Brainscape's Knowledge GenomeTM

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


See full index

Neuroanatomy > Embryology > Flashcards

Embryology Flashcards

1
Q

what is mitosis

A

cell division of all somatic cells in the human body

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

what is the funciton of mitosis and what does it produce

A
  • Functions to produce cells for growth, repair and cell replacement
  • Occurs in 5 phases
  • Produces 2 daughter (identical) cells from 1 parent cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is meiosis

A

process of 2 successive cell divisions of gametes (sex cells)

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

what does meiosis produce

A
  • Occurs in 2 cycles

* Produces 4 daughter cells with a haploid number (half the number of chromosomes, 1 set)

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

what is gametogenesis

A

the process of cell division that coverts an embryonic cell into a mature gamete (sperm or ova)

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

what is spermatogenesis/oogenesis

A
  • Spermatogenesis= formation of sperm

* Oogenesis= formation of egg

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

what is fertilization

A

the combination of a sperm and an egg

- only one sperm will penetrate an ova

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

what is a zygote

A
  • Fertilisation of the egg by a sperm
  • It is a single cell (approx. 100 microns) thinner than hair
  • Contains all the genetic information necessary to for a new person (23 chromosomes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a zygote surrounded by

A

Surrounded by a thick, transparent membrane called a Zona Pellucida, till implantation

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

How does a zygote become an embryo

A
  • Once a zygote travels through the fallopian tube and into the uterus it then implants into the wall of the uterus–> endometrial lining
  • Once the zygote undergoes implantation, it becomes an embryo (approx. week 2)
  • It remains an embryo from week 2 to week 8
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a fetus

A
  • From the end of the embryonic stage to birth (from week 8 onwards)
  • All major organs and tissues are visible by this point however they have not yet developed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is cleavage

A
  • cell division without growth
  • cell size gets smaller as cell division continues but the zona pellucida stays smae size
  • results in a single cell to multi-cell organism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is a morula

A
  • a solid ball of cells resulting from division of an ovum

- Usually forms when cell division reaches 16-32 cells

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

how does the blastocoele cavity form and what day does it occur

A
  • day 5

- The morula begins to absorb fluid and a cavity (blastocoele) forms

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

how do cells in the morula re-organise and what do they form on day 5

A

•Inner cell mass (ICM)–> what will eventually become the embryo and fetus
•Trophoblast–>a single thin layer epithelium which will develop into a large part of the placenta (provides nutrients to the embryo)
-Trophoblast and inner cell mass consist of different cell types

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

what is a blastocyst

A

an embryo which has developed to the point of having 2 different cell components and a fluid cavity
-hence when ICM and trophoblast form

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

What occurs at day 6 post fertilisation

A
  • The blastocyst begins to hatch from its shell
  • This is because the cells are still confined within the zona pellucida and hence cannot get any bigger–> in order to grow it must hatch out of its zona pellucida ‘shell’
  • This allows the blastocyst to grow to its full size
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

where and when does fertilisation occur

A

occurs 7 days after fertilisation in the uterus

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

what is fertilisation

A

the fastening of the embryo to the wall of uterus

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

how does the embryo embed into the endometrial lining

A
  • Trophoblast releases villi that attach to the endometrium and anchors itself to the endometrium
  • It will then dig itself into the endometrium, until the egg is completely covered in the endometrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is an atopic pregnancy

A

when the blastocyst is not imbedded in the endometrium but in some other place such as fallopian tube etc; these type of pregnancies

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

what are the main events of week 1 of embryological development

A 
	Fertilisation
	Zygote
	Cleavage
	Morula
	Blastocyst
	Implantation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the main events of week 2 of embryological developmen

A

 Cell Division
 Differentiation of blastocyst
 Bilaminar germ disc formation
 Start of the uteroplacental circulation
 There is a slight infolding of cells at the caudate end

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

how is the bilaminar embryonic disc produced

A

The inner cell mass differentiates into 2 layers of cells, producing a bilaminar embryonic disc

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

what is the bilaminar disc composed of

A
  • Epiblast (future embryonic ectoderm and mesoderm)–>layer of high columnar cells, not in contact with the blastocyst cavity
  • Hypoblast–>layer of small, cuboidal cells still in contact with the blastocyst cavity
  • Primitive yolk Sac–>provides nourishment to the embryo
  • Amnion space above between a single layer of epiblast cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is the purpose of the bilaminar germ disc

