This document provides an overview of the male reproductive system. It discusses the structures and functions of the testis in producing sperm through spermatogenesis and testosterone production. The process of spermatogenesis involves spermatocytogenesis, meiosis, and spermiogenesis within the seminiferous tubules. Sertoli and Leydig cells play important roles in supporting sperm production. The duct system transports mature sperm and secretions from accessory glands. Hormonal regulation by FSH and LH controls spermatogenesis. Characteristics of fertile ejaculates are also discussed.
The biological process via which the testes, the male reproductive organs, produce sperm cells is known as spermatogenesis. It begins with the development of immature germ cells from stem cells in the seminiferous tubule walls, which grow into mature sperm cells featuring a condensed nucleus, a head, and a tail.
The biological process via which the testes, the male reproductive organs, produce sperm cells is known as spermatogenesis. It begins with the development of immature germ cells from stem cells in the seminiferous tubule walls, which grow into mature sperm cells featuring a condensed nucleus, a head, and a tail.
1. Spermatogenesis (Spermatocytogenesis, Spermiogenesis, Spermiation, Shape and function of cells inside the Testis, Semen and sperm structure, Sperm journey after synthesis to outside)
Reproductive system
Anatomy of male and female reproductive system, Functions of male and female
reproductive system, sex hormones, physiology of menstruation, fertilization,
spermatogenesis, oogenesis, pregnancy and parturition
The organs of the male reproductive system include the
testes, a system of ducts (including the epididymis, ductus deferens,ejaculatory ducts, and urethra).
accessory sex glands (seminal vesicles, prostate, and bulbourethral glands),
several supporting structures, including the scrotum and the penis.
The testes (male gonads) produce sperm and secrete hormones.
The duct system transports and stores sperm, assists in their maturation, and conveys them to the exterior.
Semen contains sperm plus the secretions provided by the accessory sex glands.
The supporting structures have various functions. The penis delivers sperm into the female reproductive tract and the scrotum supports the testes.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Normal Labour/ Stages of Labour/ Mechanism of LabourWasim Ak
Normal labor is also termed spontaneous labor, defined as the natural physiological process through which the fetus, placenta, and membranes are expelled from the uterus through the birth canal at term (37 to 42 weeks
More Related Content
Similar to 24-male-reproduction-NXPowerLite-Copy.pptx
1. Spermatogenesis (Spermatocytogenesis, Spermiogenesis, Spermiation, Shape and function of cells inside the Testis, Semen and sperm structure, Sperm journey after synthesis to outside)
Reproductive system
Anatomy of male and female reproductive system, Functions of male and female
reproductive system, sex hormones, physiology of menstruation, fertilization,
spermatogenesis, oogenesis, pregnancy and parturition
The organs of the male reproductive system include the
testes, a system of ducts (including the epididymis, ductus deferens,ejaculatory ducts, and urethra).
accessory sex glands (seminal vesicles, prostate, and bulbourethral glands),
several supporting structures, including the scrotum and the penis.
The testes (male gonads) produce sperm and secrete hormones.
The duct system transports and stores sperm, assists in their maturation, and conveys them to the exterior.
Semen contains sperm plus the secretions provided by the accessory sex glands.
The supporting structures have various functions. The penis delivers sperm into the female reproductive tract and the scrotum supports the testes.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Normal Labour/ Stages of Labour/ Mechanism of LabourWasim Ak
Normal labor is also termed spontaneous labor, defined as the natural physiological process through which the fetus, placenta, and membranes are expelled from the uterus through the birth canal at term (37 to 42 weeks
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Safalta Digital marketing institute in Noida, provide complete applications that encompass a huge range of virtual advertising and marketing additives, which includes search engine optimization, virtual communication advertising, pay-per-click on marketing, content material advertising, internet analytics, and greater. These university courses are designed for students who possess a comprehensive understanding of virtual marketing strategies and attributes.Safalta Digital Marketing Institute in Noida is a first choice for young individuals or students who are looking to start their careers in the field of digital advertising. The institute gives specialized courses designed and certification.
for beginners, providing thorough training in areas such as SEO, digital communication marketing, and PPC training in Noida. After finishing the program, students receive the certifications recognised by top different universitie, setting a strong foundation for a successful career in digital marketing.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
1. Male Reproductive System
Undergraduate – Graduate
Histology Lecture Series
Larry Johnson, Professor
Veterinary Integrative
Biosciences
Texas A&M University
College Station, TX 77843
2. Objectives
To examine the testis (which produce spermatozoa), excretory ducts
(which transport and mature spermatozoa), and accessory glands
(whose secretions support the viability of spermatozoa) for
characteristics and functions the male reproductive system.
