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Studied by 170 peopleNoteStudied by 75 peopleNoteStudied by 1 personNoteStudied by 5 peopleNoteStudied by 4 peopleNoteStudied by 51 people
human reproduction I
male reproductive system
part | function |
|---|---|
epididymis | in charge of maturing and storing sperm. located at the top of the testis, connected to the sperm duct and the testis. |
penis | ejaculation, and deposits sperm in the vagina of a female during sexual intercourse. the spaces on its spongy tissue are filled with blood for an erection that facilitates semen deposit. |
prostate gland | is a gland, therefore it produces hormones, plus it produces semen providing sperm cells with nutrients. |
scrotum | bag of skin that holds the testis out of the inner body where the semen can be damaged due to a higher temperature. |
sperm duct/ vas deferens | takes the sperm away from the testis and towards the urethra, mixing it with fluids produced by the prostate glands. |
testis | produces sperm cells and testosterone. |
urethra | a tube running down the center of the penis, acting as a channel for the semen and urine to get out. a ring muscle prevents urine and semen from mixing. |
seminal vesicle | produces seminal liquid full of nutrients (proteins, sugars, water, and amino acids) to keep the sperm alive until fertilization. |
female reproductive system
part | function |
|---|---|
cervix | produces cervical mucus that works for birth control; dilates for birth; protects the uterus from pathogens; a ring of muscle that keeps the developing fetus in its place. |
ovary | contains maturing egg cells that develop responding to the hormones being released: estrogen and progesterone |
uterus | a muscular bag, in which lining, a zygote is implanted to develop and grow into a fetus, nourishing fetus development. |
vagina | menstrual pathways from the uterus towards the outside. also during birth, it is the pathway for the newborn to go out of the mother’s body, as it can expand almost 10 times itself; it is also the place where semen is received during sexual intercourse. |
oviduct | is lined with ciliated cells to push the egg cells and fertilization’s main scenery. |
gametes and fertilization
Fertilization: The fusion of the nuclei from a male gamete and a female one.
For humans, fertilization occurs in the oviduct.
Gametes have adaptations, as follows:
sperm cell | egg cell | |
|---|---|---|
has a flagellum or a tail. it enables mobility for it to reach the egg cell. | its cytoplasm contains storage of energy to keep the zygote alive until implantation. | |
contains enzymes in the head region (acrosome) to break down the corona radiate and jelly coat of the egg cell. | a jelly-like coating that changes after fertilization so that the egg cell is fertilized only by one sperm. | |
contains many mitochondria, that provide energy so that the flagellum can move for locomotion. | ||
parts | parts | |
acrosome; mid-piece (mitochondria); tail/flagellum | cell membrane; jelly coat; yolk (cytoplasm); follicle cells (mature egg cells). | |
comparison | - | - |
size | very small | large |
structure | head region and flagellum, basically many structural adaptations for its adequate working. | a cell with few structural adaptations, covered by a jelly coat. |
mobility | capable of moving. | immobile. |
numbers | produced daily in huge numbers. | thousands of immature egg cells in each ovary, but only one is released per month. |
human sex hormones
Primary sexual characteristics: are present during the development of a fetus in a uterus, basically the differences between female or male reproductive organs.
Secondary sexual characteristics: changes that occur during puberty and are controlled by the release of hormones (testosterone for males and estrogen for females).
For both, growth of sexual organs and body hair, emotional changes due to the increased levels of hormones, more interest in sex, and increased mood swings.
male secondary characteristics | female secondary characteristics |
|---|---|
growth of penis and testis. | breasts develop |
growth of facial and body hair. | body hair grows |
muscular development. | the menstrual cycle begins. |
the voice breaks and lowers its pitch. | hips get wider. |
testis starts to produce sperm. |
the menstrual cycle
starts in the early adolescence of females and is mainly controlled by sex hormones.
Average duration: 28 days per cycle.
Ovulation occurs normally halfway through the cycle, around day 14 when the egg travels through the oviduct.
when an egg is not fertilized it causes menstruation, due to the breakdown of the thickened lining of the uterus (endometrium)
Average menstruation: 5-7 days, when it starts a new menstrual cycle begins too.
After menstruation, the lining of the uterus (endometrium) starts to thicken again in preparation for possible implantation during the next cycle.
hormones
The hormones that regulate the menstrual cycle are secreted by the ovary and the pituitary gland.
Estrogen levels rise from day 1, with their peak before ovulation (day 14).
Estrogen stimulates endometrium development after menstruation and after ovulation inhibits LH and FSH production.
Progesterone stays low until ovulation has occurred, causing the endometrium to thicken further. Progesterone levels are lower when fertilization does not occur, and therefore cause menstruation.
Progesterone also inhibits FSH and LH production.
FSH stimulates egg maturation in the follicles of the ovary and stimulates estrogen secretion.
LH stimulates ovulation and results in the formation of “holes” in the ovary called corpus luteum.
interaction between hormones
The pituitary gland produces FSH, stimulating the development of a follicle in the ovary.
An egg develops on the inside of the follicle, which produces estrogen.
Estrogen causes the development and repair of the endometrium while inhibiting FSH production, just so that no more egg cells are matured.
When estrogen levels rise, it stimulates the release of LH from the pituitary gland too. This causes ovulation.
The follicle becomes the corpus luteum, which produces progesterone.
Progesterone maintains the uterus lining, but if the egg cell isn’t fertilized corpus luteum breaks down and progesterone levels drop causing menstruation.
endometrium breaks and is removed through the vagina.
If the egg IS fertilized the corpus luteum keeps producing progesterone preventing abortions due to the uterus lining breaking.
