Brainscape's Knowledge GenomeTM

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


See full index

Human Prenatal Development > Block 1 Review > Flashcards

Block 1 Review Flashcards

1
Q

Spontaneous Generation Theory

A

began i.e. “new life arises from slime and decaying matter.
Held from the time of Galen for nearly 1500 years.
Suggested life came from inanimate objects

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

Preformation Theory

A

founded i.e., “sperm or ovum contain a germ that is completely formed bu minute and invisible and expands to visible size and form during development”
Suggested that there was a pre-formed individual in every gamete

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

Epigenesis Theory

A

founded, i.e., “egg lacks internal organization and develop into a new organism

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

Germ Layer Theory

A

founded i.e., “all animal embryos are composed of three primary germ layers, ectoderm, mesoderm, and endoderm”

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

Recapitulation Theory

A

founded, i.e. “ontogeny Recapitulates Phylogeny”

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

Embryo

A

the developing individual from fertilized until the end of the second month (8th week inclusive)

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

Fetus

A

the developing individual in utero from the end of the 2nd month (8th week) until birth

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

Zygote

A

the first diploid cell formed by the union of sperm and ovum

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

Gestation

A

the period of development prior to birth

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

Congenital Abnormalities

A

abnormalities or malformations detected at birth, or shortly thereafter

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

Anomaly

A

marked deviation from the average or normal standard. A congenital defect. May be structural or metabolic

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

Malformation

A

a morphological defect that results from an abnormal developmental process and usually causes a functional deficit

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

Variation

A

a morphological deviation from an assumed standard that causes no functional deficit

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

Syndrome

A

a “package” of congenital abnormalities that occurs in several organ systems as a result of a single factor

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

True Age

A 
38 weeks (266 days) counting from the time of fertilzation or conception
Embryologists use true age and it is the age used in Gross and Developmental Anatomy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ovulation Age

A

True age + 1 day
because that oocyte has to be ovulated first and start its travel down the fallopian tube before it is normally fertilized

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

Copulation Age

A

True Age + 1 to 3 days

1 to 3 days represents the time period that a sperm is viable in the tract

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

Menstrual “Gestational” Age

A

True age + 14 days (290 days)
Obstetricians use menstrual age since this is the most practical from the clinical viewpoint. Two thirds of all deliveries occur 280 +/- 11 days from the onset of the mother’s LMP
Ovulation would have occurred about halfway through the female’s cycle - total cycle averages 28 days, so that extra 14 days is the time from LMP until ovulation

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

Mitosis vs. Meiosis

A

Mitosis: gives rise to two daughter cells, which are genetically identical to the parent cell

Meiosis: Process of reduction division of chromosomes
Takes place only in germ cells
Reduces number of chromosomes from a diploid (2N) to a haploid (1N) state
- Consists of two divisions

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

Spermatogenesis

A 
Spermatogonium (2n) - @ puberty, increase in # by Mitosis
They enlarge into primary spermatocytes (2n)
-Meiosis I takes place-
Secondary spermatocytes (1n)
-Meiosis II takes place-
Spermatids (1n)
-Spermatogenesis-
4 mature sperm (1n)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

spermiogenesis

A

when spermatids mature into mature sperm:

morphologic changes, including development of the acromosome and tail and an increase int he # of mitochondria

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

Oogenesis

A

Oogonium (2n) during early fetal life proliferate by mitosis [5,000,000 oogenia @ 12 weeks]
They enlarge into primary oocytes (diploid)
-[2,000,000 primary oocytes @ birth]
-Begin meoisis I (before birth)-
Completely meisos I (before ovulation) forming secondary oocyte (1n) and 1st polar body
-begin meiosis II at ovulation-
[300 needed and produced in lifetime]
Completely meiosis II at sperm penetration forming mature oocyte (1n) and 2nd polar body

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

Process of Fertilization

A

Passage of sperm through the corona radiate
Penetration of the zona pellucida
Fusion of plasma membranes of the two gametes
Completion of 2nd meiotic division of oocyte with formation of female pronucleus
Fusion of pronuclei, forming 2n zygote

