SlideShare a Scribd company logo
ANIMAL REPRODUCTION 
Mammalian Reproduction 
1. Human reproduction involves intricate anatomy and complex behavior 
2. Spermatogenesis and oogenesis both involve meiosis but differ in three 
significant ways
Human reproduction involves intricate anatomy 
and complex behavior 
 Reproductive Anatomy of the Human Male. 
The mammalian male reproductive system includes the 
external genitalia and the internal reproductive organs 
 The scrotum and the penis are the external components of the 
reproductive system. 
 The internal reproductive organs consist of 
 the gonads (testes) that produce gametes (sperm cells) and 
hormones 
accessory sex glands that secrete products essential to sperm 
movement 
A set of ducts that carry the sperm and glandular secretion. 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Reproductive Anatomy of the Human Male 
Fig. 46.8
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings 
Fig. 46.8
The scrotum is a fold of the body wall which aids the reproductive 
process in different ways: 
Testes develop in the abdomen and descend into the scrotum 
just before birth. This is important since sperms can not develop 
at normal body temperature. 
By having the testes hanging outside the abdominal cavity in 
the scrotum, the temperature is 2° C lower and sperm production 
can occur 
In many rodents, the testes are drawn back into the abdominal 
cavity, and sperm maturation is interrupted between breeding 
seasons. 
Some mammals whose body temperature is low enough to 
allow sperm maturation, such as monotremes, whales and 
elephants retain the testes within the abdominal cavity 
permanently.
Internal male reproductive organs are: 
 The gonads or Testes (singular testis) are the male gonads. 
 highly coiled tubules surrounded by layers of connective tissue. 
These tubules are the seminiferous tubules. 
Sperm form in seminiferous tubules. 
Leydig cells, scattered between seminiferous tubules produce 
testesterone and other androgens (male sex hormones). 
 Sperm pass from the seminiferous 
tubules into the tubules of the 
epididymis. 
 It takes 20 days for sperms to pass 
through the 6-m long tubules of each 
epididymis of a human male 
 During this passage the sperm 
become motile and gain the ability 
to fertilize.
Fig. 46.11 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
 At ejaculation, sperm are forced from the epididymis, through the vas 
deference which is a muscular duct running from epididymis and out of 
the scrotum around and behind the urinary bladder to the ejaculatory 
duct. 
 Each ejaculatory duct forms by the joining of the vas deferens duct 
with the duct from the seminal vesicle. 
 The two ejaculatory 
ducts opens into the 
urethra. 
The urethra is the 
tube that: 
Drains both the 
excretory and 
reproductive systems 
Runs through the penis and opens to the outside at the tip of the penis.
There are three sets of accessory glands associated with the male 
system. These glands add their secretions to the semen (the fluid that 
is ejaculated): 
(1) A pair of seminal vesicle is located below and behind the bladder 
and empty into the ejaculatory duct 
Their secretion is thick, yellow and 
alkaline 
 They secrete a fluid containing 
mucous, a coagulating enzyme 
(causes semen to coagulate after 
deposited in female), fructose 
(provides energy for sperm) and 
prostaglandins (stimulates female 
uterine contractions to help move 
semen to the uterus 
Seminal vesicle secretion make up 
about 60% of the total semen 
volume.
(2) The prostate gland is the largest of the semen-secreting glands: 
Surrounds the upper portion of the urethra and empties directly into it. 
It secretes a thin, milky fluid that contains anticoagulating enzymes, 
citrate (a sperm nutrient) and is slightly acidic. 
Benign (noncancerous) 
enlargement of the prostate 
occurs in more than half of all 
men over the age of 40 and in 
virtually all men over 70. 
Prostate cancer is one of the 
most common cancer in men, it 
is treated surgically or with 
drugs that inhibit gonado-tropins, 
resulting in reduced 
prostate activity and size.
(3) The bulbourethral glands are a pair of small glands below the 
prostate that empty into the urethra at the base of the penis: 
 It secretes a clear mucous before ejaculation 
 The fluid neutralizes any acidic urine remaining in the urethra. 
• A man usually ejaculates about 2 – 5 
ml of semen containing about 50–130 
million sperm/ml. 
•Once in the female reproductive tract, 
prostaglandins in the semen stimulate 
contractions of the uterine muscles, 
which help move the sperm up the 
uterus. 
•The semen is slightly alkaline 
and this neutralizes the acidic 
environment of the vagina, protecting 
the sperm and increasing their motility. 
•When first ejaculated the semen coagulates, making it easier for uterine contractions 
to move it along; then anticoagulants liquefy the semen and the sperm begins 
swimming through the female tract.
The human penis is composed of three layers of spongy erectile 
tissue. 
 During sexual arousal the erectile tissue fills with blood from 
arteries. 
 The penis of some mammals (rodents, raccoons walruses ) 
possesses a baculum, a bone that helps stiffen the penis. 
 Temporary impotence, a reversible inability to achieve an 
erection can result from the consumption of alcohol and certain 
drugs, and emotional problems: 
 Several drugs (e.g.Viagra® ) and penile implant devices are 
available for men with nonreversible impotence due to 
nervous system, or circulatory problems. 
 External structure of the penis is covered by a thick skin: 
 The head of the penis,the glans penis is covered by thinner 
skin. The glans is covered by the prepuce which may be 
removed by circumcision.
Reproduction
 Reproductive Anatomy of the Human Female. 
 External reproductive structures consists of two sets of 
labia surrounding the clitoris and vaginal opening. 
 Internal reproductive organs consist of a pair of gonads 
(ovaries) and a system of ducts and chambers. 
 The role of the ducts and chambers are involved with gamete 
movement and embryo development . 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 46.9 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 46.9 
 Ovaries are the female gonads. 
 Located in the abdominal cavity and enclosed in a tough 
protective capsule.. 
 Attached by mesentery to, the uterus. 
 Each ovary contains follicles.
 Each follicle consists of one egg cell 
surrounded by one or more layers of 
follicle cells. 
 Follicles produce the primary female 
sex hormones: estrogens. 
 Follicle cells nourish and protect the 
developing egg cell. 
 A woman is born with about 400,000 
follicles. 
