Reproductive systems Flashcards
Function of the testes
- make spermatozoa
- stored in pouch (scrotum) divided in two (each one containing testis
Function of scrotum
-contains smooth muscle
-can contract or relax to regulate the temperature of the testes
OPTIMUM TEMP for sperm production is approx. 2 degrees
Difference between secondary and primary organs
prepubescent vs since birth
Function of seminiferous tubules
contain cells that make sperm
join to form epididymis
Function of the epididymis
highly folded tubule (increase SA)
- fits against rear surface of each testis
- sperm are stored in here to mature
Function of the vas deferens
sperm duct
-carry sperm away from testes
Function of Urethra
Conducts semen and urine out of the body
Function of seminal vesicles
Secretes a fluid rich in sugars and makes up about 60% of semen
Function of prostate gland
secretes a alkaline fluid that helps active sperm
Function of bulbo urethral gland
secrete clear mucus acting as a lubricant
Function of penis
organ for passing urine and for transferring sperm to female
Function of acrosome of sperm
flattened, membrane bound vesicle containing glycoproteins and enzymes
Function of head of sperm
contains the nucleus with condensed chromatin
Function of sperm middle piece
first part of tail that contains mitochondria required to supply energy for motility
Function of sperm plasma membrane
Surrounds entire cell
Function of principle/main piece
contains the fibres needed for movement
What is the pathway of sperm
- seminiferous tubules (in testes) contain cells that undergo spermatogenesis
- epididymis
- vas deferens/sperm duct
- urethra, products from seminal vesicle, prostate, bulbo-urethral gland form semen that nourishes and activates the sperm
- vagina
- cervix
- uterus
- fallopian tube/oviduct/uterine duct
What is insemination?
Connective tissue in the males penis has a rich blood supply (erectile tissues)
- this tissues fills with blood during arousal
- the penis stiffens, enlarges = erect
- erection allows sperm to be delivered into the vagina = insemination
Function of semen
- nourishes the sperm
- neutralises the acidic conditions of the vagina
- contains enzymes that activate the sperm
What phase of meiosis is the ovum in during ovulation?
metaphase 2
-ovum is surrounded by two layers of cells
.outer layer=corona radiata
.inner layer=zona pellucida
-outer surface of the acrosome on the sperm head contains an enzyme
-the enzyme breaks down the hyaluronic acid in the cementing material that holds the corona radiate together
What is the corona radiata?
consists of follicle cells, held together by cementing materials that contain acid
What is the zona pellucida
a glycoprotein matrix that surrounds the plasma membrane of the oocyte
What is occurs during acrosomal reaction?
1 single sperm cannot penetrate the ovum layers (needs about 7000)
-once enough sperm loosen 1 may enter the corona radiata
-then encounters zona pellucida which initiates acrosomal reaction
.digestive enzymes released from this breakdown glycoprotein matrix
-sperm now has access to ovum
What is the endometrium? it’s purpose?
soft mucous lining of the uterus
- where menstrual cycle takes places
- nourishes the embryo and foetus
Endocrine gland
Glands that produce hormones and are released into the blood to travel around our bodies
Hormones
Chemical messengers; same components as proteins (steroid amine hormones)
Pituitary glands (master gland)
Produce many hormones that influence bodily processes
Gonado tropins
(gonad=reproductive systems/organs)
Purpose of Follicle-stimulating hormone (FSH)
helps control the menstrual cycle and stimulates the growth of eggs in the ovaries
- highest levels happening just before an egg is released by the ovary
- stimulates both follicle maturation and eostrogen synthesis of granulosa cells
Purpose of Oestrogen
regulates the growth, development, and physiology of the human reproductive system
- regulate the development and function of the uterus
- promotes endometrium growth
What changes can occur to the hormone concentration of luteinising hormone and progestrone during menstrual cycle?
- Luteinizing hormone stimulates egg release (ovulation) -usually occurs 16 to 32 hours after the surge begins.
- oestrogen level decreases during the surge
- progesterone level starts to increase
- During the luteal phase, luteinizing hormone and follicle-stimulating hormone levels decrease
What changes occur due to Luteinising hormone?
- triggers the start of ovulation (most fertile period)
- sexual development and functioning
- helps control the menstrual cycle
- triggers the release of an egg from the ovary (ovulation)
What changes does Progestrone cause?
- prepares the endometrium for the potential of pregnancy after ovulation
- regulates endometrium’s condition
- triggers the lining to thicken to accept a fertilized egg
- also prohibits the muscle contractions in the uterus that would cause the body to reject an egg
ovaries, placenta, and adrenal glands.
What is the ovarian cycle?
A sequence of events, which are controlled by hormones, that occur in the ovaries.
Occur in order to produce a mature ova from an immature follicle and a temporary hormone gland, the corpus luteum.
-between 20-40 days with an average 28 days
What hormones are secreted by corpus luteum, corpus albicans, and ovarian follicle? in what order?
Ovarian follicle: oestrogen and progesterone
Corpus luteum: progesterone if fertilisation occurs, if absent=corpus albicans
Corpus albicans:
Why is uterine lining thicker in sexually mature women?
-increase oestrogen causes the lining to grow and thicken to prepare the uterus for pregnancy due to an increase in sexual activity
Why does ovarian output decrease with age?
lack of follicles in ovary resulting in less oestrogen and progesterone production
Stages of ovulation
primordial primary follicle secondary follicles Graafian follicle then release
after is: ruptured follicle corpus luteum formation degeneration of corpus luteum corpus albicans