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

Results of Fertilization

A

Completion of the 2nd meiotic division of the secondary oocyte (at fertilization)
Restoration of the 2n number of chromosomes in the zygote
Mixing of the ateral and maternal chromosomes to insure diversity of species
Determination of chromosomal sex
Initiation of cleavage

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

Normal site of fertilization

A

ampulla of the uterine (fallopian) tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Normal site of implantation

A

posterior wall of the uterus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Most common site for abnormal implantation

A

within the fallopian tube near the ampulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

During week 2, trophoblast differentiates into:

A

cytotrophoblast and syncytiotrophoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

During week 2, the embryoblast differentiates into:

A

epiblast and hypoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

During week 2, the mesoderm differentiates into:

A

the somatic (epiblast) and splanchnic (hypoblast) mesoderm

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

Primary Chorionic Villi

A

solid primary villi composed of a cytotrophoblast core covered by syncytium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

secondary chorionic villi

A

mesenchyme grows into primary chorionic villi to form a mesenchymal core
-cover the entire chorionic sac at this time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

tertiary chorionic villi

A

mesenchyme differentiates into capillaries and blood cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Hydatiform Moles

A

Secrete high levels of hCG
Sometimes the trophoblast develops and forms placental membranes with little or no embryonic tissue present
Degenerating chorionic villi that form cystic swellings after embryonic death form hydatiform moles
look like grape like projections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Placenta

A

“afterbirth”
the primary site of nutrient and gas exchange between the mother and the fetus
Two components:
-fetal part - develops from chorionic sac (chorion frondosum)
-Maternal part - develops from the endometrium of the uterus (decidual basalis)
Functions: protection, respiration, nutrition, excretion, hormone production

Extraembryonic mesoderm + syncytiotriphoblast + cytotrophoblast = chorion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Decidua

A

the functional layer of the uterine endometrium in a pregnant woman
“falling off”
Three regions:
Decidua basalis: deep to the conceptus - forms the maternal part of the placenta - between teh chorionic vesicle and the myometrium
Decidua capsularis: superficial part of the decidua overlying the conceptus
Decidua parietalis: remaining endometrium lining the main cavity of the uterus

Decidual reaction: cellular and vascular changes in the endometrium as the blastocyst implants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Placenta Accreta

A

abnormal adherence of chorionic villi to the myometrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Placenta Percreta

A

when the chorion villi penetrate the full thickness of the myometrium to or through the perimetrium (peritoneal covering)

  • Abnormally tight connection between the placenta and uterine wall
  • more difficult to separate this plcenta from the uterus after birth; may require going in to scrape it out
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Placenta previa

A

most common
when the blastocyst implants close to or overlying the internal os of the uterus
Considered an ectopic site of implantation
May result in late pregnancy bleeding (3rd trimester)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Battledore Placenta

A

insertion of the umbilical cord at the placental margin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Accessory Placenta

A

can develop from a patch of chorionic villi that persisted a short distance from the main placenta
-Inspect maternal surface of placenta after birth to make sure that any portion (like a cotyledon) was not left inside the uterus - may cause bleeding it not all removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Velamentous insertion of umbilical cord

A

cord is attached to the membranes (amnion and chorion), not to the placenta; umbilical vessels leave the cord and run between the amnion and chorion before spreading to the placenta
-Vessels can be easily torn in this location, which would cause the fetus to lose blood supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Amniotic sac

A

surrounds the embryo/fetus

Enlarges to obliterate the chorionic cavity and forms the epithelial covering of the umbilical cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Amniotic Band Syndrome

A

various defects related to constriction of parts of the embryo/fetus by encircling amniotic bands; can wrap around an extremity, causing it to die or disappear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Oligohydramnios

A

low volume of amniotic fluid for gestational age
May result from:
-placental insufficiency with diminished placental blood flow
-Preterm rupture of the amniochorionic membrane
-Renal agenesis or obstructive uropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Polyhydramnios

