Human Repro NCERT Flashcards
Humans are ____ (asexually/sexually) reproducing and ___.
asexually; Viviparous
(Viviparous means Giving direct birth)
The reproductive events in humans, which includes formation of gametes is called ___.
Gametogenesis
Transfer of sperm into the female genital tract is called
Insemination
Fusion of male and female gamete that leads to formation of a zygote is called
Fertilization
Formation of the zygote is followed by formation and development of ___ and its attachment to the ___.
Blastocyst; Uterine wall
__ refers specifically to the attachment of the fertilized egg to the uterine lining.
Implantation
The average duration of human pregnancy is about nine months which is called __
Gestation period (Embryonic development)
Delivery of the baby is called __
Parturition or Childbirth
The Male reproductive system is located in the __
Pelvis region
__ system includes a pair of testes along with accessory ducts, glands, and the external genitalia.
Male reproductive system
The __ are the primary male reproductive organ
Testes
Secondary sex organs in a male are
Accessory ducts, glands, and the external genitalia
The testes are situated outside the __ cavity within a pouch called __
abdominal cavity; Scrotum
The scrotum helps in maintaining the __ of the testes. Why is it necessary for?
Low temperature;
2-2.5°C lower than the normal internal body temperature is necessary for spermatogenesis
In adults, each testis is __ in shape, with a length of about __ and a width of about __
Oval; 4 to 5 cm; 2 to 3 cm
Testis is covered or not?
Testis is covered by a dense covering.
Each testis has about __ compartments.
250 compartments
Each testis has about 250 compartments called __
Testicular lobules
Each testicular lobule contains one to three highly coiled ___ in which sperms are produced.
Seminiferous tubules
Each seminiferous tubule is lined on its inside by two types of cells called __ and __
Male germ cells (spermatogonia) and Sertoli cells
Male germ cells undergo __ divisions, finally leading to sperm formation.
Meiotic divisions
Sertoli cells provide __ to the germ cells.
nutrition
The region outside the seminiferous tubule is called?
Interstitial Space
Interstitial Space contains __
small blood vessels and interstitial cells or Leydig cells
__ cells synthesize and secrete testicular hormones called androgens
Leydig cells
Leydig cells synthesize and secrete testicular hormones called?
Androgens
The male sex accessory ducts include?
Retie testis, Vasa efferentia, epididymis and vas deferens
The seminiferous tubules of the testis open into the vasa efferentia through __
Rete testis
The Vasa efferentia leave the testis and open into __ located along the __ surface of each testis.
Epididymis; posterior surface
The epididymis leads to ____ that ascends to the abdomen and loops over the __
Vas deferens; Urinary Bladder
The vas deferens receives a duct from the ___ and opens into the urethra as the __
seminal vesicle; Ejaculatory duct
The ducts store and transport the sperms from the testis to the outside through ____
urethra
The urethra originates from the __
Urinary Bladder
The urethra originates from the urinary bladder and extends through the penis to its external opening called?
Urethra Meatus
___ is the male external genitalia. It is made up of a special tissue that helps in the erection of the penis to facilitate __
Penis; Insemination
The enlarged end of the penis is called __
Glans penis
Glans penis is covered by a loose fold of skin called __
Foreskin
Male accessory glands include -
Paired seminal vesicles, prostate, and paired bulbourethral glands
The secretion of male accessory glands constitutes ____, which is rich in __, __, and __.
Seminal plasma;
Fructose, Calcium, and certain enzymes
The secretions of ___ glands also help
in the lubrication of the penis.
Bulbourethral glands
The female reproductive system consists of a pair of ovaries along with __
A pair of oviducts, uterus, cervix, vagina and the external genitalia
The female reproductive system is located in the __
Pelvic region
Parts of the female reproductive system, along with a pair of the __ are integrated structurally and functionally to support the processes of ovulation, fertilization, pregnancy, birth, and child care.
