Exam 1 Flashcards
Female reproductive cycle (FRC)
ovarian cycle (ovulation) Menstrual cycle (menstruation) The two cycles take place simultaneously
Major target organs for female hormones
ovary, vagina, uterus, fallopian tubes
What hormones are the ovaries sensitive to?
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
What hormones is the uterus sensitive to?
Estrogen and progesterone.
Estrogens
hormones associated with characteristics contributing to “femaleness.”
3 types of estrogen
Estrone (ovaries-major, adrenal cortex-minute, fat cells-secondary estrogen)
B-estradiol
Estradiol
Major estrogen
B-estradiol
Progesterone
is secreted by the corpus luteum and is found in greatest amounts during the secretory phase of the menstrual cycle.
Prostaglandins (PGs)
oxygenated fatty acids that are produced by the cells of the endometrium and are also classified as hormones. They have varied action in the body.
Two primary types of prostaglandins
Group E and F.
PGE
Relaxes smooth muscles and is a potent vasodilator.
PGF
A potent vasoconstrictor and increases the contractility of muscles and arteries.
Hypothalamus
secretes ganodotropin-releasing hormone (GnRH) to the pituitary gland in response to signals received from the CNS.
In response to GnRH, the anterior pituitary secretes the gonadotropic hormones:
FHS and LH
FSH
is primarily responsible for the maturation of the ovarian follicle.
Ovulation
takes place following the very rapid growth of the follicle, as the sustained high level of estrogen diminishes and progesterone secretion begins.
Corpus luteum
The mass of cells that the ruptured follicle becomes following luteinization.
Ovarian Cycle
has two phases: the follicular phase (days 1-14) and the luteal phase (days 15-28 in a 28-day cycle)
Follicular phase
the immature follicle matures as a result of FSH. within the follicle, the oocyte grows.
Mittelschmerz
Midcycle pain with ovulation.
Human chorionic gonadotropin (hCG)
needed to maintain the corpus luteum.
Corpus albicans
If fertilization doesn’t take place, within about a week after ovulation the corpus luteum begins to degenerate and eventually becomes a connective tissue scar called the corpus albicans.
Menstruation
Cyclic uterine bleeding in response to cyclic hormonal changes. Begins 14 days after ovulation, in the absence of pregnancy.
Menstrual discharge/menses/menstrual flow
is composed blood mixed with fluid, cervical and vaginal secretions, bacteria, mucus, leukocytes, and other cellular debris. It is dark red and has a distinctive odor.
Factors that can alter cycle intervals:
Emotional and physical such as illness, excessive fatigue, stress or anxiety, and vigorous exercise programs can alter the cycle interval.
Environmental factors: temperature and altitude
Menstrual cycle has four phases:
Days 1-6 Menstrual, proliferative, secretory, and ischemic. Menstration occurs during the menstrual phase.
Proliferative Phase
Days 7-14 begins when the endometrial glands enlarge, becoming twisted and longer in response to increasing amounts of estrogen. Endometrium thickens 6 to 8-fold.
Spinnbarkeit
as ovulation nears, the cervical mucosa shows increased elasticity (Ferning pattern)
Secretory phase
Days 15-26, follows ovulation. The endometrium under estrogenic influence, undergoes slight cellular growth.
Ischemic phase
Days 27-28 Estrogen and progesterone levels drop Spiral arteries undergo vasoconstriction Endometrium becomes pale Blood vessels rupture Blood escapes into uterine stromal cells, gets ready to be shed.
Fertilization
The process by which a sperm fuses with an ovum to form a new diploid cell, or zygote.
Zygote
Begins life as a single cell with a complete set of genetic material, 23 chromosomes from the mother’s ovum and 23 chromosomes from the father’s sperm for a total of 46 chromosomes.
Capacitation
the removal of the plasma membrane overlying the spermatozoa’s acrosomal area and the loss of seminal plasma proteins. Takes about 7 hours.
Sperm that undergo capacitation take on three characteristics:
- ability to undergo the acrosomal reaction
- ability to bind to the zona pellucida
- the acquisition of hypermotility
Acrosomal reaction
Follows capacitation, whereby the acrosomes of the sperms surrounding the ovum release their enzymes and break down the hyaluronic acid in the ovum’s corona radiate.
Block to polyspermy
At the moment of penetration by a fertilizing sperm, the zona pellucida undergoes a reaction that prevents additional sperm from entering a single ovum. AKA the cortical reaction.
Sex chromosomes
X - female
Y - male
XX - female
XY - male
Preembryonic Development
The first 14 days of development, starting the day the ovum is fertilized. Also called the stage of the ovum.
Development after fertilization can be divided into two phases:
Cellular multiplication and cellular differentiation
Cleavage
When zygote enters a period of rapid mitotic divisions during which it divides into two cells, four cells, eight cells, and so on.
Blastomeres
Cells so small that the developing cell mass is only slightly larger than the original zygote. Blastomeres are held together by the zona pellucida, which is under the corona radiate.
Morula
Solid ball of 12 to 16 cells developed from blastomeres.
Primary germ layers
10th to 14th days after conception, the homogeneous mass of blastocyst cells differentiates into the primary germ layers. These layers are the ectoderm, mesoderm, and endoderm.
Ectoderm
Sensory epithelium of internal and external ear, nasal cavity, sinuses, moth, anal canal
Mesoderm
Skeleton Muscles (all types) Cardiovascular system (heart, arteries, veins, blood, bone marrow)
Endoderm
Respiratory tract epithelium
Chorion
Thick membrane that developes from the trophoblast, and has many fingerlike projections called chorionic villi on its surface. These villi form the fetal portion of the placenta.
Amnion
Originates from the ectoderm. It is a thin protective membrane that contains amniotic fluid.