A

high volume of amniotic fluid
May be associated with:
-severe anomalies of the CNS - improper innervation to muscles involved in the swallowing mechanism can be preventing fetus from swallowing the fluid
Esophageal atresia- fetus is unable to swallow the amniotic fluid if the esophagus does not form correctly
-Multiple gestations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Amniocentesis

A

invasive prenatal diagnostic procedure

  • Amniotic fluid is sampled by inserting a needle through the mother’s anterior abdominal and uterine walls into the amniotic cavity, requiring piercing of the chorion and amnion
  • Usually performed between 15 and 18 weeks of gestation
  • common for detecting genetic disorders
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Dizygotic twins

A

results from fertilization of two oocytes

  • always have two amnions and two chorions, but the chorions and placentas may be fused
  • shows a hereditary tendency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Monozygotic twins

A

most developed from one zygote by division of the embryoblast

  • have separate amnions
  • have a single chorionic sac
  • share a placeta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Discordant twins

A

twin-twin transfusion syndrome can cause this - there is a shunt of arterial blood from one twin through arteriovenous anastomoses into the venous circulation of the other twin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Monozygotic conjoined twins

A

embryonic disc does not divide completely or adjacent discs fuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Stages of labor

A

Dilation
Expulsion
Placental stage
Recovery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Three major processes of Gastrulation

A

Formation of the primitive streak
Development of notochord
Differentiation of three germ layers (endoderm, mesoderm, ectoderm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Primitive streak

A

a thickened band of epiblast cells on the dorsal surface of the embryonic disc
-the first sign of gastrulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Formation of the primitive streak establishes:

A

Craniocaudal axis of the embryo
Right/Left side of the embryo
Dorsal/ventral surfaces of the embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Sacrococcygeal teratoma

A

tumors that contain tissue derived from all three germ layers i incomplete stages of differentiation
-Most common tumor in newborns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Notocord

A

defines the primordial cranialcaudal axis of the embryo

  • provides some rigidity to the developing embryo
  • serves as the basis for development of the axial skeleton (bones of the head and vertebral column)
  • indicates the future site of the vertebral bodies
  • in part, persists as the nucleus pulposis of the intervertebral discs
  • functions as the primary inductor in the early embryo
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Neurulation

A

the process involved in the formation of the neural plate and neural folds and closure of the folds to form the neural tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Neurulation accomplished three major things:

A
  1. It creates the neural tube, which gives rise to the CNS
  2. It creates the neural crest, which migrates away from the dorsal surface of the neural tube, and gives rise to a diverse set of cell types
  3. It creates the definitive epidermis, which covers over the neural tube once it is created
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Primary neurulation

A

formation of the neural tube at the dorsal midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Secondary neurulation

A

secondary cavity formation at the caudal end of the neural tube to form the sacral spinal cord

62
Q

First organ system to be laid down

A

CNS = brain and spinal cord

63
Q

Fate of the neural tube:

A

Walls become brain and spinal cord
Space in the middle becomes the ventricular system of the brain and central canal of spinal cord
Neural Crest Cells

64
Q

Neural Crest Cells

A

involved with spetation of the heart (among other things)

65
Q

Neopores

A

neural tube is open at each end
Rostal neuropore = closes ~ day 25
Caudal neuropose = closes ~ day 27

Closure of the neuropores coincides with establishment of vascular system

66
Q

Neurofibramatosis

A

von Recklinghausen disease

peripheral nerve tumors

67
Q

Waardenburg syndrome

A

Autosomal dominant
Extremely pale blue eyes or heterochromia (two different colored eyes)
Partial albinism - white forelock (poliosis) of hair or early graying of hair

68
Q

CHARGE Symdrome

A 
Coloboma
Heart defects
Atresi choanae
Retardation of growth and development
Genitourinary problems
Ear abnormalities
69
Q

Alar plate

A

associated with secondary sensory neurons
Gives rise to dorsal horn of spinal cord
**We know dorsal horn is involved with sensory fibers*

70
Q

Basal plate

A

Associated with motor neurons

Gives rise to ventral horn of spinal cord

71
Q

Sulcus limitans

A

groove separating dorsal sensory from ventral motor

-This goes all the way to the medulla of the brain

72
Q

Lumbar cistern

A

enlarged area of subarachnoid space in lumbar region

-Important for lumbar punctures L4/L5

73
Q

All ganglia come from __________.