 Only several hundred of which 
will release eggs during a 
female’s reproductive years. 
 Starting at puberty and continuing to menopause, one follicle 
matures and releases its egg cell during each menstrual cycle. 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
 During ovulation, the egg is expelled from the follicle. 
 After ovulation the remaining follicular tissue 
develops into the corpus luteum. 
Secretes estrogens and progesterone. 
Maintain the uterine 
lining during pregnancy. 
If the egg is not fertilized 
(pregnancy does not 
occur) the corpus luteum 
degenerates and a new 
follicle matures during 
the next cycle. 
Fig. 46.10 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Reproduction
 At ovulation the egg is expelled into the abdominal 
cavity near the funnel-shaped opening of the 
oviduct or fallopian tube. 
The cilia-lining the oviduct draws in the egg. 
Cilia convey the egg through the oviduct to the uterus. 
 The uterus (or Womb) is a thick muscular 
organ that can expend during pregnancy to 
accommodate a 4 kg fetus. 
 The inner uterine lining , the Endometrium is 
richly supplied with blood vessels
The remaining female 
reproductive structures 
are: 
 Cervix: neck of the 
uterus, the opens into 
the vagina. 
Vagina: thin-walled 
chamber that forms the 
birth canal and is the 
repository for sperm 
during copulation.
Hymen: A vascularized membrane, usually covers the vaginal 
opening from birth until ruptured by vigorous physical activity 
or sexual intercourse. 
 Vestibule: Chamber-like area bordered by the 2 pairs of skin 
folds covering vaginal opening and the separate urethral 
opening. 
 Labia minora: The slender skin folds bordering the vestibule. 
 Labia majora: A pair of thick , fatty ridges enclosing and 
protecting the labia minora and vestibule. 
 Clitoris: bulb of erectile tissue found at the front edge of the 
vestibule. It is covered by a prepuce. It is richly supplied with 
nerve endings and is one of the most sensitive points of sexual 
stimulation. 
 Bartholin’s glands are small glands located near the vaginal 
opening that secrete mucous into the vestibule during sexual 
arousal. 
 The mucous facilitates intercourse by lubricating the vagina
Mammary glands. 
 Are present in both males and females but 
normally function only in women. 
 They are important to mammalian reproduction, 
although not actually a part of the reproductive 
system. 
 Consist of small sacs of epithelial tissue that secrete milk. 
 Milk drains into a series of ducts opening at the nipple. 
 In nonlactating female mammal, the mammary glands are 
composed primarily of fatty (adipose) tissue. 
 In males, the low level of estrogen prevents the 
development of both the secretory apparatus and the fat 
deposits, so male breasts remain small, and nipples are not 
connected to ducts. 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Spermatogenesis and oogenesis both involve 
meiosis but differ in three significant ways 
 Spermatogenesis is the production of mature sperm 
cells in adult males. 
 A continuous and process in the adult male. 
 Each ejaculation contains 100 – 650 million sperm. 
 Occurs in seminiferous tubules. 
 Begins with the differentiation of primordial germ cells into 
spermatogonia in embryonic testes. Both types of cells are diploid. 
 The spermatogonia are located near the outer wall of the seminiferous 
tubules. They increase in number through repeated mitosis throughout 
development and early life. 
 When the male matures, spermatogonia begin to differentiate into 
primary spermatocyte which are diploid. 
 Primary spermatocyte will pass through several stages before giving rise 
to mature spermatozoa: 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 46.11
 Each primary spermatocyte undergoes meiosis I to 
produce two haploid secondary spermatocytes. 
Each secondary spermatocyte undergoes meiosis II to form 
two spermatids. 
Thus, each primary spermatocyte forms four haploid 
spermatids through meiotic division. 
 Each spermatid becomes associated with a large Sertoli cell 
from which it receives nutrients. 
 All spermatids differentiate into mature spermatozoa. 
 During spermatogenesis, the developing sperm are gradually 
pushed toward the center of the seminiferous tubule and make 
their way to epididymis, where they acquire motility. 
 The process, from spermatogonia to motile sperm, takes 65 to 
75 days in the human male.
Spermatozoon (Sperm) structure: 
 The thick head contains the haploid nucleus is tipped 
with an acrosome which contains enzymes to aid in 
egg penetration. 
Behind the head the sperm contains many mitochondria that 
provide ATP for movement of the tail (flagellum). 
 Mammalian sperm shape varies from 
species to species. 
Fig. 46.12
Oogenesis is the development of ova (mature, unfertilized egg cell). 
 Begins in the embryo when primordial 
germ cells undergo mitotic divisions to 
produce diploid oogonia. 
 Each oogonium will develop into primary 
oocyte by the time of birth of the female, 
resulting in all potential ova being present 
in the ovaries at birth. 
 Between birth and puberty, primary 
oocytes enlarge and their surrounding 
follicles grow: They replicate their DNA 
and enter Prophase and remain there until 
activated by hormones (Puberty) 
 After puberty during each ovarian cycle, 
FSH stimulates a follicle to enlarge and the 
primary oocyte completes meiosis I.
Meiosis in oogenesis involves 
unequal cytokinesis 
Meiosis I produces a haploid 
secondary oocyte (large) and the 
first polar body (much smaller) 
Meiosis then stops again 
LH triggers ovulation and the 
secondary oocyte is released from 
the follicle. 
If the sperm cell penetrates the 
secondary oocytes membrane, 
meiosis II will occur and the small 
secondary polar body will separate 
from the ovum, this completes 
oogenesis.
The three important differences between spermatogeneis 
and oogenesis. 
(1) In oogenesis the unequal cytokinesis during meiosis results in 
most of the cytoplasm being in one daughter cell which will form 
the single ovum the other cells (polar bodies) will degenerate. In 
spermatogeneis all four products of meiosis I and II become mature 
spermatozoa. 
(2) Spermatogenesis is a continuous process throughout the 
reproductive life of the male as spermatogonia continue to divide 
by mitosis. At the time of the female’s birth an ovary contains all 
of the primary oocytes it will ever have. 
(3) Spermatogenesis occurs as an uninterrupted sequence; in 
oogenesis long “resting” periods occur between the formation of 
the initial steps and final production of the ovum. 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 46.13 
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

