Reproductive System Flashcards
what’s the function for a male reproductive system?
to produce and store sperm and then discharge it into a female to fertilise the egg.
what’s structure of the male reproductive system?
prostate gland
vas deferens
epididymis
testes
urethra
penis
bulbus glandis
describe the prostate gland.
adds secretions to the sperm as it passes along the vas deferens which contains fructose and enzymes which combined with the sperm where the fluid forms semen that carries sperm into the females reproductive tract where ova can be fertilised
describe the vas deferens.
tubes that carry sperm away from the testes
describe the epididymis.
where the sperm matures and is stored
describe the testes.
where the sperm is produced, made up of thousands of small tubes
describe the urethra.
tube that carries sperm, semen and urine
describe the penis.
located on the outside of the body, semen and urine can pass through
describe the bulbus glandis.
called a knot, is an erectile tissue structure on the penis of canid mammals, during copulation the tissue becomes enlarged and locks the male to the female
how do penis differ between species?
they correspond to the shape of the females vagina.
what’s an os penis?
a bone present in some species like cats and dogs to maintain an erection
what are the three columns of erectile tissue?
urethra, bulbus glandis, os penis.
what is the female reproductive system designed for?
to make eggs, provide perfect environment for fertilisation, protection and care for the foetus until birth.
what does the female reproductive system consist of?
ovaries, oviduct, uterus, cervix, vagina, vulva.
describe the ovaries.
the egg, hormones (oestrogen & progesterone) are made here
describe the oviduct.
egg is released from ovary and passed into here where fertilisation occurs, the fertilised egg travels down oviduct to the uterus where it implants in the uterus lining (pregnancy)
describe the uterus.
thick muscular structure where fertilised egg implants, it stretches to accommodate the growth of the foetus and late contracts to expel the foetus at birth. made up of uterine horns and body (shape varies with species)
describe the cervix.
a muscular barrier to seal the uterus which provides protection for the reproductive system from infection
describe the vagina.
shaped to fit the penis during mating, produces acidic mucus to kill bacteria and prevent infection
describe the vulva.
external part of the female reproductive system, in some species the vulva swells up ad is visual sign of oestrous which shows the male they are ready to mate.
what’s the role of the placenta?
provides a connection between the foetus and maternal tissue to provide nutrition, respiration, digestion, protection and excretion. its a temporary organ that develops along with the foetus along with the foetus and is attached to the uterus. contains both foetal (from umbilical cord) and maternal (from uterine wall) blood vessels
what are the different layers of the uterus, describe them?
- perimetrium - supports shape of uterus
- myometrium - muscular layer that contracts
- endometrium - forms inner layer and where implantation occurs
what are the different shapes of the uterus? (species dependent)
- duplex (rabbit) - 2 uterine horns, 2 cervices, 1 vagina.
- bicornuate (pig) - 2 uterine horns (long), common uterine body, 1 cervix.
- bipartite (cow) - smaller uterine horns.
what is fertilisation?
when DNA from 2 gametes combine.
what is implantation?
when a fertilised egg attaches itself to the uterus lining.
what’s gestation?
the length of time it takes from conception to birth.
state the process of fertilisation to implantation.
oocyte -> fertilisation -> formation of pro-nuclei -> fusion of pro-nuclei -> beginning of cell division -> two-cell state -> four-cell state -> eight-cell state -> free blastocyst -> blastocyst hatching -> nidation.
what’s the gestation length for cats, cows, dogs, pigs and rabbits?
cats - 61-72 days
cows - 279-287 days
dogs - 58-70 days
pigs - 114 -115 days
rabbits - 30-32 days
what causes delays in implantation?
the fertilised egg needs to grow and be able to join onto the uterus lining without embedding in it called centric implantation.
what are the time delays for implantation in rabbits, cats, dogs, pigs, cattle?
rabbits - 6.5 days
cats - 10-12 days
dogs - 6-10 days
pigs - 12-14 days
cattle - 30 days
what is the reproductive system controlled by?
hormones that are released by glands around the body
what are the male and female gametes?
male - sperm
female - ovum
what is the production of sperm known as?
spermatogenesis and is a continuous process in the body
what is the production of ovum known as?