A

Neural Crest Cells

74
Q

Spinal Cord Termination Levels

A

Adult: Intervertebral discs between L1/L2

Newborn: L3

75
Q

Somite Differentiation

A

Initially differentiates into dermomyatomes and sclerotomes

-then to dermatomes, myotomes, and sclerotomes

76
Q

Dermatome

A

Dermis of skin

77
Q

Myotome

A

myoblasts (develop into muscle)

78
Q

Sclerotome

A

Will form vertebrae and ribs; loosely organized mseenchyme

79
Q

Sclerotome cells found in three main areas:

A
  1. On either side of notochord
  2. Surrounding neural tube
  3. In the body wall (form ribs)
80
Q

Genes controlling somite differentiation

A

Sonic Hedgehog (Shh) causes the ventral part of the somite to form sclerotome

81
Q

Two parts of Sclerotomes that are surrounding the notochord

A
  1. cranial - loosely arranged part
  2. caudal - densely arranged part
    - Caudal portion will with combine with loosely arranged cells of next caudal sclerotome to form central body of vertebrae (centrum)
82
Q

Notochord goes on to form:

A

nucleus pulposis

83
Q

Mesenchyme around neural tube forms _______.

A

vertebral (neural) arch

84
Q

Mesenchyme in the body walls form _______.

A

Coastal processes that form ribs in the thoracic region

85
Q

Napoleonic vertebrae

A

three bony parts;

referring to ossification enters (7 weeks)

86
Q

Spina Bifida

A

problem with development of the nervous system and skeletal system

87
Q

Spina Bifida Occulta

A

cannot see it (occulta - Latin for “hidden”

  • Mildest form of spine bifida
  • May be indicated by tuft of hair or dimple
88
Q

Spina Bifida Cystica

A

indicated by high levels of alpha-fetoprotein (AFP)

89
Q

Spina Bifida Cystica with Meningocele

A

protruding sac contains meninges and CSF

-No neurological deficits because nerves are still in proper places

90
Q

Spina Bifida Cystica with Meningomyelocele

A

Cord is included in sac

-Associated with neurological deficits because nerve roots are stretches at the level of herniation

91
Q

Spina Bifida Cystica with Myeloschisis

A

Most severe type

-Open neural plate exposed so that the neural folds didn’t form

92
Q

Cervical Rib Syndrome

A

rib on C7 may put pressure on brachial plexus and/or subclavian vessels and produce symptoms (like parasthesia)

93
Q

Congenital hemivertebra

A

occurs if one of the two chondrification centers on either side of the centrum fails to develop

  • Mutation of the HOX (homobox) genes may cause
  • Can be a cause of scoliosis
94
Q

Anomalies of sternum development

A

“pigeon chest” - sternu protrudes anteriorly
Cleft sternum - worst case scenario: ectopic cardis (heart develops outside body)
Notching o the xiphoid process - xiphoid process can be naturally bifurcated
Sternal foramen

95
Q

Four Sources of Limb Tissue Development

A 
Lateral Plate Mesoderm:
gives rise to skeleton, tendons, ligaments, vasculature
Somites (Dermo-myotome): 
Musculature
Neural Crest: 
rise to Schwann cells, Dorsal root ganglia, sensory axons
Neural Tube:
gives rise to motor axons
96
Q

All muscles of the body develop from ______.

A

Mesoderm

97
Q

Epaxial Division of Myotome

A

supplied by dorsal primary ramus of a spinal nerve (epimere)

-Intrinsic (true) back muscles

98
Q

Hypaxial Division of Myotome

A

supplies by ventral primary ramus of a spinal nerve (hypomere)
-Muscles of body wall (intercostals, abdominal muscle)

99
Q

Straited muscle of the trunk develops from ______.

A

Myotomes

100
Q

Smooth muscle and cardiac muscle develop from _______.

