$\huge \sf Human \ Reproduction-I$

Question

abhisar · Answer

$\hspace{70pt}\huge \sf \text{General introduction}$
$\bigstar$ Humans are sexually reproducing and viviparous animals.
$\bigstar$ Sexual reproduction in humans involve following events
  $\bullet$ $\bf Gametogenesis$, which stands for the formation of gametes.
  $\bullet$ $\bf Insemination$, which stands for the transfer of sperms from the male to female body
  $\bullet$ $\bf Fertilisation$, which stands for the fusion of sperms with ovum.
  $\bullet$ $\bf Implantation$, it refers to the process in which the  embryo at blastocyst stage adheres to the wall of  the uterus.
  $\bullet$ $\bf Gestation$, it refers to the period of development in the uterus from conception until birth
  $\bullet$ $\bf Parturition$, it refers to the process by which a fully developed baby is ejected outside the body of mother.
$\bigstar$ To continue its own race, an organism produces offsprings like its own by the process of reproduction. Humans reproduce sexually in which two partners are involved. Both partners produce male and female gametes respective to their gender which combine or fuses to form a new individual. Formation of gametes take place in reproductive organs.

abhisar · Answer

$\hspace{100pt}\large \sf \ Primary \ sex \ organ$

These are the $\bf essential~organs~which~forms~sex~gametes.$
$\bullet$ Males → Testes
$\bullet$ Females → Ovaries
$\hspace{100pt}\large\sf Secondary~sex~organs$
These $\bf form~passage~for~the~gametes~and~help~the~union~of~\ \hspace{-26pt}male~and~ female~gametes.$
$\bf Males$
$\bullet$ Epididymis
$\bullet$ Vas deferens
$\bullet$ Seminal vesicle
$\bullet$ Prostrate
$\bullet$ Bulbourethral gland
$\bullet$ Penis
$\bf Females$
$\bullet$ Fallopian tubes
$\bullet$ Uterus
$\bullet$ Vagina

abhisar · Answer

$\hspace{65pt}\large \sf \text{Secondary sex characters or accessory sex organs}$
These are the features that appear during puberty, especially those that distinguish the two sexes of a species, but are not directly part of reproductive system. Ex. facial hairs, adam’s apple, breasts etc. $\underline{\sf \color{blue}{\text{Breasts are secondary sex character or accessory sex organs and not secondary}}}$$\underline{\sf\color{blue}{\ sex\ organs.}}$

abhisar · Answer

$\hspace{80pt}\huge \sf Male~reproductive~system$
$\bullet$ It is located in the pelvic region outside the body.
$\bullet$ It consists of $\bf testes + external~genetalia + secondary~sex~organs.$
$\bullet$ Testes or testicles are contained within an extension of the abdomen called the $\bf scrotum~or~scrotal~sacs$. It is a bag like structure situated below and outside the abdominal cavity.
$\bullet$ Scrotal sac helps in maintaining the low temperature of testis $\bf (2-2.5°C$ lower than the body temperature) required for sperm production.
$\bullet$ Scrotum is internally lined by $\bf dartos~muscles~and~spermatic~fascia.$
$\bullet$ $\bf Dartos~muscle$ helps in regulation of temperature of the testes. It promotes spermatogenesis by expanding or contracting to wrinkle the scrotal sac. Contraction reduces the surface area available for heat loss, thus reducing heat loss and warming the testicles. Expansion increases surface area available for heat loss and thus reduces the temperature of testicles. Dartos muscle works in conjunction with the cremaster muscle to elevate testes.
$\bullet$ $\bf Cremaster~muscle$ is a thin layer of skeletal muscle found in the inguinal canal and scrotum. It surrounds the testis and spermatic cord. The cremaster muscle is a paired structure, there being one on each side of the body.
$\bullet$ Each testes is attached to the walls of scrotal sac with a group flexible and elastic fibres. This group of fibres is called as $\bf gubernaculum~or~mesorchium.$
$\bullet$ Testes is attached to the dorsal body wall of abdominal cavity through $\bf spermatic~cord.$ It is made up of spermatic fascia and elastin fibres. Following are the contents of spermatic cord
  ♦ Vas deferens.
  ♦ Gonadal vein.
  ♦ Gonadal arteries.
  ♦ Nerves.
  ♦ Lymphatics.
$\bullet$ If testes does not descend down to the scrotal sac during birth then the testes becomes non functional and the condition is called as $\bf Cryptorchidism.$
$\bullet$ When undescended testes are brought down to the scrotal sac by surgical process then it is called as $\bf Orchiopexy.$
$\bigstar$ Crushing of testes in bulls to make it bullocks is called as castration. It makes them more obedient by decreasing the testosterone level.
$\bigstar$ In some animals the testis descends only in the breeding season. Ex. order rodentia, order chiroptera (Bat).
$\bigstar$ Testes of some animals are permanently placed in abdominal cavity. Their scrotum is vestigial organ. Ex. prototherian, animals of the order edentata (armadillo, pangolin, sloth), order proboscidea (elephant), order sirenia (sea cows), order cetacea (whales, dolphins, and porpoises).
$\bullet$ Each testis is connected to the abdominal cavity through a passage called as inguinal canal. Testes descends down to the scrotal sac from the abdominal cavity at the time of birth through this canal. Sometimes inguinal canal may tear leading to abnormal protrusion of abdominal contents like loops of intestine into inguinal canal. This condition is called as $\bf inguinal~hernia.$

anonymous · Answer

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abhisar · Answer

$\huge\sf\color{green}{\text{✌ﾟ$\ddot\smile$ ✌ﾟ}}$

somy · Answer

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anonymous · Answer

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