ppt 5 Flashcards
True or False
A spermatogenic cycle and wave can be observed along the length of the seminiferous tubule.
True
True or False
A spermatogenic cycle is a cycle of progressive stages occurring throughout the seminiferous tubules
False (within a particular segment of seminiferous tubules)
True or False
Spermatogenic Cycle
A single cycle would, therefore,
refer to that in which the same
stage reappears for a certain
duration at a particular
segment
True
True or False
The number of stages in a spermatogenic
cycle is the same among species.
False (differs among species)
Mouse has a cycle comprised of twelve
stages numbered from I to X occurring over
9 days
False ( from I to XII, 8.6 days)
Humans have ________ in a cycle and
it takes _________ 16-day cycles for a
spermatogonium to be transformed into a
spermatozoon
Six stages (I-VI) in a cycle, takes four 16-day cycles
Refers to the
distance
from one
stage to
another
similar stage
Spermatogenic Wave
True or False
Spermatogenic wave
Move linearly towards the
inner part of the lumen.
False (spiral -like a corkscrew)
Spermatogenesis waves
Move in spiral - like a corkscrew- towards the
_______
inner part of the lumen
Spermatogenesis waves
Outside, on the edge of the tubule and at the
beginning of the spiral, lie the ________
spermatogonia
Spermatogenesis waves
At the end of the spiral, the ________
cells are in the lumen
fully developed sperm
Spermatogenesis waves
Several differing generations can be found in a
_______ cross-section.
tubule
True or False
As time goes on, the wave of spermatogenesis is
shifted towards the left in order to always newly
begin again.
False (shifted towards the right)
________Occurs in overlapping waves
which pass along the tubules of
the testis so that the stages of
spermatogenesis observed at
any given level of a tubule will
be different from those at
another level
• Wave moves slowly
Spermatogenesis
Seminiferous tubule Spermatogenic wave
❑_______ Wave
❖ cells bordering the lumen of the tubule;
❖maturing spermatozoa or metamorphosing
spermatids
Oldest
Seminiferous tubule Spermatogenic wave
________wave
❖Cells in the middle layer of the tubular wall
Intermediate
Seminiferous tubule Spermatogenic wave
❑_________ Wave
❖Cells near the outer surface of the tubule;
❖spermatogonia ready to undergo meiosis
Youngest
Seminiferous tubule Spermatogenic wave
❑_________ Wave
❖Cells near the outer surface of the tubule;
❖spermatogonia ready to undergo meiosis
Youngest
Wave of the seminiferous tubule
True or False
At any one time, each specific
segment of the tubule is in two
stages of the cycle
False (one stage)
Wave of the Seminiferous tubule
True or False
All the stages of one cycle can be
seen taking place in sequence
within a short segment of a tubule
False (long segment)
Wave of the seminiferous tubule
What is the reason why one can observe
all the stages in just one section of
the testis?
All the stages of one cycle can be
seen taking place in sequence
within a long segment of a tubule
________: Glands in which the male
reproductive cells are formed.
Testes or testicle
Testes or testicles lie, one on each side, in the _______
scrotum
True or False
Testes or testicles: Each is an oval gland about one
and a half inches long with its long
axis directed downward, backward
and inward.
True
What are the 2 major functions of Testes or Testicles?
- producing sperm from stem
cell spermatogonia
(spermatogenesis) - producing androgens, to
maintain and regulate androgen
mediated functions throughout
the body.
True or False
One of the major functions of testes is to produce estrogen.
False (to produce ANDROGEN)
Frog’s Testis: _______ ovoid
elongated
True or False
Mammalian Testes: Elongated Ovoid
False: (Ovoid only)
A strong fibrous
coat, from which
vertical and
horizontal septa
penetrate into the
substance, thus
dividing it into
compartments or
lobules in which
the seminiferous
tubes are coiled.
Tunica albuginea
True or False
Seminiferous tubules: It is estimated that the total
length in the two glands is
little short of a mile
True
______ is consist of a basement
membrane surrounding
several layers of epithelial
cells, some of which are
constantly being
transformed into
spermatozoa or male
sexual cells.
Seminiferous tubules
Seminiferous tubules are consist of a
________ surrounding
several layers of epithelial
cells, some of which are
constantly being
transformed into
spermatozoa or male
sexual cells.
basement membrane
Seminiferous tubules are consist of a basement
membrane surrounding
several layers of ________, some of which are
constantly being
transformed into
spermatozoa or male
sexual cells.
epithelial cells
_______: a plexus of
tubules into
which the
seminiferous
tubes open.
Rete Testis
____________:
• A soft body lying behind
the testis; it is enlarged
above to form the globus
major or head, while
below is a lesser swelling,
the globus minor or tail.
• Made up of a convoluted
tube about 20 ft. long,
from which one long
diverticulum (vas
aberrans) comes off.
Epididymis
Epididymis
• A soft body lying behind
the testis; it is enlarged
above to form the _____ or head, while
below is a lesser swelling,
the ________ or tail.
globus major, globus minor
Epididymis
• Made up of a convoluted
tube about ________ long,
from which one long
diverticulum (vas
aberrans) comes off.
20 ft.
Epididymis
• Made up of a convoluted
tube about 20 ft. long,
from which one long
diverticulum (________) comes off.
vas aberrans
Epididymis
• Made up of a convoluted
tube about 20 ft. long,
from which one long
________ (vas
aberrans) comes off.
diverticulum
____________:
• is the continuation of the tube of
the epididymis and starts at the
globus minor;
• at first it is convoluted, but soon
becomes straight, and runs up on
the inner (mesial) side of the
epididymis to the external
abdominal ring in the abdominal
wall.