Until the placenta has developed when it starts secreting progesterone throughout the pregnancy.
human reproduction I
male reproductive system
part | function |
|---|---|
epididymis | in charge of maturing and storing sperm. located at the top of the testis, connected to the sperm duct and the testis. |
penis | ejaculation, and deposits sperm in the vagina of a female during sexual intercourse. the spaces on its spongy tissue are filled with blood for an erection that facilitates semen deposit. |
prostate gland | is a gland, therefore it produces hormones, plus it produces semen providing sperm cells with nutrients. |
scrotum | bag of skin that holds the testis out of the inner body where the semen can be damaged due to a higher temperature. |
sperm duct/ vas deferens | takes the sperm away from the testis and towards the urethra, mixing it with fluids produced by the prostate glands. |
testis | produces sperm cells and testosterone. |
urethra | a tube running down the center of the penis, acting as a channel for the semen and urine to get out. a ring muscle prevents urine and semen from mixing. |
seminal vesicle | produces seminal liquid full of nutrients (proteins, sugars, water, and amino acids) to keep the sperm alive until fertilization. |
female reproductive system
part | function |
|---|---|
cervix | produces cervical mucus that works for birth control; dilates for birth; protects the uterus from pathogens; a ring of muscle that keeps the developing fetus in its place. |
ovary | contains maturing egg cells that develop responding to the hormones being released: estrogen and progesterone |
uterus | a muscular bag, in which lining, a zygote is implanted to develop and grow into a fetus, nourishing fetus development. |
vagina | menstrual pathways from the uterus towards the outside. also during birth, it is the pathway for the newborn to go out of the mother’s body, as it can expand almost 10 times itself; it is also the place where semen is received during sexual intercourse. |
oviduct | is lined with ciliated cells to push the egg cells and fertilization’s main scenery. |
gametes and fertilization
Fertilization: The fusion of the nuclei from a male gamete and a female one.
For humans, fertilization occurs in the oviduct.
Gametes have adaptations, as follows:
sperm cell | egg cell | |
|---|---|---|
has a flagellum or a tail. it enables mobility for it to reach the egg cell. | its cytoplasm contains storage of energy to keep the zygote alive until implantation. | |
contains enzymes in the head region (acrosome) to break down the corona radiate and jelly coat of the egg cell. | a jelly-like coating that changes after fertilization so that the egg cell is fertilized only by one sperm. | |
contains many mitochondria, that provide energy so that the flagellum can move for locomotion. | ||
parts | parts | |
acrosome; mid-piece (mitochondria); tail/flagellum | cell membrane; jelly coat; yolk (cytoplasm); follicle cells (mature egg cells). | |
comparison | - | - |
size | very small | large |
structure | head region and flagellum, basically many structural adaptations for its adequate working. | a cell with few structural adaptations, covered by a jelly coat. |
mobility | capable of moving. | immobile. |
numbers | produced daily in huge numbers. | thousands of immature egg cells in each ovary, but only one is released per month. |
human sex hormones
Primary sexual characteristics: are present during the development of a fetus in a uterus, basically the differences between female or male reproductive organs.
Secondary sexual characteristics: changes that occur during puberty and are controlled by the release of hormones (testosterone for males and estrogen for females).
For both, growth of sexual organs and body hair, emotional changes due to the increased levels of hormones, more interest in sex, and increased mood swings.
male secondary characteristics | female secondary characteristics |
|---|---|
growth of penis and testis. | breasts develop |
growth of facial and body hair. | body hair grows |
muscular development. | the menstrual cycle begins. |
the voice breaks and lowers its pitch. | hips get wider. |
testis starts to produce sperm. |
the menstrual cycle
starts in the early adolescence of females and is mainly controlled by sex hormones.
Average duration: 28 days per cycle.
Ovulation occurs normally halfway through the cycle, around day 14 when the egg travels through the oviduct.
when an egg is not fertilized it causes menstruation, due to the breakdown of the thickened lining of the uterus (endometrium)
Average menstruation: 5-7 days, when it starts a new menstrual cycle begins too.
After menstruation, the lining of the uterus (endometrium) starts to thicken again in preparation for possible implantation during the next cycle.
hormones
The hormones that regulate the menstrual cycle are secreted by the ovary and the pituitary gland.
Estrogen levels rise from day 1, with their peak before ovulation (day 14).
Estrogen stimulates endometrium development after menstruation and after ovulation inhibits LH and FSH production.
Progesterone stays low until ovulation has occurred, causing the endometrium to thicken further. Progesterone levels are lower when fertilization does not occur, and therefore cause menstruation.
Progesterone also inhibits FSH and LH production.
FSH stimulates egg maturation in the follicles of the ovary and stimulates estrogen secretion.
LH stimulates ovulation and results in the formation of “holes” in the ovary called corpus luteum.
interaction between hormones
The pituitary gland produces FSH, stimulating the development of a follicle in the ovary.
An egg develops on the inside of the follicle, which produces estrogen.
Estrogen causes the development and repair of the endometrium while inhibiting FSH production, just so that no more egg cells are matured.
When estrogen levels rise, it stimulates the release of LH from the pituitary gland too. This causes ovulation.
The follicle becomes the corpus luteum, which produces progesterone.
Progesterone maintains the uterus lining, but if the egg cell isn’t fertilized corpus luteum breaks down and progesterone levels drop causing menstruation.
endometrium breaks and is removed through the vagina.
If the egg IS fertilized the corpus luteum keeps producing progesterone preventing abortions due to the uterus lining breaking.
Until the placenta has developed when it starts secreting progesterone throughout the pregnancy.
NoteStudied by 170 peopleNoteStudied by 75 peopleNoteStudied by 1 personNoteStudied by 5 peopleNoteStudied by 4 peopleNoteStudied by 51 people