More Related Content

What's hot

Female reproductive system
Female reproductive systemFemale reproductive system
Female reproductive system
Dr. Mohammedazim Bagban
 
Reproductive health anantomy
Reproductive health   anantomyReproductive health   anantomy
Reproductive health anantomy
mrodgersjps
 
Female Reproductive System
Female Reproductive SystemFemale Reproductive System
Female Reproductive System
itutor
 
Reproductive system
Reproductive systemReproductive system
Reproductive system
Eneutron
 
Reproductionsystem 131109102239-phpapp01
Reproductionsystem 131109102239-phpapp01Reproductionsystem 131109102239-phpapp01
Reproductionsystem 131109102239-phpapp01
Chethan Durgan
 
Human Reproductive system: Anatomy and physiology
Human Reproductive system: Anatomy and physiologyHuman Reproductive system: Anatomy and physiology
Human Reproductive system: Anatomy and physiology
A M O L D E O R E
 
Sexual reproductive system
Sexual reproductive systemSexual reproductive system
Sexual reproductive system
Dr. Shahbaz Ahmad PT Chaudhary
 
Normal physiology of female reproductive system
Normal physiology of female reproductive systemNormal physiology of female reproductive system
Normal physiology of female reproductive system
Mohannad_Sawalmeh
 
Group+8+chapter+19+powerpoint[1]
Group+8+chapter+19+powerpoint[1]Group+8+chapter+19+powerpoint[1]
Group+8+chapter+19+powerpoint[1]
111sara
 
Reproductive system
Reproductive systemReproductive system
Reproductive system
Nisha Mhaske
 
Female Reproductive System
Female Reproductive SystemFemale Reproductive System
Female Reproductive System
Rashmi Priyem Saravanan
 
The female reproductive system
The female reproductive systemThe female reproductive system
The female reproductive system
mohit rulaniya
 
Menstural cycle
Menstural cycleMenstural cycle
Menstural cycle
Neha Bhandari
 
Testis by Dr Pandian M
Testis by Dr Pandian M Testis by Dr Pandian M
Testis by Dr Pandian M
Pandian M
 
Anatomy of female reproductive organs
Anatomy of female reproductive organsAnatomy of female reproductive organs
Anatomy of female reproductive organs
amrit kaur
 
Female reproductive system
Female reproductive systemFemale reproductive system
Female reproductive system
Abhay Rajpoot
 
Anatomy and physiology2007
Anatomy and physiology2007Anatomy and physiology2007
Anatomy and physiology2007
Jozzel Dato Quito
 
Spermatogenesis and oogenesis
Spermatogenesis and oogenesisSpermatogenesis and oogenesis
Spermatogenesis and oogenesis
christenashantaram
 
Menstrual cycle and mammary glands
Menstrual cycle and mammary glandsMenstrual cycle and mammary glands
Menstrual cycle and mammary glands
Dr. Sarita Sharma
 
Human reproductive system
Human reproductive systemHuman reproductive system
Human reproductive system
som allul
 

What's hot (20)

Female reproductive system
Female reproductive systemFemale reproductive system
Female reproductive system
 
Reproductive health anantomy
Reproductive health   anantomyReproductive health   anantomy
Reproductive health anantomy
 
Female Reproductive System
Female Reproductive SystemFemale Reproductive System
Female Reproductive System
 
Reproductive system
Reproductive systemReproductive system
Reproductive system
 
Reproductionsystem 131109102239-phpapp01
Reproductionsystem 131109102239-phpapp01Reproductionsystem 131109102239-phpapp01
Reproductionsystem 131109102239-phpapp01
 
Human Reproductive system: Anatomy and physiology
Human Reproductive system: Anatomy and physiologyHuman Reproductive system: Anatomy and physiology
Human Reproductive system: Anatomy and physiology
 
Sexual reproductive system
Sexual reproductive systemSexual reproductive system
Sexual reproductive system
 
Normal physiology of female reproductive system
Normal physiology of female reproductive systemNormal physiology of female reproductive system
Normal physiology of female reproductive system
 
Group+8+chapter+19+powerpoint[1]
Group+8+chapter+19+powerpoint[1]Group+8+chapter+19+powerpoint[1]
Group+8+chapter+19+powerpoint[1]
 
Reproductive system
Reproductive systemReproductive system
Reproductive system
 
Female Reproductive System
Female Reproductive SystemFemale Reproductive System
Female Reproductive System
 
The female reproductive system
The female reproductive systemThe female reproductive system
The female reproductive system
 
Menstural cycle
Menstural cycleMenstural cycle
Menstural cycle
 
Testis by Dr Pandian M
Testis by Dr Pandian M Testis by Dr Pandian M
Testis by Dr Pandian M
 
Anatomy of female reproductive organs
Anatomy of female reproductive organsAnatomy of female reproductive organs
Anatomy of female reproductive organs
 
Female reproductive system
Female reproductive systemFemale reproductive system
Female reproductive system
 
Anatomy and physiology2007
Anatomy and physiology2007Anatomy and physiology2007
Anatomy and physiology2007
 
Spermatogenesis and oogenesis
Spermatogenesis and oogenesisSpermatogenesis and oogenesis
Spermatogenesis and oogenesis
 
Menstrual cycle and mammary glands
Menstrual cycle and mammary glandsMenstrual cycle and mammary glands
Menstrual cycle and mammary glands
 
Human reproductive system
Human reproductive systemHuman reproductive system
Human reproductive system
 

Viewers also liked

I will fly dr khalid b.m.
I will fly   dr khalid b.m.I will fly   dr khalid b.m.
I will fly dr khalid b.m.
Dr KHALID B.M
 
Presentation e commerce
Presentation e commercePresentation e commerce
Presentation e commerce
Zahid Mehraj
 
бюджет 2015
бюджет 2015бюджет 2015
бюджет 2015
irinaisaeva12
 
Top 10 mobile phones in june 2015
Top 10 mobile phones in june 2015Top 10 mobile phones in june 2015
Top 10 mobile phones in june 2015
somya sharma
 
Hadoop
HadoopHadoop
Cable Testing (using leakage signal)
Cable Testing (using leakage signal)Cable Testing (using leakage signal)
Cable Testing (using leakage signal)
Sharique Mulla
 
Ide overview
Ide overviewIde overview
Ide overview
Elhabib Atiea
 
больничные листы аркадий презентация
больничные листы аркадий презентациябольничные листы аркадий презентация
больничные листы аркадий презентация
irinaisaeva12
 
Making The Case For Mobile
Making The Case For MobileMaking The Case For Mobile
Making The Case For Mobile
Prediq Media
 
User Experience Services Overview
User Experience Services OverviewUser Experience Services Overview
User Experience Services Overview
Amit Panwar HFI - CUA
 
Imagerie du foie, des voies biliaires et du pancréas
Imagerie du foie, des voies biliaires et du pancréasImagerie du foie, des voies biliaires et du pancréas
Imagerie du foie, des voies biliaires et du pancréas
abdesselam2015
 
Apkures katli
Apkures katliApkures katli
Apkures katli
Dans.lv
 

Viewers also liked (12)

I will fly dr khalid b.m.
I will fly   dr khalid b.m.I will fly   dr khalid b.m.
I will fly dr khalid b.m.
 