Vas deferens
Vas deferens is the continuation of the tube of
the epididymis and starts at the ________
globus minor
Vas deferens:
at first it is convoluted, but soon
becomes straight, and runs up on
the inner (_______) side of the
epididymis to the external
abdominal ring in the abdominal
wall.
mesial
Connective tissue
sheath surrounding
the testis
Tunica albuginea
Testis
•oval body
• consists of 2 kinds
of epithelia:
• (1) ________
epithelium
• (2) ________
epithelium
germinal, glandular
compartments
of the testis
separated by
septula
Seminiferous tubule
Seminiferous tubule: compartments
of the testis
separated by
_________
septula
___________:
• Stratified
epithelium
• Gametogenic
cell lining the
seminiferous
tubules
Germinal Epithelium
• Somatic cells
• Form part of the glandular
epithelium of the testis
• Non-gametogenic cells
Leydig and Sertoli Cells
True or False
Leydig and Sertoli cells are gametogenic cells
False (non-gametogenic)
True or False
Leydig and Sertoli cells are somatic cells
True
Located at the septula;
ovoid cells with
granulated cytoplasm,
which are responsible
for the secretion of the
male hormone
testosterone stimulated
by LH in Ant Pit. Gld.
Leydig cells/Interstitial cells
Same size as the
active spermatogonia
found in between
seminiferous tubules
outside of the
basement membranes
Leydig cells/Interstitial cells
Leydig cells are also known as ______
interstitial cells
Leydig cells are located at the ______
septula
Located at the basal layer of
the germinal epithelium;
occur singly
Sertoli/Sustentacular cells
Few large triangular cells
which bear a prominent
nucleus; elongated
pyramidal epithelial cells
extending from the
epithelium of tubular walls
to the lumen
Sertoli/Sustentacular cells
• Pale in histological section
• Developing sex cells
function as nurse cells –
nourish the developing
sperm cells
Sertoli/Sustentacular cells
Cell Types in the Testis
Order of Development
and identified
according to location,
size, form, character of
the nucleus
• Spermatogonia
• Primary spermatocytes
• Secondary
spermatocytes
• Spermatids
• Spermatozoa
One of the figures in the ppt shows Kidney of the male frog during ______ showing spermatozoa in the
kidney tubules and Malpighian corpuscles, en route to the
uro-(mesonephric) –genital (vasa efferentia) duct.
amplexus
The male form of gamecytogenesis and involves
stem cells dividing to replace themselves and to
produce a population of cells destined to become
mature sperm.
Spermatocytogenesis
Spermatocytogenesis is the male form of __________ and involves
stem cells dividing to replace themselves and to
produce a population of cells destined to become
mature sperm.
gamecytogenesis
The stem cells involved are called spermatogonia
and are a specific type of stem cell known as
gametogonia.
Spermatocytogenesis
In spermatocytogenesis, the stem cells involved are called ______
and are a specific type of stem cell known as
_________
spermatogonia, gametogonia
Spermatocytogenesis
Three functionally separate spermatogonial cell types are recognized on the basis of the
appearance of the _________: type A dark
spermatogonia (Ad), type A pale spermatogonia
(Ap), and type B spermatogonia (B).
nuclei
• The population of spermatogonia is
maintained by type Ad spermatogonia.
• Serve to maintain the supply of stem
cells for spermatogenesis.
• Each type Ad spermatogonium divides
to produce another type Ad
spermatogonium, which can further
carry on spermatogenesis, and one
type Ap spermatogonium, which
differentiates further.
Type Ad Spermatogonia (“dark”)
Type Ad Spermatogonia serve to maintain the ___________________ for spermatogenesis.
supply of stem cells
Each type Ad spermatogonium divides
to produce another type Ad
spermatogonium, which can further
carry on spermatogenesis, and one
_________ spermatogonium, which
differentiates further.
Type Ap
• repeatedly
divide mitotically to produce identical
cell clones linked by cytoplasmic
bridges.
• The connections between cells allow
development to be synchronized.
When repeated division ceases, the
cells differentiate into type B
spermatogonia.
• This stage is referred to as the
spermatogonial phase.
Type Ap spermatogonia (“pale”)
Type Ap spermatogonia repeatedly
divide __________ to produce identical
cell clones linked by cytoplasmic
bridges.
mitotically
Type Ap spermatogonia repeatedly
divide mitotically to produce identical
cell clones linked by __________
cytoplasmic bridges
Type Ap spermatogonia (“pale”)
The connections between cells allow
development to be synchronized.
When repeated division ceases, the
cells differentiate into _________
type B spermatogonia
The connections between cells allow
development to be synchronized.
When repeated division ceases, the
cells differentiate into type B
spermatogonia.
• This stage is referred to as the
__________ phase.
spermatogonial
___________
undergo mitosis to
produce diploid
intermediate cells called
primary spermatocytes
Type B spermatogonia
Type B spermatogonia
undergo ________ to
produce diploid
intermediate cells called
primary spermatocytes
mitosis
Type B spermatogonia
undergo mitosis to
produce diploid
intermediate cells called
_________________
primary spermatocytes
• For humans, entire
process of
spermatogenesis
takes ______ days,
including the
transport on ductal
system, it takes 3
months.
74 days
• For humans, entire
process of
___________
takes 74 days,
including the
transport on ductal
system, it takes 3
months.
• Testes produce 200 to
300 million
spermatozoa daily.
spermatogenesis
• For humans, entire
process of
spermatogenesis
takes 74 days,
including the
transport on ductal
system, it takes ________
3 months
• For humans,
Testes produce ___________
spermatozoa daily.
200 to 300 million
In rats,
spermatogenesis is ______
days
20
In _______,
spermatogenesis is 20
days
rats
