning in the _______ month of foetal life the germ cells called ______ (equivalent to the spermatogonia of males) undergo mitotic division to form between _ and _ million ________ oocytes by the _____ month of gestation.
second
oogonia
6
7
primary
fifth
Maturation:
During the remainder of foetal development many of these primary oocytes degenerate with only ________to _________ surviving until birth. Surviving primary oocytes then undergo a period of growth and become surrounded by a single layer of __________ __________ ____. The primary oocyte surrounded by the follicular cells is referred to as a _________ ______.
The primordial follicles (containing the primary oocyte) then enter a state of __________ _________ until puberty (although during this time there is still a slow rate of _________ of primary oocytes).
By the time puberty is reached (typically _-__ years of age in females) there are approximately ________ primordial follicles remaining and during each cycle a few of the primordial follicles continue onto the next stage.
300,000
400,000
flattened follicular cells
primordial follicle
suspended animation
degeneration
8-13
200,000
Understand the changes in follicular structure that are associated with the ovarian cycle
- flattened follicular cells of primordial cells -> cuboidal (primary follicle)
- follicular cells secrete glycoprotein -> thin coat around oocyte (zona pellucida)
- primary oocytes increase and cuboidal cells proliferate -> multi layered sheath (secondary follicle)
- follicular cells secrete oestrogen -> oestrogen-rich fluid-filled cavity (antrum)
- secondary follicles continue growth until day 10 of ovarian cycle (12-16 mm diameter) consisting of the ooycte (now known as secondary oocyte) surrounded by large no. follicular cells and large fluid-filled antrum - this structure, signals end of the follicular phase (a mature/graafian follicle)
Be able to describe the changes in circulating hormone levels that are associated with the ovarian cycle
- At puberty, secretion of gonadotropin releasing hormone (GnRH) by the hypothalamus begins to increase -> causes an increase in both (FSH) and (LH) secretion by the anterior pituitary gland which act on the ovaries and initiate follicular development.
- the establishment of developing follicles at this time is responsible for an increase in circulating oestrogen levels which in turn stimulate secondary sex characteristics, growth and is responsible for the development of libido.
- At the beginning of an established (adult) cycle, GnRH, LH, FSH, oestrogen
and progesterone levels are all low.
circulating hormone levels of follicular phase
- GnRH secretion by the hypothalamus begins to increase and this stimulates LH and FSH release from the anterior pituitary
- a few primordial follicles begin to develop and the follicular cells of the developing follicles begin to secrete oestrogen
- The oestrogen stimulates further follicular development and exerts a negative feedback effect on the hypothalamus and anterior pituitary which maintains FSH, LH levels relatively constant for the remainder of the follicular phase
towards the end of the follicular phase the proliferating follicular cells from the dominant follicle cause a gradual increase in circulating oestrogen levels
circulating hormone levels of ovulatory phase
- the negative feedback exerted by oestrogen during the follicular phase suddenly become a positive feedback loop
- instead of inhibiting the hypothalamus and anterior pituitary, oestrogen now stimulates these structures and so we see a rapid increase in circulating levels of FSH and LH
- The sudden peak in LH (LH surge) is the trigger for ovulation at around day 14 of the cycle
- After ovulation oestrogen levels begin to decline due to the damage done to the mature follicle following ovulation
circulating hormone levels of luteal phase
- The LH surge during the ovulatory phase stimulates the corpus luteum (endocrine gland) to secrete progesterone (and a little oestrogen) - both levels begin to rise
- rising oestrogen exerts a positive feedback effect on the anterior pituitary and hypothalamus while progesterone exerts a negative feedback on the same structures. Because the progesterone inhibitory effect predominates, LH and FSH levels tend to gradually decline during the luteal phase
- Towards the end, the corpus luteum begins to degenerate and consequently levels of oestrogen and progesterone decline towards the end of the cycle
the structural and functional changes that take place in the uterus during the menstrual phase
If fertilisation has not occurred in the previous cycle the declining oestrogen and progesterone levels cause the arteries of the endometrium to go into spasm and kink. This loss of blood supply interferes with the integrity of the outer layer of the endometrium (the functional layer) and this is shed leaving the relatively thin basal layer underneath. The detached functional layer is lost as menstrual fluid.
the structural and functional changes that take place in the uterus during the proliferative phase
Under the influence of the rising oestrogen levels from the developing follicles the functional layer of the endometrium regenerates from the basal layer. The functional layer progressively thickens, endometrial glands develop in the wall and the inner surface becomes coated in a thick mucus.
the structural and functional changes that take place in the uterus during the secretory phase
Under the influence of the now rising progesterone levels (from the corpus luteum) the functional layer becomes thicker, the endometrial glands become more elaborate (and begin to secrete glycogen) and the whole layer becomes more vascular. The endometrium is now primed to support the early developing embryo and provide a thick vascular tissue suitable for implantation. If fertilisation does not occur, the declining oestrogen and progesterone levels trigger the menstrual phase and the cycle begins once again.
Know where oestrogen comes from and be able to describe its developmental and ongoing physiological roles.
The establishment of developing follicles at this time is responsible for an increase in circulating oestrogen levels which in turn stimulate secondary sex characteristics, growth and is responsible for the development of libido.
- Follicular cells secrete oestrogen
- Corpus luteum secretes a little oestrogen
Understand the physiological processes involved in the female sexual act.
- psychogenic stimuli as well as local stimulation of the vulva, vagina and clitoris
- Both these forms of stimuli cause an increase in parasympathetic tone to the arterioles supplying the external genitalia causing them to swell.
- parasympathetic flow to the vaginal epithelium stimulates mucus secretion which provides the major source of lubrication for intercourse
- These local excitatory stimuli are greatly enhanced by the entry and thrusting of the penis during intercourse which culminates in the female orgasm
- The female orgasm is characterised by rhythmic contraction of perineal muscles and the distal portion of the vagina, waves of contraction in the uterus and an intense feeling of well being.
If fertilisation does not occur then the corpus luteum continues to secrete both hormones until the end of the luteal phase and then it breaks down to form a white scar in the ovary called the ______ ______. If fertilisation does occur then the corpus luteum continues to play an important role in the early stages of _______.
corpus albicans
pregnancy
Some of the follicular cells remain attached to the oocyte forming a structure known as the ______ _______
corona radiata
ovulated oocyte is swept up into the fallopian tube by currents in the peritoneal fluid created by the _______. Although only one mature follicle usually undergoes ovulation, in approximately _____ of all ovulations, two or more mature follicles may rupture resulting in _____ ovulations. If two of these oocytes become fertilised then the offspring are known as ______ (or dizygotic) twins.
fimbriae
1-2%
multiple
fraternal
During the proliferative phase of the uterine cycle the layer of tissue from which the endometrium regenerates is called the?
basal layer
