4.1 Sexual reproduction in animals (female) Flashcards
What are is the order of follicle in an ovary?
Primary follicle, secondary follicle, Graafian follicle
How can a secondary follicle be identified?
It has an antrum
What occurs halfway through the menstrual cycle?
Ovulation
What does the corpus luteum secrete?
Progesterone
What does progesterone do?
Lots of progesterone= everything stays in
Low progesterone= period
What part of Oogenesis occurs before birth?
Oogonia divide by mitosis and enlarge to produce primary oocytes, matures
Primary oocyte begins Meiosis 1 but stops at prophase 1
What part of Oogenesis happens at puberty?
- One of follicles which has primary oocyte matures, producing Secondary oocyte and polar body
-Secondary oocyte goes Meiosis 2 but stops at Metaphase 2
-Ovum is formed but Meiosis 2 only complete if fertilisation occurs
What does Lactobacillus secrete?
-Lactic acid
-Maintains low pH to inhibit growth of other microbes
What are the cells surrounding the secondary follicle called?
Granulosa cells
What are the cells surrounding a follicle after ovulation called?
Corona Radiata
What separates the follicle and granulosa cells?
Zona pellucida
What happens during Follicular stage?
-Anterior pituitary gland secretes FSH
-FSH stimulates primary follicle to develop into secondary follicle
-Maturing follicle secretes oestrogen
What does Oestrogen do?
-Stimulate growth of endometrium and bloody supply increases
-Inhibits FSH, suppressing follicle development
-Stimulates growth of uterine wall
-Stimulates ant/pit to make and store luteinising hormone
What happens during ovulation?
-Peak oestrogen triggers ant/pit to release Luteinising hormone
-Oestrogen decreases
-Luteinising hormone induces ovulation on day 14
-luteinising hormone stimulates maturation of graafian follicle into corpus luteum
What happens during luteal phase if no implantation occurs?
-Corpus luteum secretes progesterone
-Falling levels of FSH and LH cause corpus luteum to degenerate
-Endometrium breaks down
-Progesterone drops and no longer inhibits FSH, new cycle starts
What happens during luteal phase if implantation occurs?
-Blastocyst releases HCG which maintains corpus luteum for 16 weeks and stimulates progesterone production whilst placenta develops
What does progesterone do?
-Maintain endometrium
-Inhibit FSH and LH
What hormones are made by the anterior pituitary gland?
-Luteinising Hormone and Follicle Stimulating Hormone
What hormones are made in the reproductive system?
-Progesterone (corpus luteum)
-Oestrogen (Secondary follicle)
What hormonal changes occur during pregnancy?
-Embryo secretes HCG to 16 weeks
-Placenta takes over and secretes progesterone and oestrogen, inhibiting LH and FSH
-Progesterone stops contraction of uterus, whilst oestrogen causes uterus and mammary glands to grow
- Progesterone inhibits oxytocin
What hormonal changes happen at birth?
1) Just before birth Oestrogen levels increase and progesterone decreases
2) Oxytocin is no longer inhibited, oxytocin stimulates contraction of uterine wall, stimulating secretion pf more oxytocin (positive feedback)
How do hormones produce milk?
Prolactin secreted by anterior pituitary gland during and after birth stimulates production of milk by mammary glands