Mammary glands
__ are the primary female sex organs that produce the female gamete (ovum) and several steroid hormones.
Ovaries
Generally, most ovarian hormones chemically are __
Steroid hormones
Estrogens and progesterone are __ hormones.
Ovarian hormones
The ovaries are located one on each side of the __
Lower abdomen
Each ovary is about __ in length and is connected to the pelvic wall and uterus by ligaments.
2 to 4 cm
Ovaries are connected to the pelvic wall and uterus by __
Ligaments
Each ovary is covered by a thin epithelium which encloses the __
Ovarian Stroma
The stroma is divided into __ zones.
Two
The stroma is divided into two zones -
A peripheral cortex and an inner medulla
The oviducts (fallopian tubes), uterus, and vagina constitute the __
Female accessory ducts
Each fallopian tube is about __ long
10-12 cm
The part closer to the ovary is the funnel-shaped __
Infundibulum
The edges of the infundibulum possess finger-like projections called __
Fimbriae
Fimbriae help in the collection of the ovum after __
Ovulation
The part of the oviduct closer o the ovary is __
Infundibulum
The wider and second part of the oviduct is called __
Ampulla
The last and narrow part of the oviduct is called __
Isthmus
Isthmus has a ___, and its joins the __
narrow lumen; Uterus
The uterus is also called __
Womb
The shape of the uterus is like an __
Inverted pear
____ is supported by ligaments attached to the pelvic
wall
Uterus
The uterus opens into the vagina through a __
Narrow cervix
The cavity of the cervix is called __
Cervical canal
Cervical canal, along with vagina forms the __
Birth canal
The wall of the uterus has __ layers of tissue
3 layers
The external ___ (thick/thin) membranous layer of the uterus is called __.
thin; External thin membranous perimetrium
The Middle ____ (thick/thin) layer of smooth muscles in the uterus is called __
thick; Myometrium
The inner glandular layer of the uterus is called __ that lines the uterine cavity.
Endometrium
The __ undergoes cyclical changes during the menstrual cycle.
Endometrium
The ____ exhibits strong contraction during
delivery of the baby.
Myometrium
The female external genitalia include __
Mons pubis, labia majora, labia minora, hymen and clitoris
In the female external genitalia, a cushion-like fatty tissue covered by skin and pubic hair is called __
Mons pubis
____ are fleshy folds of tissue which extend down from the Mons pubis and surround the vaginal opening.
Labia majora
____ are paired folds of tissue under the labia major.
Labia minora
The opening of the vagina is often covered partially by a membrane called __.
Hymen Membrane
A tiny finger-like structure, which lies at the upper junction of the two labia minora above the urethral opening, is called __
Clitoris
The hymen is often torn during the
First coitus (intercourse)
In some women, the hymen persists even after coitus
Hymen can also be broken by some incidents like __
i) Sudden fall or jolt,
ii) Insertion of a vaginal tampon,
iii)Active participation in some sports like horseback riding, cycling, etc.
The presence or absence of a hymen is not a reliable indicator of __
Virginity or sexual experience
A functional mammary gland is characteristic of all __ mammals.
Female
The mammary glands are paired structures called ___ that contain ____ tissue and variable amount of fat.
breasts; glandular
The glandular tissue of each breast is divided into __
15-20 mammary lobes
Mammary lobes containing clusters of cells are called __
Alveoli
The cells of Alveoli secrete milk, which is stored in the __ of Alveoli.
Cavities (Lumens)
The Alveoli open into __
Mammary Tubules
The tubules of each lobe joins to form a __
Mammary duct
Several mammary ducts join to form a wider ___ which is connected to __ through which milk is sucked out
mammary ampulla; Lactiferous duct
The primary sex organs - Testis in males & Ovaries in females - produce gametes (i.e., sperms and ovum, respectively) by the process called?
Gametogenesis
In testis, the immature male germ cells (Spermatogonia) produce sperms by ___ that begin at ___.
