Human reproduction Flashcards
What is puberty?
The changes that happen to your body between childhood and adulthood
These changes are controlled by hormones in the blood.
What role do hormones play in puberty?
They control the changes that prepare the body to reproduce
FSH and LH are key hormones involved in this process.
What is the function of FSH in males?
Stimulates sperm production
FSH stands for Follicle-Stimulating Hormone.
What does LH do in males?
Starts secretion of testosterone
LH stands for Luteinizing Hormone.
What hormones are released in females during puberty?
Estrogen
FSH and LH stimulate the release of estrogen in women.
What are secondary sexual characteristics in men?
Extra hair on face and body, muscle development, penis and testicles enlargement, sperm production, deepening of voice
These changes are triggered by testosterone.
What changes occur in women during puberty?
Extra hair on underarms and pubic area, hips widen, development of breasts, ovum released, start of periods
These changes are triggered by estrogen.
What are sperm?
The male gametes made in the testes after puberty
Sperm are mixed with fluid to create semen.
What is the purpose of the scrotum?
Holds testes outside the body and controls their temperature
This is important for sperm production.
What is the vas deferens?
The sperm ducts that carry sperm away from the testis
It plays a crucial role in the male reproductive system.
What is the urethra’s function?
Carries urine and semen out of the body
It serves dual purposes in the male reproductive system.
What type of fertilization occurs in humans?
Internal fertilization
This means that sperm must enter the woman’s internal reproductive tract for fertilization to occur.
Fill in the blank: The penis enters the vagina to deliver _______.
semen
What is the primary role of the male reproductive system?
To produce and deliver sperm
This includes the production of semen during ejaculation.
What do the seminal vesicles and prostate gland produce?
Seminal fluid which nourishes the sperm
This fluid is essential for sperm health and mobility.
What is the primary function of sperm’s motility?
To swim towards the egg in the oviduct
Sperm motility is crucial for fertilization.
What provides the energy for sperm movement?
Respiration in mitochondria using sugar from seminal fluid
Mitochondria are the powerhouses of the sperm cells.
What is the role of the acrosome in sperm?
To dissolve its way into the egg using a digestive enzyme
The acrosome is critical for fertilization.
What does the nucleus of sperm contain?
The male 23 chromosomes
These chromosomes carry genetic information from the male parent.
What is the function of the flagellum in sperm?
Used for swimming
The flagellum propels the sperm towards the egg.
What is the function of the vagina in the female reproductive system?
Receives the penis during intercourse
The vagina is also part of the birth canal.
What is produced by the ovaries?
Eggs
Ovaries are the female gonads responsible for gamete production.
What is the function of the uterus?
Muscular sac where the fetus develops
The uterus is essential for gestation.
What is the role of the oviducts (fallopian tubes)?
Carry the eggs from the ovaries to the uterus where fertilization occurs
Fertilization typically occurs in the oviduct.
What are female gametes called?
Ovum (eggs)
Female gametes are larger than male gametes.
Fill in the blank: Eggs are the largest cells in the human body and contain _______ as an energy source for the developing embryo before the placenta forms.
fats
These fats support the embryo until the placenta can provide nutrients.
What do the female chromosomes in the nucleus represent?
Genetic information from the female parent
Female gametes also carry 23 chromosomes.
What is the process of fertilisation?
The sperm penetrates the egg, and its nucleus fuses with the egg nucleus to form a zygote.
How many chromosomes do gametes have?
Each gamete has half the required chromosomes.
Where does fertilisation take place?
In the oviduct.
What develops after the zygote undergoes mitosis?
An embryo.
What is the role of the placenta?
Allows the exchange of food, oxygen, and waste between the mother and embryo by diffusion.
What gases are exchanged through the placenta?
Carbon dioxide and oxygen.
What nutrients does the embryo obtain from the placenta?
Oxygen, glucose, amino acids, vitamins, and fatty acids.
What hormone does the placenta produce to maintain the uterus lining?
Progesterone.
Fill in the blank: The amnion membrane surrounds the embryo with _______ to cushion and protect it.
amniotic fluid.
What are the adaptations of the placenta for efficient diffusion?
- Villi for large surface area
- Thin walls for short diffusion pathway
- Large concentration gradient
What is the significance of the embryo becoming a foetus?
It becomes recognisably human.
List the steps of birth.
- Cervix dilates
- Uterus contracts
- Baby is pushed through cervix and vagina
- Afterbirth is delivered
True or False: The placenta allows the blood of the embryo and mother to mix.
False.
What happens to the amnion during birth?
It tears, allowing the fluid to escape.
What process forms gametes?
Meiosis.
What is the average duration of the menstrual cycle?
28 days
The menstrual cycle can vary, but 28 days is the average length.
What happens to the uterus lining if the egg is not fertilized?
It is shed
This process is known as menstruation.
During which phase does the uterine lining thicken to accept a fertilized egg?
Days 5 - 14
This phase is part of the follicular phase of the menstrual cycle.
What occurs on day 14 of the menstrual cycle?
Ovulation
An egg is released during ovulation.
What is the duration of menstrual bleeding?
Usually lasts 5 days
This is the shedding of the uterine lining.
What hormone is primarily responsible for thickening the uterine wall?
Oestrogen
Oestrogen is released from the developing follicle.
What hormone stimulates the development of immature egg cells in the ovary?
FSH (Follicle-Stimulating Hormone)
FSH is produced in the pituitary gland.
What does LH stand for, and what is its role?
Luteinizing Hormone; it stimulates ovulation and the development of the corpus luteum
LH is also produced in the pituitary gland.
Fill in the blank: The corpus luteum develops and releases _______ to maintain the uterine lining.
Progesterone
Progesterone is crucial for maintaining the uterine lining after ovulation.
What happens during the follicular phase of the menstrual cycle?
The follicle develops and estrogen is released
This phase occurs from day 1 to day 14.
True or False: The uterine wall is maintained from day 14 to day 28 of the menstrual cycle.
True
This maintenance is primarily due to progesterone from the corpus luteum.
What triggers ovulation?
LH (Luteinizing Hormone)
LH surge causes the release of the mature egg.
What is the primary source of Oestrogen?
Produced in the ovary
What are the effects of Oestrogen on the uterine wall?
Causes growth and thickening of the uterine wall
How does Oestrogen affect LH and FSH production?
Stimulates production of LH, but inhibits FSH production
When do Oestrogen levels typically drop?
Around 14 days
What is the primary source of Progesterone?
Produced in the ovary
What role does Progesterone play in the uterus?
Maintains the thickness of the uterus wall and stops more eggs from being released
What happens to Progesterone production if there is no pregnancy?
The corpus luteum breaks down and progesterone production drops, leading to shedding of the uterus wall
If the egg cell is fertilised, what happens to the corpus luteum?
The corpus luteum remains for 12 weeks and keeps making progesterone
What is the function of progesterone during pregnancy?
To maintain the uterus wall and stop any more eggs from being released
Who produces progesterone after 12 weeks of pregnancy?
The placenta