Presentation e commerce
Presentation e commercePresentation e commerce
Presentation e commerce
 
бюджет 2015
бюджет 2015бюджет 2015
бюджет 2015
 
Top 10 mobile phones in june 2015
Top 10 mobile phones in june 2015Top 10 mobile phones in june 2015
Top 10 mobile phones in june 2015
 
Hadoop
HadoopHadoop
Hadoop
 
Cable Testing (using leakage signal)
Cable Testing (using leakage signal)Cable Testing (using leakage signal)
Cable Testing (using leakage signal)
 
Ide overview
Ide overviewIde overview
Ide overview
 
больничные листы аркадий презентация
больничные листы аркадий презентациябольничные листы аркадий презентация
больничные листы аркадий презентация
 
Making The Case For Mobile
Making The Case For MobileMaking The Case For Mobile
Making The Case For Mobile
 
User Experience Services Overview
User Experience Services OverviewUser Experience Services Overview
User Experience Services Overview
 
Imagerie du foie, des voies biliaires et du pancréas
Imagerie du foie, des voies biliaires et du pancréasImagerie du foie, des voies biliaires et du pancréas
Imagerie du foie, des voies biliaires et du pancréas
 
Apkures katli
Apkures katliApkures katli
Apkures katli
 

Similar to Reproduction

HUMAN REPRODUCTION.pptx
HUMAN  REPRODUCTION.pptxHUMAN  REPRODUCTION.pptx
HUMAN REPRODUCTION.pptx
barunmahto001
 
Human reproduction system
Human reproduction system Human reproduction system
Human reproduction system
SurpriseMahlangu
 
Human Reproducton and biological change.pptx
Human Reproducton and biological change.pptxHuman Reproducton and biological change.pptx
Human Reproducton and biological change.pptx
bholu803201
 
COT 2.ppt
COT 2.pptCOT 2.ppt
COT 2.ppt
Rowenick1
 
The reproductive system
The reproductive systemThe reproductive system
The reproductive system
hscteacher04
 
2. Human reproduction.pptx
2. Human reproduction.pptx2. Human reproduction.pptx
2. Human reproduction.pptx
SrivatsanSP1
 
HUMAN REPRODUCTION
HUMAN REPRODUCTION HUMAN REPRODUCTION
HUMAN REPRODUCTION
MarbleRamonetha
 
Human reproduction - A detailed study ( medical information)
Human reproduction - A detailed study ( medical information)Human reproduction - A detailed study ( medical information)
Human reproduction - A detailed study ( medical information)
martinshaji
 
178-Anatomy-Reproductive-System.ppt
178-Anatomy-Reproductive-System.ppt178-Anatomy-Reproductive-System.ppt
178-Anatomy-Reproductive-System.ppt
sadiaahmad30
 
Reproductive sys a&p
Reproductive sys a&pReproductive sys a&p
Reproductive sys a&p
Jay Patel
 
THE REPRODUCTION SYSTEMS.pdf
THE REPRODUCTION SYSTEMS.pdfTHE REPRODUCTION SYSTEMS.pdf
THE REPRODUCTION SYSTEMS.pdf
MarkdanielRamos4
 
Human reproduction by BNP.pdf
Human reproduction by BNP.pdfHuman reproduction by BNP.pdf
Human reproduction by BNP.pdf
College of pharmaceutical sciences
 
22 Reproductive
22 Reproductive22 Reproductive
22 Reproductive
Mrs. Taber
 
Reproductive System
Reproductive SystemReproductive System
Reproductive System
Mayur Gaikar
 
Female reproductive system jonathan
Female reproductive system jonathanFemale reproductive system jonathan
Female reproductive system jonathan
JONATHAN MANUEL RODRIGUEZ BAÑOS
 
Reproductive System
Reproductive SystemReproductive System
Reproductive System
logan_xavi93
 
Reproductive system
Reproductive systemReproductive system
Reproductive system
Zofia Różańska
 
Mammalian Reproduction
Mammalian ReproductionMammalian Reproduction
Mammalian Reproduction
guestcfdf1fef
 
7. Male and Female reproductive system.pptx
7. Male and Female reproductive system.pptx7. Male and Female reproductive system.pptx
7. Male and Female reproductive system.pptx
AbhiDabra
 
Ch3 L1 2 Male Female Reproductive Systems 3 2 Use
Ch3 L1 2 Male Female Reproductive Systems 3 2  UseCh3 L1 2 Male Female Reproductive Systems 3 2  Use
Ch3 L1 2 Male Female Reproductive Systems 3 2 Use
guest39fe8bc
 

Similar to Reproduction (20)

HUMAN REPRODUCTION.pptx
HUMAN  REPRODUCTION.pptxHUMAN  REPRODUCTION.pptx
HUMAN REPRODUCTION.pptx
 
Human reproduction system
Human reproduction system Human reproduction system
Human reproduction system
 
Human Reproducton and biological change.pptx
Human Reproducton and biological change.pptxHuman Reproducton and biological change.pptx
Human Reproducton and biological change.pptx
 
COT 2.ppt
COT 2.pptCOT 2.ppt
COT 2.ppt
 
The reproductive system
The reproductive systemThe reproductive system
The reproductive system
 
2. Human reproduction.pptx
2. Human reproduction.pptx2. Human reproduction.pptx
2. Human reproduction.pptx
 
HUMAN REPRODUCTION
HUMAN REPRODUCTION HUMAN REPRODUCTION
HUMAN REPRODUCTION
 
Human reproduction - A detailed study ( medical information)
Human reproduction - A detailed study ( medical information)Human reproduction - A detailed study ( medical information)
Human reproduction - A detailed study ( medical information)
 
178-Anatomy-Reproductive-System.ppt
178-Anatomy-Reproductive-System.ppt178-Anatomy-Reproductive-System.ppt
178-Anatomy-Reproductive-System.ppt
 
Reproductive sys a&p
Reproductive sys a&pReproductive sys a&p
Reproductive sys a&p
 
THE REPRODUCTION SYSTEMS.pdf
THE REPRODUCTION SYSTEMS.pdfTHE REPRODUCTION SYSTEMS.pdf
THE REPRODUCTION SYSTEMS.pdf
 
Human reproduction by BNP.pdf
Human reproduction by BNP.pdfHuman reproduction by BNP.pdf
Human reproduction by BNP.pdf
 
22 Reproductive
22 Reproductive22 Reproductive
22 Reproductive
 
Reproductive System
Reproductive SystemReproductive System
Reproductive System
 
Female reproductive system jonathan
Female reproductive system jonathanFemale reproductive system jonathan
Female reproductive system jonathan
 
Reproductive System
Reproductive SystemReproductive System
Reproductive System
 
Reproductive system
Reproductive systemReproductive system
Reproductive system
 
Mammalian Reproduction
Mammalian ReproductionMammalian Reproduction
Mammalian Reproduction
 
