mnsr 39 Flashcards
the – produce gametes and act as endocrine glands
gonads
the sex hormones are all – based —
cholesterol based steroids
( cholesterol is a molecule of 27 carbons )
the first step of steroid production removes — producing an intermediate of —- known as —- which is then converted into active — which are divided into – groups based on the number of — in the structure:
the carbon-21 steroid is :
the carbon 19:
the carbon 18:
- terminal 6 carbons
- 21 carbons
- pregnenolone
- active sex steroids
- 3 groups
- number of carbons
- prostergone, cortisol , aldosterone
- androgens
- estrogen’s
the hormones produces in the testes are called —-
androgens
some 95% of the circulating testasteon is produced by —
leydig cells of the testis
at puberty under the influence of —- the intestinal cells begin to secrete – and continue to do so during the reproductive life through reading peak about —
- pitutry LH
- testosterone
- 20 years
the functions of testatsron includes:
- mainatance of male ducts and glands as penis and prostate
- stimulates and supports spermatogenesis
- induce and maintain the male secondary sexual characteristics such as: body hair , beard growth , lower voice , aggressive behaviour
- anabolic effects as muscle build up, nitrogen retention and male shape
- during the FETAL LIFE from the 7th week small quantities are produced by the testes which differentiate male ducts and organs
— is a hormone that stimulates Sertoli cells and promotes spermatogenesis , secretions of androgens binding proteins and inhibin which is the -ve feedback mechanism of this hormone secretion
FSH
— stimulates the leydig cells and induce the secretion of testastron as its released into the blood stream by systemic circulation and directly into the seminferfous tubules ( bound and concentrated by AMP )
LH
the hormones produced by the ovaries are in 2 groups —- and — and they are both controlled by —-
( CHECK SLIDE 10)
estrogen ( has 3 main types ) and prosterogen
both are controlled by FSH and LH
—- is the most active and most abundant during woman’s reproductive years and produced by granulosa cells developing in the ovarian follicle
estradiol-17
—- produced in large amount by the placenta in pregnant woman
estriol
— main estrogen and found in post-menopausal women and produced within the peripheral tissue especially adipose tissue
estrone
the main functions of estrogen:
- mainatance of female ducts and increase the division of vaginal epithelium and uterine endometrium
- induce and maintain the female secondary characyertsic such as: breast enlargement, deposition of adipose tissue, external genital hair , distribution of hair , skeletal effects as shorter stature and broader pelvis
- physiological effects including mainatance of bone density , anti- inflammatory signalling m liver and cardiac function , cognitive function
the most active progestogen hormone is — which is secreted by —- and during pregnancy by —
- progesteron
- cells in the corpus lutem
- placenta
the functions of progesterone:
- functions primarily as: pregnancy hormone
1- prepare the uterine endometrium for implantation specially in the development of coiled glands
2- stimulates the secretory alveoli in the mammry glands and prepares for milk production ( progesterone inhibits lactation during pregnancy )
3- reduces uterine smooth muscle sensitivity to oxytocin ( reduces the uterine contraction )
the name of the sexual cycle at the beginning of puberty which is under the control of the endocrine system is —
oestrous which means heat and when females are most receptive to males
in most mammals they will mate only in the oestrous and at other times the reproductive system is quiescent , the females will not mate is said to be —–
when mammals show succession of cycles are said to be —- as primates , rodents , domesticated animals
when mamas only breed at certain times of the year are said to be — as: carnivores and wild ungulates
- an anoestrus
- polyestrous
- monstrous
( CHECK GRAPH ON SLIDE 13)
Humans are not really — because they don’t show marked changes of behvaoirs at oestrous .
Mammals vary in the timing of —-
Most mammals are —– by which they ovulate spontaneously as part of the oestrous cycle
Other mammals are — who only ovulate after the stimulation of copulation as: rabbits kitties and ferret
- polyestrous
- ovulation
- spontaneous ovulators
- induced ovulators
– is the loss of blood as a result of endometrium degradation where the ovum is not fertilised and only found in higher primates as humans apes and old world monkey
menstrual cycles ( ceases at pregnancy , starts at puberty and continuous till menopause between ages of 45-50 )
( CHECK GRAPHS ON SLIDE 15,16)
at the end of the menstrual cycle most mammals will reabsorb the —- and won’t experience —-.