A
  • The bilaminar germ disc is the beginnings of embryo and involves cell differentiation
  • This is a process of induction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the main events of week 3 of embryological development

A
  • granulation
  • trilaminar germ disc
  • notochord formation
  • somite formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is granulation

A
  • formation of trilaminar disc layer from bilaminar
  • from the bilaminar layer, cells migrate towards primitive streak–> line at which cells fold in epiblast layer
  • epiblast starts to form 2 layers (mesoderm and endoderm) and itself becomes the ectoderm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is the notochord

A
  • Derived from mesoderm primarily
  • Defines the midline
  • Forms a tube and then solid cylinder–>enables embryo to form around it
  • Eventually becomes vertebral bodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what are somites

A

-From mesoderm
-Form the vertebral bodies, ribs and differentiate and become voluntary muscle
-Axial skeleton, voluntary muscle
-Skin dermis
-Organises vertebral alignment and peripheral NS
37 somite pairs:
•1-4 - occiput, bones of face and inner ear
•5-12-cervical spine
•13-24-thoracic spine
•25-29-lumbar spine
•30-34-sacral vertebrae
•35-37-coccyx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the ectoderm layer in the trilaminar germ disc for

A

outermost layer; central and peripheral nervous systems (all neural tissue, brain, spinal cord), lining of respiratory and digestive systems

32
Q

What is the ectoderm layer in the mesoderm germ disc for

A

intermediate layer; skeletal and muscular systems, cardiovascular system

33
Q

What is the ectoderm layer in the endoderm germ disc for

A

respiratory and digestive tracts–>innermost layer, hence affects inside structures

34
Q

what is the placenta for

A
  • Develops from the trophoblast

- Highly specialised organ that supports growth and development of embryo and fetus

35
Q

what are the functions of placenta

A 
	Gas exchange
	Nutrient uptake
	Thermos-regulation
	Waste elimination
	Fights internal; infection-->Won’t fight major infectors, only minor once, hence mother needs to be immunised
	Produces hormones to sustain pregnancy
36
Q

what are the main events of week 4 of embryological development

A

Beginning of organogenesis–> when all the basic organs start to develop

  • Differentiation of the somites and the NS
  • Segmental development and integration
  • Limb buds
  • Rudimentary heart and lungs (as well as beginning of other body systems)
37
Q

what is neuralation

A
  • formation of neural tube
  • Conversion of neural plate into a neural tube by a process of folding
  • CSF flows through here
  • Fold starts at somite 5
  • Proceeds in both cephalad and caudal directions
38
Q

what is the limb development for the embryo

A

 Limb buds appear on day 24 (mid-week 4)
 Growth occurs from weeks 4-8 (including rotation of the limbs)
 UL is slightly earlier than LL
 Hand plates appear by day 33
 Digital rays appear by week 6 (UL) and week 7 (LL)

39
Q

how does lung/respiratory development occur

A

 Lung buds start forming during the 4th week
 Initially appear as the respiratory diverticulum, which is a ventral outgrowth of foregut endoderm
 Lungs are immature at birth
 Post-natal increase in bronchioles, growth and maturation of alveoli and lungs
 Lungs are fluid filled at birth the first breath expels fluid
 Surfactant on surface of alveoli

40
Q

How does the heart develop

A

 Heart begins to beat 22-23 days
 Blood flow during 4th week
 Septation= separate chambers ~ 6th week
 Prenatal and postnatal circulation different
 At birth foramen ovale (between atria) is open and closes early in neonatal life

41
Q

how does the trachea and oesophagus develop

A

 Splitting of foregut into oesophagus and trachea
 If the 2 don’t separate clearly, then when the child is born and they have their first feed, they will cough cause it’ll will go into lungs
 Sometimes they have a fistula that is very small which they only detect if that mother reports the child coughing every time they feed

42
Q

How do the abdominal and thoracic cavities get separated

A

 Development of the septum transversum and diaphragm
 Extension of the septum transversum partially divides abdominal and thoracic cavities
 Diaphragm is important as it separates abdominal and thoracic cavity and prevents herniation of abdominal into thoracic space, and vice versa