A

Splanchnic mesoderm

101
Q

“Prune Belly”

A

absence of abdominal muscles, can sometimes see loops of intestines

102
Q

Thalidomide

A

a potent teratogen that can acuse severe limb defects

103
Q

Amerlia

A

absence of limbs

104
Q

Meromelia

A

arrest of disturbance of growth of limbs during development; results in limbs being only partially developed

105
Q

Syndactyly

A

Cutaneous: failure of webs to degenerate between two or more digits
Osseous: notches between digital rays do not develop; resulting in lack of separation of the digits

106
Q

Polydactyly

A

extra digit(s)

107
Q

Cleodocranial Dysostosis

A

autosomal dominant incomplete formation or absence of the clavicle

108
Q

1st bone in body to ossify

A

Clavicle

-Initially intramembraneous ossification, then endochondral ossification.

109
Q

Achondroplasia

A

autosomal dominant impairment of cartilage development in the epiphyseal plates of bones

  • Most common cause of dwarfism
  • Fibroblast growth factor receptor 3 (FGFR-3) is invovled
110
Q

Anomalies of the Integumentary System

A

Ichthyosis: superficial layer does not slough off

Hemangioma or Angioma: problems with capillary plexi leading to an abnorma buildup of vessels in the skin
-Considered benign tumors

Port-wine stains: birthmarks in which swollen blood vessels create a reddish-purplish discoloration of the skin

111
Q

Polymastia

A

extra breast

112
Q

Polythelia

A

extra nipple(s)

113
Q

Macromastia

A

hypertrophy of the breast

114
Q

Micromastia

A

breast hypoplasia (underdevelopment of breast tissue)

115
Q

Angioblastic Cord canalization

A

at 22 days

form endocardial heart tubes

116
Q

________ helps move heart into correct anatomical position.

A

brain development

117
Q

Adult Derivative of Embryonic Structure:

Truncus arteriosus

A

Aorta and Pulmonary Trunk

-separated by aorticopulmonary septum which involes NCC

118
Q

Adult Derivative of Embryonic Structure:

Bubus cordis

A

Infundibulum/Cons Arterious = smooth part of right vetricle

Aortic vestibule = smooth part of left ventricle

119
Q

Adult Derivative of Embryonic Structure:

Primitive Ventricle

A

Trabeculae carneae of L and R ventricles

120
Q

Adult Derivative of Embryonic Structure:

Primitive atrium

A

Trabeculated (pectinate muscles) part of L and R atria

121
Q

Adult Derivative of Embryonic Structure:

Sinus venosus

A 
Sinus venarum (smooth part of R atrium)
Coronary sinus, oblique vein of L atrium
122
Q

Crista terminalis

A

junction of muscular and membraneous regions of R atrium

123
Q

Blood flow input through sinus venous

A

common cardinal vv.
Umbilical vv.
Vitelline vv.

124
Q

Atrioventricular canal

A

endocardinal cushions approach each other and fuse, dividing canal into Right AV canal (becomes tricuspid valve) and left AV canal (becomes mitral valve)

125
Q

Foramen primum

A

foramen between free edge of septum primum and the endocardial cushions

126
Q

R horn of sinus venosus becomes _______.

A

Sinus Venarum (smooth walled part of right atrium separated by cristae terminalis)

127
Q

L horn of sinus venosus becomes _______.

A

Coronary sinus and Olbique vein of L atrium

128
Q

Fetal Circulation

A

Placents - Umbilical vein - 1/2 ductus venosus (connects umbilical v. to IVC) - 1/2 Liver sinusoids - hepatic veins - inferior veina cava - right atrium - foramen ovale - left atrium - left ventricle - ascending aorta - superior vena cava - right atrium - right ventricle - pulmonary trunk - Ductus Arteriosus - umbilical arteries (2x) - placenta

129
Q

Probe patent foramen ovale

A

more frequent in females
probe can be passed through the superior part of the foramen ovale
Usually small, not clinically significant - physiologic but not anatomic
Results from failure of the valve of the foramen ovale (septum primum) to fuse with the septum secondum at birth

130
Q

Tetralogy of Fallot

A

Cynosis is a major symptom

  • Pulmonary stenosis
  • Ventricular septal defect
  • Overriding aorta
  • Right ventricular hypertrophy
131
Q

most common single cause of cyanotic heart disease in newborn infants

A

transposition of great arteries

132
Q

Aortic Arch Derivatives:

First Aortic Arch

A

largely disappears
Maxillary AA
-contributes to external carotid aa

133
Q

Aortic Arch Derivatives:

Second Aortic Arch

A

Stapedial aa.

