Reproduction and Final Exam Flashcards
Males can produce up to 120 million sperm cells per day. True/false
True
The prostate gland adds alkaline fluid to semen. (True/False)
True
What triggers the release of FSH and LH from the anterior pituitary?
a. Testosterone b. GnRH c. Androgens d. Prolactin
B- GnRH
Ovulation typically occurs on about day 14 of the menstrual cycle (True/False)
True
What hormone is produced by the maturing egg that drives the positive feedback loop required for ovulation?
a. FSH
b. LH
c. estrogen
d. progesterone
C- Estrogen
At approximately which age does menopause occur?–
a. 13
b. 15
c. 37
d. 46
e. 59
D- 46
Where does fertilization typically occur?
a. ovary
b. Fallopian tube
c. uterus
d. vagina
B- Fallopian/uterine tubules
What is the primary constituent of human milk?
a. water
b. fat
c. lactose
d. antibodies
A-Water
Maternal and fetal blood are allowed to freely mix in the placenta. (True/False)
False
What is the site of sperm production
Seminiferous tubules
What is the site of sperm maturation
Epididymis
What is the site of sperm storage?
Vas Deferens
How long can sperm be held and where is it held?
Can be stored in the vas deferens for about a month
What is the function of the seminal vesicles?
secrete fructose, citric acid, prostaglandins, and fibrinogen into semen
What is the function of prostaglandins in reproduction/sexual activity
prostaglandins make female cervical mucus more receptive to sperm and cause reverse peristaltic contractions in the uterine wall and Fallopian tubes to draw sperm into the female reproductive tract faster
In ejaculate, how much of it is from seminal vesicles
60%
What is the function of the prostate gland?
secretes alkaline fluid and clotting enzymes into semen
What is the prostate gland’s function in reproduction/sexual activity
the clotting enzymes work on the fibrinogen from the seminal vesicles to form a “fibrin coagulum” at the cervix in the female to hold sperm deeper in the female reproductive tract for a longer period of time. Fibrin coagulum breaks down in 15-30 minutes. Alkaline fluid counteracts the acidic fluid in the vagina to create an optimal pH environment for sperm movement.
What percentage of prostate secretions are in ejaculate-
30% of ejaculate is made of prostatic secretions
Function of bulbourethral glands
secrete mucus to make semen slippery to reduce friction, not much volume
What is the optimum temperature for fertility?
2 degrees cooler than body temp
How long can sperm live at body temperature
24-48 hours
How long and what temperature can sperm be preserved in
-100 C for years
What produces testosterone?-
Leydig cells
Functions of testosterone in males
masculinizes the male body
occurs in high levels during fetal development and first 10 weeks of life; then virtually none until age 13, then rises to adulthood and tapers off after age 50
Leutenizing hormone (LH Function)-
stimulates Leydig cells to secrete testosterone
amount of testosterone secreted increases in direct proportion to the amount of LH secreted
testosterone works at the level of the hypothalamus to decrease GnRH secretion in a negative feedback loop
FSH Function
binds with receptors on Sertoli cells and causes them to grow and secrete substances that initiate spermatogenesis
testosterone diffusing in from the Leydig cells aids in this process
Sertoli cells secrete inhibin which inhibits the AP from releasing FSH in a negative feedback loop
Ovaries
Site of egg production
Fallopian tubes
Transfer the ovum(egg) to the uterus, fertilization occurs here
Uterus
Development of fetus, placenta, and fetal membrane occurs here
Vagina
Entrance to the female reproductive tract
Women Age 9-12
pituitary begins to secrete FSH/LH and levels progressively increase
Women Age 11-15
puberty and menarche
Women Age 13-46
400-500 primary oocytes mature and are ovulated into Fallopian tubes, most degenerate or become atretic
Women Age 46 ish
menopause occurs when a female runs out of primary oocytes
Describe the negative feedback control in females
GnRH from hypothalamus triggers release of FSH and LH from AP which triggers the release of estrogen and progesterone from ovaries
Describe the role of FSH in women
Stimulates 6-12 primary follicles to continue development
Rapid proliferation of granulosa cells
Spindle cells from ovarian interstitium give rise to theca cells
Theca interna secrete estrogen and progesterone
Theca externa develops into a highly vascular connective tissue that surrounds the developing follicle
Granulosa cells secrete high levels of estrogen
Describe the positive feedback loop that drives follicle maturation
Accumulation of estrogen causes an antrum to appear in the granulosa cells
Greatly accelerated growth of follicle occurs because
Describe the ovarian cycle
day 1-14: follicular phase
day 14-28: luteal phase
Describe the uterine cycle
a. menstrual: days 1-5
b. proliferative: days 5-14
c. secretory: days 14-28
Proliferative phase of the uterine cycle
post-menstruation, endometrium is thin
estrogen causes proliferation of endometrium
at ovulation, endometrium is 3-5 mm thick
Secretory phase of the uterine cycle
estrogen and progesterone cause more proliferation of endometrium (peaks at 5-6 mm thick)
increase blood supply
increase lipid and glycogen supply
increase exocrine gland activity
basically gets uterus ready for pregnancy
Menstrual phase of the uterine cycle
if pregnancy does NOT occur, the corpus luteum degenerates and falling estrogen and progesterone levels allow endometrial lining to slough off and leave the body
vasospastic blood vessels
local hemorrhage with necrosis of endometrium with sloughing
Menstrual phase of the uterine cycle
if pregnancy does NOT occur, the corpus luteum degenerates and falling estrogen and progesterone levels allow endometrial lining to slough off and leave the body
vasospastic blood vessels
local hemorrhage with necrosis of endometrium with sloughing
Functions of progesterone in the Uterus
promotes changes in secretory function during the latter half of the menstrual cycle to prepare uterus for implantation
Functions of progesterone in the fallopian/uterine tubules
promotes secretions to nourish fertilized egg
Functions of progesterone in the breasts
promotes development of lobules and alveoli (milk-secreting tissue) and causes swelling in 2nd half of cycle but need prolactin for milk production
Hypogonadism
less than normal secretion of ovaries caused by poorly formed ovaries, lack of ovaries, or genetically abnormal ovaries can result in irregular menses or amenorrhea; if ovaries are absent/nonfunctional before puberty female eunichism occurs which results in prolonged growth of long bones (taller than normal), lack of secondary female sexual characteristics, infantile sex organs
Hypersecretion by ovaries
rare because of the negative feedback effects of estrogens on the AP; usually caused by a tumor that functions independently of AP to produce large quantities of hormones; sometimes results in irregular bleeding
Primary Oocyte
still in ovary, arrested in prophase 1 of meiosis
Secondary Oocyte
meiosis 1 is completed at the time of ovulation and a first polar body is ejected
Corona Radiata
secondary oocyte with a hundred or more attached granulosa cells is expelled into peritoneal cavity
Fimbriae
(activated by estrogen) help move oocyte into oviducts
Describe the process of implantation
Blastocyst remains in uterine cavity ~ 1 to 3 days before implantation
Implantation usually occurs ~ 1 week after ovulation
Before implantation, uterine milk secreted from endometrial cells support blastocyst
Trophoblast cells develop over the surface of the blastocyst that secrete proteolytic enzymes that digest and liquefy endometrial cells around blastocyst
Blastocyst cells and endometrial cells proliferate rapidly to form placenta and pregnancy membranes
How are early embryos given nutrition?