43
Q

what are numerical chromosomal defects

A
  • Missing a chromosome from a pair (monosomy)

* Missing more than 2 chromosomes (trisomy)

44
Q

what are structural chromosomal defects

A
  • Deletions
  • Duplications
  • Translocations
  • Inversions
  • Substitutions
45
Q

what is a genetic disorder

A

❖ Caused by a change in the DNA sequence

❖ Inheritance of a mutated disease-causing gene that is passed on

46
Q

what is an example of a monogenetic disorder

A

CF

47
Q

what is Duchenne Muscular dystrophy

A

DMD–> mother is the carrier

  • only affects boys
  • when skeletal muscle fibres are replaced by soft tissue, hnce lose muscle tissue and become weaker
  • eventually need ventilation support, lungs and heart start to fail
48
Q

what are environmentally derived abnormalities

A 
Maternal lifestyle:
❖ Poor nutrition
❖ Alcohol no save dosage
❖ Illicit drugs amphetamines, cannabis etc.
❖ Smoking
❖ Domestic violence
Maternal infections:
❖ Rubella
49
Q

what is the chromosomal defect causing downs syndrome

A

trisomy 21

50
Q

what is the pathogenesis of downs syndrome

A

❖ Non-disjunction –> failure during meiosis
➢ The older the mum (over 35/40yo) the higher the chance of child having down syndrome–> older= ova differentiating becomes more abnormal
❖ Translocation –> fusing of chromosomes 21 to 13, 14 and 15 during gametogenesis
❖ Mosaic –>mutation during mitosis after formation of zygote

51
Q

what are the central defects in downs syndrome

A

➢ Cerebellar dysfunction smaller and lighter cerebellum

➢ Cerebrum cortex smaller and smoother, fewer shallow sulci

52
Q

what are the peripheral defects of downs syndrome

A

muscle abnormality

53
Q

what are the cerebellum defects in downs syndrome

A

➢ Though to be damaged to cortex and deep nuclei
➢ Results in decreased input to lateral vestibular nucleus, motor cortex and brain stem motor nuclei
➢ Therefore decreased resting muscle state of muscle= hypotonic

54
Q

what are the upper motor neuron defects in downs syndrome

A

➢ Decreased segmental motor neuron pool excitability
➢ Stretch reflex pathology conflicting evidence
• Normal or reduced short latency myotatic reflexes (0-50ms) DTR respond at normal time but can’t generate enough power quick enough hence seems slower
• Delayed postural response

55
Q

what is the muscle abnormality in downs syndrome

A

➢ Hyper-extensibility
➢ Decreased muscle stiffness
➢ Decreased muscle damping:
• Decreased internal frictional force of the muscle
• Decreased control about an end position

56
Q

list some impairments in downs syndrome

A 
❖ Intellectual disability
❖ Hypotonic
❖ Muscle hyper-extensibility
❖ Ligamentous laxity
❖ Atlanto-axial instability (4%)
❖ Risk of arthritis especially RA
❖ Heart defects (45%)
❖ Respiratory vulnerability
❖ Visual defects (myopia, nystagmus) (60%)
❖ Low frequency hearing loss (60-80%)
❖ Leukaemia (2%)acute lymphoblastic leukaemia
❖ Premature aging Alzheimer’s
57
Q

what is spina bifida

A

❖ Birth defect where there is incomplete closing of the tissue/membranes surrounding the developing spinal cord of foetus
❖ Abnormal neurulation folding process in vertebrae of embryos
❖ Abnormal canalisationformation of CNS of new pathways by repeated passage of nerve impulses
➢ S2 onwards
➢ Canalisation lesions less likely to have associated CNS malformations

58
Q

what are causes of spina bifida

A

➢ Genetics
➢ Nutritional deficiencies
➢ Drug and alcohol associations
➢ Folate is protective hence important to take folate during pregnancy to prevent this should have folate before thinking of becoming pregnant

59
Q

what is myelomeningocele

A

❖ Commonly referred to as spina bifida
❖ Open spinal cord defect
❖ Not skin covered might be a thin layer of meninges
❖ Spinal nerve damage motor and sensory loss in LL depending on site
❖ CSF leak have nervous tissue in this space (nerve roots etc)

