Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuroscience > Lecture #1 > Flashcards

Lecture #1 Flashcards

1
Q

what are the two periods of human development?

A

prenatal and postnatal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the two periods of development from fertilization to birth?

A

embryonic and fetal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when do the most visible changes occur?

A

embryonic period - weeks 3-8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when do the most critical stages of devlopemnt occur?

A

the first trimester

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

when does the embryo become classified as a fetus?

A

at the end of the first 12 weeks - all tissues and organs are formed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the stage from infancy to 1 year of age?

A

neonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the first menstrual cycle called?

A

menarche

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe the meiosis of the sperm:

A

occurs in the testis - starting from the primary spermatocyte, is then complete withe the formation of 4 sperms (two with 23 chromosomes and an X, and two with 23 chromosomes and a Y)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe the meiosis of the the egg:

A

occurs in the ovary - formation of the primary oocyte starts meiosis, but is interrupted soon after the initial development

in the second maturation there is the production of the structure that is big than the first one, and the second oocyte is surrounded by the follicular cells (accessory cells) causing the formation of the antrum (a cavity) - at this point the meiosis starts again and then is again interrupted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe the number of oocytes present at different stages of life:

A

approx. 2 million primary oocytes in the ovaries of a neonate, but most of them regress during childhood so that by adolescence no more than 40,000 remain

during puberty there is a degeneration of most of them, and only around 400 become secondary oocytes and are expelled at occupation during the repro period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what has been found to be correlated with the age of the mother?

A

disorders - oocyte is blocked in meiosis for many years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe the path of sperm and the creation of semen:

A
  • development in the testis / scrotum
  • mature sperm collected in the epididymus
  • sperm move through the ductus deferent from the testis to the prostate
  • in the prostate there is the junction of the bulbourethral gland (in front of the prostate) and the seminal gland (behind the prostate)
  • then outside
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what does the bulbourethral gland release?

A

transparent solution rich in salt and characterized by a pH of 8-9

release occurs before ejaculation and serves as a cleaning fluid for the urethra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is released in the prostate?

A

several supporting and growth factors that are fundamental to increase the survival of the sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is released by the seminal glands?

A

most of the fluid that are released with ejaculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the two main regions of the uterus?

A

anterior part (cervix) and the body (fundus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the infundibulum?

A

the proximal part of each horn connected to the egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what pathway does the egg travel during ovulation?

A

secondary oocyte with the antrum (follicular anthem is the portion of an ovary follicle filled with collicular fluid) is pushes to one side of the ovary and then is released thanks to the contraction of the smoothie muscles that surround the ovary

then it is captured by the infundibulum and starts its journey to the uterus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

where does fertilization occur?

A

in the short part of the duct called the ampulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the three layers of the uterus?

A

endometrium (inner layer), myometrium (contains the vessels and glands),and the perimetrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is released along with the oocyte?

A

a complex structure surrounded by a membrane:
-zone pellucida: an additional external membrane composed by three glycoproteins (ZO1, ZO2, ZO3)
-corona radiata: function to protect the egg and support it with the release of facts and nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is present in the head of the sperm, and what does this allow the sperm to do?

A

acrosome: a thin vesicle containing a huge number of hydrolases → most important of which is hyaluronidase which is fundamental for the infiltration of the sperm into the zona radiata

another hydrolase called elastase: fundamental to open a small hole in the zona pellucida and make contact between the cell and the two membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how long does fertilization take?

A

it needs 24-48 hours of capacitation which depends on the hormones and factors released by the uterus → capacitation doesn’t alter the sperm morphology, but is fundamental to change the sperm motility because it increases the speed at which the flagella rotate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

when the egg and the sperm interact, what two transmembrane proteins are fundamental in stabilizing the interaction?

A

JUNO and ISUMO

if transgenic mice are created without JUNO, no fertilization occurs

25
Q

what is the first level of polyspermy block?

A

involves the variation of salts occurring in a very tiny space between the cell membrane and the cytoplasm of the egg → usually the effects membrane potential is negative, but soon after fertilization there is the opening of a specific ion channel inducing the influx of Na+ inside the cell membrane inside the cell for a very short time causing depolarization

fusion of the egg and sperm can only occur when the membrane potential is -70mV

26
Q

what is the second level of polyspermy block?

A

cortical reaction: process through which the cortical granules from the oocytes are released to prevent polyspermy: induces a change in terms of organization of the zone pelucida that starts to acquire a different configuration by acquiring a space between the cell membrane and the outer part of the egg → establishes a permanent barrier to sperm entry

27
Q

what is the third level of polyspermy block?