7. Male and Female reproductive system.pptx
7. Male and Female reproductive system.pptx7. Male and Female reproductive system.pptx
7. Male and Female reproductive system.pptx
 
Ch3 L1 2 Male Female Reproductive Systems 3 2 Use
Ch3 L1 2 Male Female Reproductive Systems 3 2  UseCh3 L1 2 Male Female Reproductive Systems 3 2  Use
Ch3 L1 2 Male Female Reproductive Systems 3 2 Use
 

More from Naveen Gupta

Dynamic memory allocation
Dynamic memory allocationDynamic memory allocation
Dynamic memory allocation
Naveen Gupta
 
stem cells
stem cellsstem cells
stem cells
Naveen Gupta
 
Mitosis2
Mitosis2Mitosis2
Mitosis2
Naveen Gupta
 
Mestrual cycle
Mestrual cycleMestrual cycle
Mestrual cycle
Naveen Gupta
 
Menstrual cycle 2
Menstrual cycle 2Menstrual cycle 2
Menstrual cycle 2
Naveen Gupta
 
Lecture 1 family planning
Lecture 1 family planningLecture 1 family planning
Lecture 1 family planning
Naveen Gupta
 
Human reproduction
Human reproductionHuman reproduction
Human reproduction
Naveen Gupta
 
Genetic engineering
Genetic engineeringGenetic engineering
Genetic engineering
Naveen Gupta
 
sequencing of genome
sequencing of genomesequencing of genome
sequencing of genome
Naveen Gupta
 
Cell reproduction mitosis&meosis
Cell reproduction mitosis&meosisCell reproduction mitosis&meosis
Cell reproduction mitosis&meosis
Naveen Gupta
 
Cell respiration
Cell respirationCell respiration
Cell respiration
Naveen Gupta
 
Asexual and sexual_reproduction
Asexual and sexual_reproductionAsexual and sexual_reproduction
Asexual and sexual_reproduction
Naveen Gupta
 
Biotechnology and genetic engineering
Biotechnology and genetic engineeringBiotechnology and genetic engineering
Biotechnology and genetic engineering
Naveen Gupta
 

More from Naveen Gupta (13)

Dynamic memory allocation
Dynamic memory allocationDynamic memory allocation
Dynamic memory allocation
 
stem cells
stem cellsstem cells
stem cells
 
Mitosis2
Mitosis2Mitosis2
Mitosis2
 
Mestrual cycle
Mestrual cycleMestrual cycle
Mestrual cycle
 
Menstrual cycle 2
Menstrual cycle 2Menstrual cycle 2
Menstrual cycle 2
 
Lecture 1 family planning
Lecture 1 family planningLecture 1 family planning
Lecture 1 family planning
 
Human reproduction
Human reproductionHuman reproduction
Human reproduction
 
Genetic engineering
Genetic engineeringGenetic engineering
Genetic engineering
 
sequencing of genome
sequencing of genomesequencing of genome
sequencing of genome
 
Cell reproduction mitosis&meosis
Cell reproduction mitosis&meosisCell reproduction mitosis&meosis
Cell reproduction mitosis&meosis
 
Cell respiration
Cell respirationCell respiration
Cell respiration
 
Asexual and sexual_reproduction
Asexual and sexual_reproductionAsexual and sexual_reproduction
Asexual and sexual_reproduction
 
Biotechnology and genetic engineering
Biotechnology and genetic engineeringBiotechnology and genetic engineering
Biotechnology and genetic engineering
 

Recently uploaded

poikilocytosis 237654378658585210854.pptx
poikilocytosis 237654378658585210854.pptxpoikilocytosis 237654378658585210854.pptx
poikilocytosis 237654378658585210854.pptx
muralinath2
 
poikilocytosis 23765437865210857453257844.pptx
poikilocytosis 23765437865210857453257844.pptxpoikilocytosis 23765437865210857453257844.pptx
poikilocytosis 23765437865210857453257844.pptx
muralinath2
 
SCIENCEgfvhvhvkjkbbjjbbjvhvhvhvjkvjvjvjj.pptx
SCIENCEgfvhvhvkjkbbjjbbjvhvhvhvjkvjvjvjj.pptxSCIENCEgfvhvhvkjkbbjjbbjvhvhvhvjkvjvjvjj.pptx
SCIENCEgfvhvhvkjkbbjjbbjvhvhvhvjkvjvjvjj.pptx
WALTONMARBRUCAL
 
Gametogenesis: Male gametes Formation Process / Spermatogenesis .pdf
Gametogenesis: Male gametes Formation Process / Spermatogenesis .pdfGametogenesis: Male gametes Formation Process / Spermatogenesis .pdf
Gametogenesis: Male gametes Formation Process / Spermatogenesis .pdf
SELF-EXPLANATORY
 
20240710 ACMJ Diagrams Set 3.docx . Apache, Csharp, Mysql, Javascript stack a...
20240710 ACMJ Diagrams Set 3.docx . Apache, Csharp, Mysql, Javascript stack a...20240710 ACMJ Diagrams Set 3.docx . Apache, Csharp, Mysql, Javascript stack a...
20240710 ACMJ Diagrams Set 3.docx . Apache, Csharp, Mysql, Javascript stack a...
Sharon Liu
 
Active and Passive Surveillance of pharmacovigillance
Active and Passive Surveillance of pharmacovigillanceActive and Passive Surveillance of pharmacovigillance
Active and Passive Surveillance of pharmacovigillance
SejalAgrawal43
 
largeintestinepathologiesconditions-240627071428-3c936a47 (2).pptx
largeintestinepathologiesconditions-240627071428-3c936a47 (2).pptxlargeintestinepathologiesconditions-240627071428-3c936a47 (2).pptx
largeintestinepathologiesconditions-240627071428-3c936a47 (2).pptx
muralinath2
 
Keys of Identification for Indian Wood: A Seminar Report
Keys of Identification for Indian Wood: A Seminar ReportKeys of Identification for Indian Wood: A Seminar Report
Keys of Identification for Indian Wood: A Seminar Report
Gurjant Singh
 
Gasification and Pyrolyssis of plastic Waste under a Circular Economy perpective
Gasification and Pyrolyssis of plastic Waste under a Circular Economy perpectiveGasification and Pyrolyssis of plastic Waste under a Circular Economy perpective
Gasification and Pyrolyssis of plastic Waste under a Circular Economy perpective
Recupera
 
Anatomy, and reproduction of Gnetum.pptx
Anatomy, and reproduction of Gnetum.pptxAnatomy, and reproduction of Gnetum.pptx
Anatomy, and reproduction of Gnetum.pptx
karthiksaran8
 
