XII: Chapter 3- Human reproduction Flashcards
How many testicular lobules are present in each testis?
250
How many seminiferous tubules are present in each testicular lobule?
1 to 3
What lines the inside of the seminiferous tubules in humans?
Male germ cells and sertoli cells
Male germ cells in humans are called
Spermatogonia
Name the ducts of reproductive system of human males in order from seminiferous tubules to ejaculatory duct.
Seminiferous tubules -> Rete testis -> vasa efferentia -> epididymis -> vas diferens -> ejaculatory duct
Secretions of which glands help in lubrication of penis?
Bulbourethral gland
What is the length of a human ovary?
2 to 4 cm
Each ovary is covered by a thin epithelium. True/false?
True
Name the female accessory ducts.
Oviducts, uterus and vagina
The uterus is pear shaped. True/false?
False. The uterus is inverted pear shaped.
How is the uterus (in human females) attached to the pelvic wall?
Through ligaments
Name the layers of uterine wall.
Outer perimetrium
Middle myometrium
Inner endometrium
The cushion of fatty tissue covered by skin and pubic hair in the reproductive system of human females is called
Mons pubis
What are the fleshy folds which extend down from mons pubis and surround the vagina called?
Labia majora
How many mammary lobes are present in each mammary gland?
15-20
The alveoli of mammary glands open into
Mammary tubules
Mammary duct in mammary gland is formed by
All the mammary tubules of each lobe
What do the mammary ducts of mammary gland join and form?
Mammary ampulla
Secondary spermatocytes in males undergo equational division to form
Spermatids
What is the process of transformation of spermatids to spermatozoa called?
Spermiogenesis
What is spermiation?
It is the process of release of spermatozoa from the seminiferous tubule.
Luteinising hormone in males acts on which cells? What are these cells stimulated to do?
LH acts on Leydig cells and stimulates synthesis and secretion of androgens.
Which process do the androgens in male regulate?
Spermatogenesis
FSH in males acts on which cells? What are these cells stimulated to do?
FSH acts on sertoli cells and stimulates the secretion of factors which help in spermiogenesis
How many sperms are produced by human males during coitus?
200 to 300 million sperms
For normal fertility, what percentage of total sperms released by males during coitus must have normal shape and size?
60%
For normal fertility, what percentage of total sperms released by males during coitus must show vigorous motility?
40%
Secretions of which ducts are important for maturation and motility of sperms in humans?
Epididymis, vas deferens, seminal vesicles, and prostrate
How many oogonia are formed in each fetal ovary?
Couple of million
At which stage are the primary oocyte (in human females) arrested?
Diplotene stage of Prophase I
How many primary follicles are left in each ovary at birth?
60,000- 80,000
Which oocyte does a secondary follicle have?
Primary oocyte
Antrum is present in which follicle in a human female?
Tertiary follicle
Inside which follicle does the primary oocyte in females complete its first meiotic division?
tertiary follicle
How many blastomeres does the morula have?
8 to 16
WHat forms chorionic villi?
Trophoblast layer of blastocyst
The levels of cortisol and thyroxine are high during preganancy. True/false?
True
Foetus develops forelimbs by which month of pregnancy?
Second month
By which month of pregnancy do the eyelids separate?
6th month
By which month of pregnancy is the body covered with fine hair?
6th month
What is nidation?
Implantation (of blastocyst)
In which month of pregnancy do the testis of foetus descend into scrotum?
7th month
Where are testis formed in humans?
Abdominal cavity
How do the testis descend from abdominal cavity into scrotum?
Through inguinal canal
What connects the lower end of testis to scrotal wall?
Gubernaculum
Are both testis in males present on the same level?
No, left testis is lower than right testis.
What carries blood vessels, nerves, lymphatics and vas deferens inside inguinal canal?
Spermatic cord
Name the muscle present in scrotum?
Dartos and cremaster muscle
How do the dartos and cremaster muscles maintain the temperature of scrotum in winter?
Dartos- contracts and causes wrinkling of scrotal skin
Cremaster- Contracts and pulls scrotum towards abdomen
Where is testis located in elephants?
Inside abdominal cavity
Where is testis located in whales?
Inside abdominal cavity
What is the outermost double layer peritonium called in testis?
Tunica vaginalis
What is the white fibrous connective tissue surrounding the testis called?
Tunica albuginea
Testicular septa are formed by
Invaginations of tunica albuginea
What is the innermost, highly vascular layer that surrounds the testicular lobules in testis called?
Testicular vasculosa
What is the straight part of seminiferous tubules called?
Tubuli recti
The structure formed by the fusion of tubuli recti is called
Rete testis
How many vasa efferentia are present in a testis?
12-15
Where do sperms mature?
Cauda epididymis
Intra-testicular duct system in humans includes?
Tubuli recti
Rete testis
Vasa efferentia
What is the failure of descent of testis into scrotum called?
Cryptorchidism
Monorchidism is observed in which animal?
Ascaris
Which is the most coiled part of epididymis?
Caput epididymis
How long does the epididymis store sperms?
from one to two weeks upto one months
What is the function of stereocilia in epididymis?
Absorption of fluid in caput
What does the epididymis in humans develop from?
