Brainscape's Knowledge GenomeTM

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


See full index

Block 1 Week 3 > Human Embryology 1 > Flashcards

Human Embryology 1 Flashcards

1
Q

What is the study of development?

A

-Study of fertilized egg (zygote) transformation into a multicellualr organisms made of many different cell types that differentiated from one single cell

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

Developments big question?

A

how generate variety of cells and how put them together into something that makes sense and provides speicifc functions

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

Questions asked in development?

A

1) how are cells made
2) how are diff cells generated from the zygote
3) how are emerging cells organized into organs
4) what controls their behavior?

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

What is cell growth and differentiation? What is it controlled by?

A
  • controlled behavior & expression of certain genes in specific cells that give us developmental diversity
  • controlled by gene expression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

two chick embryos and neurocrest cells?

A

1) chick #1 embryo see neurocrest cells emerging from the spine and spreading down spinal column
2) chick #2 neurcrest cells staying right around midbrain

-demonstrares how diff cells can express differently in different organisms

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

Preformationism?

A
  • the preformed theory
  • theory that organisms develop from miniature versions of themselves ( sperm contains little human inside)
  • was form that grew bigger than recreated itself by magic (like Russian dolls)
  • heavily based on religious ideals
  • went away…ressurfaced in 17th cent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Epigenesis

A
  • progressive generation of structures “knitting a net”

- a generation of form, not created from what existed before

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

cell theory

A

1) all living organisms are made of cells
2) cells are the basic unit of life
3) new cells are formed by the division of preexisting cells

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

who came up with cell theory?

A

-shwann, schledien, remark, virchow

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

Lazzaro Spallanzani

A
  • showed both oocyte & sperm were necessary for initiating development of a new animal
  • suggested the sperm was fertilizing agent that initiated the developmental processes
  • did artificial insemination in frogs, and dogs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Heinrich Christian Pander

A
  • Discovered three germ layers of the embryo:
    1) Ectoderm
    2) Mesoderm
    3) Endoderm
  • Suggested interdependence (communication) for their differentiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Three germ layers of the embryo:

A

1) Ectoderm
2) Mesoderm
3) Endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Martin Heinrich Rathke

A

-involved in comparative embryology of frogs fish turtles, mammals

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

Karl Ern von Baer (1827)

A

1) saw first unfertilized human & mammalian egg
2) developed Pander’s germ layer theory; studied their fates during embryonic development
3) comparative embryology

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

Karl Ern von Baer discovered what about the get layers?

A

1) “cutaneous” layer (external layer) transformed into superficial epidermis &CNS
2) “muscular” layer (somites) formed muscles, skeleton and connective tissues

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

Etienne Saint Hilaire &Isidore Saint Hilaire

A

-father & son
-first studies of abnormal
development in 1818
-animal experiments designed to produce birth defects–>Teratology

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

Teratology

A

the scientific study of congenital abnormalities and abnormal formations.

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

Mendel laws? What scientist proved Mendel as correct?

A

Law of:

1) Segregation
2) Independent Assortment
3) Dominance
- mendels laws solidified by Hertwig, Beneden, Weismann, Fleming, & Strasburger

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

Oscar Hertwig

A
  • sperm and egg meet at fertilization

- Meiosis in sea urchin eggs in 1876

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

Van Beneden

A

chromosomes combine in meiosis, making gametes

-1883

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

Fleming, & Strasburger

A
  • nucleoplasm and cytoplasm.
  • new cell nuclei can only arise from the division of other cell nuclei
  • 1878-1894
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

August Weismann

A
  • germ (egg and sperm) cells and somatic (body) cells
  • genetic contribution made exclusively by germ cells
  • 1892
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

developmental genetics; who led by (x3)?

A

-1980s
-Systematic Analysis of genetic Mutations,
Phenotypes and Inheritance
1) Lewis
2)Nüsslein-Volhard
3) Wieschaus

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

what is development?

A

-an orderly succession of different cell behaviors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is development dependent on?

A
  • a progressive series of instructions
  • a generative program that relies on a list of actions w/ each action built upon the previous action (can’t skip steps
  • Nodal Points
  • toolkit genes
26
Q

Nodal Points

A
  • integrate complex information and yield simple outputs

- 5 diff mechanisms that tell us we are thirsty, simple output is drinking water

27
Q

toolkit genes

A
  • recycling instructions
  • have functions of development that are reused multiple times for different purposes
  • often highly conserved across species
  • some involved w/ cancer or mutations
  • many are trxn factors
28
Q

How control genes that have multiple different in different tissues?

A
  • trxn factors
  • proteins that are expressed at speicifc times, are context dependent, and trxn only genes we need in the tissue we need
29
Q

Pax6

A
  • trxn factor, highly expressed in developing eye
  • the master regulator of eye development
  • essential in neural & Eye development
  • role in eye development is conserved in multiple model organisms and humans
30
Q

Pax6 conservation?

A
  • Pax6 sequence & function are highly conserved between species
  • flies & mice: mutant phenotype = absence of eyes
31
Q

Human Pax6?

