Jan 29 - The Reproductive System Flashcards
What is reproduction dependant on?
It depends on the union of male and female gametes to form a new individual. The male and female reproductive systems are designed to enable the union of genetic material
What are the primary reproductive organs?
The gonads. In males, they consist of a pair of testes. In females, they consist of a pair of ovaries. In a developing fetus, these are bi-potential gonads (they could go either way; testes or ovaries)
What are the functions of mature gonads?
Producing gametes (gametogenesis) -Spermatozoa (sperm) in males -Ova (eggs) in females Secreting sex hormones -Testosterone in males -Estrogen and progesterone in females
What is the reproductive tract?
A system of specialized ducts that transport or house gametes after they are produced
What are accessory sex gland?
They empty supportive secretions into reproductive tract (the female breasts are considered accessory sex organs)
What is external genitalia?
Externally visible portions of the reproductive system
What are secondary sexual characteristics?
External characteristics that are not directly involved in reproduction that distinguishes males and females (body configuration, hair distribution)
What are the male reproductive functions?
Production of sperm (spermatogenesis)
Delivery of sperm to female
What are the organs of the male reproductive system?
Testes
Accessory sex glands
Penis
Male reproductive tract
Describe the testes
They are the sperm-producing organs. They are suspended outside the abdominal tract in a skin-covered sac (scrotum)
What are the male accessory sex gland? What is their function?
They include the seminal vesicles, the prostate gland and the bulbourethral glands. Their secretions provide the bulk of semen (liquid substance that is conductive to sperm viability)
What is the function of the penis with regards to reproduction?
It is the organ used to deposit semen in the female
What makes up the male reproductive tract?
The epididymis, the ductus (vas) deferens, the ejaculatory duct, which empties into the urethra (the canal running the length of the penis that empties into the exterior
What are the functions of the female reproductive system?
Cyclical production of the ova (oogenesis)
Reception of sperm
Transport of sperm and ovum to common site for union (fertilization or conception)
Maintenance of the developing fetus until it can survive in the outside world (gestation or pregnancy)
Giving birth to the baby (parturition)
Nourishing the infant after birth by milk production (lactation)
What is the product of fertilization?
The embryo. After the first two months of intrauterine development, the embryo is known as a fetus
What are the female reproductive organs?
Oviducts
Uterus
Vagina
Vulva
Describe the oviducts
They are inclose association with the ovaries
They pick up ova on ovulation
They serve as the site for fertilization
What are the functions of the uterus?
It is responsible for maintenance of the fetus during development
It is responsible for expelling at the end of pregnancy
Describe the vagina
Muscular, expandable tube that connects the uterus to the external environment
The lower portion is called the cervix
The vaginal opening is located in the perineal region between the urethral opening and the anal opening
Partially covered by thin mucous membrane, hymen (typically disrupted by first sexual intercourse)
Labia minora and labia majora are the skin folds that surround the vaginal and urethral openings
The clitoris is a small erotic structure located at the anterior end of folds of labia minora
Describe the cervix
It is a single, small opening that serves as a pathway for sperm. It also serves as a passageway for the delivery of the baby from the uterus
What is the vulva?
A collective term for the female external genitalia
How are body cells (somatic cells) different than gametes cells?
They contain 46 chromosomes (diploid number) that can be sorted into 23 homologous pairs
Describe gametes
They have 23 chromosomes (haploid number)
They contain only one member of each homologous pair of chromosomes
How is gametogenesis accomplished?
By meiosis
What are autosomes?
22 pairs of chromosomes which code for general human characteristics and specific traits such as eye colour
What are sex chromosomes?
The remaining pair chromosomes. There are two genetically different types; the larger X chromosome and the smaller Y chromsome
Describe gametogenesis
Nuclear division in the specialized case of gametes is accomplished by meiosis. Only a half of the genetic information is distributed to each of the four new daughter cells. More than 8 million (223) different mixtures of the 23 paternal and maternal chromosomes are possible. This genetic mixing provides novel combinations of chromosomes. Crossing-over contributes even further to genetic diveristy
How is sex determined?
It depends on the combination of sex chromosomes. Genetic females have two X chromosomes. Genetic males have an X and a Y chromosome. Genetic sex is determined at the time of conception and it depends on the type of sex chromosome is contained within the fertilizing sperm
What is the function of the Y chromosome?
Responsible for all the anatomic and functional distinctions between males and females
What are the three levels of differences between males and females?
Genetic (depends on a combination of sex chromosomes at the time of conception)
Gonadal (depends on the development of testes or ovaries, which depends on the presence or absence of the Y chromosome)
Phenotypic (the apparent anatomic sex of the individual, which is determined by gonadal sex)
When does gonadal specificity begin to appear?
It appears during the seventh week of intrauterine life when the indifferent gonadal tissue of a genetic male begins to differentiate into testes under the influence of sex-determining region of the Y chromosome (SRY)
What is phenotypic sex?
The apparent anatomic sex of an individual, which depends on the genetically determined gonadal sex
What is sexual differentiation?
The term sexual differentiation refers to the embryonic development of the external genitalia and reproductive tract along either male or female lines
How does the male-type reproductive system develop?
Differentiation into a male-type reproductive system is induced by androgens, which are masculinizing hormones secreted by the developing testes