Humans lose about — of blood on an average of – days
The menstrual cycle commences from day – of the menstruation and the average cycle lasts — days
The regular mestrual cycle of women are series of —
- endometrial lining
- loss of blood
- 50-100 ml
- 5 days
- from day one and lasts 28 days
- oestrous cycles
——- is a stage in the menstrual cycle by which the follicles will develop and is controlled primary by — and it ends at —-
- follicular phase
- estrogen of LH , FSH
- ovulation
— begins following ovulation where the — will develop from an ovarian follicle and begins to secrete —-
this stage ends by the —- which trigger — and the beginning of the next cycle
- luteal phase
- corpus lutem
- progesterone
- falling levels of progesterone
- mesuutartion
( CHECK GRAPH 17 )
follicular phase:
1- prior to menstruation, high levels of —- from the corpus lutem suppress the production of —
2- degradation of the —- causes a sharp decrease in the —— which triggers — and removes —–
3- under the influence of —- the – will be secreted between 6-12 primary follicle in the ovary to start enlarging into —-
4- —– induce secondary follicles to start the secretion of —-
5- — will trigger the regrowth of the endometrial lining
6- estrigen inhibits —- causing —- to drop down
7- reduced —- causes most of the follicles to die leaving behind one or two occasionally —-
- estrogen and progestrerne will supress LH + FSH
- corpus lutem , progesnterone and estradiol17, trigger mestruation and removes -ve feedback on the production of FSH + LH
- gonandtrophin releasing hormone ( GnRH) , FSH , secondary follicle
- LH + FSH , estradiol-17
- estrogen
- GnRH causing FSH + LH levels to drop back down
- LH + FSH , dominat follcile
ovulation:
1- blood — levels peak one to two days before —
2- once the levels of — reach threshold , their previous inhibitory on GnRH will be —-
3- — stimulates large amount of — producing — and smaller amount of —
4- This surge of gonandtropins causes the —- to ovulate within — around or on – day of the cycle
- estradiol-17 , ovulation
- estrogen , temporary reversed
- estrogen , LH , LH surge , FSH
- graffian follciule , 18 hours , 14th day
luteal phase:
1- the peak of — cause lutenizarion of the membrane granulosa cells of the follicle becoming —
2- this body grows for 7 to 8 days after ovulation producing large amount of —– and — which inhibits the hypothalamus and pitutry to produce —–
3- – levels of —- during luteal phase of the cycle causes the ednomaterium to proliferate further
- LH , corpus lutem
- progesterone and estradiol-17 , inhibits production of LH and FSH
- high, progesterone
in the absence of fertilisation the —- starts to age , regress , and degrentrates by the day — of the cycle
this leads to sharp — of —— causes constriction in the spiral arteries in the endometrium which starts to break down
the — level of — and — will remove the -ve inhibition of hypothalamus and pitutry and —- will start to rise again and triggers the next ccycle
- corpus lutem , 26th
- drop of progesterone and estradiol-17
- decreasing level of progesterone and estrogen , FSH + LH
pregnancy:
1- should fertilisation take place in — will implant on the endometrial wall some 6 to 7 days after ovulation
2- the first task is to maintain the — until the — takes over about – week of the pregnancy
3- the blastocysts will secrete —- which maintain the corpus lutem aka progestren and estrogen levels
4- this hormone peaks at — and then they begin to fall low for the rest of the pregnancy
5- the — produces considerable amount of —– which climb steadily thoughout the pregnancy reaching levels —- those in — phase
6- another hormone secreted by the placenta is —— which has —- and — properties
- blastocysts
- corpus lutem , placenta , 6th week
- Human chorionic gonandtrophin HCG
- 60 days
- placenta , oestrogen and progesterone , 10x and 200x , luteal phase
- Human Placental lactogen HPL ,growth hormone and prolactin
the pregnancy evtenually culminates in the process of — by which the foetus and the placenta are expelled from the uterus by contractions of the myeometruim at 280 days aka 9th month
parturition aka labour
the role of placenta and foetal hormones are unlike by the might be liked with —-
- drop of progetroen and rise of estrogen levels from 36th week tio initiate the process
- oxytocin and prostaglandin play a role too
