EMBRYO

Question 1

Fetal landmarks Day 0

Answer 1

Fertilization by sperm, initiating embryogenesis

Question 2

Fetal landmarks Within week 1

Answer 2

Implantation (as a blastocyst)

Question 3

Fetal landmarks Within week 2

Answer 3

Bilaminar disk (epiblast:hypoblast).

Question 4

Fetal landmarks Within week 3

Answer 4

Gastrulation. Primitive streak, notochord, and neural plate begin to form

Question 5

Fetal landmarks Weeks 3–8 wk

Answer 5

Neural tube formed. Organogenesis. Extremely susceptible to teratogens.

Question 6

Fetal landmarks Week 4

Answer 6

Heart begins to beat: 4 chambers in week 4. Upper and lower limb buds begin to form.

Question 7

Fetal landmarks Week 8

Answer 7

Fetal movement; fetus looks like a baby.

Question 8

Fetal landmarks Week 10

Answer 8

Genitalia have male/female characteristics.

Question 9

Fetal landmarks plates with functions

Answer 9

Alar plate - Sensory Basal plate - Motor

Question 10

Embryologic derivatives Neural crest

Answer 10

ANS, dorsal root ganglia, melanocytes, chromaffin cells of adrenal medulla, enterochromaffin cells, pia and arachnoid, celiac ganglion, Schwann cells, odontoblasts, parafollicular (C) cells of thyroid, laryngeal cartilage, bones of the skull

Question 11

Embryologic derivatives Endoderm

Answer 11

Gut tube epithelium and derivatives (e.g., lungs, liver, pancreas, thymus, parathyroid, thyroid follicular cells).

Question 12

Fetal landmarks first week

Answer 12

Fertilization - day 1 Zygote - day 2 Morula - day 3 blastocyst - day 5 implantation - day 6

Question 13

Embryologic derivatives Mesoderm

Answer 13

Dura mater, connective tissue, muscle, bone, cardiovascular structures, lymphatics, blood urogenital structures, serous linings of body cavities (e.g., peritoneal), spleen, adrenal cortex, kidneys.

Question 14

Embryologic derivatives Notochord

Answer 14

Induces ectoderm to form neuroectoderm (neural plate). Its only postnatal derivative is the nucleus pulposus of the intervertebral disk.

Question 15

Teratogens effect/cause Alcohol

Answer 15

Birth defects and mental retardation (leading cause); fetal alcohol syndrome

Question 16

Teratogens effect/cause ACE inhibitors

Answer 16

Renal damage

Question 17

Teratogens effect/cause

Abnormal fetal development and fetal addiction

Answer 17

Cocaine

Question 18

Teratogens effect/cause Diethylstilbestrol (DES)

Answer 18

Vaginal clear cell adenocarcinoma

Question 19

Teratogens effect/cause Iodide

Answer 19

Congenital goiter or hypothyroidism

Question 20

Teratogens effect/cause 13-cis-retinoic acid

Answer 20

Extremely high risk for birth defects (hearing and visual impairment, missing earlobes, facial dysmorphism, and mental retardation)

Question 21

Tetarogens effect/cause Thalidomide

Answer 21

Limb defects (“flipper” limbs)

Question 22

Teratogens effect/cause

Tobacco

Answer 22

Preterm labor, placental problems, attention-deficit hyperactivity disorder (ADHD)

Question 23

Teratogens effect/cause Warfarin

Answer 23

multiple

Question 24

Teratogens effect/cause anticonvulsants

Answer 24

multiple

Question 25

Teratogens effect/cause Xrays

Answer 25

multiple

Question 26

FAS | what are the defects

Answer 26

craniofacial abnormalities microcephaly | limb dislocation heart and lung fistulas

Question 27

FAS mech

Answer 27

unknown, but may include inhibition of cell migration

Question 28

Rule of 2’s for 2nd week

Answer 28

- -2 germ layers (bilaminar disk): epiblast, hypoblast. --2 cavities: amniotic cavity, yolk sac. - -2 components to placenta: cytotrophoblast, syncytiotrophoblast.

Question 29

The epiblast | precursor to what and what it does/forms

Answer 29

(precursor to ectoderm) invaginates to form primitive streak. Cells from the primitive streak give rise to both intraembryonic mesoderm and endoderm.

Question 30

Rule of 3’s for 3rd week

Answer 30

3 germ layers (gastrula): ectoderm, mesoderm, endoderm.

Question 31

Embryologic derivatives Neuroectoderm

Answer 31

Neurohypophysis, CNS neurons, oligodendrocytes, astrocytes, ependymal cells, pineal gland.

Question 32

Embryologic derivatives Surface ectoderm

Answer 32

Adenohypophysis; lens of eye; epithelial linings of skin, ear, eye, and nose; epidermis.

Question 33

Branchial apparatus | different parts and what they are from

Answer 33

Branchial clefts are derived from ectoderm. Branchial arches are derived from mesoderm and neural crests. Branchial pouches are derived from endoderm.