Progesterone secreted by the corpus luteum converts endometrial stromal cells into decidual cells that contain glycogen, proteins, lipids, and some minerals to support conceptus during the first 8 weeks of development (trophoblastic period of nutrition)
Decidual cells are the only source of nourishment for the first week, but then placenta starts to help
Pituitary secretions during pregnancy
Anterior pituitary of mother enlarges at least 50%
Increased production of corticotropin, thyrotropin, and prolactin
Secretion of FSH and LH falls almost to zero because of negative feedback from estrogens and progesterones from placenta
Corticosteroid secretion during pregnancy
Glucocorticoid secretion is moderately increased during pregnancy, possibly to help mobilize amino acids from maternal tissues for use by the fetus
2X increase in aldosterone by end of gestation which causes excess sodium reabsorption and therefore water reabsorption which can lead to pregnancy-induced hypertension
Thyroid Gland Secretion during pregnancy
Thyroid gland enlarges 50% and secretes more thyroxine
Induced by placental secretion of human chorionic gonadotropin and human chorionic thyrotropin
Parathyroid gland secretion during pregnancy
Usually enlarge during pregnancy to cause calcium absorption from mother’s bones to make it available to fetus
Effects intensify during lactation
Response of mother’s body to pregnancy
Uterus increases from 50 grams to 1100 grams
Breasts double in size
Vagina enlarges
Can develop acne, edema, and masculine or acromegalic features
Weight gain during pregnancy
Average = 24 lbs with most in the last 2 trimesters
7 lbs is fetus; 4 lbs is amniotic fluid, placenta, and fetal membranes; 2 lbs is uterus; 2 lbs is breasts; 6 lbs of maternal blood and ECF increase; 3 lbs of fat accumulation
Removal of nutrients from maternal blood by fetus and hormonal changes cause an increase in desire for food
Metabolism during pregnancy
Increased secretion of thyroxine, adrenocortical hormones, and the sex hormones cause a 15% increase in BMR
Leads to a perception of being hot
More energy expended to carry increased load
Nutrition during pregnancy
Greatest growth of fetus occurs during the last trimester; fetal weight almost doubles
Mother cannot absorb enough protein, calcium, phosphates, and iron from diet to supply fetus
Prior storage of these in normal storage areas of mother and in placenta to support fetus
Hormonal factors that increase Uterine contractility
Increased ratio of estrogens to progesterone: progesterone decreases uterine contractility and estrogen increases uterine contractility
Oxytocin effects: uterine muscle increases oxytocin receptors during last few months of pregnancy; rate of oxytocin secretion increases during labor; labor is prolonged in animals without a pituitary gland; cervical irritation triggers an increase in oxytocin secretion
Fetal tissues secrete oxytocin, cortisol, and prostaglandins that increase uterine contractility
Mechanical factors that increase uterine contractility
Stretch of smooth muscle in uterus increases contractility; fetal movement causes more stretch close to term to increase contractility
Stretch or irritation of the cervix increases contractility probably through myogenic transmission of signals from cervix to body of uterus
Estrogen role in lactation
(and growth hormone, prolactin, adrenal glucocorticoids, and insulin): trigger growth of ductal system throughout pregnancy; prohibits actual secretion of milk
Progesterone role in lactation
additional growth of breast lobules and budding of alveoli; triggers secretory function of cells in alveoli; prohibits actual secretion of milk
Prolactin role in lactation
promotes milk secretion; starts to increase in 5th week of pregnancy to about 10 to 20 X normal by end of pregnancy
Colostrum role in lactation
secreted few days before baby is born to a few days after; secreted at 1/100th the rate of milk; contains same concentrations of proteins and lactose as milk but no fat
Milk supply can be maintained for several years, but
decreases significantly after 7-9 months
Milk ejection is controlled by
neurogenic and hormonal (oxytocin) factors
Human milk contents
Contains: 88.5% water, 3.3% fat, 6.8% lactose, 0.9% casein, 0.4% lactalbumin and other proteins, 0.2% ash
Height of lactation: up to 1.5 L/day
Contains antibodies, anti-infectious agents, neutrophils, macrophages