Possible Anthropogenic Contributions to the LAMP-observed Surficial Icy Regol...
Possible Anthropogenic Contributions to the LAMP-observed Surficial Icy Regol...Possible Anthropogenic Contributions to the LAMP-observed Surficial Icy Regol...
Possible Anthropogenic Contributions to the LAMP-observed Surficial Icy Regol...
Sérgio Sacani
 
degree Certificate of Aston University
degree Certificate of Aston Universitydegree Certificate of Aston University
degree Certificate of Aston University
ebgyz
 
2. Osmotic pressure, osmotic potential, turgor pressure, wall pressure, water...
2. Osmotic pressure, osmotic potential, turgor pressure, wall pressure, water...2. Osmotic pressure, osmotic potential, turgor pressure, wall pressure, water...
2. Osmotic pressure, osmotic potential, turgor pressure, wall pressure, water...
khadija07kubra
 
HAZARDOUS ENERGIES -LOTO Training Program.pptx
HAZARDOUS ENERGIES -LOTO Training Program.pptxHAZARDOUS ENERGIES -LOTO Training Program.pptx
HAZARDOUS ENERGIES -LOTO Training Program.pptx
ArfanSubhani
 
A slightly oblate dark matter halo revealed by a retrograde precessing Galact...
A slightly oblate dark matter halo revealed by a retrograde precessing Galact...A slightly oblate dark matter halo revealed by a retrograde precessing Galact...
A slightly oblate dark matter halo revealed by a retrograde precessing Galact...
Sérgio Sacani
 
Forces grade 9 slideshow used for grade 9
Forces grade 9 slideshow used for grade 9Forces grade 9 slideshow used for grade 9
Forces grade 9 slideshow used for grade 9
manavhelamuki
 
Lunar Mobility Drivers and Needs - Artemis
Lunar Mobility Drivers and Needs - ArtemisLunar Mobility Drivers and Needs - Artemis
Lunar Mobility Drivers and Needs - Artemis
Sérgio Sacani
 
Science-Technology Quiz (School Quiz 2024)
Science-Technology Quiz (School Quiz 2024)Science-Technology Quiz (School Quiz 2024)
Science-Technology Quiz (School Quiz 2024)
Kashyap J
 
SCIENTIFIC INVESTIGATIONS – THE IMPORTANCE OF FAIR TESTING.pptx
SCIENTIFIC INVESTIGATIONS – THE IMPORTANCE OF FAIR TESTING.pptxSCIENTIFIC INVESTIGATIONS – THE IMPORTANCE OF FAIR TESTING.pptx
SCIENTIFIC INVESTIGATIONS – THE IMPORTANCE OF FAIR TESTING.pptx
JoanaBanasen1
 
Komodo Dragon I PPT
Komodo Dragon I PPT Komodo Dragon I PPT
Komodo Dragon I PPT
alokitapramanik0
 

Recently uploaded (20)

poikilocytosis 237654378658585210854.pptx
poikilocytosis 237654378658585210854.pptxpoikilocytosis 237654378658585210854.pptx
poikilocytosis 237654378658585210854.pptx
 
poikilocytosis 23765437865210857453257844.pptx
poikilocytosis 23765437865210857453257844.pptxpoikilocytosis 23765437865210857453257844.pptx
poikilocytosis 23765437865210857453257844.pptx
 
SCIENCEgfvhvhvkjkbbjjbbjvhvhvhvjkvjvjvjj.pptx
SCIENCEgfvhvhvkjkbbjjbbjvhvhvhvjkvjvjvjj.pptxSCIENCEgfvhvhvkjkbbjjbbjvhvhvhvjkvjvjvjj.pptx
SCIENCEgfvhvhvkjkbbjjbbjvhvhvhvjkvjvjvjj.pptx
 
Gametogenesis: Male gametes Formation Process / Spermatogenesis .pdf
Gametogenesis: Male gametes Formation Process / Spermatogenesis .pdfGametogenesis: Male gametes Formation Process / Spermatogenesis .pdf
Gametogenesis: Male gametes Formation Process / Spermatogenesis .pdf
 
20240710 ACMJ Diagrams Set 3.docx . Apache, Csharp, Mysql, Javascript stack a...
20240710 ACMJ Diagrams Set 3.docx . Apache, Csharp, Mysql, Javascript stack a...20240710 ACMJ Diagrams Set 3.docx . Apache, Csharp, Mysql, Javascript stack a...
20240710 ACMJ Diagrams Set 3.docx . Apache, Csharp, Mysql, Javascript stack a...
 
Active and Passive Surveillance of pharmacovigillance
Active and Passive Surveillance of pharmacovigillanceActive and Passive Surveillance of pharmacovigillance
Active and Passive Surveillance of pharmacovigillance
 
largeintestinepathologiesconditions-240627071428-3c936a47 (2).pptx
largeintestinepathologiesconditions-240627071428-3c936a47 (2).pptxlargeintestinepathologiesconditions-240627071428-3c936a47 (2).pptx
largeintestinepathologiesconditions-240627071428-3c936a47 (2).pptx
 
Keys of Identification for Indian Wood: A Seminar Report
Keys of Identification for Indian Wood: A Seminar ReportKeys of Identification for Indian Wood: A Seminar Report
Keys of Identification for Indian Wood: A Seminar Report
 
Gasification and Pyrolyssis of plastic Waste under a Circular Economy perpective
Gasification and Pyrolyssis of plastic Waste under a Circular Economy perpectiveGasification and Pyrolyssis of plastic Waste under a Circular Economy perpective
Gasification and Pyrolyssis of plastic Waste under a Circular Economy perpective
 
Anatomy, and reproduction of Gnetum.pptx
Anatomy, and reproduction of Gnetum.pptxAnatomy, and reproduction of Gnetum.pptx
Anatomy, and reproduction of Gnetum.pptx
 
Possible Anthropogenic Contributions to the LAMP-observed Surficial Icy Regol...
Possible Anthropogenic Contributions to the LAMP-observed Surficial Icy Regol...Possible Anthropogenic Contributions to the LAMP-observed Surficial Icy Regol...
Possible Anthropogenic Contributions to the LAMP-observed Surficial Icy Regol...
 
degree Certificate of Aston University
degree Certificate of Aston Universitydegree Certificate of Aston University
degree Certificate of Aston University
 
2. Osmotic pressure, osmotic potential, turgor pressure, wall pressure, water...
2. Osmotic pressure, osmotic potential, turgor pressure, wall pressure, water...2. Osmotic pressure, osmotic potential, turgor pressure, wall pressure, water...
2. Osmotic pressure, osmotic potential, turgor pressure, wall pressure, water...
 
