LC Biology- Human Reproduction

definitions + be able to draw a diagram of male/female reproductive system, hormone graph and germ layers diagram.

testes

produces sperm and testosterone

epididymis

sperms cells made/ stored here

sperm duct

brings sperm to uethra

seminal vesicles, prostate gland and cowper’s gland

produces seminal fluid and nourishes sperm

what are secondary sexual characteristics

refers to part of male and females that distinguish them from each other apart from sex organelles.

sperm functions: acrosome

digestive enzymes

sperm functions: nucleus

23 chromo

sperm functions: collar

contains mitochondria

sperm functions: flagellum

allows sperm to swim

male secondary sexual characteristics

broadening of shoulders, voice box breaks and body hair growth

Testosterone

responsible for development of primary and secondary male characteristics, primary: male reproductive parts

3 male sex hormones

FSH: causes diploid cells in testes to divide and from haploid sperm, LH: causes testes to produce testosterone, testosterone

infertility

the inability to produce offspring

cause/treatment of infertility

low sperm count, hormone supplements

ovaries

produces egg

fallopian tubes

site of fertilisation

uterus

lining thickens each month, site of implantation

vagina

allows entry of sperm into male system

what is a the menstrual cycle?

a 28 day sequence of events that produces and egg and prepares body for pregnancy

days 1-5

lining of uterus is shed (menstruation)

days 6-14

hormone oestrogen is produced by developing graafian follicle

day 14

ovulation occurs, release of egg from graafian follicle

day 14-28

the graafian follicle develops into corpus luteum, further thickens lining and prevents new eggs from forming

menstruation

the shedding of the lining of the uterus

menopause

end of a woman’s reproductive life

functions of oestrogen

causes endometrium to develop, inhibits FSH

functions of progesterone

maintains endometrium, inhibits LH and FSH secretion

4 female secondary sexual characteristics

increased body fat, growth spurts, widening of pelvis, growth of pubic hair

cause of female infertility

pituitary gland fails to produce FSH or LH

corrective measures for female infertility

hormone injections

functions of FSH (follicle stimulating hormone)

stimulates growth of graafian follicle, causes production of progesterone day 5-14

functions of LH (luteinising hormone)

causes ovulation, causes graafian follicle to become corpus luteum.

disorder and cause:

endometriosis, abnormal response to oestrogen

treatment for endometriosis

large fibroids removed by surgery

3 main stages of copulation

sexual arousal, copulation and orgasm

ejaculation

release of semen from penis

insemination

release of semen into vagina

fertilisation

the fusion of egg and sperm nuclei to form a diploid zygote

where does fertilization occur?

the fallopian tube

life span of sperm/egg

sperm-7 days egg-2 days

implantation

when the embryo embeds in the endometrium

IVF (in-vitro fertilisation)

removing eggs from outside the ovary and fertilising them outside the body

describe the formation of the placenta

the embryo forms an outer layer (chorion) this surrounds the amnion and embryo, formed by BV in endometrium and chorion villi

function of placenta

allows gases, nutrients and waste to be exchanged between mother and baby

describe the sequence of a fertilised egg from morula to blastocyst (day 1)

day 1: zygote-46 chromo,

describe the sequence of a fertilised egg from morula to blastocyst (day 3)

day 3: morula is a solid ball of cells from a zygote by mitosis

describe the sequence of a fertilised egg from morula to blastocyst (day 5)

day 5: morula forms a hollow ball of cells called blastocyst

germ layers

basic layers of cells in the blastocyst where all tissues and organs will form

ectoderm

produces hair,skin,nails and nervous system

mesoderm

produces muscles, skeletal, excretory and respiratory system,

endoderm

produces digestive system

amnion

contains amniotic fluid, acts as a shock absorber for developing embryo

development of embryo (day 10)

day 10: inner cell mass forms embryotic disk, consists of germ layers

development of embryo (8 weeks)

8 weeks: all systems in place, referred to as fetus

development of embryo (3 months)

bones replaces cartilage, gender of fetus can be seen in scans

gestation

the length of time from fertilisation to birth (38 weeks)

process of birth (stage 1)

stage 1:

process of birth (stage 2)

process of birth (stage 3)