Mesonephric/wolffian duct
What does the seminal vesicle in humans develop from?
Mesonephric/wolffian duct
Fibrinogen is present in which male reproductive gland’s secretions?
Seminal vesicles
Can semen clot?
Yes
Are citrate ions present in semen?
Yes
Where are cowper’s glands located?
In the membranous urethra
Where do the cowper’s glands open?
In the penile urethra
Pre-ejaculatory fluid in males is formed by
Cowper’s glands
Which glands are present on the prepuce of the penis?
Tyson’s glands
What is the function of tyson’s glands?
Lubricated glans penis with their secretions
What is the secretion of tyson’s gland called?
Smegma
What signals the erection of penis?
Nitric oxide
Which somatic nervous system controls the erection of penis?
Parasympathetic nervous system
Which somatic nervous system controls ejaculation?
Sympathetic nervous system
What percent of secretions in semen are of prostate gland?
20-30%
What is the quantity of semen ejected per intercourse?
2-3 ml
Male germ cells in testis are formed from
Mesoderm of yolk sac
WHen do the male germ cells migrate into gonads in humans?
5th week of pregnancy
When do the gonads differentiate into testis and ovary in foetus?
8th week of pregnancy
Sustentacular cells in testis are also called
Sertoli cells
What type of epithelium is germinal epithelium of seminiferous tubules?
Columnar epithelium
Which cells phagocitise dead sperms?
Sertoli cells
What protects the sperms from body’s immune system?
Sertoli cell barrier (blood testis barrier)
Which hormones are secreted by sertoli cells?
Androgen binding protein
Inhibin
Mullerian inhibitory/ anti mullerian hormone
Which hormone concentrates testosterone in seminiferous tubules?
Androgen binding protein
What is the function of inhibin secreted by sertoli cells?
Inhibits FSH
What is the function of mullerian inhibitory hormone?
It inhibits mullerian duct in embryonic life
When does the luminal part of seminiferous tubule form?
At puberty
What are the phases of spermatogenesis?
Multiplication phase
Growth phase
Maturation phase
Spermiogenesis
What happens in the multiplication phase of spermatogenesis?
Mitosis of spermatogonia
What happens in the maturation phase of spermatogenesis?
Meiosis of primary spermatocytes leading to the formation of spermatids
How many days does it take on average to form mature sperms?
74 days
Are sperms of all animals flagellated?
Yes (exception- Ascaris)
Which is the smallest part of a sperm?
Neck
Which part of sperm contains sperm lysins?
Acrosome
What type of sperm lysin is present in sperms?
Hyaluronidase
What is the difference between the proteins found in normal human cell when compared to sperm?
Sperm has no histone proteins but other cells do.
How many centrioles are present in a sperm?
2
What is the function of proximal centriole in sperms?
Role in first cleavage
What is the function of distal centriole in sperms?
Forms basal body for axoneme
How many mitochondria are present in sperms?
20-25
How are mitochondria arranged in a sperm?
They are spirally arranged around axoneme
What is the arrangement of microtubules found in flagella of sperms?
9+2
WHat is the sheath of middle piece of sperm called?
Manchette
What is andropause?
Reduced secretion of testosterone in aging males (50+)
What is aspermia?
Semen is not produced
What is azospermia?
Semen does not contain sperms
What is oligospermia?
Sperm count below 15-20 million sperm per milliliter (mL)
What is inguinal hermia?
Passage of dislocated intestine though inguinal canal
Name the female reproductive glands?
Mammary glands, bartholian gland, skene gland
What attaches ovary to uterus?
Ovarian ligament
What attaches ovary to body wall?
Mesovarium
What kind of tissue is the stroma of ovary?
Fibrous connective tissue
IN which portion of stroma of ovary are the different follicles present?
Cortex
What are salpinges?
Fallopian tube
Which is the widest and longest part of fallopian tube?
Ampulla
Which is the smallest part of fallopian tube?
Interstitium/intramural part
What is the length of fallopian tube?
10-12 cm
What is the fallopian tube called in non mammalian vertebrates?
Oviduct
What are the non ciliated cells present in fallopian tube called?
Peg cells
What is the function of peg cells of fallopian tube?
Secrete tubular fluid to nourish sperms/eggs/zygote
Is the uterus situated in front of the rectum or behind?
Behind
Is the uterus situated in front of the urinary bladder or behind?
Front
How is the uterus positioned in humans?
Anteverted
Do humans have simplex uterus?
Yes
How many sphincters are present in the cervix?
Internal os, external os
Which is the strongest and most powerful sphinctre of the body?
External os of cervix of females
Which muscles are present in the myometrium of uterus?
Circular, longitudinal and oblique
What tissues is the endometrium made of?
Columnar epithelium
What are the two layers of endometrium of uterus?
Stratum basalis
Stratum functionalis
What type of blood vessels are present in stratum basalis of endometrium of uterus?
Straight blood vessels
What type of blood vessels are present in stratum functionalis of endometrium of uterus?
Tortuous blood vessels
How does progesterone change tubular glands of endometrium of uterus?
Makes the corckscrew shaped
What secretes uterine milk in humans?
Corkscrew shaped tubular glands present in stratum functionalis of endometrium of uterus