To learn what structures and hormonal regulation facilitate the male
gonad to produce an exocrine secretion (the spermatozoon) and an
endocrine secretion (testosterone).
4. First scientific endocrine
study involved the testes
of roosters studying the
observable effects of
testosterone on the
secondary sex structures.
Transplanted tested
maintained wattles and
comb growth in castrated
roosters.
hen
5. Functions of Male Reproductive System are to:
- produce, maintain, and transport mature spermatozoa (the
male gametes),
- produce nutritive and protective fluid (semen), and
- discharge the spermatozoa-containing semen within the
female reproductive tract during mating.
17. Details of spermatozoa
The
annulus marks the
end of the middle
piece (houses the
mitochondria) and
beginning of the
principal piece of the
spermatozoon
Horse
22. Human testis toluidine blue
19680
Spermatozoa are produced in the seminiferous epithelium lining
the lumen of the testicular tubules. Testosterone is synthesized
by Leydig cells located between seminiferous tubules.
Seminiferous
epithelium
Leydig
cells
Seminiferous
tubules
23. Human testis toluidine blue
Two kinds of cells present in the seminiferous
epithelium: Sertoli cells and germ cells:
Sertoli cells nurse germ cell development.
Germ cells
Nuclei of Sertoli cells 19680
467
28. UT165 larger secondary spermatocyte nuclei and smaller Golgi phase spermatid nuclei
human testis
Meiotic activity
29. #92 secondary spermatocytes
To find secondary spermatocytes, one needs to find a tubule in stage VI of the spermatogenic cycle
with metaphase figures in meiosis and no (almost no) pachytene primary spermatocytes. The
pachytene primary spermatocytes are the immediate precursor to secondary spermatocytes.
metaphase figures in meiosis
Pachytene primary
spermatocytes
Letotene primary
spermatocytes
30. Slide 92: Testis
Sertoli cells
Leydig (interstitial)
cells
Tunica albuginea
Basement membrane
Myoid cell
Seminiferous tubules
Residual bodies
Early and late spermatids
31. Spermatogenesis is Divided into
3 Main Events
Event Cell Type Duration
Spermatocytogenesis Spermatogonia 27 Days
Meiosis Spermatocytes 24 Days
Spermiogenesis Spermatids 23 Days
Combined Duration = 74 Days
33. Spermatocytogenesis
Has Two Functions
Produces primary spermatocytes which result in
the production of sperm 47 days later.
Produces stem cells which insure a constant
supply of germ-cell precursors throughout life.
35. Meiosis (only in spermatogenesis
and oogenesis)
Exchange of genetic material in homologous
chromosomes (leptotene, zygotene,
pachytene, and diplotene steps of
development)
Produces haploid condition of gametes
42. Spermiogenesis
(differentiation of spermatids with round nuclei
to those characteristic of spermatozoa)
Acrosome from Golgi
Nuclear condensation and
elongation with appearance
of the spermatid manchette
Flagellum (projects through
the flagellar cannel during
development)
Shedding excess cytoplasm Manchette
Flagellar cannel
47. Cis face
Spermatid showing the developing acrosome
over its nucleus. Acid phosphatase enzymes
(black precipitates) first appear in the trans face
of the Golgi apparatus and are transferred to the
developing acrosome via transport vesicles.
Nucleus
Cytosol
Golgi
Trans face
Transport vesicles
Golgi
Acrosomic vesicle
of a spermatid
Testis
Black acid
phosphatase
precipitates in
the developing
acrosome
Acrosomal
cap
48. Manchette is a transient organelle
as it is not found in spermatozoa
Flagellar
cannel
50. Flagellar
cannel
Annulus
When the annulus migrates to end
of middle piece, it removes the cell
membrane of the flagellar cannel
from the surface of the developing
flagellum in the middle piece region
and allows mitochondria access to
that portion of developing tail.
Mitochondria are found only in the
middle piece on spermatozoa as that
is the only region with access.