Question 34

Branchial apparatus aka/s

Answer 34

Branchial apparatus is also called pharyngeal apparatus. Clefts are also called grooves

Question 35

Branchial apparatus layers

Answer 35

CAP covers outside from inside | Clefts = ectoderm, Arches = mesoderm, Pouches = endoderm

Question 36

Branchial arch 1 derivatives cartilage

Answer 36

Meckel’s cartilage, Mandible, | Malleus, incus, sphenoMandibular ligament.

Question 37

Branchial arch 1 derivatives muscles

Answer 37

Muscles: Muscles of Mastication (temporalis, Masseter, lateral and Medial pterygoids) Mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini, anterior 2⁄3 of tongue.

Question 38

Branchial arch 1 derivatives nerves

Answer 38

Nerve: CN V2 and CN V3

Question 39

Branchial arch 2 derivatives cartilage

Answer 39

Reichert’s cartilage: Stapes, Styloid process, lesser horn of hyoid, Stylohyoid ligament.

Question 40

Branchial arch 2 derivatives muscle

Answer 40

Muscles: muscles of facial expression, Stapedius, Stylohyoid, posterior belly of digastric.

Question 41

Branchial arch 2 derivatives nerves

Answer 41

Nerve: CN VII.

Question 42

Branchial arch 3 derivatives cartilage

Answer 42

Cartilage: greater horn of hyoid.

Question 43

Branchial arch 3 derivatives muscle

Answer 43

Muscle: stylopharyngeus.

Question 44

Branchial arch 3 derivatives nerves

Answer 44

Nerve: CN IX

Question 45

Branchial arch 4,6 derivatives cartilages

Answer 45

Cartilages: thyroid, cricoid, arytenoids, corniculate, cuneiform.

Question 46

Branchial arch 4 derivatives muscle

Answer 46

Muscles (4th arch): most pharyngeal constrictors, cricothyroid, levator veli palatini.

Question 47

Branchial arch 4 derivatives nerves

Answer 47

Nerve: 4th arch––CN X (superior laryngeal branch);

Question 48

Branchial arch 6 derivatives muscles

Answer 48

Muscles (6th arch): all intrinsic muscles of larynx except cricothyroid.

Question 49

Branchial arch 6 derivatives nerves

Answer 49

6th arch––CN X (recurrent laryngeal branch).

Question 50

Which Branchial arch | form posterior 1/3 of tongue.

Answer 50

Arches 3 and 4

Question 51

which Branchial arch | makes no major developmental contributions.

Answer 51

Arch 5

Question 52

Branchial arch innervation and implications

Answer 52

Arch 1 -- CN V2 and V3. Arch 2 -- CN VII. Arch 3 -- CN IX. Arch 4 and 6 --CN X. with the exception of V2(no motor) these are the only CN's that have both sensory and motor components

Question 53

Branchial cleft derivatives 1st

Answer 53

1st cleft develops into external auditory meatus.

Question 54

Branchial cleft derivatives 2nd-4th

Answer 54

2nd through 4th clefts form temporary cervical sinuses which are obliterated by proliferation of 2nd arch mesenchyme.

Question 55

Persistent cervical sinus can lead to | what and where

Answer 55

a branchial cyst in the lateral neck. | Thyroglossal duct cyst in midline neck.

Question 56

Ear development Bones

Answer 56

Malleus/incus–– 1st arch Stapes––2nd arch

Question 57

Ear development Muscles

Answer 57

``` Tensor tyMpani (V3)––1st arch Stapedius (VII)––2nd arch ```

Question 58

Branchial pouch derivatives 1st pouch

Answer 58

middle ear cavity, eustachian tube, mastoid air cells.

Question 59

Branchial pouch derivatives 2nd pouch

Answer 59

develops into epithelial lining of palatine tonsil.

Question 60

Branchial pouch derivatives 3rd pouch

Answer 60

``` 3rd pouch (dorsal wings) develops into inferior parathyroids. 3rd pouch (ventral wings) develops into thymus ```

Question 61

Branchial pouch derivatives develops into thymus.

Answer 61

3rd pouch (ventral wings)

Question 62

Branchial pouch derivatives | develops into superior parathyroids.

Answer 62

4th pouch

Question 63

Branchial pouch Aberrant development of 3rd | and 4th pouches →

Answer 63

DiGeorge syndrome

Question 64

Cleft lip

Answer 64

failure of fusion of the maxillary and medial nasal processes (formation of 1° palate).

Question 65

failure of fusion of the maxillary and medial nasal processes (formation of 1° palate).

Answer 65

Cleft lip

Question 66

Cleft palate

Answer 66

failure of fusion of the lateral palatine processes, the nasal septum, and/or the median palatine process (formation of 2° palate).

Question 67

failure of fusion of the lateral palatine processes, the nasal septum, and/or the median palatine process (formation of 2° palate).

Answer 67

Cleft palate

Question 68

Increase in AFP

Answer 68

Neural Tube defect and omphocele

Question 69

Decrease in AFP

Answer 69

Down Syndrome