134
Q

Aortic Arch Derivatives:

Third Aortic Arch

A

Common Carotid aa.

-from prox. parts of 3rd arch

135
Q

Aortic Arch Derivatives:

Fourth aortic Arch

A

Left: pr of Arch of Aorta

Right: Right subclavian a.

136
Q

Aortic Arch Derivatives:

Fifth Aortic Arch

A

usually disappears

137
Q

Aortic Arch Derivatives:

SIxth Aortic Arch

A

Left: Proximal - Left pulmonary A.
Distal: Ductus Arteriosus

Right: Right Pulmonary Artery

138
Q

Determining location of recurrent pharyngeal nerves

A

Right recurrent laryngeal n. - goes around R subclavian

Left recurrent laryngeal n. - wraps around aortic arch passing lateral to the ligamentum arteriosum

139
Q

Tracheoesophageal septum

A

formed by tracheoesphageal folds

-divides esophagus and trachea to form laryngotracheal tube (trachea and larynx)

140
Q

Tracheoesophageal fistula

A

results from incomplete division of the cranial part of the foregut into respiratory and esophageal part
-causes choking and regurgitation because esophagus goes down into respiratory system

141
Q

Esophageal atresia

A

blind sac of esophagus

-baby’s can’t swallow amniotic fluid - Polyhydramnios -> excess amniotic fluid

142
Q

Four stages of lung development

A

landular stage (pseudoglandular)
canalicular stage
saccular stage
alveolar stage

143
Q

Pseudoglanular stage

A

During 6th-16th weeks there is repeated branching to the level of terminal bronchioles
All major elements of lungs formed BUT not those involve in gas exchange
RESPIRATION NOT POSSIBLE
Fetuses born during this period unable to survive

144
Q

Canalicular period

A

Lumina of bronchi and terminal bronchioles become larger
16-26 weeks
Lung tissue highly vascularized
Terminal bronchiles give rise to 2+ respiratory bronchioles –> terminal saccules (primordial alveoli) and 3-6 alveolar ducts
RESPIRATION POSSIBLE
-fetus may survive with intensive care

145
Q

Terminal sac period

A

increase # of terminal saccules
26 weeks - birth
terminal sac epithelium becomes very thin
invaded by capillaries
establish blood-air barrier
adequate gas exchange possible is fetus born prematurely

146
Q

Type I alveolar cells/pneumocytes

A

gas exchange

Squamous epithelial cells - line terminal sacs

147
Q

Type II alveolar cells/pneumocytes

A

pulmonary surfactant secretion

Rounded epithelial cells

148
Q

Surfactant

A

monomolecular film in terminal sacs, lowers surface tension

149
Q

Alveolar period

A

strucutre analogous to alveoli are present at 32 weeks
Type I alveolar cells are thin enough to form the alveolarcapillary membrane - pulmonary diffusion membrane or respiratory membrane
NO PROBLEMS with survival

150
Q

Three factors important for normal lung development

A

Adequate thoracic space for lung growth
Fetal breathing movements
Adequate amniotic fluid volume

151
Q

Respiratory Distress Syndrome

A 
hyaline membrane disease (HMD)
-2% of live born infants
-14% of infants weighing less than 2500 grams
-white infants > black infants
-Male 2x > female
Symptoms:
-Rapid labored breathing shortly after birth
-Expiratory grunting
-Nasal flaring
-subcostal and intercostal retractions
-cyanosis

Treated by:
Intensive respiratory assistance
Surfactant therapy including surfactant lipoprotein and surfactant associated protein A, B & C

SURFACTANT DEFICIENCY IS MAJOR CAUSE OF RDS/HMD

Human Prenatal Development (1 decks)

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