A

granular release involving calcium waves that re triggered by the entrance of the first sperm → secretory vesicles located in the region below the pm of the oocyte are fused with the oocyte pm and hydrolytic enzymes harder the vitelline envelope

28
Q

what does fertilization generate?

A

zygote

29
Q

during the first and second division, describe the allocation of cytoplasm:

A

100% of the cytoplasm is contained in the egg, while the other cells depriving from this division (globular polar cells) contain very little cytoplasm, and are released and eliminated

30
Q

where does the knowledge that we have about early development come from?

A

the study of sea urchins → fertilization occurs outside of their body

31
Q

what is the 8 cell cluster stage referred to as, and what surrounds it?

A

the morula, inside of the zona pellucida

32
Q

what does the high concentration inside of the morula cause?

A

outer cells of the morula start to express proteins that are fundamental for the generation of tight junctions → water can flux through these junctions which goes from the inside to the outside due to the salt gradient → creates the generation of the blastocystic cavity

33
Q

what are the inner cell mass cells (ICM)?

A

small number of cells in contact with the cavity → embryonic stem cells from which all tissues and organs will be formed

34
Q

besides the ICM cells, what other cell type is present?

A

trophectoderm cells: will not generate any tissues or organs but are fundamental for the implantation and generation of extra-embryonic tissues such as the placenta

35
Q

what is the further transformation that occurs of the ICM cells?

A

some of them become aligned with the blastocyst cavity forming the primitive endoderm cells → become other fundamental extracellular tissues called the epiblast and the ipoblast

36
Q

what must happen for implantation to occur?

A
  • zona pellucida must be eliminated
  • something destroys the zona pellucida allowing the embryo to make contact with the uterine wall
  • trochoderm cells interact and start to change morphology inducing an increasing nuclear division without the division of the cytoplasm
  • generation of the syncytium trophectoderm: infiltrate the uterine wall and start to interact with glands and vessels
37
Q

after implantation occurs, what stage of development begins?

A

gastrulation

38
Q

what does gastrulation specifically refer to?

A

the transformation of the embryo from 2 layers (diploblastic) to three layers (triploblastic)

39
Q

what are the first and second cavities called during development?

A

yolk sac + amnion cavity

40
Q

what is the function of these two new cavities?

A

provide shock absorption

41
Q

at the beginning of gastrulation, what two types of cells are present?

A

ipoblasts and epiblasts

42
Q

what three layers are formed in gastrulation?

A

ectoderm, mesoderm, endoderm

43
Q

what change occurs in the epiblast cells?

A

the midline starts to increase drastically as their rates of cell division increase but they do not have enough room to move tangentially → start to invaginate in the middle to detach from the layer and generate the endoderm

44
Q

what is this invagination called?

A

primitive streak

45
Q

what is the terminal part of the primitive streak called, and what does this go on to form?

A

Hensen’s node: will create the generation of the notochord, and a subpopulation of the mesoderm is fundamental for the induction of the head

46
Q

what does the hypoblast form?

A

formation of extra-embryonic tissues such as the umbilical vessels fundamental for the connection of the embryo to the placenta

47
Q

what does the endoderm go on to form?

A

development of the liver, gut, pancreas, lungs, and digestive tube

48
Q

what does the mesoderm go on to form?

A

development of skeletal muscles, kidney, ovaries, testis, and bones

49
Q

what does the ectoderm go on to form?

A

development of the brain, spinal cord, PNS, CNS, glands, and bones / skin of the head

50
Q

where do the cells of the epiblast move to form?

A

detach and actively migrate between the primitive endoderm (ipoblast) and the epiblast forming the mesoderm and the endoderm

51
Q

soon after gastrulation, what occurs?

A

the embryo becomes elongated growing along a specific axis

52
Q

what joins the elongation process?

A

notochord running from the anterior-posterior axis

53
Q

what is the notochord the precursor for?

A

the induction of the CNS

54
Q

describe the generation of the extra embryonic structures:

A

first there is the wave of cells deriving from the epiblast (endoderm) that displaces the epiblast at the periphery

formation of the secondary layer of cells between the trophectoderm and the placenta

55
Q

what is the formation of the second layer in the placenta fundamental for?

A

the formation of chorionic activity

56
Q

what does the generation of the amniotic cavity generate space for?

A

the formation of the CNS

57
Q

what is the embryo connected to the placenta by?

A

the umbilical stalk

58
Q

what is the cavity between the umbilical stalk called?

A

allantois: will become the lungs → allows for the exchange of gases from the placenta to the embryo

Neuroscience (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions