DHUBS1 - week 12 Flashcards
(25 cards)
the purpose of the reproductive system:
to ensure the survival of human species
- by sexually reproducing and combinnig genetic materials form both parents
reproductive system organs
gonads
ducts
accessory glands and organs
perineal structures/external genitalia
testes/ovaries
purpose of male reproductive system
to produce spermatozoa
to deliver speratozoa into the uterus and fallopian tubes
what are the accessory glands?
seminal glands: secrete fluid for semen production
prostate glands: produces prostatic fluid
bulbourethral glands: mucous secreting gland
external genitalia: penis and scrotum
male reproductive anatomy
testes: produce spermatozoa
epididymis: maturation and storage fo spermatozoa
ductus deferns: spermatozoa storage
urethra: ejection of speram/semen
glands: semen production
external genetalia: scrotum and penis
what is spermatogenesis
- Production of spermatozoa beings in outermost layer of seminiferous tubule walls
- Proceeds towards lumen -> each production step sperm cells get closer towards the lumen
what is spermatozoa
- Begins as a stem cells (spermatogonium)
- Divide by mitosis to produce daughter cells
- Spermatocytes undergo meiosis to from gametes
- Spermatids begin to mature into spermatozoa and are released into lumen
what is spermiogenesis
spermatids mature into sperm
movement of sperm
epididymis to ductus deferens to urethra
what are nurse cells
- Maintenance of blood-testis barrier
- Supports mitosis and meiosis
- Supports spermiogenesis
- Secretion of inhibin
- Secretes androgen-binding protein
- Secretes Mullerian-inhibiting factor
what are Interstitial cells of Leydig
- Are in between seminiferous tubules
- Secretes androgens
Most important in males – testosterone
functions of testosterone
Synthesised form cholesterol in Leydig cells
Released in response to the Luteinising hormone from pituitary.
Controls development, growth and maintenance of male sex organs.
Development and maintenance of male secondary sex characteristics.
Stimulates bone and muscle growth.
Sexual behaviour
Final maturation of sperm.
Stimulates descent of testes.
factors that influence sperm formation
- Varicoceles
- Increased testicular temperature
- Smoking
- Stress
- Alcohol
- Increased BMI and poor diet
- Infrequent ejaculation
- Aging
- Infection of male reproductive organs
- Cancer
- Pollution toxins and radiation
- High intake of caffeine
- Recreational drugs and medications
purpose of the fmeale reproductive system
- To produce haploid ova (oocytes)
to provide an environment for the fertilisation and development of ova - To expel offspring form the body
- The provide the interstitial nutrition to the offspring by lactation
organs of the fmeale reproductive system
ovaries: production of oocyte
fallopian tubes: transportation and nourishment for oocyte
uterus: - Mechanical protection, nutritional support and waste removal for embryo/foetus
vagina:holds spermatozoa after sexual intercourse
external genitalia:
mammary glands: milk production
three layers of the urerus
Perimetrium
Myometrium (muscular layer)
Endometrium: stratum basalis and stratum functionalis
what is the female cycle
- Ovarian cycle: monthly series of events associated with the maturation of an ovum
- Menstrual cycle (uterine cycle): series of changes in the endometrium of a non-pregnant female
what is oogenesis
- Mitosis occurs before birth.
- Meiosis I occurs from 3-7 months of foetal development.
- Meiosis I halts in prophase until puberty.
- Hormones in puberty then stimulate some primary oocytes each month to finalise meiosis I and form a secondary oocyte.
- Meiosis II – the secondary oocyte halts in metaphase until oocyte released and fertilisation with a spermatozoa occurs, and it becomes a mature ovum.
- During oogenesis, the thecal and granulosa cells of the primary follicle produce the hormone estrogen
the menstural cycle
- Menstrual cycle is the process of readying the uterus for receiving the fertilized oocyte (ovum).
- Proliferative Phase – Day 8-14 – replacement of functional zone.
- Ovulation at Day 14 – marks change to new phase of the menstrual cycle.
- Secretory Phase – Day 15-28 – secretion/thickening of functional zone.
- Menses – Day 0-7 – will take place if there is no fertilisation of the oocyte with a spermatozoa.
female reproductive hormones
- GnRH (gonadotropin Releasing hormone)
- FSH (follicle stimulating hormone)
- LH (luteinzing hormone)
- Estrogens
- Progesterone
- Inhibin
whats estrogens
Responsible for female secondary sexual characteristics
influences the production of cervical mucus and the structure of vaginal epithelium
Causes the proliferation of the uterine endometrium.
Encourages fluid retention.
Inhibits FSH production as levels rise, triggers LH production
what is progestrone
Only act on tissue which have previously been affected by estrogen.
causes:
- Endometrial growth
- Secretory changes in the lining of the uterus
- Causes the body temperature rises by 0.5 degrees Celsius after ovulation
A drop in the levels of progesterone triggers menstruation.
what regulates the ovarian cycle
FSH
LH
what is menopuase
- Cessation of ovulation and menstruation.
- After approx. 450 ovarian cycles (45-55 years).
- Fluctuating and decreasing levels of hormones.
