Chapter 4: Weeks 3-8 Flashcards
Which germ layers are present at the end of week 3 of development (day 21)?
(A) Epiblast only (B) Epiblast and hypoblast (C) Ectoderm and endoderm (D) Ectoderm, mesoderm, and endoderm (E) Epiblast, mesoderm, and hypoblast
(D) Ectoderm, mesoderm, and endoderm
Which process establishes the three definitive germ layers?
(A) Neurulation (B) Gastrulation (C) Craniocaudal folding (D) Lateral folding (E) Angiogenesis
(B) Gastrulation
The first indication of gastrulation in the embryo is
(A) formation of the primitive streak
(B) formation of the notochord
(C) formation of the neural tube
(D) formation of extraembryonic mesoderm
(E) formation of tertiary chorionic villi
(A) formation of the primitive streak
Somites may differentiate into which of the following?
(A) Urogenital ridge (B) Kidneys (C) Notochord (D) Epimeric and hypomeric muscles (E) Epithelial lining of the gastrointestinal tract
(D) Epimeric and hypomeric muscles
Intermediate mesoderm will give rise to the
(A) neural tube (B) heart (C) kidneys and gonads (D) somites (E) notochord
(C) kidneys and gonads
The developing embryo has a distinct human appearance by the end of
(A) week 4 (B) week 5 (C) week 6 (D) week 7 (E) week 8
(E) week 8
The lateral mesoderm is divided into two distinct layers by the formation of the
(A) extraembryonic coelom (B) intraembryonic coelom (C) cardiogenic region (D) notochord (E) yolk sac
(B) intraembryonic coelom
Very often the first indication a woman has that she is pregnant is a missed menstrual period. In which week of embryonic development will a woman experience her first missed menstrual period?
(A) Start of week 3 (B) Start of week 4 (C) Start of week 5 (D) Start of week 8 (E) End of week 8
(A) Start of week 3
A female newborn was found to have a large midline tumor in the lower sacral area, which was diagnosed as a sacrococcygeal tumor. Which of the following courses of treatment is recommended for this child?
(A) Immediate chemotherapy and radiation treatment
(B) Surgical removal by age 6 months
(C) Surgical removal at age 4–5 years
(D) Surgical removal at age 13–15 years
(E) No treatment because this tumor normally regresses with age
(B) Surgical removal by age 6 months
A woman has her pregnancy suddenly terminated due to intrauterine fetal death. At autopsy, the fetus shows severe pallor, gener- alized edema, and hepatosplenomegaly. Which of the following would you suspect?
(A) VATER (B) B-Thalassemia minor (C) B-Thalassemia major (D) Hydrops fetalis (E) VACTERL
(D) Hydrops fetalis
The specialized group of mesenchymal cells that aggregate to form blood islands centrally and primitive blood vessels peripherally are called
(A) fibroblasts (B) cardiac progenitor cells (C) angioblasts (D) myoblasts (E) osteoblasts
(B) cardiac progenitor cells
The epiblast is capable of forming which of the following germ layers?
(A) Ectoderm only (B) Ectoderm and mesoderm only (C) Ectoderm and endoderm only (D) Ectoderm, mesoderm, endoderm (E) Mesoderm and endoderm only
(D) Ectoderm, mesoderm, endoderm
A male newborn has a hemangioma on the left frontotemporal region of his face and scalp. The cells forming the hemangioma are derived from which of the following cell layers?
(A) Ectoderm only (B) Mesoderm only (C) Endoderm only (D) Ectoderm and mesoderm (E) Endoderm and mesoderm
(B) Mesoderm only
Which structure is derived from the same embryonic primordium as the dorsal root ganglia?
(A) Gonads (B) Kidney (C) Pineal gland (D) Liver (E) Adrenal medulla
(E) Adrenal medulla
- Which structure is derived from the same embryonic primordium as the kidney?
(A) Gonads (B) Epidermis (C) Pineal gland (D) Liver (E) Adrenal medulla
(A) Gonads