60. Human spermatogenesis: path followed by given cell
Blood Testis Barrier
Basal compartment
with spermatocytogenesis
Adluminal compartment with meiosis and spermiogenesis
61. Intercellular Bridges
(cytoplasmic bridges)
Cause - incomplete cytokinesis
Found among clusters of spermatogonia,
spermatocytes, or spermatids (never between cells
in different steps of development, e.g., never
between spermatogonia and spermatocytes)
Possible functions
Mediate both differentiation and degeneration of
spermatogonia
Maintain synchronous development
74. Extragenital Components of
the
Male Reproductive System
Excretory Ducts
Composition (Rete
Testis, Efferent Ducts,
Epididymis, Ductus
Deferens, Ejaculatory
Ducts, Urethra)
75.
76.
77. Human testis: junction of seminiferous tubule and rete
testis for sperm to exit (toluidine blue)
19709
Junction of
seminiferous tubule
and rete testis tubule
Rete
testis
Region of the
mediastinum testis
78. Testis and epididymis – efferent
duct and epididymis
467
Profiles of the
epididymal duct
Efferent
ducts
Rete testis
tubules
Seminiferous
tubules
79. Efferent ducts
199
Lumen
Efferent ducts have a characteristic scalloped
luminal profile due to alternating groups of high and
low columnar cells in the lining epithelium
True cilia on their apical
surface help move
sperm through the duct.
19673
Horse efferent duct
80. True ciliated cells (efferent duct) and stereociliated cells
(epididymis, with sperm in lumen) of psudostratified columnar
epithelium (toluidine blue)
19678
Efferent duct
Epididymis
81. 199
Epididymis
467
19673
19716
Extremely long (30µm), branching
microvilli (stereocilia) projects from
the apical surface of these cells
Stereocilia
Head
Tail of epididymis
Head
Smooth muscle
layer is thicker in
more distal
regions of
epididymis
Efferent duct
Efferent duct
90. DUCTUS DEFERENS IN THE SPERMATIC CORD
Blood vessels and ductus deferens
Smooth muscle,
extremely thick
layers
Psudostratified columnar epithelium,
but lower in height
Nerve
Epithelium
and its
lamina
propria,
showing
longitudinal
folds into
the lumen
196
91. Mechanisms of Sperm Transport
Location Force
Seminiferous tubules Bulk flow (10 ul/g/hr) minor
Contractions of myoid cells
Rete testis Bulk flow ciliary action
Efferent ducts Bulk flow ciliary action
Epididymis Contractions of smooth
muscle
Ductus deferens Contractions of smooth
muscle during ejaculation
speed is 800 mm/second
100. Prostate
271
Prostate is a firm mass of
collagenous connective tissue and
smooth muscle that is invaded by
numerous glandular outpocketings of
the urethra
Note the abundance of smooth
muscle in its interstitium.
Lumen
of gland
106. Two main function of male
reproductive system are to:
Produce male gametes
Deliver male gametes
107.
108. Penis – transitional epithelium and
surrounding spongy cavernous of penal urethra
277
Dense connective tissue bands surround the cavernous erectile
tissue. There is erectile tissue (spongy cavernous) that surrounds
the penile urethra. This allows the urethra to stretch when seminal
fluids are traveling down its length when the penis is rigid.
Spongy cavernous
Cavernous
erectile tissue
Transitional
epithelium
Smooth
muscle
Nerve
110. Fig. Mechanism of erection
Erection occurs as a complex process, constituted
by psychological, neurological, hormonal, and
vascular factors.
the penis is composed of three basic anatomical
structures – two longitudinal cavernous bodies (a
kind of chambers) and one spongy body, including
the urethra. These are the cavernous bodies that
(supplied by respective arteries) increase their
volume during erection, owing to the inflowing blood.
arteries (as opposed to veins) have their muscular
layer composed of smooth muscles which – by
dilation or contraction – regulate the blood flow.
111.
112. Sexual arousal and increasing activity of the autonomic
nervous system stimulates the release of neurotransmitters at
nerve endings in the cavernous bodies or in the endothelium
of the arteries. This leads to secretion of NO – nitric oxide,
which is one of the strongest smooth muscle relaxants. With
dilated cavernous arteries, the amount of blood flowing into
the penis increases, and its outflow is hindered by a
physiological compression of some specific veins. Moreover,
contraction of the ischiocavernous muscle stabilises the penis
in erectile position. A key factor of effective erection is the
condition of the vascular system, ensuring a proper perfusion
of the reproductive organs. Any pathologies of this system
(e.g., atherosclerosis, coronary disease, hypertension) lead to
problems with erection.