Spermatogonia; puberty
Each spermatogonium is __ (Haploid/Diploid)
Diploid
Each spermatogonium contains __ chromosomes.
46 chromosomes
Some of the spermatogonia called primary spermatocytes periodically undergo __
Meiosis
A primary spermatocyte completes the first meiotic division (reduction division), leading to the formation of two equal, haploid cells called?
Secondary spermatocytes
A secondary spermatocyte has only __ chromosomes.
23 chromosomes
The secondary spermatocytes undergo the second meiotic division to produce four equal, __
Haploid spermatids
The spermatids are transformed into __ by the process called spermiogenesis
Spermatozoa (sperms)
After spermiogenesis, sperm heads become embedded in the ___.
Sertoli cells
After spermiogenesis, sperm heads become embedded in the Sertoli cells and are finally released from the seminiferous tubules by the process called?
Spermiation
Spermatogenesis starts at the age of puberty due to the significant increase in the secretion of ___ hormone.
Gonadotropin-releasing hormone (GnRH)
GnRH is a ____ hormone.
Hypothalamus hormone
The increased levels of GnRH act at the:-
Anterior pituitary gland
GnRH stimulates secretion of two gonadotropins -
Luteinizing hormone (LH) and Follicle Stimulating Hormone (FSH)
LH acts at the __ cells and stimulates the synthesis and secretion of androgens.
Leydig cells
LH acts at the Leydig cells and stimulates synthesis and secretion of
Androgens
FSH stimulates the secretion of some factors which help in the process of __
Spermiogenesis
Sperm is a microscopic structure composed of __
Head, neck, a middle piece, and a tail
A __ envelops the whole body of sperm
Plasma Membrane
The sperm head contains an elongated __
Haploid nucleus
The anterior portion of the sperm is covered by a cap-like structure called __
Acrosome
The acrosome is filled with enzymes that help __ of the ovum
Fertilization of the ovum
The middle piece of a sperm possesses __
Mitochondria
Sperm motility is essential for __
Fertilization
The human male ejaculates about __ million sperms during a coitus
200 to 300 million
Secretions of __, __, __ and __ are essential for the maturation and motility of sperms
Epididymis, Vas deferens, seminal vesicles and prostate
The seminal plasma, along with the sperms constitute the __
Semen
The functions of the male sex accessory ducts and glands are maintained by the __ hormones
Testicular hormones (androgens)
The process of formation of a mature female gamete is called __
Oogenesis
Oogenesis initiated during the __ stage
Embryonic development
Gamete mother cells are called __
Oogonia
A couple of million gamete mother cells (oogonia) are formed within each __.
Fetal Ovary
Gamete mother cells start division and enter into Prophase-I of the meiotic division and get temporarily arrested at a stage called __
Primary oocytes
Each primary oocyte gets surrounded by a layer of granulosa cells and is called the __
Primary follicle
A large number of primary follicles degenerate during the phase from birth to __
Puberty
The primary follicles get surrounded by more layers of granulosa cells and a new theca and are called?
Secondary follicles
The secondary follicle soon transforms into a:-
Tertiary follicle
The secondary follicle soon transforms into a tertiary follicle which is characterized by a fluid-filled cavity called?
Antrum
The primary oocyte within the tertiary follicle grows in size and completes its first:-
Meiotic division
The first meiotic division is an unequal division resulting in the formation of a large haploid __ and a tiny first __.
Secondary oocyte; Polar body
The __ oocyte retains the bulk of the nutrient-rich cytoplasm of the primary oocyte
Secondary oocyte
The tertiary follicle further changes into the __
Mature follicle
A mature follicle is also known as __
Graafian follicle
The secondary oocyte forms a new membrane called __ surrounding it.
Zona pellucida
The Graafian follicle ruptures to release the secondary oocyte (ovum) from the ovary by the process called?