HAZARDOUS ENERGIES -LOTO Training Program.pptx
HAZARDOUS ENERGIES -LOTO Training Program.pptxHAZARDOUS ENERGIES -LOTO Training Program.pptx
HAZARDOUS ENERGIES -LOTO Training Program.pptx
 
A slightly oblate dark matter halo revealed by a retrograde precessing Galact...
A slightly oblate dark matter halo revealed by a retrograde precessing Galact...A slightly oblate dark matter halo revealed by a retrograde precessing Galact...
A slightly oblate dark matter halo revealed by a retrograde precessing Galact...
 
Forces grade 9 slideshow used for grade 9
Forces grade 9 slideshow used for grade 9Forces grade 9 slideshow used for grade 9
Forces grade 9 slideshow used for grade 9
 
Lunar Mobility Drivers and Needs - Artemis
Lunar Mobility Drivers and Needs - ArtemisLunar Mobility Drivers and Needs - Artemis
Lunar Mobility Drivers and Needs - Artemis
 
Science-Technology Quiz (School Quiz 2024)
Science-Technology Quiz (School Quiz 2024)Science-Technology Quiz (School Quiz 2024)
Science-Technology Quiz (School Quiz 2024)
 
SCIENTIFIC INVESTIGATIONS – THE IMPORTANCE OF FAIR TESTING.pptx
SCIENTIFIC INVESTIGATIONS – THE IMPORTANCE OF FAIR TESTING.pptxSCIENTIFIC INVESTIGATIONS – THE IMPORTANCE OF FAIR TESTING.pptx
SCIENTIFIC INVESTIGATIONS – THE IMPORTANCE OF FAIR TESTING.pptx
 