60
Q

what is meningocele

A

❖ Spina bifida apearta but less severe
❖ Skin covered
❖ Spinal nerve damage may be less extensive
❖ Contains membranes or non-functional nerves
❖ ‘Not a clean cut’ kind of lesion

61
Q

what is lipoma

A

❖ Spina bifida occulta
❖ Subcutaneous fat mass cephalad to gluteal cleft
❖ Associated with:
➢ Abnormal pigmentation
➢ Hirsuitism
➢ Dimples
❖ Lipomatous or fibromatous tract runs from lipoma into subdural space adjacent to SC
❖ Classified according to location of the tract
❖ Has enough cover to not be exposed
❖ Severity of the condition will depend on where on the SC it is, and how much it is covered

62
Q

what is congenital scoliosis

A

❖ Hemivertebrae lack of formation of one half of vertebral body
❖ Rotation/twisting of spine compromises heart and lung function as it disrupts the space

63
Q

is congenital talipes equinovarus a structural or positional defect

A

structural–> because occurs in the utero

64
Q

what is the presentation of congenital talipes equinovarus

A 
➢ Antenatal ultrasound or at birth
➢ Ankle and subtalar joints PF (equinus)
➢ Hindfootvarus (turned in)
➢ Forefoot inversion and adduction
➢ 1st ray drops to create cavus
65
Q

what are the structural changes to skeletal system in congenital talipes equinovarus

A

❖ Talus smaller, deformed, uncovered laterally, equinus position
❖ Navicular orientated downwards
❖ Calcaneum hypoplastic

66
Q

what are the structural changes to muscular system in congenital talipes equinovarus

A

❖ Ligaments thickened
❖ Muscles hypoplastic
❖ Cellular changes

67
Q

is talipes equinovarus structural or positional

A

positional–> because the foot is still mobile

68
Q

what is the presentation of talipes equinovarus

A

❖ Hindfoot PF’ed (equinus) and inverted (varus)
❖ Forefoot adducted and supinated
❖ +/- deep medial crease
❖ No structural abnormality to skeletal or muscular systems
❖ Can correct foot passively
❖ ‘Normal’ 4-6 weeks post natally

69
Q

what are the degrees of severity in developmental hip dysplasia

A

❖ Ligamentous laxity transient in the newborn due to maternal hormones
❖ Acetabular dysplasia shallow, flattened socket
❖ Subluxation incompletely covered femoral head – deficient cartilaginous roof of acetabulum

70
Q

what is a diaphragmatic hernia

A

❖ Birth defect with abnormal opening in diaphragm, allowing parts of organs from abdominal cavity to move into thoracic cavity and vice versa

71
Q

what is a non-cyanotic congenital heart defect

A

Non-cyanotic= not present at birth

-Congestive heart failure and respiratory distress

72
Q

what is patent ductus arteriosus (PA)

A
  • congenital non-cyanotic heart defect
    ➢ Patent= persistent
    ➢ Failure of ductus to close in early weeks of life
    ➢ Allows blood to flow between aorta and pulmonary artery= increase in flow in lung circulation
    ➢ Circulation of oxygenated blood in lungs
    ➢ Mixing of oxygenated and deoxygenated blood
73
Q

what is ventricular septal defect (VSD)

A
  • congenital non-cyanotic heart defect\
    ➢ Hole in the heart
    ➢ Hole occurs in the wall (septum) that separates the left and right ventricles
    ➢ Allows blood to pass from the left to right side of heart
74
Q

what is atrial spetal defect (ASD)

A
  • congenital non-cyanotic heart defect
    ➢ Hole in the wall between the 2 upper chambers of heart- atria
    ➢ Allows blood to flow between atria
75
Q

what is tetralogy of fallot (TOF)

A

-cyanotic congenital heart defect
➢ Combination of 4 congenital abnormalities VSD, pulmonary valve stenosis, misplaced aorta ad thicken right ventricular wall (right ventricular hypertrophy)
➢ Blueish skin tone
➢ Limits blood flow to lungs

76
Q

what is Transposition of the great arteries (TGA)

A

➢ Aorta connected to right ventricle
➢ Pulmonary artery connected to left ventricle
➢ Arteries transposed from their normal position

77
Q

what is defined as a preterm birth

A

-born <37 weeks gestational age

Neuroanatomy (18 decks)

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