Ovulation
The cycle of events starting from one menstruation till the next one is called the:-
Menstrual cycle
The first menstruation begins at puberty and is called?
Menarche
The cycle starts with the menstrual phase when menstrual flow occurs, and it lasts for __ days
3-5 days
The menstrual flow results due to the breakdown of the endometrial lining of the uterus and its blood vessels which forms a liquid that comes out through __
Vagina
Lack of menstruation may be indicative of __
Pregnancy
Some other causes of lack of menstruation are __
Stress, poor health, etc
The menstrual phase is followed by the __ phase
Follicular Phase
During __ phase, the primary follicles in the ovary grow to become a fully mature Graafian follicle
Follicular phase
During the follicular phase, the endometrium of uterus regenerates through
Proliferation
During the menstrual cycle, changes in the ovary and the uterus are induced by changes in the levels of __ and __ hormones
Pituitary and ovarian hormones
The secretion of __ increases gradually during the follicular phase
Gonadotropins
Rapid secretion of LH leading to its maximum level during the mid-cycle called __ induces rupture of Graafian follicle
LH surge
Ruptured Graafian follicle releases __
Ovum
Release of Ovum from the ruptured Graafian follicle is called __
Ovulation
The ovulation is followed by the luteal phase, during which the remaining parts of the Graafian follicle transform as the:-
Corpus luteum
Corpus luteum secretes large amounts of:-
Progesterone
Progesterone is essential for the maintenance of the __
Endometrium
During pregnancy, all events of the __ stop and there is no __
Menstrual cycle; menstruation
In the absence of fertilization, the __ degenerates
Corpus luteum
The disintegration of the endometrium leads to menstruation, making a:-
New cycle
In human beings, menstrual cycles cease around 50 years of age; that is termed as __
Menopause
Cyclic menstruation is an indicator of normal reproductive phase and extends between ____ and ____.
Menarche and Menopause
During copulation (coitus) semen is released from the penis into the __
Vagina
The motile sperms swim rapidly, pass through the cervix, enter into the uterus and finally reach the __ of the fallopian tube
Ampullary region
Fertilization can only occur if the ovum and sperms are transported simultaneously to the __
Ampullary region
The ovum released by the ovary is also transported to the __ region, where fertilization takes place
Ampullary
The process of fusion of a sperm with an ovum is called __
Fertilization
During fertilization, a sperm comes in contact with the __ layer of the ovum
Zona pellucida layer
When sperm comes in contact with the Zona pellucida layer, it includes changes in the membrane that blocks the entry of:-
Additional sperms
Blocking of the entry of additional sperms ensures the entry of only:-
One sperm
The secretions of the acrosome help the sperm enter into the ____ of the ovum through the Zona pellucida
Cytoplasm
Entry of sperm induces the completion of the meiotic division of the:-
Secondary oocyte
The haploid nucleus of the sperm and that of the ovum fuse together to form a:-
Diploid zygote
The chromosome pattern in the human female is:-
XX
The chromosome pattern in the human male is:-
XY
In the male gametes (sperms) the sex chromosome could be either __ or __
Either X or Y
After the fusion of the male and female gametes, the zygote would carry either __ or __
Either XX or XY
The zygote carrying XX would develop into a __ baby
Female baby
The zygote carrying XY would develop into a __ baby
Male baby
Scientifically, it is correct to say that the sex of the baby is determined by the __ and not by the __
Father; Mother
The meiotic division starts as the zygote moves through the isthmus of the oviduct called?
Cleavage
2,4,8 and 16 daughter cells formed by cleavage of a fertilized ovum are called __
Blastomeres
The embryo with 8 to 16 blastomeres is called a __
Morula
The morula continues to divide and transforms into __ as it moves further into the uterus
Blatocyst
The blastomeres in the blastocyst are arranged into an outer layer called?