Komodo Dragon I PPT
Komodo Dragon I PPT Komodo Dragon I PPT
Komodo Dragon I PPT
 

Reproduction

  • 1. ANIMAL REPRODUCTION Mammalian Reproduction 1. Human reproduction involves intricate anatomy and complex behavior 2. Spermatogenesis and oogenesis both involve meiosis but differ in three significant ways
  • 2. Human reproduction involves intricate anatomy and complex behavior  Reproductive Anatomy of the Human Male. The mammalian male reproductive system includes the external genitalia and the internal reproductive organs  The scrotum and the penis are the external components of the reproductive system.  The internal reproductive organs consist of  the gonads (testes) that produce gametes (sperm cells) and hormones accessory sex glands that secrete products essential to sperm movement A set of ducts that carry the sperm and glandular secretion. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 3. Reproductive Anatomy of the Human Male Fig. 46.8
  • 4. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 46.8
  • 5. The scrotum is a fold of the body wall which aids the reproductive process in different ways: Testes develop in the abdomen and descend into the scrotum just before birth. This is important since sperms can not develop at normal body temperature. By having the testes hanging outside the abdominal cavity in the scrotum, the temperature is 2° C lower and sperm production can occur In many rodents, the testes are drawn back into the abdominal cavity, and sperm maturation is interrupted between breeding seasons. Some mammals whose body temperature is low enough to allow sperm maturation, such as monotremes, whales and elephants retain the testes within the abdominal cavity permanently.
  • 6. Internal male reproductive organs are:  The gonads or Testes (singular testis) are the male gonads.  highly coiled tubules surrounded by layers of connective tissue. These tubules are the seminiferous tubules. Sperm form in seminiferous tubules. Leydig cells, scattered between seminiferous tubules produce testesterone and other androgens (male sex hormones).  Sperm pass from the seminiferous tubules into the tubules of the epididymis.  It takes 20 days for sperms to pass through the 6-m long tubules of each epididymis of a human male  During this passage the sperm become motile and gain the ability to fertilize.
  • 7. Fig. 46.11 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 8.  At ejaculation, sperm are forced from the epididymis, through the vas deference which is a muscular duct running from epididymis and out of the scrotum around and behind the urinary bladder to the ejaculatory duct.  Each ejaculatory duct forms by the joining of the vas deferens duct with the duct from the seminal vesicle.  The two ejaculatory ducts opens into the urethra. The urethra is the tube that: Drains both the excretory and reproductive systems Runs through the penis and opens to the outside at the tip of the penis.
  • 9. There are three sets of accessory glands associated with the male system. These glands add their secretions to the semen (the fluid that is ejaculated): (1) A pair of seminal vesicle is located below and behind the bladder and empty into the ejaculatory duct Their secretion is thick, yellow and alkaline  They secrete a fluid containing mucous, a coagulating enzyme (causes semen to coagulate after deposited in female), fructose (provides energy for sperm) and prostaglandins (stimulates female uterine contractions to help move semen to the uterus Seminal vesicle secretion make up about 60% of the total semen volume.
  • 10. (2) The prostate gland is the largest of the semen-secreting glands: Surrounds the upper portion of the urethra and empties directly into it. It secretes a thin, milky fluid that contains anticoagulating enzymes, citrate (a sperm nutrient) and is slightly acidic. Benign (noncancerous) enlargement of the prostate occurs in more than half of all men over the age of 40 and in virtually all men over 70. Prostate cancer is one of the most common cancer in men, it is treated surgically or with drugs that inhibit gonado-tropins, resulting in reduced prostate activity and size.
  • 11. (3) The bulbourethral glands are a pair of small glands below the prostate that empty into the urethra at the base of the penis:  It secretes a clear mucous before ejaculation  The fluid neutralizes any acidic urine remaining in the urethra. • A man usually ejaculates about 2 – 5 ml of semen containing about 50–130 million sperm/ml. •Once in the female reproductive tract, prostaglandins in the semen stimulate contractions of the uterine muscles, which help move the sperm up the uterus. •The semen is slightly alkaline and this neutralizes the acidic environment of the vagina, protecting the sperm and increasing their motility. •When first ejaculated the semen coagulates, making it easier for uterine contractions to move it along; then anticoagulants liquefy the semen and the sperm begins swimming through the female tract.
  • 12. The human penis is composed of three layers of spongy erectile tissue.  During sexual arousal the erectile tissue fills with blood from arteries.  The penis of some mammals (rodents, raccoons walruses ) possesses a baculum, a bone that helps stiffen the penis.  Temporary impotence, a reversible inability to achieve an erection can result from the consumption of alcohol and certain drugs, and emotional problems:  Several drugs (e.g.Viagra® ) and penile implant devices are available for men with nonreversible impotence due to nervous system, or circulatory problems.  External structure of the penis is covered by a thick skin:  The head of the penis,the glans penis is covered by thinner skin. The glans is covered by the prepuce which may be removed by circumcision.
  • 14.  Reproductive Anatomy of the Human Female.  External reproductive structures consists of two sets of labia surrounding the clitoris and vaginal opening.  Internal reproductive organs consist of a pair of gonads (ovaries) and a system of ducts and chambers.  The role of the ducts and chambers are involved with gamete movement and embryo development . Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 15. Fig. 46.9 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 16. Fig. 46.9  Ovaries are the female gonads.  Located in the abdominal cavity and enclosed in a tough protective capsule..  Attached by mesentery to, the uterus.  Each ovary contains follicles.
  • 17.  Each follicle consists of one egg cell surrounded by one or more layers of follicle cells.  Follicles produce the primary female sex hormones: estrogens.  Follicle cells nourish and protect the developing egg cell.  A woman is born with about 400,000 follicles.  Only several hundred of which will release eggs during a female’s reproductive years.  Starting at puberty and continuing to menopause, one follicle matures and releases its egg cell during each menstrual cycle. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 18.  During ovulation, the egg is expelled from the follicle.  After ovulation the remaining follicular tissue develops into the corpus luteum. Secretes estrogens and progesterone. Maintain the uterine lining during pregnancy. If the egg is not fertilized (pregnancy does not occur) the corpus luteum degenerates and a new follicle matures during the next cycle. Fig. 46.10 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 20.  At ovulation the egg is expelled into the abdominal cavity near the funnel-shaped opening of the oviduct or fallopian tube. The cilia-lining the oviduct draws in the egg. Cilia convey the egg through the oviduct to the uterus.  The uterus (or Womb) is a thick muscular organ that can expend during pregnancy to accommodate a 4 kg fetus.  The inner uterine lining , the Endometrium is richly supplied with blood vessels
  • 21. The remaining female reproductive structures are:  Cervix: neck of the uterus, the opens into the vagina. Vagina: thin-walled chamber that forms the birth canal and is the repository for sperm during copulation.
  • 22. Hymen: A vascularized membrane, usually covers the vaginal opening from birth until ruptured by vigorous physical activity or sexual intercourse.  Vestibule: Chamber-like area bordered by the 2 pairs of skin folds covering vaginal opening and the separate urethral opening.  Labia minora: The slender skin folds bordering the vestibule.  Labia majora: A pair of thick , fatty ridges enclosing and protecting the labia minora and vestibule.  Clitoris: bulb of erectile tissue found at the front edge of the vestibule. It is covered by a prepuce. It is richly supplied with nerve endings and is one of the most sensitive points of sexual stimulation.  Bartholin’s glands are small glands located near the vaginal opening that secrete mucous into the vestibule during sexual arousal.  The mucous facilitates intercourse by lubricating the vagina
  • 23. Mammary glands.  Are present in both males and females but normally function only in women.  They are important to mammalian reproduction, although not actually a part of the reproductive system.  Consist of small sacs of epithelial tissue that secrete milk.  Milk drains into a series of ducts opening at the nipple.  In nonlactating female mammal, the mammary glands are composed primarily of fatty (adipose) tissue.  In males, the low level of estrogen prevents the development of both the secretory apparatus and the fat deposits, so male breasts remain small, and nipples are not connected to ducts. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 24. Spermatogenesis and oogenesis both involve meiosis but differ in three significant ways  Spermatogenesis is the production of mature sperm cells in adult males.  A continuous and process in the adult male.  Each ejaculation contains 100 – 650 million sperm.  Occurs in seminiferous tubules.  Begins with the differentiation of primordial germ cells into spermatogonia in embryonic testes. Both types of cells are diploid.  The spermatogonia are located near the outer wall of the seminiferous tubules. They increase in number through repeated mitosis throughout development and early life.  When the male matures, spermatogonia begin to differentiate into primary spermatocyte which are diploid.  Primary spermatocyte will pass through several stages before giving rise to mature spermatozoa: Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 26.  Each primary spermatocyte undergoes meiosis I to produce two haploid secondary spermatocytes. Each secondary spermatocyte undergoes meiosis II to form two spermatids. Thus, each primary spermatocyte forms four haploid spermatids through meiotic division.  Each spermatid becomes associated with a large Sertoli cell from which it receives nutrients.  All spermatids differentiate into mature spermatozoa.  During spermatogenesis, the developing sperm are gradually pushed toward the center of the seminiferous tubule and make their way to epididymis, where they acquire motility.  The process, from spermatogonia to motile sperm, takes 65 to 75 days in the human male.
  • 27. Spermatozoon (Sperm) structure:  The thick head contains the haploid nucleus is tipped with an acrosome which contains enzymes to aid in egg penetration. Behind the head the sperm contains many mitochondria that provide ATP for movement of the tail (flagellum).  Mammalian sperm shape varies from species to species. Fig. 46.12
  • 28. Oogenesis is the development of ova (mature, unfertilized egg cell).  Begins in the embryo when primordial germ cells undergo mitotic divisions to produce diploid oogonia.  Each oogonium will develop into primary oocyte by the time of birth of the female, resulting in all potential ova being present in the ovaries at birth.  Between birth and puberty, primary oocytes enlarge and their surrounding follicles grow: They replicate their DNA and enter Prophase and remain there until activated by hormones (Puberty)  After puberty during each ovarian cycle, FSH stimulates a follicle to enlarge and the primary oocyte completes meiosis I.
  • 29. Meiosis in oogenesis involves unequal cytokinesis Meiosis I produces a haploid secondary oocyte (large) and the first polar body (much smaller) Meiosis then stops again LH triggers ovulation and the secondary oocyte is released from the follicle. If the sperm cell penetrates the secondary oocytes membrane, meiosis II will occur and the small secondary polar body will separate from the ovum, this completes oogenesis.
  • 30. The three important differences between spermatogeneis and oogenesis. (1) In oogenesis the unequal cytokinesis during meiosis results in most of the cytoplasm being in one daughter cell which will form the single ovum the other cells (polar bodies) will degenerate. In spermatogeneis all four products of meiosis I and II become mature spermatozoa. (2) Spermatogenesis is a continuous process throughout the reproductive life of the male as spermatogonia continue to divide by mitosis. At the time of the female’s birth an ovary contains all of the primary oocytes it will ever have. (3) Spermatogenesis occurs as an uninterrupted sequence; in oogenesis long “resting” periods occur between the formation of the initial steps and final production of the ovum. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
  • 31. Fig. 46.13 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Editor's Notes

  1. The vaginal and urethral openings are located within the vestibule. The vestibule is surrounded by the labia minora. The labia majora enclose and protect the labia minor and vestibule.