114. Functional Properties of the Accessory Glands
Specific contributions of seminal plasma as measured by the
split ejaculate method
Fraction of
Ejaculate Contains Source
First 90% Of All Citrate Prostate
90% Of All Sperm Ductus Deferens
Last 90% Of All Fructose Seminal Vesicles
Developmental response to androgens
119. Bruce Alberts, et al. 1983. Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY.
Bruce Alberts, et al. 1994. Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY.
William J. Banks, 1981. Applied Veterinary Histology. Williams and Wilkins, Los Angeles, CA.
Hans Elias, et al. 1978. Histology and Human Microanatomy. John Wiley and Sons, New York, NY.
Don W. Fawcett. 1986. Bloom and Fawcett. A textbook of histology. W. B. Saunders Company,
Philadelphia, PA.
Don W. Fawcett. 1994. Bloom and Fawcett. A textbook of histology. Chapman and Hall, New York, NY.
Arthur W. Ham and David H. Cormack. 1979. Histology. J. S. Lippincott Company, Philadelphia, PA.
Luis C. Junqueira, et al. 1983. Basic Histology. Lange Medical Publications, Los Altos, CA.
L. Carlos Junqueira, et al. 1995. Basic Histology. Appleton and Lange, Norwalk, CT.
L.L. Langley, et al. 1974. Dynamic Anatomy and Physiology. McGraw-Hill Book Company, New York, NY.
W.W. Tuttle and Byron A. Schottelius. 1969. Textbook of Physiology. The C. V. Mosby Company, St.
Louis, MO.
Leon Weiss. 1977. Histology Cell and Tissue Biology. Elsevier Biomedical, New York, NY.
Leon Weiss and Roy O. Greep. 1977. Histology. McGraw-Hill Book Company, New York, NY.
Nature (http://www.nature.com), Vol. 414:88,2001.
A.L. Mescher 2013 Junqueira’s Basis Histology text and atlas, 13th ed. McGraw
Internet images and videos on biological presentations
Many illustrations in these VIBS Histology YouTube videos were modified
from the following books and sources: Many thanks to original sources!
120. During the hour of this lecture the
average male produced 6.6 million
spermatozoa
121.
122.
123.
124.
125. Spermatogenesis is Divided into
3 Main Events
Event Cell Type Duration
Spermatocytogenesis Spermatogonia 27 Days
Meiosis Spermatocytes 24 Days
Spermiogenesis Spermatids 23 Days
Combined Duration = 74 Days
126. Spermatogenic Cycle
Cycle of seminiferous epithelium is the series of
changes in a given region of seminiferous
epithelium between two appearances of the
same developmental step.
Using spermiation as a reference developmental
step, the cycle would be all events that occur
between two consecutive spermiations.
127.
128. Similarities
College vs. Spermatogenesis
Duration of entire process is longer
than the cycle length
Multiple groups of participants develop
simultaneously
Attrition of participants reduce product
yield
Timing of entry of participants in
different groups create defined
stages of the cycle
130. Human spermatogenesis: path followed through
spermatocytogenesis, meiosis, and spermiogenesis as
a given cell travels through five spermatogenic cycles
131.
132.
133.
134. Stage
A stage of the cycle of seminiferous epithelium is
defined by an association of spermatogonia,
spermatocytes, and spermatids whose
developmental age differs by a multiple of the
cycle length plus a common remainder.
The value of the remainder differs for each stage
of the cycle.
135. Multiple Remainder Multiple Remainder
72/16 = 4 + 8 66/16 = 4 + 2
56/16 = 3 + 8 50/16 = 3 + 2
40/16 = 2 + 8 34/16 = 2 + 2
24/16 = 1 + 8 18/16 = 1 + 2
8/16 = 0 + 8 2/16 = 0 + 2
Stage II Stage VI
Stage (cycle of the seminiferous epithelium or spermatogenic cycle)
- man-made (man defined) divisions of the spermatogenic cycle
- cellular association of germ cells at defined developmental steps
- association of spermatogonia, spermatocytes and spermatids whose
developmental ages differ by a multiple of the cycle length plus a
common remainder (unique for a given stage)
136.
137.
138. Differences
College vs. Spermatogenesis
Multiplying component of
participants in
spermatogenesis
Continuous entry of
participants in
spermatogenesis
manifested by the wave of
spermatogenesis along
the tubular length
139. Wave of the seminiferous
epithelium (not in humans)
"The wave is in space what
the cycle is in time."
Horse