A
  • heterozygous (most common): called aniridia (absence of irises)
  • homozygous: eyeless phenotype
32
Q

overview of human development (x4)

A

1) sperm + egg fuse (zygote)
2) produce identical pluripotent cells (can give rise to any cell types)
3) cells being to specialize/ differentiate
4) get a fetus w/ a variable combo of traits from both parents

33
Q

zygote

A
  • a eukaryotic cell formed by fertilization between two gametes.
  • zygote’s genome is a combo DNA in each gamete, contains all the genetic info to form a fetus
34
Q

Germ cells

A

-gonad Diploid
cells that produce
gametes (egg/sperm)

35
Q

Gametes

A
  • haploid

- sperms and eggs

36
Q

Zygote

A

-diploid
-fused sperm
& egg

37
Q

Somatic cells

A
  • diploid

- all other body cells

38
Q

Meiosis broad steps?

A

1) DNA replication
2) recombination
3) first meiotic division
4) second meiotic division

39
Q

Spermatogenesis

A
  • occurs in testes
    1) spermatogonia: have A0-A4 intermediate then B type cont. to next step
    2) primary spermocyte; undergo first meiotic divsion(4n; 46 chrom pairs)
    3) secondary spermocyte: 2n, 23 chrom pairs (first meiotic division complete); does 2nd meiotic divison
    4) spermatids: haploid (n); 23 chromosomes
    5) mature sperms haploid (2X; 2Y)
40
Q

sperm proliferation & maturation?

A

-lifelong in males, increases at puberty decreases with older age
-100 X10^6 viable
sperm daily

41
Q

Syncytium

A
  • single cell or cytoplasmic mass w/ several nuclei

- formed by fusion of cells or by division of nuclei.

42
Q

Spermatogenesis & syncytium?

A
  • spermaocytes arent seperated until reach mature sperm stage
  • undergo meiosis 1, 2 & make spermatid while still linked/together
  • shows differentiation occurs very late
43
Q

Gametogenesis & the testes process?

A
  • Gametogenesis occurs in seminiferous tubules in the
  • the premature sperms are distributed within the tubes according to maturation
    1) Spermatogonia: outside
    2) primary/secondary spermatocytes: closer inside
    3) mature sperm: in lumen w/ fluid that can transport it for ejaculation
44
Q

where is sperm produced? how store it and deliver it (ejaculate)?

A
  • made in seminiferous tubules of testis
  • moves into epididymis, where non-mobile sperm is stored, becomes mobile when ejaculate
  • moves up epididymus…past prostate & seminal glands then released to penis
45
Q

Epididymis

A
  • in adults 6-7ft long,
  • connects ducts from rear of each testicle to its vas deferens
  • stores non-motile sperm, which becomes motile in ejaculate
46
Q

vas deferens

A

the duct that conveys sperm from the testicle to the urethra

47
Q

Sperm structure?

A
  • large head w/ acrosome at tip that covers the nucleus
  • neck that connects to thick middle tail piece that contains mito
  • thin tail
  • thinner end piece of tail (flagellum)
  • all together= 5um
  • is very inefficient at getting shit done
48
Q

Oocyte structure?

A

-overall 75um

49
Q

how know when sperm is mature?

A

-when acrosome is mature, sperm is mature

50
Q

centrioles in sperm production?

A
  • are what flagellum grow from

- flagellum=microtubules

51
Q

Sperm genome?

A
  • sperm nuclei is 5um; human genome= 1.82m
  • means that the sperm genome has to be highly condensed chromatin, more so than even in normal nuclei since the sperm is so small
  • have to do a lot of epigenetic changes to fit everything in
52
Q

Sperm genome epigenetic changes?

A

-DNA methylation
-Replacement of standard histones w/ nucleo-protamines
(MOST histones replaced, few do remain)
-creation of toroidal chromatin subunits

53
Q

nucleo-protamines

A
  • are proteins that help compact sperm genome
  • replace most standard histones in sperm nuclei
  • bind DNA condensing spermatid genome (making genetically inactive)`
54
Q

toroidal chromatin subunits

A

-DNA coiled & condensed into these much larger, subunits

55
Q

Are histones retained in sperm nuclei?

A
  • Yes. ~10-15% of the sperm’s genome remain packaged by histones
  • is thought to be so that genes that endow proteins important for sperm maturity and early fertilization can still be trxn/active
  • other than this 10-15% the DNA is so compacted it is incredibly hard to trxn genes
56
Q

Normal Spermatozoon morphology?

A
  • Smooth, symmetric, oval nucleus
  • absence of vacuoles
  • Acrosome, post-acrosomal lamina
  • Neck and Tail
  • no cytoplasm around the head
57
Q

Oogenesis

A

-occurs in the ovary
1) primary oocyte underwent replication is 4n; in primary follicle
2) folilicle grows w/ primary oocyte still in it; begins meisois 1
3) secondary oocyte now has 2n (23 chrom pairs) . meisosis 1 completeled, polar body remains inside oocyte
^remains here until fertilization
4) fertilized oocyte, completes second meiotic division; second polar body is in the oocyte

58
Q

Do the polar bodies get expelled? when?

A

polar bodies not expelled, but do usually dissolve as oocyte becomes mature & fertilized

59
Q

oocytes in female body?

A

400,000 at birth; remain arrested as primary oocyte until puberty

  • then maturing one every 28 days after puberty
  • only complete meisosis 2 once fertilized
  • only ~400 ovulated
  • women thought to not make more eggs once born
60
Q

Argument against claim that can’t make more stem cells once born?

A
  • presence of oocyte stem cells in ovaries
  • argument that the newly prorudced eggs are the ones being used and contributing to oocytes
  • suggested by Jonathan Tilly

Block 1 Week 3 (8 decks)

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