Reproductive System Flashcards
What type of sex is determined by the presence or absence of a Y chromosome?
chromosomal sex
What are the chormosomes for males and females
XY and XX respectively
What is the first degree of sex determination that depends on the presence of testes or ovaries?
Gonadal sex
What is the gene that determines gonad presentation?
SRY
Where is the SRY gene normally located?
Y chromosome
What protein does the SRY gene produce?
TDF protein
What does TDF stand for?
Testis-determining Factor
What does the TDF cause?
A fetus to develop male gonads
What is the second degree of sex determination that refers to the genitalia present?
Phenotypic sex
What is phenotypix sex determined by?
Hormonal products of gonads and cell sensitivity to those hormones
What can crossing over of the SRY gene cause?
gene moves from Y to X causing possible female characteristics in an XY individual and male characeristics in an XX individual
What syndrome creates XX chromosomal females to develop male physical features?
XX Male Syndrome
What syndrome creates XY chromosomal males to develop female physical features?
Swyer Syndrome
What occurs if TDG fails to be released?
XY chromosomal males may not develop testes
What occurs in the testes fail to produce enough androgens?
Results in range of effects, from undescended testes to having a completely female phenotype
What is 5-alpha-reductase?
An enzyme that is required to convert testosterone to the more potent form called DHT
What happens if there is a deficiency in the amount of 5-alpha-reductase that a person produces?
Can result in ambiguous genitalia, but testes and other sex characteristics may develop during puberty with the increase in hormones
What organ are sperm produced in?
Testes
What is the testes surrounded by?
Scrotum
What temperature is sperm production optimized at?
35 degrees
How does the scrotum help maintain the appropriate temperature in the testes?
Muscle tissues in the scrotum move testes closer to the body when they are cold and further from the body when hot
What is the site of sperm production?
Seminiferous tubules
What secretes testosterone in males?
Leydig cells
What are the support cells for developing sperm?
Sertoli cells
What is the purpose of Sertoli cells?
Protect and nurture developing cells and provide them with ATP and growth factor etc.
How are the various stages of developed sperm organized in the seminiferous tubules?
Least developed are against the walls of the tubules and as they develop they move closer to the center
How many sperm does the average male produce daily?
About 100-200 million
What is the creation of sperm called?
Spermatogenesis
What is the final product of spermatogenesis?
Spermatozoa
Other than DNA, what is contained in the head of the sperm?
Acrosome
What is the acrosome?
Vesicle containing enzymes that aid in penetrating the egg
What is contained in the nucleus of the sperm?
Haploid genetic material
What aids in the mobility of the sperm?
Tail
What is the site of sperm maturation?
Epididymis
What tube connects the epididymis to the urethra?
Vas deferens (ductus deferens)
What is the site of a vasectomy?
Vas deferens
What 2 body systems is the urethra involved in?
Excretory system and reproductive system
What are the accessory structures of the male reproductive system?
Epididymis, vas deferens, and urethra
What are the accessory glands of the male reproductive system?
Seminal vessicle, prostate gland, and bulbourethral (Cowper’s) gland
What type of fluid does the seminal vessicle produce and what is it for?
Fructose-rich fluid used by the sperm as an energy source
What type of fluid does the prostate gland produce and what is it for?
Alkaline (basic) fluid that decreases the acidity of the urethra and vagina
What type of fluid does the bulbourethral (Cowper’s) gland produce and what is it for?
Alkaline (basic) fluid that decreases the acidity of the urethra and lubricates the tip of the penis
Which gland releases its material prior to ejaculation?
Bulbourethral (Cowper’s) gland
What are the 3 stages of ejaculation?
Erection, emission, ejaculation
What system allows for erection of the penis?
Parasympathetic Nervous System
How does the release of nitrous oxides into the penile tissue help with erection?
Vasodilation of the arterioles (so more blood going in) and vasoconstriction of the dorsal vein (so less blood coming out)
What is emission in relation to the male reproductive system?
Rhythmic contraction of muscles in the ducts and accessory glands which moves sperm and secretion into the urethra
What is ejactulation in relation to the male reproductive system?
Contractions of the muscles at the base of the penis and forces semen out of the urethra
What is the bone that is contained in the penis of some mammals? Do humans have one?
Baculum, and no.
Which tropic hormone is released by the hypothalamus in males?
Gonadotropin releasing hormone (GnRH)
What does GnRH act on and what is the result?
Anterior pituitary which releases LH and FSH
What is the role of LH in the male reproductive system?
Stimulates release of testosterone
What is the role of FSH in the male reproductive system?
Stimulates sperm production
What hormone is released by Sertoli cells?
Inihibin
What is the role of inhibin in the male reproductive system?
Exerts negative feedback on the anterior pituitary and hypothalamus
At what age is the average age of the onset of puberty in males?
About 10-11 years old
At what age is the average age of the completion of puberty in males?
About age 15-17
What changes during puberty are caused by an increase in FSH?
Volume of seminiferous tubules increases, leading to an increase in testicular size
As Leydig cells develop in males during puberty, what hormone level also increases?
Testosterone
Aside from secondary male sex characteristics, what changes does the increase in testosterone affect in males during puberty?
Maturation of prostate gland and seminal vesicles
What are some examples of secondary male sex characteristics?
Body hair, increase in muslce mass, deepening voice etc.
What is the male equivalent of menopause called?
Andropause
What is andropause characterized by?
A drop in testosterone over the age of 40
What do steroids mimic in the body?
Testosterone
What are the 2 types of steroids and what are their effects?
Androgenic - Masculinizing
Anabolic - Size growth
What are some of the side effects of steroids?
Premature bone maturation, increased impulsivity, increased aggression, mania, psychosis, damage to liver and kidneys, hypertension (high blood pressure), liver cancer (especially in men)
Who is most at risk for negative side effects of steroids?
Adolesence
What effects may steroids have on females?
Androgenic effects including lack of menstruation, breast shrinking, acne, change in body shape etc.
What do 1/3 men suffer when using steroids long term?
Extra androgens are converted to estrogen so they may see breast development, testicular shrinkage, and infertility
What is the site of egg production?
Ovaries
What are contained in ovarian follicles?
Egg cell and support cells
What are support cells in the ovaries that release estrogen called?
Granulosa cells
About how many follicles does the average female have at birth?
1-2 million
About how many follicles does the average female have by puberty?
About 300 thousand
What holds the ovary in place?
A ligament that connects it to the uterus
Where does fertilization occur?
Fallopian tubes (oviducts)
What is the site of “getting tubes tied” in females?
Fallopian tubes (oviducts)
What structure draws the egg into the fallopian tube?
The fimbriae of the tubes
What is the site of fetal development?
Uterus
Where is implantation supposed to occur?
Uterus
What are the 3 layers of the uterus?
Perimetrium, Myometrium, Endometrium
What is the main function of the myometrium?
Contains muscles used for labour
What is the main functions of the 2 layers of the endometrium?
One is shed during menstruation, one is highly vascularized and used to regenerate a new surface for each cycle
What hormone is released from the hypothalamus in the female reproductive system?
Gonadotropin Releasing Hormone (GnRH)
What is the function of GnRH in the female reproductive system?
Stimulate anterior pituitary to release FSH and LH
What does FSH and what is it’s primary function?
Follicle Stimulating Hormone and it stimulates egg production
How many eggs are stimulated per cycle?
About 6-12
What happens to the follicles after a week of growing?
Dominant follicle is determined and continues to grow
What process do the non-dominant follicles go through once the dominant follicle is established?
Atresia, which is degeneration
What hormones do the follicles produce?
Estrogen and progesterone
What is the dominant hormone during the follicular phase?
Estrogen
During the initial part of the follicular phase, what is the effect of estrogen on the anterior pituitary and why is this important?
Inhibitory so that ovulation does not occur prematurely
When in the menstrual cycle does estrogen result in a positive feedback system and why is this important?
Day 12-14, results in a surge of LH, and subsequently ovulation
What does LH stand for?
Luteinizing Hormone
What is the main role of LH?
Stimulates ovulation
What is the effect of LH on the follicle after ovulation?
Converts it to a corpus luteum
What does the corpus luteum secrete?
Progesterone (primary) and estrogen
What prevents another follicle from developing after ovulation?
Estrogen and progesterone exerting negative feedback on anterior pituitary, inhibiting release of FSH and LH
If fertilization does not occur, what causes the corpus luteum to deteriorate?
Drop in LH
What happens when fertilization does not occur and the corpus luteum deteriorates?
Estrogen and progesterone level drops and menstruation begins
What is considered day 1 during the menstrual cycle?
The period beginning
When does menopause generally occur?
About 45-55 years old
What is the clinical indication that a patient is in menopause?
Absence of menstruation for a year and/or abnormally high levels of FSH
What is surgical menopause?
Menopause caused by a complete hysterectomy
What happens to the remaining follicles during menopause?
Atresia (degeneration)
Why does LH and FSH become abnormally high during menopause?
Fewer follicles responding to the hormone, so less estrogen is created, so the negative feedback system does not work
What are some symptoms of menopause?
Hot flashes, mood swings, insomnia, osteoporosis
Why is osteoporosis releated to menopause?
Estrogen plays a role with osteoblasts and osteoclasts (which build and break down bown respectively)
What hormones are produced by the placenta that is detected by pregnancy tests?
Human Chorionic Gonadotropin
What does HCG stand for?
Human Chorionic Gonadotropin
What is the function of HCG?
Support function of corpus luteum
What roles does progesterone play during pregnancy?
Establish placenta, stimulates growth of blood vessles, inhibits uterin contractions, and strengthens pelvic muscles to prepare for labour
What produces progesterone during pregnancy?
Placenta
What roles does estrogen play during pregnancy?
Helps uterus growth, maintains uterus lining, helps fetal organs develop, activate and regulate other hormones
What produces estrogen during pregnancy?
Placenta
Where is prolactin produced during pregnancy?
Pituitary
What hormone inhibits lactation during pregnancy?
Progesterone
What is the main hormone for milk production?
Prolactin
Other than milk production, what other roles does prolactin play?
Contributes to mammary gland enlargement and prepares mammary glands for milk production
Where is relaxin produced during pregnancy?
Placenta
What are the roles of relaxin during pregnancy?
Inhibits uterine contractions, increases blood flow to placenta and kidneys, during birth relaxes joint of pelvis and softens and lengthens the cervix
Where is oxytocin produced during pregnancy?
Pituitary gland
What is responsible for uterine contractions during a period?
Prostaglandins
What hormone may be used to induce labor?
Oxytocin