oogenesis and is apart of the menstrual cycle
what’s the process of oogenesis and spermatogenesis called?
gametogenesis
what are the processes of gametogenesis controlled by?
luteinising hormone (LH) & follicle stimulating hormone (FSH)
describe spermatogenesis.
it occurs continuously in the body, LH stimulates testosterone to be produced causing the production of maturation of sperm and inhibit is produced by Sertoli cells and inhibits FSH to stop spermatogenesis
describe oogenesis.
part of the menstrual cycle, FSH stimulates 1 or more follicles to mature and LH stimulates mature follicle to produce more oestrogen and inhibit LH and FSH production however the increase of oestrogen levels stimulate LH and FSH production which leads to ovulation
what’s the role & effect of gonadotropin releasing hormone?
secreted by the hypothalamus and controls other reproductive hormones, light stimulates pineal gland which reduces melatonin secretion allowing GnRH to be secreted which stimulates production of LH and FSH
what’s the role & effect of oestrogen?
rebuilds uterine lining after menstruation and stimulates release of LH by the pituitary
what’s the role & effect of progesterone?
maintains lining of the uterus ready for fertilised egg, inhibits the production of FSH by the pituitary. mostly produced by corpus luteum and in smaller parts of ovaries
what’s the role & effect of testosterone?
produced by testes and enables development of sex organ tissues and secondary sexual characteristics
what’s the role & effect of androgen binding hormone?
produced by seminiferous tubules and helps maintain high concentrations of testosterone in testes
what’s the role & effect of prostaglandins?
helps with urine contractions and are produced by most cells
what’s the role & effect of oxytocin?
produced by hypothalamus and released by pituitary gland. helps stimulate urine contraction and lactation
what’s the role & effect of cortisol?
stress hormone and linked to increase maternal interest in their offspring
what are the different groups of animals in the oestrous cycle? describe them
polyoestrous - become fertile more than once a year (cattle, mice, pigs)
seasonally polyoestrous - more than one oestrous cycle but only certain periods of the year (horses, sheep, goats)
mono oestrous - one oestrous cycle a year (wolves, dogs, foxes, bears)
describe polyoestrous in sheep.
linked to the high light levels causing melatonin to be released into pineal gland, melatonin inhibits release of LH and FSH so when light levels begin to decrease, decreased inhibitation of LH and FSH and presence of LH and FSH increase triggering oestrous
describe the 4 stages in the oestrous cycle.
dioestrous - levels of progesterone peak
pro oestrous - follicle enlarges, decrease in progesterone levels lead to increase in oestrogen levels & GnRH is released
oestrous - oestrogen increases along with LH and FSH leading to ovulation
met oestrous - corpus luteum starts to decay, increasing progesterone levels and inhibits oestrogen release and the level drops
what’s the role of hormones in parturition and lactation?
progesterone levels decrease allowing other hormones to effect uterine muscles (species dependent - drop depends on placenta or corpus luteum)
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oestrogen & oxytocin levels rise leading to uterine contractions and cervical softening (parturition begins)
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relaxin secreted by ovaries relaxes the pelvic ligaments and opens birth canal
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oestrogen and progesterone levels drop allowing prolactin to be secreted triggering lactation
what’s parturition?
giving birth
what’s the role of cortisol in parturition?
the body prioritises making cortisol so progesterone levels drop which causes a high oestrogen: progesterone ratio and leads to early labour
what is lactation?
production of milk by females mammary system
what does lactation do?
allows a mother to provide her offspring with highly nutritious milk to aid its survival. the offspring suckle on the mammary system which stimulates milk release. it is vital that the offspring consume milk as it supports them until weaning and ready to move onto other foods.
what’s the role of hormones in lactation?
starts milk production, stimulates milk let down and then restarts the reproductive process
describe the process of lactation.
nerve impulses caused by :
- calf suckling
- sound of milking machine
- sight of calf
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release of oxytocin
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release of milk
how does prolactin play a part in the process of lactation?
it starts the lactation process as it triggers the mammary gland to start milk production
what happens to the mammary gland in the process of lactation?
begins to release milk due to oxytocin that stimulates due to the offspring suckling at the teat