Trophoblast
An inner group of cells attached to the trophoblast called the __ mass
Inner cells mass
The trophoblast layer then gets attached to the __
Endometrium
The inner cell mass gets differentiated as the __
Embryo
The blastocyst becomes embedded in the endometrium of the uterus, called __
Implantation
After implantation, finger-like projections appear on the trophoblast called?
Chorionic Villi
Chorionic Villi are surrounded by the __ tissue and maternal blood.
Uterine tissue
The Chorionic villi and uterine tissue become interdigitated with each other and jointly form a structural and functional unit between the developing embryo and maternal body called?
Placenta
The placenta is connected to the embryo through an __ cord
Umbilical cord
The umbilical cord helps in the transport of substances to and from the __
Embryo
Placenta also acts as an __ tissue and produces several hormones.
Endocrine tissue
In the layer phase of pregnancy, a hormone called __ is also secreted by the ovary
Relaxin
The hormones produced during pregnancy are __
hCG, hPL and relaxin
During pregnancy the levels of other hormones like __, __, __, __, __ etc., are increased several folds in the maternal blood
Estrogens, progestogens, cortisol, prolactin, and thyroxine
Increasing the production of hormones like estrogens, progesterone, cortisol, etc., is essential for supporting the __, __, and __.
Fetal growth, metabolic changes in the mother & maintenance of pregnancy
Immediately after implantation, the inner cell mass differentiates into an outer layer called __ and an inner layer called __
Ectoderm; Endoderm
A __ soon appears between the ectoderm and the endoderm
Mesoderm
The three layers - ectoderm, mesoderm, and endoderm give rise to all __ in adults.
tissues
The inner cell mass contains certain cells called __ cells which have the potency to give rise to all the tissues and organs.
Stem cells
The human pregnancy lasts for -
9 months
In human beings, after __ months of pregnancy, the embryo’s heart is formed
one
The first sign of a growing fetus may be noticed by listening to the heart sound carefully through the __
Stethoscope
By the end of the __ month of pregnancy, the fetus develops limbs and digits
second month of pregnancy
By the end of __ of pregnancy, most of the major organ systems are formed
12 weeks (1st trimester)
The first movements of the fetus and the appearance of hair on the head are usually observed during the __ month
fifth month
By the end of about __ of pregnancy, the body is covered with fine hair, eyelids separate, and eyelashes are formed.
24 weeks (2nd trimester)
By the end of about __ of pregnancy, the fetus is fully developed and is ready for delivery.
9 months
The average duration of human pregnancy is about nine months which is called?
Gestation period
Vigorous contraction of the uterus at the end of pregnancy causes __ of the fetus
Expulsion/delivery
The process of delivery of the fetus (childbirth) is called __
Parturition
Parturition is induced by a complex __ mechanism
neuroendocrine
The signals for parturition originate from the fully developed fetus and the __
Placenta
The signals for parturition originate from the fully developed fetus and the placenta, which induce mild uterine contractions called?
Foetal ejection reflex
Foetal ejection reflex triggers the release of oxytocin from the:-
Maternal pituitary
Oxytocin acts on the uterine muscle and causes stronger __ contractions
Uterine contractions
Stronger uterine contractions stimulate further secretion of __
Oxytocin
The stimulatory reflex between the __ contraction and __ secretion continues resulting in stronger and stronger contractions
Uterine; oxytocin
Contractions lead to expulsion of the baby out of the uterus through the __
Birth canal
Soon after the infant is delivered, the placenta is also expelled out of the __
Uterus
The mammary glands of the female undergo differentiation during pregnancy and starts producing __ towards the end of pregnancy
milk
Mammary glands start producing milk towards the end of pregnancy by a process called?
Lactation
The milk produced during the initial few days of lactation is called __
Colostrum
Colostrum contains several __ absolutely essential to develop resistance for the new-born babies
Antibodies
Antibodies present in colostrum are essential to develop __ for the new-born babies
resistance
