Human Reproduction Flashcards
Ampella
Widened section of the vas defrens
Stages of menstrual cycle
- menstruation occurs
- FSH releasing factor
- FSH is released
- FSH stimulates follicles to grow in ovary
- follicle produces oestrogen
- oestrogen stimulates growth of endometrium
- high oestrogen triggers LH release
- LH causes ovulation
- follicle bursts and ovum is released, forming corpus luteum
- corpus luteum produces progesterone
- no fertilisation- corpus luteum dies
- progesterone levels fall, triggering menstruation
Where is FSH and LH released from
Pituitary gland
Activated by releasing factor- from hypothalamus
What does oestrogen do
Growth of endometrium
High oestrogen triggers LH
How are primary spermatocytes formed
When spermatogonia are pushed away from the centre of the seminiferous tubule and undergo growth
What are the differences between oogenesis and spermatogenesis
Oogenesis occurs in two places not one
Oogenesis - discontinuous, produces 1 large ovum and 1/3 polar bodies
spermatogenesis - continuous, produces 4 equal sperm
What days of the ovarian cycle does follicular phase occur?
1-12
What are the hormones and their roles in the ovarian cycle
- FSH triggers follicle growth
- follicle releases oestrogen & progesterone
- high oestrogen levels trigger LH production
- LH causes ovulation
- corpus luteum produces progesterone
- corpus luteum dies and low progesterone levels trigger endometrial lining shed
What’s the name of the lung bypass in the foetus
Ductus arteriosis
1st stage of ovarian cycle
Follicle grows around developing oocyte
Where is FSH and LH released
Pituitary gland
What does FSH do
Stimulates follicle growth
3rd stage of ovarian cycle
Fluid accumulated in follicle, follicle enlarges and moves to surface of ovary
Epididymus
Stores spermatids while they mature into spermatozoa
What does Leuitenising hormone do?
Causes ovulation
Testes
Produces sperm and hormones (testosterone)
Where does spermatogenesis occur
Seminiferous tubules (testes)
Where is progesterone released from
Corpus luteum
Where is oestrogen released from
Follicles
Some from corpus luteum
Where does Oogenesis occur
Ovaries and Fallopian tubes
Month 5 of foetal development
Fine hair covers body, gripping reflexes developed, increased growth,
What is HCG
Human chorionic gonadotrophin
Produced by developing placenta to maintain corpus luteum
Role of oxytocin in pregnancy
Released from pituitary gland
Stimulates smooth muscle contraction of uterus
Contraction of muscle cells surrounding breast lobules
Mesoderm
Middle layer
Skeleton, muscles, connective tissue, heart, blood
Role of progesterone in pregnancy
From corpus luteum
Development & maintenance of placenta
Development of milk secreting glands in the breasts
Explain what occurs during fertilisation
- where female and male pronuclease form a zygote
- occurs in Fallopian tube
- capacitation ( secretion from the uterus make spermatozoa hyperactive)
- acrosomal reaction (enzymes activated in head of sperm (acrosome) allowing it to break down glycoprotein matrix of zonia pellucid a so sperm can access plasma membrane of oocyte
What occurs during the cleavage stage of the pre embryonic period
The zygote undergoes rapid mitosis in the Fallopian tube. (2,4,6,8,16 - morellula), blastocyst
- enters the uterus day 6 as blastocyst
- nutrients- uterine milk
What happens during implantation
Blastocyst embeds into uterine lining (day 6)
- sinks into endometrium and attaches to uterine wall
- becomes vascularised for nutrients
Whats cell differentiation
When the inner cell mass of the blastocyst (stem cells) become more specific/specialised
What factors affect foetal development
Alcohol, tetrogens, drugs, diet